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Rainwater TR, Griess J, Murphy TM, Boylan SM, Parrott BB, Kohno S, Rainwater KA, Richards SM, Guillette M, Mills T, Platt SG, Wilkinson PM, Guillette LJ. Leucistic American Alligator Hatchlings in Coastal South Carolina. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Thomas R. Rainwater
- Tom Yawkey Wildlife Center and Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, PO Box 596, Georgetown, SC 29440
| | - Jane Griess
- US Fish and Wildlife Service, Savannah Coastal Refuges Complex, 694 Beech Hill Lane, Hardeeville, SC 29927
| | | | - Shane M. Boylan
- South Carolina Aquarium, 100 Aquarium Wharf, Charleston, SC 29401
| | - Benjamin B. Parrott
- University of Georgia, Odum School of Ecology, Savannah River Ecology Laboratory, Jackson, SC 29831
| | - Satomi Kohno
- Department of Biology, St. Cloud State University, 720 4th Avenue South, St. Cloud, MN 56301
| | | | - Sean M. Richards
- Department of Biological and Environmental Sciences, University of Tennessee at Chattanooga, 615 McCallie Avenue, Chattanooga, TN 37403
| | - Matthew Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, 331 Ft. Johnson Road, Charleston, SC 29412
| | - Tony Mills
- Spring Island Trust, 40 Mobley Oaks, Lane, Okatie SC 29909
| | - Steven G. Platt
- Wildlife Conservation Society–Myanmar Program, No. 100, Yadanar Street, Kamayut Township, Yangon, Myanmar
| | | | - Louis J. Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, 331 Ft. Johnson Road, Charleston, SC 29412
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Lawson AJ, Moore CT, Rainwater TR, Nilsen FM, Wilkinson PM, Lowers RH, Guillette LJ, McFadden KW, Jodice PGR. Nonlinear patterns in mercury bioaccumulation in American alligators are a function of predicted age. Sci Total Environ 2020; 707:135103. [PMID: 31863991 DOI: 10.1016/j.scitotenv.2019.135103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 06/10/2023]
Abstract
Mercury is a widespread, naturally occurring contaminant that biomagnifies in wetlands due to the methylation of this element by sulfate-reducing bacteria. Species that feed at the top trophic level within wetlands are predicted to have higher mercury loads compared to species feeding at lower trophic levels and are therefore often used for mercury biomonitoring. However, mechanisms for mercury bioaccumulation in sentinel species are often poorly understood, due to a lack of long-term studies or an inability to differentiate between confounding variables. We examined mercury bioaccumulation patterns in the whole blood of American alligators (Alligator mississippiensis) from a long-term mark-recapture study (1979-2017) in South Carolina, USA. Using a growth model and auxiliary information on predicted age at first capture, we differentiated between age- and size-related variation in mercury bioaccumulation, which are often confounded in alligators due to their determinate growth pattern. Contrary to predictions that the oldest or largest individuals were likely to have the highest mercury concentrations, our best-supported model indicated a peak in mercury concentration at 30-40 years of age, depending on the sex, and lower concentrations in the youngest and oldest animals. To evaluate the robustness of our findings, we re-analyzed data from a previously published study of mercury in alligators sampled at Merritt Island National Wildlife Refuge in Florida. Unlike the South Carolina data, the data from Florida contained minimal auxiliary information regarding age, yet the best supported model similarly indicated a peaked rather than increasing relationship between mercury and body size, a less-precise indicator of age. These findings highlight how long-term monitoring can differentiate between confounding variables (e.g., age and size) to better elucidate complex relationships between contaminant exposure and demographic factors in sentinel species.
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Affiliation(s)
- Abigail J Lawson
- Department of Forestry and Environmental Conservation, Clemson University, 261 Lehotsky Hall, Clemson, SC 29634, USA.
| | - Clinton T Moore
- U.S. Geological Survey, Georgia Cooperative Fish and Wildlife Research Unit, Warnell School of Forestry and Natural Resources, University of Georgia, 180 E. Green Street, Athens, GA 30602, USA.
| | - Thomas R Rainwater
- Department of Forestry and Environmental Conservation, Clemson University, 261 Lehotsky Hall, Clemson, SC 29634, USA; Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442, USA; Tom Yawkey Wildlife Center, 1 Yawkey Way, Georgetown, SC 29440, USA.
| | - Frances M Nilsen
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, SC 29412, USA.
| | | | - Russell H Lowers
- Integrated Mission Support Service (IMSS), Kennedy Space Center, FL 32899, USA.
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, SC 29412, USA
| | - K W McFadden
- U.S. Geological Survey, South Carolina Cooperative Fish and Wildlife Research Unit, 261 Lehotsky Hall, Clemson University, Clemson, SC 29634, USA
| | - Patrick G R Jodice
- U.S. Geological Survey, South Carolina Cooperative Fish and Wildlife Research Unit, 261 Lehotsky Hall, Clemson University, Clemson, SC 29634, USA.
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Nilsen FM, Rainwater TR, Wilkinson PM, Brunell AM, Lowers RH, Bowden JA, Guillette LJ, Long SE, Schock TB. Examining maternal and environmental transfer of mercury into American alligator eggs. Ecotoxicol Environ Saf 2020; 189:110057. [PMID: 31835046 PMCID: PMC11005113 DOI: 10.1016/j.ecoenv.2019.110057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
American alligators are exposed to mercury (Hg) throughout their natural range and may maternally transfer Hg into their eggs. Wildlife species are highly sensitive to Hg toxicity during embryonic development and neonatal life, and information on Hg transfer into eggs is critical when attempting to understand the effects of Hg exposure on developing oviparous organisms. To examine Hg transfer in alligators, the objectives of the present study were to 1) determine Hg concentrations in yolk (embryonic and neonatal food source) from wild alligator eggs collected from three locations - Yawkey Wildlife Center SC (YWC), Lake Apopka FL (LA), and Lake Woodruff FL (LW); 2) examine the relationship between THg concentrations in wild alligator nest material and egg yolk at Merritt Island National Wildlife Refuge, FL; 3) examine the Hg concentrations in wild maternal female alligators (blood) and the THg in corresponding egg yolks and embryos across three nesting seasons at a single location (YWC), and evaluate the relationship between nesting female THg concentrations (blood) and their estimated age and number of nesting years (YWC); and 4) assess the transfer of biologically-relevant Hg concentrations (based on Hg measured in maternal female blood) into embryos using an egg-dosing experiment. Mean total Hg (THg) concentrations observed at each site were 26.3 ng/g ± 11.0 ng/g (YWC), 8.8 ng/g ± 5.1 ng/g (LA), and 22.6 ng/g ± 6.3 ng/g (LW). No relationship was observed between THg in alligator nest material and corresponding yolk samples, nor between THg in maternal alligator blood and estimated age and number of nesting years of these animals. However, significant positive relationships were observed between THg in blood of nesting female alligators and THg in their corresponding egg yolk. We observed that 12.8% of the maternal blood THg is found in the corresponding egg yolk, and a highly significant correlation was observed between the two sample types (r = 0.66; p < 0.0001). The egg dosing experiment revealed that Hg did not transfer through the eggshell at developmental stage 19. Overall, this study provides new information regarding Hg transfer in American alligators which can improve biomonitoring efforts and may inform ecotoxicological investigations and population management programs in areas of high Hg contamination.
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Affiliation(s)
- Frances M Nilsen
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA; Medical University of South Carolina, Marine Bio-Medicine and Environmental Science Program, Charleston, SC, USA.
| | - Thomas R Rainwater
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC, USA; Tom Yawkey Wildlife Center, South Carolina Department of Natural Resources, 1 Yawkey Way South, Georgetown, SC, USA.
| | - Phil M Wilkinson
- Tom Yawkey Wildlife Center, South Carolina Department of Natural Resources, 1 Yawkey Way South, Georgetown, SC, USA
| | - Arnold M Brunell
- Florida Fish & Wildlife Conservation Commission, 601 W. Woodward Ave., Eustis, FL, USA.
| | | | - John A Bowden
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA; Current Address- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
| | - Louis J Guillette
- Medical University of South Carolina, Marine Bio-Medicine and Environmental Science Program, Charleston, SC, USA
| | - Stephen E Long
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA.
| | - Tracey B Schock
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA.
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Kohno S, Zhu J, Guillette LJ. Stress responses in the chemistry and mRNA abundance of the peripheral blood in the American alligator. J Exp Zool A Ecol Integr Physiol 2019; 333:151-163. [PMID: 31885208 DOI: 10.1002/jez.2337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 11/07/2022]
Abstract
To monitor physiological and toxicological conditions in an endangered species, noninvasive to minimally invasive sampling methods are needed. We analyzed peripheral blood cells to determine if we could monitor some physiological responses of the American alligator following capture stress. Juvenile American alligators were restrained for 16 h to examine the stress response in plasma and blood cells. Plasma corticosterone concentrations were increased by restraint as were plasma concentrations of aspartate aminotransferase (AST), creatine kinase (CK), uric acid, and glucose; a sexually dimorphic response was seen in AST and CK concentrations. The lapse time of restraint was associated with altered messenger RNA (mRNA) levels of the glucocorticoid receptor (GCR) in red blood cells and JUN proto-oncogene in both white and red blood cells. A two-way cluster analysis revealed that two major clusters of factors were associated with the responses seen: (a) mRNA levels of GCR and heat-shock proteins in both blood cells were associated with plasma corticosterone concentration, whereas (b) androgen receptors and JUN mRNA levels in both blood cells were associated with cloacal temperature and body composition. Blood cells appear to be an excellent source to examine the cellular stress response to steroid hormone signals in mRNA levels. We propose that this approach, using blood cells, could provide essential insights into the molecular responses associated with stress in reptiles as well as many other nontraditional model species, including endangered species.
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Affiliation(s)
- Satomi Kohno
- Department of Biology, St Cloud State University, St Cloud, Minnesota.,Department of Obstetrics and Gynecology, Hollings Marine Laboratory, CoEE Center for Marine Genomics and Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC), and Charleston, Charleston, South Carolina
| | - Jianguo Zhu
- Department of Obstetrics and Gynecology, Hollings Marine Laboratory, CoEE Center for Marine Genomics and Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC), and Charleston, Charleston, South Carolina
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Hollings Marine Laboratory, CoEE Center for Marine Genomics and Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC), and Charleston, Charleston, South Carolina
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Nilsen FM, Bowden JA, Rainwater TR, Brunell AM, Kassim BL, Wilkinson PM, Guillette LJ, Long SE, Schock TB. Examining toxic trace element exposure in American alligators. Environ Int 2019; 128:324-334. [PMID: 31078001 PMCID: PMC6857802 DOI: 10.1016/j.envint.2019.04.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
Toxic trace element exposure occurs through release of the ubiquitous and naturally occurring elements arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). The unique environmental conditions of the wetland ecosystems along the southeastern Atlantic coast of the United States lead to the accumulation of Hg which is greater than in most other ecosystems in the country. There are also point sources of As, Cd, and Pb in this region. To effectively monitor trace element concentrations, and consequently the potential human exposure, accessible local sentinel species are needed. In this study, concentrations of As, Cd, Pb, Hg and six other trace elements (Al, Ni, Cu, Zn, Se, Mo) were examined in American alligators (Alligator mississippiensis) from seven wetland sites in South Carolina and Florida and assessed for their utility as a sentinel species for human trace element exposure. Alligators were chosen as a potential sentinel as they share a common exposure with the local human population through their aquatic diet, and they are directly consumed commercially and through recreation hunting in this region. Sex was significantly related to the concentration of Zn, Mo, and Al, but not As, Pb, Hg, Cd, Se, or Cu. Site specific differences in element concentrations were observed for As, Pb, Hg, Cd, Se, Zn, and Mo. Size/age was significantly related to the element Hg and Pb concentrations observed. The observed concentration ranges for the four toxic elements, As (6-156 ng/g), Cd (0.3-1.3 ng/g), Pb (3-4872 ng/g), and Hg (39-2765 ng/g), were comparable to those previously reported in diverse human populations. In this region alligators are hunted recreationally and consumed by the local community, making them a vehicle of direct human toxic element exposure. We propose that the similarity in As, Cd, Pb, and Hg concentrations between alligators observed in this study and humans underscores how alligators can serve as a useful sentinel species for toxic element exposure.
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Affiliation(s)
- Frances M Nilsen
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA; Medical University of South Carolina, Marine Bio-medicine and Environmental Science Program, Charleston, SC, USA.
| | - John A Bowden
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA; Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
| | - Thomas R Rainwater
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC, USA; Tom Yawkey Wildlife Center, South Carolina Department of Natural Resources, 1 Yawkey Way South, Georgetown, SC, USA
| | - Arnold M Brunell
- Florida Fish & Wildlife Conservation Commission, Eustis, FL, USA.
| | - Brittany L Kassim
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA
| | - Phil M Wilkinson
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC, USA
| | - Louis J Guillette
- Medical University of South Carolina, Marine Bio-medicine and Environmental Science Program, Charleston, SC, USA
| | - Stephen E Long
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA.
| | - Tracey B Schock
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC, USA.
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Galligan TM, Hale MD, McCoy JA, Bermudez DS, Guillette LJ, Parrott BB. Assessing impacts of precocious steroid exposure on thyroid physiology and gene expression patterns in the American alligator (Alligator mississippiensis). Gen Comp Endocrinol 2019; 271:61-72. [PMID: 30408484 DOI: 10.1016/j.ygcen.2018.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/17/2018] [Accepted: 11/04/2018] [Indexed: 10/27/2022]
Abstract
The thyroid gland is sensitive to steroid hormone signaling, and many thyroid disrupting contaminants also disrupt steroid hormone homeostasis, presenting the possibility that thyroid disruption may occur through altered steroid hormone signaling. To examine this possibility, we studied short-term and persistent impacts of embryonic sex steroid exposure on thyroid physiology in the American alligator. Alligators from a lake contaminated with endocrine disrupting contaminants (Lake Apopka, FL, USA) have been shown to display characteristics of thyroid and steroid hormone disruption. Previous studies suggest these alterations arise during development and raise the possibility that exposure to maternally deposited contaminants might underlie persistent organizational changes in both thyroidal and reproductive function. Thus, this population provides a system to investigate contaminant-mediated organizational thyroid disruption in an environmentally-relevant context. We assess the developmental expression of genetic pathways involved in thyroid hormone biosynthesis and find that expression of these genes increases prior to hatching. Further, we show that nuclear steroid hormone receptors are also expressed during this period, indicating the developing thyroid is potentially responsive to steroid hormone signaling. We then explore functional roles of steroid signaling during development on subsequent thyroid function in juvenile alligators. We exposed alligator eggs collected from both Lake Apopka and a reference site to 17β-estradiol and a non-aromatizable androgen during embryonic development, and investigated effects of exposure on hatchling morphometrics and thyroidal gene expression profiles at 5 months of age. Steroid hormone treatment did not impact the timing of hatching or hatchling size. Furthermore, treatment with steroid hormones did not result in detectable impacts on thyroid transcriptional programs, suggesting that precocious or excess estrogen and androgen exposure does not influence immediate or long-term thyroidal physiology.
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Affiliation(s)
- Thomas M Galligan
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; Virginia Polytechnic Institute and State University, College of Natural Resources and the Environment, Department of Fish and Wildlife Conservation, 101 Cheatham Hall, 310 West Campus Drive, Blacksburg, VA 24060, USA.
| | - Matthew D Hale
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802, USA; University of Georgia, Eugene P. Odum School of Ecology, 140 E. Green Street, Athens, GA 30602.
| | - Jessica A McCoy
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; College of Charleston, 66 George Street, Charleston, SC 29424, USA
| | - Dieldrich S Bermudez
- Mars Inc., Global Innovation Center, 1132 W. Blackhawk Street, Chicago, IL 60642, USA
| | - Louis J Guillette
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Benjamin B Parrott
- Medical University of South Carolina, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; University of Georgia, Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802, USA; University of Georgia, Eugene P. Odum School of Ecology, 140 E. Green Street, Athens, GA 30602.
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Hale MD, Galligan TM, Rainwater TR, Moore BC, Wilkinson PM, Guillette LJ, Parrott BB. Corrigendum to "AHR and CYP1A expression link historical contamination events to modern day development in the American alligator" [Environ. Pollut. 230 (2017) 1050-1061]. Environ Pollut 2018; 242:2096-2098. [PMID: 29937149 DOI: 10.1016/j.envpol.2018.06.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Matthew D Hale
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States
| | - Thomas M Galligan
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC 29442, United States
| | - Brandon C Moore
- Department of Biology, Sewanee: the University of the South, Sewanee, TN 37383, United States
| | - Philip M Wilkinson
- Tom Yawkey Wildlife Center Heritage Preserve, South Carolina Department of Natural Resources, Georgetown, SC 29440, United States
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States.
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Hale MD, McCoy JA, Doheny BM, Galligan TM, Guillette LJ, Parrott BB. Embryonic estrogen exposure recapitulates persistent ovarian transcriptional programs in a model of environmental endocrine disruption†. Biol Reprod 2018; 100:149-161. [DOI: 10.1093/biolre/ioy165] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/12/2018] [Indexed: 11/15/2022] Open
Affiliation(s)
- Matthew D Hale
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
- Odum School of Ecology, University of Georgia, Athens, Georgia, USA
| | | | - Brenna M Doheny
- School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Thomas M Galligan
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, USA
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina, USA
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, Aiken, South Carolina, USA
- Odum School of Ecology, University of Georgia, Athens, Georgia, USA
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Edwards TM, Hamlin HJ, Freymiller H, Green S, Thurman J, Guillette LJ. Nitrate induces a type 1 diabetic profile in alligator hatchlings. Ecotoxicol Environ Saf 2018; 147:767-775. [PMID: 28942280 DOI: 10.1016/j.ecoenv.2017.09.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/16/2017] [Accepted: 09/18/2017] [Indexed: 06/07/2023]
Abstract
Type 1 diabetes (T1D) is a chronic autoimmune disease that affects 1 in 300 children by age 18. T1D is caused by inflammation-induced loss of insulin-producing pancreatic beta cells, leading to high blood glucose and a host of downstream complications. Although multiple genes are associated with T1D risk, only 5% of genetically susceptible individuals actually develop clinical disease. Moreover, a growing number of T1D cases occur in geographic clusters and among children with low risk genotypes. These observations suggest that environmental factors contribute to T1D etiology. One potential factor, supported primarily by epidemiological studies, is the presence of nitrate and nitrite in drinking water. To test this hypothesis, female hatchling alligators were exposed to environmentally relevant concentrations of nitrate in their tank water (reference, 10mg/L, or 100mg/L NO3-N) from hatch through 5 weeks or 5 months of age. At each time point, endpoints related to T1D were investigated: plasma levels of glucose, triglycerides, testosterone, estradiol, and thyroxine; pancreas, fat body, and thyroid weights; weight gain or loss; presence of immune cells in the pancreas; and pancreatic beta cell number, assessed by antibody staining of nkx6.1 protein. Internal dosing of nitrate was confirmed by measuring plasma and urine nitrate levels and whole blood methemoglobin. Cluster analysis indicated that high nitrate exposure (most animals exposed to 100mg/L NO3-N and one alligator exposed to 10mg/L NO3-N) induced a profile of endpoints consistent with early T1D that could be detected after 5 weeks and was more strongly present after 5 months. Our study supports epidemiological data correlating elevated nitrate with T1D onset in humans, and highlights nitrate as a possible environmental contributor to the etiology of T1D, possibly through its role as a nitric oxide precursor.
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Affiliation(s)
- Thea M Edwards
- Department of Biology, University of the South, Sewanee, TN, USA; Department of Biology, University of Florida, Gainesville, FL, USA; School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA.
| | - Heather J Hamlin
- School of Marine Sciences, University of Maine, Orono, ME, USA; Department of Biology, University of Florida, Gainesville, FL, USA
| | - Haley Freymiller
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Stephen Green
- School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA
| | - Jenna Thurman
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Louis J Guillette
- Department of Biology, University of Florida, Gainesville, FL, USA; Marine Biomedicine & Environmental Sciences, Medical University of South Carolina and Hollings Marine Laboratory, Charleston, SC, USA
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10
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McCoy KA, Amato CM, Guillette LJ, St Mary CM. Giant toads (Rhinella marina) living in agricultural areas have altered spermatogenesis. Sci Total Environ 2017; 609:1230-1237. [PMID: 28787797 PMCID: PMC5600858 DOI: 10.1016/j.scitotenv.2017.07.185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 06/07/2023]
Abstract
Across diverse taxa, germ cell development is controlled by an intricate cascade of processes that are tightly controlled by the hypothalamic-pituitary-gonadal axis. Endocrine disturbances, such as those induced by endocrine disrupting chemicals (EDCs) can negatively affect spermatogenesis. Here, we investigate whether spermatogenesis is altered in the giant toad, Rhinella marina, living in agricultural areas where EDCs are used relative to suburban areas. We also ask if reductions in spermatogenesis were associated with developmental gonadal abnormalities (intersex) found in the same frogs. We found that toads in agricultural areas exhibited reduced spermatogenesis relative to non-agricultural animals, and that those reductions were not associated with gross gonadal abnormalities. All toads living in agricultural areas had reduced spermatogenesis relative to those living in non-agricultural areas regardless of whether they had gonadal abnormalities originating during development. Similarities in reproductive dysfunction among diverse taxa living in agricultural areas, including humans, suggest that many vertebrate taxa living in agricultural areas around the globe are likely experiencing some level of reproductive dysfunction.
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Affiliation(s)
- Krista A McCoy
- Department of Biology, East Carolina University, Greenville, NC 27858, USA.
| | - Ciro M Amato
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology (L.J.G.), Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, SC 29425, USA
| | - Colette M St Mary
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
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Nilsen FM, Dorsey JE, Lowers RH, Guillette LJ, Long SE, Bowden JA, Schock TB. Evaluating mercury concentrations and body condition in American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), Florida. Sci Total Environ 2017; 607-608:1056-1064. [PMID: 28724244 DOI: 10.1016/j.scitotenv.2017.07.073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 07/06/2017] [Accepted: 07/08/2017] [Indexed: 06/07/2023]
Abstract
Concentrations of mercury (Hg) are not well studied in free-ranging wildlife. Atmospheric deposition patterns of Hg have been studied in detail and have been modeled for both global and specific locations and often correlate to environmental impact. However, monitoring the impact of Hg deposition in wildlife is complicated due to local environmental conditions that can affect the transformation of atmospheric Hg to the biologically available forms (e.g., rainfall, humidity, pH, the ability of the environment to methylate Hg), as well as affect the accessibility to organisms for sampling. In this study, Hg concentrations in blood samples from a population of American alligators (Alligator mississippiensis) at Merritt Island National Wildlife Refuge (MINWR), FL, USA, over a seven-year period (2007 to 2014; n=174 individuals) were examined to assess Hg variation in the population, as well as the difference in Hg concentration as a function of health status. While most of this population is healthy, 18 individuals with low body mass indices (BMI, defined in this study) were captured throughout the sampling period. These alligators exhibited significantly elevated Hg concentrations compared to their age/sex/season matched counterparts with normal BMI, suggesting that health status should be taken into account when examining Hg concentrations and effects. Alligator blood Hg concentrations were related to the interaction of age/size, sex, and season. This study illustrates the value of a routinely monitored population of large predators in a unique coastal wetland ecosystem, and illuminates the value of long-term environmental exposure assessment.
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Affiliation(s)
- Frances M Nilsen
- Medical University of South Carolina, Charleston, SC, USA; National Institute of Standards and Technology, Hollings Marine Lab, Charleston, SC, USA.
| | | | | | | | - Stephen E Long
- National Institute of Standards and Technology, Hollings Marine Lab, Charleston, SC, USA
| | - John A Bowden
- National Institute of Standards and Technology, Hollings Marine Lab, Charleston, SC, USA
| | - Tracey B Schock
- National Institute of Standards and Technology, Hollings Marine Lab, Charleston, SC, USA
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12
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Tipton JJ, Guillette LJ, Lovelace S, Parrott BB, Rainwater TR, Reiner JL. Analysis of PFAAs in American alligators part 1: Concentrations in alligators harvested for consumption during South Carolina public hunts. J Environ Sci (China) 2017; 61:24-30. [PMID: 29191311 PMCID: PMC6582648 DOI: 10.1016/j.jes.2017.05.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/04/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids (PFAAs) were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis, as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina (SC) public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size (total length), sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate (PFOS) was found in all alligator meat samples and at the highest concentrations (median 6.73ng/g). No relationship was found between PFAA concentrations and total length or sex. Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations (median 16.0ng/g; p=0.0001). Alligators harvested specifically from Berkley County, SC (located in the Middle Coastal hunt unit) had the highest PFOS concentrations and the greatest number of PFAAs detected (p<0.0001). The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.
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Affiliation(s)
| | - Louis J Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, Charleston, SC 29425, USA
| | | | - Benjamin B Parrott
- University of Georgia, Odum School of Ecology, Savannah River Ecology Laboratory, Jackson, SC 29831, USA
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442, USA
| | - Jessica L Reiner
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC 29412, USA.
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13
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Tipton JJ, Guillette LJ, Lovelace S, Parrott BB, Rainwater TR, Reiner JL. Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat. J Environ Sci (China) 2017; 61:31-38. [PMID: 29191313 PMCID: PMC6526952 DOI: 10.1016/j.jes.2017.05.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/04/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat.
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Affiliation(s)
| | - Louis J Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, Charleston, SC 29425, USA
| | | | - Benjamin B Parrott
- University of Georgia, Odum School of Ecology, Savannah River Ecology Laboratory, Jackson, SC 29831, USA
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442, USA
| | - Jessica L Reiner
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, Charleston, SC 29412, USA.
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14
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Hale MD, Galligan TM, Rainwater TR, Moore BC, Wilkinson PM, Guillette LJ, Parrott BB. AHR and CYP1A expression link historical contamination events to modern day developmental effects in the American alligator. Environ Pollut 2017; 230:1050-1061. [PMID: 28764121 DOI: 10.1016/j.envpol.2017.07.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 05/16/2023]
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that initiates a transcriptional pathway responsible for the expression of CYP1A subfamily members, key to the metabolism of xenobiotic compounds. Toxic planar halogenated aromatic hydrocarbons, including dioxin and PCBs, are capable of activating the AHR, and while dioxin and PCB inputs into the environment have been dramatically curbed following strict regulatory efforts in the United States, they persist in the environment and exposures remain relevant today. Little is known regarding the effects that long-term chronic exposures to dioxin or dioxin-like compounds might have on the development and subsequent health of offspring from exposed individuals, nor is much known regarding AHR expression in reptilians. Here, we characterize AHR and CYP1A gene expression in embryonic and juvenile specimen of a long-lived, apex predator, the American alligator (Alligator mississippiensis), and investigate variation in gene expression profiles in offspring collected from sites conveying differential exposures to environmental contaminants. Both age- and tissue-dependent patterning of AHR isoform expression are detected. We characterize two downstream transcriptional targets of the AHR, CYP1A1 and CYP1A2, and describe conserved elements of their genomic architecture. When comparisons across different sites are made, hepatic expression of CYP1A2, a direct target of the AHR, appears elevated in embryos from a site associated with a dioxin point source and previously characterized PCB contamination. Elevated CYP1A2 expression is not persistent, as site-specific variation was absent in juveniles originating from field-collected eggs but reared under lab conditions. Our results illustrate the patterning of AHR gene expression in a long-lived environmental model species, and indicate a potential contemporary influence of historical contamination. This research presents a novel opportunity to link contamination events to critical genetic pathways during embryonic development, and carries significant potential to inform our understanding of potential health effects in wildlife and humans.
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Affiliation(s)
- Matthew D Hale
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States
| | - Thomas M Galligan
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC 29442, United States
| | - Brandon C Moore
- Department of Biology, Sewanee: the University of the South, Sewanee, TN 37383, United States
| | - Philip M Wilkinson
- Tom Yawkey Wildlife Center Heritage Preserve, South Carolina Department of Natural Resources, Georgetown, SC 29440, United States
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Program, Hollings Marine Laboratory and the Medical University of South Carolina, Charleston, SC 29412, United States
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, United States; Odum School of Ecology, University of Georgia, Athens, GA 30602, United States.
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15
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Nilsen FM, Kassim BL, Delaney JP, Lange TR, Brunell AM, Guillette LJ, Long SE, Schock TB. Trace element biodistribution in the American alligator (Alligator mississippiensis). Chemosphere 2017; 181:343-351. [PMID: 28456036 DOI: 10.1016/j.chemosphere.2017.04.102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 04/17/2017] [Accepted: 04/21/2017] [Indexed: 06/07/2023]
Abstract
Routine monitoring of contaminant levels in wildlife is important for understanding chemical exposure and ultimately the link to ecosystem and human health. This is particularly important when the monitored species is recreationally hunted for human consumption. In the southeastern United States, recreational alligator harvesting takes place annually and in locations that are known to be contaminated with environmental pollutants. In this study, we investigated the biodistribution of trace elements in the American alligator (Alligator mississippiensis) from five sites in Florida, USA. These sites are locations where annual recreational alligator harvesting is permitted and two of the sites are identified as having high mercury contamination with human consumption advisories in effect. We utilized routinely collected monitoring samples (blood and scute), a commonly consumed tissue (muscle), and a classically analyzed tissue for environmental contaminants (liver) to demonstrate how the trace elements were distributed within the American alligator. We describe elemental tissue compartmentalization in an apex predator and investigate if noninvasive samples (blood and scute) can be used to estimate muscle tissue concentrations for a subset of elements measured. We found significant correlations for Hg, Rb, Se, Zn and Pb between noninvasive samples and consumed tissue and also found that Hg was the only trace metal of concern for this population of alligators. This study fills a gap in trace elemental analysis for reptilian apex predators in contaminated environments. Additionally, comprehensive elemental analysis of routinely collected samples can inform biomonitoring efforts and consumption advisories.
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Affiliation(s)
- Frances M Nilsen
- National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Charleston, SC 29412, USA; Department of Obstetrics and Gynecology and Marine Biomedicine and Environmental Sciences, Medical University of South Carolina (MUSC), Charleston, SC 29425-6190, USA.
| | - Brittany L Kassim
- National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Charleston, SC 29412, USA.
| | - J Patrick Delaney
- Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Ave, Eustis, FL 32726, USA.
| | - Ted R Lange
- Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Ave, Eustis, FL 32726, USA.
| | - Arnold M Brunell
- Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Ave, Eustis, FL 32726, USA.
| | - Louis J Guillette
- Department of Obstetrics and Gynecology and Marine Biomedicine and Environmental Sciences, Medical University of South Carolina (MUSC), Charleston, SC 29425-6190, USA
| | - Stephen E Long
- National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Charleston, SC 29412, USA.
| | - Tracey B Schock
- National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Charleston, SC 29412, USA.
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16
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Bangma JT, Bowden JA, Brunell AM, Christie I, Finnell B, Guillette MP, Jones M, Lowers RH, Rainwater TR, Reiner JL, Wilkinson PM, Guillette LJ. Perfluorinated alkyl acids in plasma of American alligators (Alligator mississippiensis) from Florida and South Carolina. Environ Toxicol Chem 2017; 36:917-925. [PMID: 27543836 PMCID: PMC5494598 DOI: 10.1002/etc.3600] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/09/2016] [Accepted: 08/18/2016] [Indexed: 05/21/2023]
Abstract
The present study aimed to quantitate 15 perfluoroalkyl acids (PFAAs) in 125 adult American alligators at 12 sites across the southeastern United States. Of those 15 PFAAs, 9 were detected in 65% to 100% of samples: perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), perfluorododecanoic acid, perfluorotridecanoic acid (PFTriA), perfluorotetradecanoic acid, perfluorohexanesulfonic acid (PFHxS), and perfluorooctane sulfonate (PFOS). Males (across all sites) showed significantly higher concentrations of 4 PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at both Merritt Island National Wildlife Refuge (FL, USA) and Kiawah Nature Conservancy (SC, USA) exhibited some of the highest PFOS concentrations (medians of 99.5 ng/g and 55.8 ng/g, respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length were observed in both sexes, suggesting that PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. The present study is the first to report PFAAs in American alligators, to reveal potential PFAA hot spots in Florida and South Carolina, and to provide a contaminant of concern when assessing anthropogenic impacts on ecosystem health. Environ Toxicol Chem 2017;36:917-925. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
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Affiliation(s)
- Jacqueline T. Bangma
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - John A. Bowden
- Hollings Marine Laboratory, Chemical Sciences Division, National Institute of Standards and Technology, Charleston, South Carolina, USA
| | - Arnold M. Brunell
- Florida Fish and Wildlife Conservation Commission, Eustis, Florida, USA
| | - Ian Christie
- Grice Marine Laboratory, College of Charleston, Charleston, South Carolina, USA
| | | | - Matthew P. Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Martin Jones
- Department of Mathematics, College of Charleston, Charleston, South Carolina, USA
| | - Russell H. Lowers
- Integrated Mission Support Service, Kennedy Space Center, Titusville, Florida, USA
| | - Thomas R. Rainwater
- Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, South Carolina, USA
| | - Jessica L. Reiner
- Hollings Marine Laboratory, Chemical Sciences Division, National Institute of Standards and Technology, Charleston, South Carolina, USA
- Address correspondence to
| | | | - Louis J. Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
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17
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Rice ES, Kohno S, John JS, Pham S, Howard J, Lareau LF, O'Connell BL, Hickey G, Armstrong J, Deran A, Fiddes I, Platt RN, Gresham C, McCarthy F, Kern C, Haan D, Phan T, Schmidt C, Sanford JR, Ray DA, Paten B, Guillette LJ, Green RE. Improved genome assembly of American alligator genome reveals conserved architecture of estrogen signaling. Genome Res 2017; 27:686-696. [PMID: 28137821 PMCID: PMC5411764 DOI: 10.1101/gr.213595.116] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 12/13/2016] [Indexed: 12/12/2022]
Abstract
The American alligator, Alligator mississippiensis, like all crocodilians, has temperature-dependent sex determination, in which the sex of an embryo is determined by the incubation temperature of the egg during a critical period of development. The lack of genetic differences between male and female alligators leaves open the question of how the genes responsible for sex determination and differentiation are regulated. Insight into this question comes from the fact that exposing an embryo incubated at male-producing temperature to estrogen causes it to develop ovaries. Because estrogen response elements are known to regulate genes over long distances, a contiguous genome assembly is crucial for predicting and understanding their impact. We present an improved assembly of the American alligator genome, scaffolded with in vitro proximity ligation (Chicago) data. We use this assembly to scaffold two other crocodilian genomes based on synteny. We perform RNA sequencing of tissues from American alligator embryos to find genes that are differentially expressed between embryos incubated at male- versus female-producing temperature. Finally, we use the improved contiguity of our assembly along with the current model of CTCF-mediated chromatin looping to predict regions of the genome likely to contain estrogen-responsive genes. We find that these regions are significantly enriched for genes with female-biased expression in developing gonads after the critical period during which sex is determined by incubation temperature. We thus conclude that estrogen signaling is a major driver of female-biased gene expression in the post-temperature sensitive period gonads.
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Affiliation(s)
- Edward S Rice
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Satomi Kohno
- Department of Biology, St. Cloud State University, St. Cloud, Minnesota 56301, USA
| | - John St John
- Driver Group, LLC, San Francisco, California 94158, USA
| | - Son Pham
- BioTuring, Incorporated, San Diego, California 92121, USA
| | - Jonathan Howard
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | - Liana F Lareau
- California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA
| | - Brendan L O'Connell
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA.,Dovetail Genomics, LLC, Santa Cruz, California 95060, USA
| | - Glenn Hickey
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Joel Armstrong
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Alden Deran
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Ian Fiddes
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Roy N Platt
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409, USA
| | - Cathy Gresham
- Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Fiona McCarthy
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona 85721, USA
| | - Colin Kern
- Department of Animal Science, University of California, Davis, California 95616, USA
| | - David Haan
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Tan Phan
- HCM University of Science, Ho Chí Minh, Vietnam 748500
| | - Carl Schmidt
- Department of Animal and Food Sciences, University of Delaware, Newark, Delaware 19717, USA
| | - Jeremy R Sanford
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064, USA
| | - David A Ray
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas 79409, USA
| | - Benedict Paten
- Center for Biomolecular Science and Engineering, University of California, Santa Cruz, California 95064, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Medical University of South Carolina, Charleston, South Carolina 29412, USA
| | - Richard E Green
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA.,California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.,Dovetail Genomics, LLC, Santa Cruz, California 95060, USA
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18
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Bangma JT, Reiner JL, Jones M, Lowers RH, Nilsen F, Rainwater TR, Somerville S, Guillette LJ, Bowden JA. Variation in perfluoroalkyl acids in the American alligator (Alligator mississippiensis) at Merritt Island National Wildlife Refuge. Chemosphere 2017; 166:72-79. [PMID: 27689886 PMCID: PMC5548459 DOI: 10.1016/j.chemosphere.2016.09.088] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 05/22/2023]
Abstract
This study aimed to quantify concentrations of fifteen perfluoroalkyl acids (PFAAs) in the plasma of American alligators (Alligator mississippiensis) inhabiting wetlands surrounding the Kennedy Space Center (KSC) in Florida, USA located at Merritt Island National Wildlife Refuge (MINWR). Approximately 10 male and 10 female alligators (ntotal = 229) were sampled each month during 2008 and 2009 to determine if seasonal or spatial trends existed with PFAA burden. PFOS represented the highest plasma burden (median 185 ng/g) and PFHxS the second highest (median 7.96 ng/g). While no significant seasonal trends were observed, unique spatial trends emerged. Many of the measured PFAAs co-varied strongly together and similar trends were observed for PFOS, PFDA, PFUnA, and PFDoA, as well as for PFOA, PFHxS, PFNA, PFTriA, and PFTA, suggesting more than one source of PFAAs at MINWR. Higher concentrations of PFOS and the PFAAs that co-varied with PFOS were collected from animals around sites that included the Shuttle Landing Facility (SLF) fire house and the Neil Armstrong Operations and Checkout (O&C) retention pond, while higher concentrations of PFOA and the PFAA that co-varied with PFOA were sampled from animals near the gun range and the old fire training facility. Sex-based differences and snout-vent length (SVL) correlations with PFAA burden were also investigated.
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Affiliation(s)
- Jacqueline T Bangma
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC 29412, USA
| | - Jessica L Reiner
- National Institute of Standards and Technoclogy, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Martin Jones
- College of Charleston, Department of Mathematics, 66 George Street, Charleston, SC 29424, USA
| | - Russell H Lowers
- Integrated Mission Support Service (IMSS), Kennedy Space Center, FL, USA
| | - Frances Nilsen
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC 29412, USA; National Institute of Standards and Technoclogy, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center & Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442, USA
| | - Stephen Somerville
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC 29412, USA
| | - Louis J Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC 29412, USA
| | - John A Bowden
- National Institute of Standards and Technoclogy, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA.
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19
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Doheny BM, Kohno S, Parrott BB, Guillette LJ. In ovo treatment with an estrogen receptor alpha selective agonist causes precocious development of the female reproductive tract of the American alligator (Alligator mississippiensis). Gen Comp Endocrinol 2016; 238:96-104. [PMID: 26994582 DOI: 10.1016/j.ygcen.2016.02.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/29/2016] [Indexed: 11/27/2022]
Abstract
The molecular signaling processes involved the differentiation of the Müllerian duct (MD) into the female reproductive tract, or oviduct, in non-mammalian vertebrates are not well understood. Studies in mammals and birds indicate that steroid hormones play a role in this process, as the embryonic MD has been shown to be vulnerable to exogenous estrogens and progestins and environmental endocrine disrupting contaminants. In a previous study, developmental treatment with an estrogen receptor α (ERα) agonist, 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT), induced significant enlargement of the MD in alligator embryos incubated at a male-producing temperature, which was not observed in embryos treated with an estrogen receptor β (ERβ) agonist, 7-bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY 200070), or with 17β-estradiol (E2). In order to understand the role of estrogen signaling in female alligator oviduct development, we incubated eggs at a female-producing temperature and treated them with E2 and these ER selective agonists, PPT and WAY 200070, just prior to the thermosensitive window of sex determination. At stage 27, one stage prior to hatching, PPT induced significant enlargement of the MD with precocious development of secretory glands and connective tissue differentiation similar to characteristics of mature adult oviduct. PPT treatment in ovo increased mRNA expression of ERβ, progesterone receptor, androgen receptor and insulin-like growth factor 1 in MD at stage 27, while expression of ERα was decreased. Neither WAY 200070 nor E2 treatment induced these effects seen in PPT-treated MD. The results of this study provide insight into the critical factors for healthy reproductive system formation in this sentinel species, although further investigation is needed to determine whether the observed phenomena are directly due to selective stimulation of ERα or related to some other aspect of PPT treatment.
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Affiliation(s)
- Brenna M Doheny
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA.
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Benjamin B Parrott
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
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McCoy JA, Hamlin HJ, Thayer L, Guillette LJ, Parrott BB. The influence of thermal signals during embryonic development on intrasexual and sexually dimorphic gene expression and circulating steroid hormones in American alligator hatchlings (Alligator mississippiensis). Gen Comp Endocrinol 2016; 238:47-54. [PMID: 27080549 DOI: 10.1016/j.ygcen.2016.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/09/2016] [Indexed: 10/22/2022]
Abstract
Incubation temperatures experienced by developing embryos exert powerful influences over gonadal sex determination and differentiation in many species. However, the molecular mechanisms controlling these impacts remain largely unknown. We utilize the American alligator to investigate the sensitivity of the reproductive system to thermal signals experienced during development and ask specifically whether individuals of the same sex, yet derived from different incubation temperatures display persistent variation in the expression patterns of sex biased transcripts and plasma sex hormones. Our analysis focuses on assessments of circulating sex steroids and transcript abundance in brain and gonad, two tissues that display sexually dimorphic gene expression and directly contribute to diverse sexually dimorphic phenotypes. Whereas our results identify sexually dimorphic patterns for several target gonadal genes in postnatal alligators, sex linked variation in circulating 17β-estradiol, testosterone, and expression of two brain transcripts (aromatase and gonadotropin releasing hormone) was not observed. Regarding intrasexual variation, we found that AMH transcript abundance in hatchling testes is positively correlated with temperatures experienced during sexual differentiation. We also describe highly variable patterns of gene expression and circulating hormones within each sex that are not explained by the intensity of embryonic incubation temperatures. The magnitude of sexually dimorphic gene expression, however, is directly associated with temperature for SOX9 and AMH, two transcripts with upstream roles in Sertoli cell differentiation. Collectively, our findings regarding temperature linked variation provide new insights regarding the connections between embryonic environment and persistent impacts on sexual differentiation in a reptile species that displays temperature dependent sex determination.
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Affiliation(s)
- Jessica A McCoy
- Department of Obstetrics and Gynecology & Marine Biomedicine and Environmental Sciences Program, Medical University of South Carolina and Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Heather J Hamlin
- School of Marine Sciences, Aquaculture Research Institute, University of Maine, 5751 Murray Hall, Orono, ME 04469, USA
| | - LeeAnne Thayer
- School of Marine Sciences, Aquaculture Research Institute, University of Maine, 5751 Murray Hall, Orono, ME 04469, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology & Marine Biomedicine and Environmental Sciences Program, Medical University of South Carolina and Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Benjamin B Parrott
- Department of Obstetrics and Gynecology & Marine Biomedicine and Environmental Sciences Program, Medical University of South Carolina and Hollings Marine Laboratory, Charleston, SC 29412, USA.
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Hamlin HJ, Edwards TM, McCoy J, Cruze L, Guillette LJ. Environmentally relevant concentrations of nitrate increase plasma testosterone concentrations in female American alligators (Alligator mississippiensis). Gen Comp Endocrinol 2016; 238:55-60. [PMID: 27118707 DOI: 10.1016/j.ygcen.2016.04.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 04/22/2016] [Indexed: 11/25/2022]
Abstract
Anthropogenic nitrogen is a ubiquitous environmental contaminant that is contributing to the degradation of freshwater, estuarine, and coastal ecosystems worldwide. The effects of environmental nitrate, a principal form of nitrogen, on the health of aquatic life is of increasing concern. We exposed female American alligators to three concentrations of nitrate (0.7, 10 and 100mg/L NO3-N) for a duration of five weeks and five months from hatch. We assessed growth, plasma sex steroid and thyroid hormone concentrations, and transcription levels of key genes involved in steroidogenesis (StAR, 3β-HSD, and P450scc) and hepatic clearance (Cyp1a, Cyp3a). Exposure to 100mg/L NO3-N for both five weeks and five months resulted in significantly increased plasma testosterone (T) concentrations compared with alligators in the reference treatment. No differences in 17β-estradiol, progesterone, or thyroid hormones were observed, nor were there differences in alligator weight or the mRNA abundance of steroidogenic or hepatic genes. Plasma and urinary nitrate concentrations increased with increasing nitrate treatment levels, although relative plasma concentrations of nitrate were significantly lower in five month, versus five week old animals, possibly due to improved kidney function in older animals. These results indicate that environmentally relevant concentrations of nitrate can increase circulating concentrations of T in young female alligators.
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Affiliation(s)
- Heather J Hamlin
- School of Marine Sciences, Aquaculture Research Institute, University of Maine, 5751 Murray Hall, Orono, ME 04469, USA; Department of Obstetrics and Gynecology, Medical University of South Carolina, and Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; Department of Biology, University of Florida, P.O. Box 118525, Gainesville, FL 32611, USA.
| | - Thea M Edwards
- Department of Biology, University of the South, 159 Spencer Hall, Sewanee, TN 37383, USA; Department of Biology, University of Florida, P.O. Box 118525, Gainesville, FL 32611, USA
| | - Jessica McCoy
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Lori Cruze
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; Department of Biology, University of Florida, P.O. Box 118525, Gainesville, FL 32611, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, USA; Department of Biology, University of Florida, P.O. Box 118525, Gainesville, FL 32611, USA
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22
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Guillette LJ, Parrott BB, Nilsson E, Haque MM, Skinner MK. Epigenetic programming alterations in alligators from environmentally contaminated lakes. Gen Comp Endocrinol 2016; 238:4-12. [PMID: 27080547 PMCID: PMC5064863 DOI: 10.1016/j.ygcen.2016.04.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/31/2016] [Accepted: 04/09/2016] [Indexed: 11/29/2022]
Abstract
Previous studies examining the reproductive health of alligators in Florida lakes indicate that a variety of developmental and health impacts can be attributed to a combination of environmental quality and exposures to environmental contaminants. The majority of these environmental contaminants have been shown to disrupt normal endocrine signaling. The potential that these environmental conditions and contaminants may influence epigenetic status and correlate to the health abnormalities was investigated in the current study. The red blood cell (RBC) (erythrocyte) in the alligator is nucleated so was used as an easily purified marker cell to investigate epigenetic programming. RBCs were collected from adult male alligators captured at three sites in Florida, each characterized by varying degrees of contamination. While Lake Woodruff (WO) has remained relatively pristine, Lake Apopka (AP) and Merritt Island (MI) convey exposures to different suites of contaminants. DNA was isolated and methylated DNA immunoprecipitation (MeDIP) was used to isolate methylated DNA that was then analyzed in a competitive hybridization using a genome-wide alligator tiling array for a MeDIP-Chip analysis. Pairwise comparisons of alligators from AP and MI to WO revealed alterations in the DNA methylome. The AP vs. WO comparison identified 85 differential DNA methylation regions (DMRs) with ⩾3 adjacent oligonucleotide tiling array probes and 15,451 DMRs with a single oligo probe analysis. The MI vs. WO comparison identified 75 DMRs with the ⩾3 oligo probe and 17,411 DMRs with the single oligo probe analysis. There was negligible overlap between the DMRs identified in AP vs. WO and MI vs. WO comparisons. In both comparisons DMRs were primarily associated with CpG deserts which are regions of low CpG density (1-2CpG/100bp). Although the alligator genome is not fully annotated, gene associations were identified and correlated to major gene class functional categories and pathways of endocrine relevance. Observations demonstrate that environmental quality may be associated with epigenetic programming and health status in the alligator. The epigenetic alterations may provide biomarkers to assess the environmental exposures and health impacts on these populations of alligators.
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Affiliation(s)
- Louis J Guillette
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Sciences Program, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Benjamin B Parrott
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Sciences Program, Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Eric Nilsson
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - M M Haque
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Michael K Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA.
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23
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Oka K, Kohno S, Ohta Y, Guillette LJ, Iguchi T, Katsu Y. Molecular cloning and characterization of the aryl hydrocarbon receptors and aryl hydrocarbon receptor nuclear translocators in the American alligator. Gen Comp Endocrinol 2016; 238:13-22. [PMID: 27174749 DOI: 10.1016/j.ygcen.2016.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/27/2016] [Accepted: 05/06/2016] [Indexed: 11/22/2022]
Abstract
Aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, binds to a variety of chemical compounds including various environmental contaminants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin. This receptor regulates expression of target genes through dimerization with the AHR nuclear translocator (ARNT). Since AHR-ARNT signaling pathways differ among species, characterization of AHR and ARNT is important to assess the effects of environmental contamination and for understanding the molecular mechanism underlying the intrinsic function. In this study, we isolated the cDNAs encoding three types of AHR and two types of ARNT from a reptile, the American alligator (Alligator mississippiensis). In vitro reporter gene assays showed that all complexes of alligator AHR-ARNT were able to activate ligand-dependent transcription on a xenobiotic response element. We found that AHR-ARNT complexes had higher sensitivities to a ligand than AHR-ARNT2 complexes. Alligator AHR1B showed the highest sensitivity in transcriptional activation induced by indigo when compared with AHR1A and AHR2. Taken together, our data revealed that all three alligator AHRs and two ARNTs were functional in the AHR signaling pathway with ligand-dependent and isoform-specific transactivations in vitro.
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Affiliation(s)
- Kaori Oka
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo, Japan
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, and Marine Biomedicine and Environmental Science Center, Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, SC, USA
| | - Yasuhiko Ohta
- Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Koyama, Tottori, Japan
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, and Marine Biomedicine and Environmental Science Center, Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, SC, USA
| | - Taisen Iguchi
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, and Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Yoshinao Katsu
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo, Japan.
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Yatsu R, Katsu Y, Kohno S, Mizutani T, Ogino Y, Ohta Y, Myburgh J, van Wyk JH, Guillette LJ, Miyagawa S, Iguchi T. Characterization of evolutionary trend in squamate estrogen receptor sensitivity. Gen Comp Endocrinol 2016; 238:88-95. [PMID: 27072832 DOI: 10.1016/j.ygcen.2016.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/08/2016] [Indexed: 11/29/2022]
Abstract
Steroid hormones are a key regulator of reproductive biology in vertebrates, and are largely regulated via nuclear receptor families. Estrogen signaling is regulated by two estrogen receptor (ER) subtypes alpha and beta in the nucleus. In order to understand the role of estrogen in vertebrates, these ER from various species have been isolated and were functionally analyzed using luciferase reporter gene assays. Interestingly, species difference in estrogen sensitivity has been noted in the past, and it was reported that snake ER displayed highest estrogen sensitivity. Here, we isolated additional ER from three lizards: chameleon (Bradypodion pumilum), skink (Plestiodon finitimus), and gecko (Gekko japonicus). We have performed functional characterization of these ERs using reporter gene assay system, and found high estrogen sensitivity in all three species. Furthermore, comparison with results from other tetrapod ER revealed a seemingly uniform gradual pattern of ligand sensitivity evolution. In silico 3D homology modeling of the ligand-binding domain revealed structural variation at three sites, helix 2, and juncture between helices 8 and 9, and caudal region of helix 10/11. Docking simulations indicated that predicted ligand-receptor interaction also correlated with the reporter assay results, and overall squamates displayed highest stabilized interactions. The assay system and homology modeling system provides tool for in-depth comparative analysis of estrogen function, and provides insight toward the evolution of ER among vertebrates.
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Affiliation(s)
- Ryohei Yatsu
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
| | - Yoshinao Katsu
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC 29412, USA.
| | - Takeshi Mizutani
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
| | - Yukiko Ogino
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
| | - Yasuhiko Ohta
- Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Koyama, Tottori 680-8553, Japan.
| | - Jan Myburgh
- Department of Paraclinical Sciences, University of Pretoria, Private Bag 04, Onderstepoort 0110, South Africa.
| | - Johannes H van Wyk
- Department of Botany & Zoology, University of Stellenbosch, Stellenbosch 7600, South Africa.
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Shinichi Miyagawa
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
| | - Taisen Iguchi
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
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Cantu TM, Bowden JA, Scott J, Pérez-Viscasillas JB, Huncik K, Guillette MP, Guillette LJ. Alterations in eicosanoid composition during embryonic development in the chorioallantoic membrane of the American alligator (Alligator mississippiensis) and domestic chicken (Gallus gallus). Gen Comp Endocrinol 2016; 238:78-87. [PMID: 27401262 PMCID: PMC5584055 DOI: 10.1016/j.ygcen.2016.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 06/23/2016] [Accepted: 07/07/2016] [Indexed: 12/21/2022]
Abstract
Eicosanoids are signaling lipids known to regulate several physiological processes in the mammalian placenta, including the initiation of parturition. Though all amniotes construct similar extraembryonic membranes during development, the composition and function of eicosanoids in extraembryonic membranes of oviparous reptiles is largely unknown. The majority of effort placed in eicosanoid investigations is typically targeted toward defining the role of specific compounds in disease etiology; however, comprehensive characterization of several pathways in eicosanoid synthesis during development is also needed to better understand the complex role of these lipids in comparative species. To this end, we have examined the chorioallantoic membrane (CAM) of the American alligator (Alligator mississippiensis) and domestic chicken (Gallus gallus) during development. Previously, our lab has demonstrated that the CAM of several oviparous species shared conserved steroidogenic activity, a feature originally attributed to mammalian amniotes. To further explore this, we have developed a liquid chromatography/tandem mass spectrometry method that is used here to quantify multiple eicosanoids in the CAM of two oviparous species at different stages of development. We identified 18 eicosanoids in the alligator CAM; the cyclooxygenase (COX) pathway showed the largest increase from early development to later development in the alligator CAM. Similarly, the chicken CAM had an increase in COX products and COX activity, which supports the LC-MS/MS analyses. Jointly, our findings indicate that the CAM tissue of an oviparous species is capable of eicosanoid synthesis, which expands our knowledge of placental evolution and introduces the possibility of future comparative models of placental function.
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Affiliation(s)
- Theresa M Cantu
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States.
| | - John A Bowden
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Jacob Scott
- Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Jimena B Pérez-Viscasillas
- Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Rd, Charleston, SC 29412, United States
| | - Kevin Huncik
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Matthew P Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Louis J Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
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Bowers RR, Temkin AM, Guillette LJ, Baatz JE, Spyropoulos DD. The commonly used nonionic surfactant Span 80 has RXRα transactivation activity, which likely increases the obesogenic potential of oil dispersants and food emulsifiers. Gen Comp Endocrinol 2016; 238:61-68. [PMID: 27131391 DOI: 10.1016/j.ygcen.2016.04.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 01/22/2023]
Abstract
Obesity has reached pandemic proportions, and there is mounting evidence that environmental exposures to endocrine disrupting chemicals known as "obesogens" may contribute to obesity and associated medical conditions. The Deepwater Horizon (DWH) oil spill resulted in a massive environmental release of crude oil and remediation efforts applied large quantities of Corexit dispersants to the oil spill. The Corexit-enhanced Water Accommodated Fraction (CWAF) of DWH crude oil contains PPARγ transactivation activity, which is attributed to dioctyl sodium sulfosuccinate (DOSS), a probable obesogen. In addition to its use in oil dispersants, DOSS is commonly used as a stool softener and food additive. Because PPARγ functions as a heterodimer with RXRα to transcriptionally regulate adipogenesis we investigated the potential of CWAF to transactivate RXRα and herein demonstrated that the Corexit component Span 80 has RXRα transactivation activity. Span 80 bound to RXRα in the low micromolar range and promoted adipocyte differentiation of 3T3-L1 preadipocytes. Further, the combination of DOSS and Span 80 increased 3T3-L1 adipocyte differentiation substantially more than treatment with either chemical individually, likely increasing the obesogenic potential of Corexit dispersants. From a public health standpoint, the use of DOSS and Span 80 as food additives heightens concerns regarding their use and mandates further investigations.
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Affiliation(s)
- Robert R Bowers
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Alexis M Temkin
- Marine Biomedical Sciences Program, Medical University of South Carolina, Charleston, SC, USA
| | - Louis J Guillette
- Marine Biomedical Sciences Program, Medical University of South Carolina, Charleston, SC, USA; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC, USA
| | - John E Baatz
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC, USA; Department of Pediatrics and Neonatology, Medical University of South Carolina, Charleston, SC, USA
| | - Demetri D Spyropoulos
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Marine Biomedical Sciences Program, Medical University of South Carolina, Charleston, SC, USA; Department of Pediatrics and Neonatology, Medical University of South Carolina, Charleston, SC, USA.
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Spiteri ID, Guillette LJ, Crain DA. The functional and structural observations of the neonatal reproductive system of alligators exposed in ovo to atrazine, 2,4-D, or estradiol. Toxicol Ind Health 2016. [DOI: 10.1177/074823379901500115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Wild alligators exposed to persistent organochlorine contaminants, municipal waste compounds, and contemporary-use herbicides exhibit reproductive alterations that are thought to be caused by endocrine disruption. This study tests the hypothesis that these alterations, at least in part, result from exposure of alligator embryos to contemporary-use herbicides. Alligator eggs were collected early in development, exposed to estradiol-17β, atrazine, or 2,4-D (at dosages of 0.14, 1.4, and 14 ppm, plus a dosage of 0.014 ppm for estradiol-17β only) before the period of gonadal differentiation, and incubated at a temperature that would produce either 100% males or 100% females. Analysis of histology was performed on the gonads and reproductive tracts of hatchlings. In females, epithelial cell height of the Müllerian duct and medullary regression of the ovary were assessed, whereas in males, sex-cord diameter was measured. Eggs incubated at the female-determining temperature produced all female hatchlings, whereas the estradiol-17β treatments caused the production of females at the male-determining temperature. Neither atrazine nor 2,4-D had this effect. Both Müllerian duct epithelial cell height and medullary regression were increased in estradiol-treated animals, but no differences were noted between herbicide-treated alligators and controls. A previous study found that male alligators exposed to 14 ppm atrazine had elevated gonadal aromatase activity, but there was no difference in sex-cord diameter in this or any other treatment group. Additionally, we observed that hepatic aromatase activity was not altered by in ovo exposure to any of the treatments. These results indicate that these herbicides alone are not responsible for the gonadal abnormalities previously reported for juvenile alligators from Lake Apopka and emphasize the importance of anlyzing both the function ( i.e., steroidogenic enzyme activity) and the structure ( i.e., histological analysis) of the reproductive system. Structural assessment alone may be insufficient for detecting subtle endocrine alterations.
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Affiliation(s)
| | | | - D. Andrew Crain
- Department of Zoology, University of Florida, Gainesville, Florida,
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Schug TT, Johnson AF, Birnbaum LS, Colborn T, Guillette LJ, Crews DP, Collins T, Soto AM, Vom Saal FS, McLachlan JA, Sonnenschein C, Heindel JJ. Minireview: Endocrine Disruptors: Past Lessons and Future Directions. Mol Endocrinol 2016; 30:833-47. [PMID: 27477640 PMCID: PMC4965846 DOI: 10.1210/me.2016-1096] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 07/12/2016] [Indexed: 11/19/2022] Open
Abstract
Within the past few decades, the concept of endocrine-disrupting chemicals (EDCs) has risen from a position of total obscurity to become a focus of dialogue, debate, and concern among scientists, physicians, regulators, and the public. The emergence and development of this field of study has not always followed a smooth path, and researchers continue to wrestle with questions about the low-dose effects and nonmonotonic dose responses seen with EDCs, their biological mechanisms of action, the true pervasiveness of these chemicals in our environment and in our bodies, and the extent of their effects on human and wildlife health. This review chronicles the development of the unique, multidisciplinary field of endocrine disruption, highlighting what we have learned about the threat of EDCs and lessons that could be relevant to other fields. It also offers perspectives on the future of the field and opportunities to better protect human health.
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Affiliation(s)
- Thaddeus T Schug
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Anne F Johnson
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Linda S Birnbaum
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Theo Colborn
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Louis J Guillette
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - David P Crews
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Terry Collins
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Ana M Soto
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Frederick S Vom Saal
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - John A McLachlan
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Carlos Sonnenschein
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
| | - Jerrold J Heindel
- National Institute of Environmental Health Sciences/National Institutes of Health (T.T.S., J.J.H.), Division of Extramural Research, Research Triangle Park, North Carolina 27560; 2MDB, Inc (A.F.J.), Durham, North Carolina 27713; National Cancer Institute and National Institute of Environmental Health Sciences (L.S.B.), National Institutes of Health, Research Triangle Park, North Carolina 27709; The Endocrine Disruption Exchange (T.Colb.), Paonia, Colorado 81428; Department of Obstetrics and Gynecology (L.J.G.), Medical University of S Carolina, and Hollings Marine Laboratory, Charleston, South Carolina 29425; Section of Integrative Biology (D.C.), University of Texas at Austin, Austin, Texas 78712; Department of Chemistry (T.Coll.), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213; Department of Anatomy and Cellular Biology (A.M.S., C.S.), Tufts University School of Medicine, Boston, Massachusetts 02155; Division of Biological Sciences and Department (F.S.v.S.),University of Missouri-Columbia, Columbia, Missouri 65211; and Department of Pharmacology (J.A.M.), Tulane University School of Medicine, New Orleans, Louisiana 70118
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Brock JW, Bell JM, Guillette LJ. Urinary Phthalate Metabolites in American Alligators (Alligator mississippiensis) from Selected Florida Wetlands. Arch Environ Contam Toxicol 2016; 71:1-6. [PMID: 26743198 DOI: 10.1007/s00244-015-0260-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/08/2015] [Indexed: 05/27/2023]
Abstract
Phthalates have been shown to cause endocrine disruption in laboratory animals and are associated with altered development of the reproductive system in humans. Further, human have significant exposure to phthalates. However, little is known concerning the exposure of wildlife to phthalates. We report urinary phthalate metabolite concentrations from fifty juvenile alligators from three Florida lakes and a site in the Everglades. Urinary phthalate monoester concentrations varied widely among alligators from the different sites but also among alligators from the same site. Mono-2-ethylhexy phthalate and monobutyl phthalate were found in most samples of alligator urine with maximums of 35,700 ng/mL and 193 ng/mL, respectively. Monobenzyl phthalate was found in 5 alligators with a maximum of 66.7 ng/mL. Other monoesters were found in only one or two alligator urine samples. The wide variation within and among sites, in addition to the high levels of mEHP, mBP and mBzP, is consistent with exposure arising from the intermittent spraying of herbicide formulations to control invasive aquatic plants in Florida freshwater sites. Phthalate diesters are used as adjuvants in many of these formulations.
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Affiliation(s)
- John W Brock
- Department of Chemistry, University of North Carolina at Asheville, Asheville, NC, 28804, USA.
| | - Jane Margaret Bell
- Department of Chemistry, Warren Wilson College, Asheville, NC, 28805, USA
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, Charleston, SC, 29412, USA
- Hollings Marine Laboratory, Charleston, SC, 29412, USA
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Gunderson MP, Pickett MA, Martin JT, Hulse EJ, Smith SS, Smith LA, Campbell RM, Lowers RH, Boggs ASP, Guillette LJ. Variations in hepatic biomarkers in American alligators (Alligator mississippiensis) from three sites in Florida, USA. Chemosphere 2016; 155:180-187. [PMID: 27111470 PMCID: PMC4909370 DOI: 10.1016/j.chemosphere.2016.04.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 05/21/2023]
Abstract
Sub-individual biomarkers are sub-lethal biological responses commonly used in the assessment of wildlife exposure to environmental contaminants. In this study, we examined the activity of glutathione-s-transferase (GST) and lactate dehydrogenase (LDH), and metallothionein (MT) concentrations among captive-raised alligator hatchlings, wild-caught juveniles, and wild-caught adults. Juveniles and adults were collected from three locations in Florida (USA) with varying degrees of contamination (i.e. Lake Apopka (organochlorine polluted site), Merritt Island National Wildlife Refuge (NWR) (metal polluted site), and Lake Woodruff NWR (reference site)). We examined whether changes in the response of these three biomarkers were age and sex dependent or reflected site-specific variations of environmental contaminants. Juvenile alligators from Merritt Island NWR had higher MT concentrations and lower GST activity compared to those from the other two sites. This outcome was consistent with higher metal pollution at this location. Sexually dimorphic patterns of MT and GST (F > M) were observed in juvenile alligators from all sites, although this pattern was not observed in adults. GST activity was lower in captive-raised alligators from Lake Apopka and Merritt Island NWR as compared to animals from Lake Woodruff NWR, suggesting a possible developmental modulator at these sites. No clear patterns were observed in LDH activity. We concluded that GST and MT demonstrate age and sex specific patterns in the alligators inhabiting these study sites and that the observed variation among sites could be due to differences in contaminant exposure.
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Affiliation(s)
- Mark P Gunderson
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA.
| | - Melissa A Pickett
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Justin T Martin
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Elizabeth J Hulse
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Spenser S Smith
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Levi A Smith
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Rachel M Campbell
- The College of Idaho, Department of Biology, 2112 Cleveland Blvd., Caldwell, ID 83605, USA
| | - Russell H Lowers
- Inomedic Health Applications, Aquatics Division, Mail Code IHA-300, Kennedy Space Center, FL, USA
| | - Ashley S P Boggs
- Marine Biomedicine and Environmental Sciences Center, Department of Obstetrics and Gynecology, Medical University South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Center, Department of Obstetrics and Gynecology, Medical University South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
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31
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Christie I, Reiner JL, Bowden JA, Botha H, Cantu TM, Govender D, Guillette MP, Lowers RH, Luus-Powell WJ, Pienaar D, Smit WJ, Guillette LJ. Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus). Chemosphere 2016; 154:72-78. [PMID: 27038902 PMCID: PMC4921786 DOI: 10.1016/j.chemosphere.2016.03.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/15/2016] [Accepted: 03/16/2016] [Indexed: 05/03/2023]
Abstract
Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area.
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Affiliation(s)
- Ian Christie
- Grice Marine Laboratory, College of Charleston, 205 Fort Johnson Road, Charleston, SC, USA
| | - Jessica L Reiner
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, USA.
| | - John A Bowden
- National Institute of Standards and Technology, Chemical Sciences Division, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC, USA
| | - Hannes Botha
- Scientific Services, Mpumalanga Tourism and Parks Agency, Nelspruit, 1200, South Africa; Department of Biodiversity, University of Limpopo, Sovenga, 0727, South Africa
| | - Theresa M Cantu
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC, USA
| | - Danny Govender
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa; Scientific Services, South African National Parks, Skukuza, 1350, South Africa
| | - Matthew P Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC, USA
| | - Russell H Lowers
- InoMedic Health Applications (IHA), Ecological Program, Kennedy Space Center, IHA 300, FL 32899, USA
| | | | - Danie Pienaar
- Scientific Services, South African National Parks, Skukuza, 1350, South Africa
| | - Willem J Smit
- Department of Biodiversity, University of Limpopo, Sovenga, 0727, South Africa
| | - Louis J Guillette
- Medical University of South Carolina, Department of Obstetrics and Gynecology, 221 Fort Johnson Road, Charleston, SC, USA
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32
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Bowden JA, Somerville SE, Cantu TM, Guillette MP, Botha H, Boggs ASP, Luus-Powell W, Guillette LJ. On-Site Classification of Pansteatitis in Mozambique Tilapia ( Oreochromis mossambicus) using a Portable Lipid-Based Analyzer. Anal Methods 2016; 8:6631-6635. [PMID: 28729886 PMCID: PMC5514565 DOI: 10.1039/c6ay00446f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
While no pansteatitis-related large-scale mortality events have occurred since 2008, the current status of pansteatitis (presence and pervasiveness) in the Olifants River system and other regions of South Africa remain largely unknown. In part, this is due to both a lack of known biological markers of pansteatitis and a lack of suitable non-invasive assays capable of rapidly classifying the disease. Here, we propose the application of a point-of-care (POC) device using lipid-based test strips (total cholesterol (TC) and total triglyceride (TG)), for classifying pansteatitis status in the whole blood of pre-spawning Mozambique tilapia (Oreochromis mossambicus). Using the TC strips, the POC device was able to non-lethally classify the tilapia as either healthy or pansteatitis-affected; the sexes were examined independently because sexual dimorphism was observed for TC (males p = 0.0364, females χ2 = 0.0007). No significant difference between diseased and pansteatitis-affected tilapia was observed using the TG strips. This is one of the first described applications of using POC devices for on-site environmental disease state testing. A discussion on the merits of using portable lipid-based analyzers as an in-field disease-state diagnostic tool is provided.
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Affiliation(s)
- John A Bowden
- National Institute of Standards and Technology (NIST), Material Measurement Laboratory, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, Charleston, SC 29412 USA
| | - Stephen E Somerville
- Departments of Obstetrics and Gynecology and Public Health Sciences and the Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC) and the Hollings Marine Laboratory (HML), Charleston, SC 29425-6190 USA
| | - Theresa M Cantu
- Departments of Obstetrics and Gynecology and Public Health Sciences and the Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC) and the Hollings Marine Laboratory (HML), Charleston, SC 29425-6190 USA
| | - Matthew P Guillette
- Departments of Obstetrics and Gynecology and Public Health Sciences and the Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC) and the Hollings Marine Laboratory (HML), Charleston, SC 29425-6190 USA
| | - Hannes Botha
- Scientific Services, Mpumalanga Tourism and Parks Agency, Nelspruit, 1200 South Africa
- Department of Biodiversity, University of Limpopo, Sovenga, 0727 South Africa
| | - Ashley S P Boggs
- National Institute of Standards and Technology (NIST), Material Measurement Laboratory, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, Charleston, SC 29412 USA
| | - Wilmien Luus-Powell
- Department of Biodiversity, University of Limpopo, Sovenga, 0727 South Africa
| | - Louis J Guillette
- Departments of Obstetrics and Gynecology and Public Health Sciences and the Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina (MUSC) and the Hollings Marine Laboratory (HML), Charleston, SC 29425-6190 USA
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33
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Bowden JA, Cantu TM, Chapman RW, Somerville SE, Guillette MP, Botha H, Hoffman A, Luus-Powell WJ, Smit WJ, Lebepe J, Myburgh J, Govender D, Tucker J, Boggs ASP, Guillette LJ. Predictive Blood Chemistry Parameters for Pansteatitis-Affected Mozambique Tilapia (Oreochromis mossambicus). PLoS One 2016; 11:e0153874. [PMID: 27115488 PMCID: PMC4846142 DOI: 10.1371/journal.pone.0153874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 04/05/2016] [Indexed: 11/19/2022] Open
Abstract
One of the largest river systems in South Africa, the Olifants River, has experienced significant changes in water quality due to anthropogenic activities. Since 2005, there have been various “outbreaks” of the inflammatory disease pansteatitis in several vertebrate species. Large-scale pansteatitis-related mortality events have decimated the crocodile population at Lake Loskop and decreased the population at Kruger National Park. Most pansteatitis-related diagnoses within the region are conducted post-mortem by either gross pathology or histology. The application of a non-lethal approach to assess the prevalence and pervasiveness of pansteatitis in the Olifants River region would be of great importance for the development of a management plan for this disease. In this study, several plasma-based biomarkers accurately classified pansteatitis in Mozambique tilapia (Oreochromis mossambicus) collected from Lake Loskop using a commercially available benchtop blood chemistry analyzer combined with data interpretation via artificial neural network analysis. According to the model, four blood chemistry parameters (calcium, sodium, total protein and albumin), in combination with total length, diagnose pansteatitis to a predictive accuracy of 92 percent. In addition, several morphometric traits (total length, age, weight) were also associated with pansteatitis. On-going research will focus on further evaluating the use of blood chemistry to classify pansteatitis across different species, trophic levels, and within different sites along the Olifants River.
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Affiliation(s)
- John A. Bowden
- National Institute of Standards and Technology (NIST), Material Measurement Laboratory, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, Charleston, South Carolina, United States of America
- * E-mail:
| | - Theresa M. Cantu
- Departments of Obstetrics and Gynecology, Medical University of South Carolina (MUSC), Charleston, South Carolina, United States of America
| | - Robert W. Chapman
- Marine Resources Research Institute, South Carolina Department of Natural Resources, Hollings Marine Laboratory, Charleston, South Carolina, United States of America
| | - Stephen E. Somerville
- Departments of Obstetrics and Gynecology, Medical University of South Carolina (MUSC), Charleston, South Carolina, United States of America
| | - Matthew P. Guillette
- Departments of Obstetrics and Gynecology, Medical University of South Carolina (MUSC), Charleston, South Carolina, United States of America
| | - Hannes Botha
- Scientific Services, Mpumalanga Tourism and Parks Agency, Nelspruit, South Africa
- Department of Biodiversity, University of Limpopo, Sovenga, South Africa
| | - Andre Hoffman
- Scientific Services, Mpumalanga Tourism and Parks Agency, Nelspruit, South Africa
| | | | - Willem J. Smit
- Department of Biodiversity, University of Limpopo, Sovenga, South Africa
| | - Jeffrey Lebepe
- Department of Biodiversity, University of Limpopo, Sovenga, South Africa
| | - Jan Myburgh
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Danny Govender
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
- Scientific Services, South African National Parks, Skukuza, South Africa
| | - Jonathan Tucker
- Marine Resources Research Institute, South Carolina Department of Natural Resources, Hollings Marine Laboratory, Charleston, South Carolina, United States of America
| | - Ashley S. P. Boggs
- National Institute of Standards and Technology (NIST), Material Measurement Laboratory, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, Charleston, South Carolina, United States of America
| | - Louis J. Guillette
- Departments of Obstetrics and Gynecology, Medical University of South Carolina (MUSC), Charleston, South Carolina, United States of America
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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Nilsen FM, Parrott BB, Bowden JA, Kassim BL, Somerville SE, Bryan TA, Bryan CE, Lange TR, Delaney JP, Brunell AM, Long SE, Guillette LJ. Global DNA methylation loss associated with mercury contamination and aging in the American alligator (Alligator mississippiensis). Sci Total Environ 2016; 545-546:389-97. [PMID: 26748003 PMCID: PMC4972023 DOI: 10.1016/j.scitotenv.2015.12.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/10/2015] [Accepted: 12/13/2015] [Indexed: 04/13/2023]
Abstract
Mercury is a widespread environmental contaminant with exposures eliciting a well-documented catalog of adverse effects. Yet, knowledge regarding the underlying mechanisms by which mercury exposures are translated into biological effects remains incomplete. DNA methylation is an epigenetic modification that is sensitive to environmental cues, and alterations in DNA methylation at the global level are associated with a variety of diseases. Using a liquid chromatography tandem mass spectrometry-based (LC-MS/MS) approach, global DNA methylation levels were measured in red blood cells of 144 wild American alligators (Alligator mississippiensis) from 6 sites with variable levels of mercury contamination across Florida's north-south axis. Variation in mercury concentrations measured in whole blood was highly associated with location, allowing the comparison of global DNA methylation levels across different "treatments" of mercury. Global DNA methylation in alligators across all locations was weakly associated with increased mercury exposure. However, a much more robust relationship was observed in those animals sampled from locations more highly contaminated with mercury. Also, similar to other vertebrates, global DNA methylation appears to decline with age in alligators. The relationship between age-associated loss of global DNA methylation and varying mercury exposures was examined to reveal a potential interaction. These findings demonstrate that global DNA methylation levels are associated with mercury exposure, and give insights into interactions between contaminants, aging, and epigenetics.
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Affiliation(s)
- Frances M Nilsen
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States.
| | - Benjamin B Parrott
- Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29403, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - John A Bowden
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Brittany L Kassim
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Stephen E Somerville
- Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29403, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Teresa A Bryan
- Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29403, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Colleen E Bryan
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Ted R Lange
- Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Ave, Eustis, FL 32726, United States
| | - J Patrick Delaney
- Deseret Ranches- 13754 Deseret Lane, St. Cloud, Florida 34773-9381, United States
| | - Arnold M Brunell
- Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Ave, Eustis, FL 32726, United States
| | - Stephen E Long
- National Institute of Standards and Technology, Chemical Sciences Division, Environmental Chemical Sciences Group, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
| | - Louis J Guillette
- Medical University of South Carolina, Marine Biomedicine and Environmental Sciences, 221 Fort Johnson Road, Charleston, SC 29412, United States; Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, SC 29403, United States; Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States
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Wise SS, Wise C, Xie H, Guillette LJ, Zhu C, Wise JP, Wise JP. Hexavalent chromium is cytotoxic and genotoxic to American alligator cells. Aquat Toxicol 2016; 171:30-6. [PMID: 26730726 PMCID: PMC4721530 DOI: 10.1016/j.aquatox.2015.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/02/2015] [Accepted: 12/10/2015] [Indexed: 05/03/2023]
Abstract
Metals are a common pollutant in the aquatic ecosystem. With global climate change, these levels are anticipated to rise as lower pH levels allow sediment bound metals to be released. The American alligator (Alligator mississippiensis) is an apex predator in the aquatic ecosystem and is considered a keystone species; as such it serves as a suitable monitor for localized pollution. One metal of increasing concern is hexavalent chromium (Cr(VI)). It is present in the aquatic environment and is a known human carcinogen and reproductive toxicant. We measured the cytotoxicity and genotoxicity of Cr(VI) in American alligator cells derived from scute tissue. We found that particulate and soluble Cr(VI) are both cytotoxic and genotoxic to alligator cells in a concentration-dependent manner. These data suggest that alligators may be used as a model for assessing the effects of environmental Cr(VI) contamination as well as for other metals of concern.
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Affiliation(s)
- Sandra S Wise
- Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103, USA
| | - Catherine Wise
- Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103, USA; Program in Environmental and Molecular Toxicology, Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Hong Xie
- Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103, USA
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, USA
| | - Cairong Zhu
- Department of Epidemiology and Biostatistics, West China School of Public Health, Sichuan University, Chengdu 610044, China
| | - John Pierce Wise
- Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103, USA; Department of Health Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - John Pierce Wise
- Wise Laboratory of Environmental and Genetic Toxicology, Maine Center for Toxicology and Environmental Health, Department of Applied Medical Science, University of Southern Maine, Science Building, 96 Falmouth Street, Portland, ME 04103, USA.
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36
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Yatsu R, Miyagawa S, Kohno S, Parrott BB, Yamaguchi K, Ogino Y, Miyakawa H, Lowers RH, Shigenobu S, Guillette LJ, Iguchi T. RNA-seq analysis of the gonadal transcriptome during Alligator mississippiensis temperature-dependent sex determination and differentiation. BMC Genomics 2016; 17:77. [PMID: 26810479 PMCID: PMC4727388 DOI: 10.1186/s12864-016-2396-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 01/14/2016] [Indexed: 11/26/2022] Open
Abstract
Background The American alligator (Alligator mississippiensis) displays temperature-dependent sex determination (TSD), in which incubation temperature during embryonic development determines the sexual fate of the individual. However, the molecular mechanisms governing this process remain a mystery, including the influence of initial environmental temperature on the comprehensive gonadal gene expression patterns occurring during TSD. Results Our characterization of transcriptomes during alligator TSD allowed us to identify novel candidate genes involved in TSD initiation. High-throughput RNA sequencing (RNA-seq) was performed on gonads collected from A. mississippiensis embryos incubated at both a male and a female producing temperature (33.5 °C and 30 °C, respectively) in a time series during sexual development. RNA-seq yielded 375.2 million paired-end reads, which were mapped and assembled, and used to characterize differential gene expression. Changes in the transcriptome occurring as a function of both development and sexual differentiation were extensively profiled. Forty-one differentially expressed genes were detected in response to incubation at male producing temperature, and included genes such as Wnt signaling factor WNT11, histone demethylase KDM6B, and transcription factor C/EBPA. Furthermore, comparative analysis of development- and sex-dependent differential gene expression revealed 230 candidate genes involved in alligator sex determination and differentiation, and early details of the suspected male-fate commitment were profiled. We also discovered sexually dimorphic expression of uncharacterized ncRNAs and other novel elements, such as unique expression patterns of HEMGN and ARX. Twenty-five of the differentially expressed genes identified in our analysis were putative transcriptional regulators, among which were MYBL2, MYCL, and HOXC10, in addition to conventional sex differentiation genes such as SOX9, and FOXL2. Inferred gene regulatory network was constructed, and the gene-gene and temperature-gene interactions were predicted. Conclusions Gonadal global gene expression kinetics during sex determination has been extensively profiled for the first time in a TSD species. These findings provide insights into the genetic framework underlying TSD, and expand our current understanding of the developmental fate pathways during vertebrate sex determination. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2396-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ryohei Yatsu
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Shinichi Miyagawa
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Benjamin B Parrott
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Katsushi Yamaguchi
- National Institute for Basic Biology, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
| | - Yukiko Ogino
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, 350 Mine-machi, Utsunomiya, Tochigi, 321-8505, Japan.
| | - Russell H Lowers
- Innovative Health Applications, Kennedy Space Center, Merritt Island, FL, 32899, USA.
| | - Shuji Shigenobu
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,National Institute for Basic Biology, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Taisen Iguchi
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
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Boggs ASP, Hamlin HJ, Nifong JC, Kassim BL, Lowers RH, Galligan TM, Long SE, Guillette LJ. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators. Gen Comp Endocrinol 2016; 226:5-13. [PMID: 26684734 PMCID: PMC4778256 DOI: 10.1016/j.ygcen.2015.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/20/2015] [Accepted: 12/08/2015] [Indexed: 11/29/2022]
Abstract
The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology.
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Affiliation(s)
- Ashley S P Boggs
- National Institute of Standards and Technology, Environmental Chemical Sciences, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA.
| | - Heather J Hamlin
- University of Maine, School of Marine Sciences, 316 Murray Hall Orono, ME 04469, USA
| | - James C Nifong
- University of Florida, Fisheries and Aquatic Sciences, NW 71st Street, Gainsville, FL 32653, USA
| | - Brittany L Kassim
- National Institute of Standards and Technology, Environmental Chemical Sciences, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA
| | - Russell H Lowers
- National Aeronautics and Space Administration, InoMedic Health Applications Inc., SR 405, Kennedy Space Center, FL 32899, USA
| | - Thomas M Galligan
- Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Medical University of South Carolina, Department of Obstetrics and Gynecology, 331 Fort Johnson Rd, Charleston, SC 29412, USA
| | - Stephen E Long
- National Institute of Standards and Technology, Environmental Chemical Sciences, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA
| | - Louis J Guillette
- Hollings Marine Laboratory, 331 Fort Johnson Rd, Charleston, SC 29412, USA; Medical University of South Carolina, Department of Obstetrics and Gynecology, 331 Fort Johnson Rd, Charleston, SC 29412, USA
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38
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Temkin AM, Bowers RR, Magaletta ME, Holshouser S, Maggi A, Ciana P, Guillette LJ, Bowden JA, Kucklick JR, Baatz JE, Spyropoulos DD. Effects of Crude Oil/Dispersant Mixture and Dispersant Components on PPARγ Activity in Vitro and in Vivo: Identification of Dioctyl Sodium Sulfosuccinate (DOSS; CAS #577-11-7) as a Probable Obesogen. Environ Health Perspect 2016; 124:112-9. [PMID: 26135921 PMCID: PMC4710608 DOI: 10.1289/ehp.1409672] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/09/2015] [Indexed: 05/22/2023]
Abstract
BACKGROUND The obesity pandemic is associated with multiple major health concerns. In addition to diet and lifestyle, there is increasing evidence that environmental exposures to chemicals known as obesogens also may promote obesity. OBJECTIVES We investigated the massive environmental contamination resulting from the Deepwater Horizon (DWH) oil spill, including the use of the oil dispersant COREXIT in remediation efforts, to determine whether obesogens were released into the environment during this incident. We also sought to improve the sensitivity of obesogen detection methods in order to guide post-toxicological chemical assessments. METHODS Peroxisome proliferator-activated receptor gamma (PPARγ) transactivation assays were used to identify putative obesogens. Solid-phase extraction (SPE) was used to sub-fractionate the water-accommodated fraction generated by mixing COREXIT, cell culture media, and DWH oil (CWAF). Liquid chromatography-mass spectrometry (LC-MS) was used to identify components of fractionated CWAF. PPAR response element (PPRE) activity was measured in PPRE-luciferase transgenic mice. Ligand-binding assays were used to quantitate ligand affinity. Murine 3T3-L1 preadipocytes were used to assess adipogenic induction. RESULTS Serum-free conditions greatly enhanced the sensitivity of PPARγ transactivation assays. CWAF and COREXIT had significant dose-dependent PPARγ transactivation activities. From SPE, the 50:50 water:ethanol volume fraction of CWAF contained this activity, and LC-MS indicated that major components of COREXIT contribute to PPARγ transactivation in the CWAF. Molecular modeling predicted several components of COREXIT might be PPARγ ligands. We classified dioctyl sodium sulfosuccinate (DOSS), a major component of COREXIT, as a probable obesogen by PPARγ transactivation assays, PPAR-driven luciferase induction in vivo, PPARγ binding assays (affinity comparable to pioglitazone and arachidonic acid), and in vitro murine adipocyte differentiation. CONCLUSIONS We conclude that DOSS is a putative obesogen worthy of further study, including epidemiological and clinical investigations into laxative prescriptions consisting of DOSS. CITATION Temkin AM, Bowers RR, Magaletta ME, Holshouser S, Maggi A, Ciana P, Guillette LJ, Bowden JA, Kucklick JR, Baatz JE, Spyropoulos DD. 2016. Effects of crude oil/dispersant mixture and dispersant components on PPARγ activity in vitro and in vivo: identification of dioctyl sodium sulfosuccinate (DOSS; CAS #577-11-7) as a probable obesogen. Environ Health Perspect 124:112-119; http://dx.doi.org/10.1289/ehp.1409672.
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Affiliation(s)
| | - Robert R. Bowers
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | - Steven Holshouser
- Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases, University of Milan, Milan, Italy
| | - Paolo Ciana
- Center of Excellence on Neurodegenerative Diseases, University of Milan, Milan, Italy
| | - Louis J. Guillette
- Marine Biomedical Sciences Program, and
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - John A. Bowden
- National Oceanic and Atmospheric Administration, and
- National Institute of Standards and Technology, Charleston, South Carolina, USA
| | - John R. Kucklick
- National Oceanic and Atmospheric Administration, and
- National Institute of Standards and Technology, Charleston, South Carolina, USA
| | - John E. Baatz
- National Oceanic and Atmospheric Administration, and
- National Institute of Standards and Technology, Charleston, South Carolina, USA
- Department of Pediatrics and Neonatology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Demetri D. Spyropoulos
- Marine Biomedical Sciences Program, and
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
- National Oceanic and Atmospheric Administration, and
- National Institute of Standards and Technology, Charleston, South Carolina, USA
- Address correspondence to D.D. Spyropoulos, Pathology and Laboratory Medicine, MUSC, Darby Children’s Research Institute, CRI 207, 173 Ashley Ave., Charleston, SC 29425 USA. Telephone: (843) 792-1625. E-mail:
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Yatsu R, Miyagawa S, Kohno S, Saito S, Lowers RH, Ogino Y, Fukuta N, Katsu Y, Ohta Y, Tominaga M, Guillette LJ, Iguchi T. TRPV4 associates environmental temperature and sex determination in the American alligator. Sci Rep 2015; 5:18581. [PMID: 26677944 PMCID: PMC4683465 DOI: 10.1038/srep18581] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 11/20/2015] [Indexed: 12/28/2022] Open
Abstract
Temperature-dependent sex determination (TSD), commonly found among reptiles, is a sex determination mode in which the incubation temperature during a critical temperature sensitive period (TSP) determines sexual fate of the individual rather than the individual’s genotypic background. In the American alligator (Alligator mississippiensis), eggs incubated during the TSP at 33 °C (male producing temperature: MPT) yields male offspring, whereas incubation temperatures below 30 °C (female producing temperature: FPT) lead to female offspring. However, many of the details of the underlying molecular mechanism remains elusive, and the molecular link between environmental temperature and sex determination pathway is yet to be elucidated. Here we show the alligator TRPV4 ortholog (AmTRPV4) to be activated at temperatures proximate to the TSD-related temperature in alligators, and using pharmacological exposure, we show that AmTRPV4 channel activity affects gene expression patterns associated with male differentiation. This is the first experimental demonstration of a link between a well-described thermo-sensory mechanism, TRPV4 channel, and its potential role in regulation of TSD in vertebrates, shedding unique new light on the elusive TSD molecular mechanism.
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Affiliation(s)
- Ryohei Yatsu
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan.,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan
| | - Shinichi Miyagawa
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan.,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston SC 29412 USA
| | - Shigeru Saito
- Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan
| | - Russell H Lowers
- Innovative Health Applications, Kennedy Space Center, Merritt Island FL 32899 USA
| | - Yukiko Ogino
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan.,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan
| | - Naomi Fukuta
- Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan
| | - Yoshinao Katsu
- Graduate School of Life Science and Department of Biological Sciences, Hokkaido University, Sapporo Hokkaido 062-8520 Japan
| | - Yasuhiko Ohta
- Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Koyama Tottori 680-8553 Japan
| | - Makoto Tominaga
- Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan.,Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston SC 29412 USA
| | - Taisen Iguchi
- Department of Basic Biology, SOKENDAI (The Graduate University for Advanced Studies), Okazaki Aichi 444-8787 Japan.,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki Aichi 444-8787 Japan
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40
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McCoy JA, Parrott BB, Rainwater TR, Wilkinson PM, Guillette LJ. Incubation history prior to the canonical thermosensitive period determines sex in the American alligator. Reproduction 2015; 150:279-87. [DOI: 10.1530/rep-15-0155] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 07/16/2015] [Indexed: 11/08/2022]
Abstract
Despite the widespread occurrence of environmental sex determination (ESD) among vertebrates, our knowledge of the temporal dynamics by which environmental factors act on this process remains limited. In many reptiles, incubation temperature determines sex during a discrete developmental window just prior to and coincident with the differentiation of the gonads. Yet, there is substantial variation in sex ratios among different clutches of eggs incubated at identical temperatures during this period. Here, we test the hypothesis that temperatures experienced prior to the reported thermosensitive period for alligators (Alligator mississippiensis) can impact how the sex determination system responds to thermal cues later in development. Temperature shift experiments on eggs collected from the field within 24 h of oviposition were employed to decouple various maternal influences from thermal effects, and results demonstrate a previously undefined window of thermosensitivity occurring by stage 15 of embryonic development, six stages earlier than previously reported. We also examine the intrasexual expression of several male- and female-biased genes and show that while male-biased genes display no intrasexual differences, ovarian CYP19A1 (aromatase) transcript abundance differs by approximately twofold depending on thermal exposures experienced at early stages of embryonic development. These findings expand our understanding of the ESD in the alligator and provide the rationale for reevaluation of the temporal dynamics of sex determination in other crocodilians.
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Miyagawa S, Yatsu R, Kohno S, Doheny BM, Ogino Y, Ishibashi H, Katsu Y, Ohta Y, Guillette LJ, Iguchi T. Identification and Characterization of the Androgen Receptor From the American Alligator, Alligator mississippiensis. Endocrinology 2015; 156:2795-806. [PMID: 25974402 PMCID: PMC4511131 DOI: 10.1210/en.2015-1037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgens are essential for the development, reproduction, and health throughout the life span of vertebrates, particularly during the initiation and maintenance of male sexual characteristics. Androgen signaling is mediated by the androgen receptor (AR), a member of the steroid nuclear receptor superfamily. Mounting evidence suggests that environmental factors, such as exogenous hormones or contaminants that mimic hormones, can disrupt endocrine signaling and function. The American alligator (Alligator mississippiensis), a unique model for ecological research in that it exhibits environment-dependent sex determination, is oviparous and long lived. Alligators from a contaminated environment exhibit low reproductive success and morphological disorders of the testis and phallus in neonates and juveniles, both associated with androgen signaling; thus, the alterations are hypothesized to be related to disrupted androgen signaling. However, this line of research has been limited because of a lack of information on the alligator AR gene. Here, we isolated A mississippiensis AR homologs (AmAR) and evaluated receptor-hormone/chemical interactions using a transactivation assay. We showed that AmAR responded to all natural androgens and their effects were inhibited by cotreatment with antiandrogens, such as flutamide, p,p'-dichlorodiphenyldichloroethylene, and vinclozolin. Intriguingly, we found a spliced form of the AR from alligator cDNA, which lacks seven amino acids within the ligand-binding domain that shows no response to androgens. Finally, we have initial data on a possible dominant-negative function of the spliced form of the AR against androgen-induced AmAR.
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Affiliation(s)
- Shinichi Miyagawa
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Ryohei Yatsu
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Satomi Kohno
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Brenna M Doheny
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Yukiko Ogino
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Hiroshi Ishibashi
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Yoshinao Katsu
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Yasuhiko Ohta
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Louis J Guillette
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | - Taisen Iguchi
- Okazaki Institute for Integrative Bioscience (S.M., R.Y., Y.Og., T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8787, Japan; Department of Obstetrics and Gynecology (S.K., B.M.D., L.J.G.), Medical University of South Carolina and Hollings Marine Laboratory, Charleston, South Carolina 29412; Department of Life Environmental Conservation (H.I.), Faculty of Agriculture, Ehime University, Matsuyama, Ehime 790-8566, Japan; Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo 060-0810, Japan; and Department of Veterinary Medicine (Y.Oh.), Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
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Kohno S, Bernhard MC, Katsu Y, Zhu J, Bryan TA, Doheny BM, Iguchi T, Guillette LJ. Estrogen receptor 1 (ESR1; ERα), not ESR2 (ERβ), modulates estrogen-induced sex reversal in the American alligator, a species with temperature-dependent sex determination. Endocrinology 2015; 156:1887-99. [PMID: 25714813 PMCID: PMC5393338 DOI: 10.1210/en.2014-1852] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
All crocodilians and many turtles exhibit temperature-dependent sex determination where the temperature of the incubated egg, during a thermo-sensitive period (TSP), determines the sex of the offspring. Estrogens play a critical role in sex determination in crocodilians and turtles, as it likely does in most nonmammalian vertebrates. Indeed, administration of estrogens during the TSP induces male to female sex reversal at a male-producing temperature (MPT). However, it is not clear how estrogens override the influence of temperature during sex determination in these species. Most vertebrates have 2 forms of nuclear estrogen receptor (ESR): ESR1 (ERα) and ESR2 (ERβ). However, there is no direct evidence concerning which ESR is involved in sex determination, because a specific agonist or antagonist for each ESR has not been tested in nonmammalian species. We identified specific pharmaceutical agonists for each ESR using an in vitro transactivation assay employing American alligator ESR1 and ESR2; these were 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT) and 7-bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY 200070), respectively. Alligator eggs were exposed to PPT or WAY 200070 at a MPT just before the TSP, and their sex was examined at the last stage of embryonic development. Estradiol-17β and PPT, but not WAY 200070, induced sex reversal at a MPT. PPT-exposed embryos exposed to the highest dose (5.0 μg/g egg weight) exhibited enlargement and advanced differentiation of the Müllerian duct. These results indicate that ESR1 is likely the principal ESR involved in sex reversal as well as embryonic Müllerian duct survival and growth in American alligators.
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Affiliation(s)
- Satomi Kohno
- Department of Obstetrics and Gynecology (S.K., J.Z., T.A.B., L.J.G.), Medical University of South Carolina, Charleston, South Carolina 29425; Marine Biomedicine and Environmental Science Center (S.K., M.C.B., T.A.B., B.M.D., L.J.G.), Hollings Marine Laboratory, Charleston, South Carolina 29412; Graduate Program in Marine Biology at the College of Charleston (M.C.B.), Charleston, South Carolina 29412; Graduate School of Life Science and Department of Biological Sciences (Y.K.), Hokkaido University, Sapporo, 060-0808 Japan; Department of Biology (T.A.B.), University of Florida, Gainesville, Florida 32611; Okazaki Institute for Integrative Bioscience (T.I.), National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, 444-8585 Japan; and Department of Basic Biology (T.I.), The Graduate University for Advanced Studies (SOKENDAI), Okazaki, 444-8585 Japan
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43
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Rosenblatt AE, Nifong JC, Heithaus MR, Mazzotti FJ, Cherkiss MS, Jeffery BM, Elsey RM, Decker RA, Silliman BR, Guillette LJ, Lowers RH, Larson JC. Factors affecting individual foraging specialization and temporal diet stability across the range of a large "generalist" apex predator. Oecologia 2015; 178:5-16. [PMID: 25645268 DOI: 10.1007/s00442-014-3201-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 12/15/2014] [Indexed: 11/30/2022]
Abstract
Individual niche specialization (INS) is increasingly recognized as an important component of ecological and evolutionary dynamics. However, most studies that have investigated INS have focused on the effects of niche width and inter- and intraspecific competition on INS in small-bodied species for short time periods, with less attention paid to INS in large-bodied reptilian predators and the effects of available prey types on INS. We investigated the prevalence, causes, and consequences of INS in foraging behaviors across different populations of American alligators (Alligator mississippiensis), the dominant aquatic apex predator across the southeast US, using stomach contents and stable isotopes. Gut contents revealed that, over the short term, although alligator populations occupied wide ranges of the INS spectrum, general patterns were apparent. Alligator populations inhabiting lakes exhibited lower INS than coastal populations, likely driven by variation in habitat type and available prey types. Stable isotopes revealed that over longer time spans alligators exhibited remarkably consistent use of variable mixtures of carbon pools (e.g., marine and freshwater food webs). We conclude that INS in large-bodied reptilian predator populations is likely affected by variation in available prey types and habitat heterogeneity, and that INS should be incorporated into management strategies to efficiently meet intended goals. Also, ecological models, which typically do not consider behavioral variability, should include INS to increase model realism and applicability.
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Affiliation(s)
- Adam E Rosenblatt
- Department of Biologica Sciences, Marine Sciences Program, Florida International University, North Miami, FL, 33181, USA,
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44
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Horai S, Itai T, Noguchi T, Yasuda Y, Adachi H, Hyobu Y, Riyadi AS, Boggs ASP, Lowers R, Guillette LJ, Tanabe S. Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA. Chemosphere 2014; 108:159-167. [PMID: 24698170 DOI: 10.1016/j.chemosphere.2014.01.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/20/2014] [Accepted: 01/25/2014] [Indexed: 06/03/2023]
Abstract
Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (p<0.05) obtained from MINWR. Significant enrichment of some trace elements in adults, relative to juveniles, was observed at all three sampling areas. Specifically, Fe, Pb and Hg were significantly elevated in adults when compared to juveniles, suggesting age-dependent accumulation of these elements. Further, As, Se and Sn showed the same trend but only in animals collected from MINWR. Mean Fe concentrations in the livers of adults from LA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities.
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Affiliation(s)
- Sawako Horai
- Faculty of Regional Environment, Tottori University, Japan; Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Takaaki Itai
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Takako Noguchi
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Yusuke Yasuda
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Haruki Adachi
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Yuika Hyobu
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Adi S Riyadi
- Center for Marine Environmental Studies (CMES), Ehime University, Japan
| | - Ashley S P Boggs
- Department of Obstetrics and Gynecology, Medical University of South Carolina, USA
| | - Russell Lowers
- Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, USA; Hollings Marine Laboratory, Charleston, USA; Innomedic Health Applications, Mail code IHA-300, Kennedy Space Center, USA
| | - Louis J Guillette
- Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, USA; Hollings Marine Laboratory, Charleston, USA; Innomedic Health Applications, Mail code IHA-300, Kennedy Space Center, USA
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies (CMES), Ehime University, Japan.
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45
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Bourtis CM, Francis-Floyd R, Reyier EA, Yanong RP, Guillette LJ. Development of a nonlethal health assessment for wild Red Drum using a health index. J Aquat Anim Health 2014; 26:91-95. [PMID: 24895862 DOI: 10.1080/08997659.2014.886633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nonlethal methods are needed to assess the health of wild fish and quantify the robustness of the broader population. Results could be used to indicate exposure to various stressors, such as contaminants, infectious disease, external parasite loads, and fishing pressure, to monitor changes in fish population health over time. The wild Red Drum Sciaenops ocellatus population in the Kennedy Space Center Reserve of Merritt Island National Wildlife Refuge was used to develop a protocol to define the health of free-ranging fish using nonlethal techniques. This health index incorporated morphometric measurements, weight, an evaluation for external parasite fauna, notation of physical deformities, and the presence of lesions. A total of 126 adult Red Drum were collected using hook-and-line angling during prespawning (May), spawning (September and October), and postspawning (December) periods. All fish were released alive back into their environment. The nonlethal health assessment scored fish in the "healthy" range of the health index during the prespawning and spawning periods. Fish caught during the postspawning period scored slightly below this range. Parasite load contributed to the depressed score during the postspawning period. Fish collected in all sampling periods were rated on average as "excellent" for condition factor, which suggests that the sampled population in the reserve were thriving.
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Affiliation(s)
- Carla M Bourtis
- a Kennedy Space Center Ecological Program, InoMedic Health Applications , Mail Code IHA-300, Kennedy Space Center , Florida 32899 , USA
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Hamlin HJ, Lowers RH, Kohno S, Mitsui-Watanabe N, Amano H, Hara A, Ohta Y, Miyagawa S, Iguchi T, Guillette LJ. The reproductive hormone cycle of adult female American alligators from a barrier island population. Reproduction 2014; 147:855-63. [DOI: 10.1530/rep-14-0031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Comparatively, little data are available detailing the geographic variation that exists in the reproductive endocrinology of adult alligators, especially those living in barrier islands. The Merritt Island National Wildlife Refuge (MI) is a unique barrier island environment and home to the Kennedy Space Center (FL, USA). Seasonal patterns of sex steroids were assessed in adult female American alligators from MI monthly from 2008 to 2009, with additional samples collected at more random intervals in 2006, 2007, and 2010. Plasma 17β-estradiol and vitellogenin concentrations peaked in April, coincident with courtship and mating, and showed patterns similar to those observed in adult female alligators in other regions. Plasma concentrations of progesterone, however, showed patterns distinctly different than those reported for alligator populations in other regions and remained relatively constant throughout the year. Plasma DHEA peaked in July around the time of oviposition, decreased in August, and then remained constant for the remaining months, except for a moderate increase in October. Circulating concentrations of DHEA have not been previously assessed in a female crocodilian, and plasma concentrations coincident with reproductive activity suggest a reproductive and/or behavioral role. Interestingly, plasma testosterone concentrations peaked in May of 2008, as has been shown in female alligator populations in other regions, but showed no peak in 2009, demonstrating dramatic variability from year to year. Surveys showed 2009 to be particularly depauperate of alligator nests in MI, and it is possible that testosterone could serve as a strong indicator of breeding success.
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Bowden JA, Cantu TM, Scheidt DM, Lowers RH, Nocito BA, Young VY, Guillette LJ. Examination of metals from aerospace-related activity in surface water samples from sites surrounding the Kennedy Space Center (KSC), Florida. Environ Sci Technol 2014; 48:4672-4680. [PMID: 24738662 DOI: 10.1021/es4047796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Metal contamination from Space Shuttle launch activity was examined using inductively coupled plasma-atomic emission spectroscopy in a two-tier study sampling surface water collected from several sites at the Kennedy Space Center (KSC) and associated Merritt Island National Wildlife Refuge in east central Florida. The primary study examined both temporal changes in baseline metal concentrations (19 metals) in surface water (1996 to 2009, 11 sites) samples collected at specific long-term monitoring sites and metal deposition directly associated with Space Shuttle launch activity at two Launch Complexes (LC39A and LC39B). A secondary study examined metal concentrations at additional sites and increased the amount of elements measured to 48 elements. Our examination places a heavy focus on those metals commonly associated with launch operations (e.g., Al, Fe, Mn, and Zn), but a brief discussion of other metals (As, Cu, Mo, Ni, and Pb) is also included. While no observable accumulation of metals occurred during the time period of the study, the data obtained postlaunch demonstrated a dramatic increase for Al, Fe, Mn, and Zn. Comparing overall trends between the primary and secondary baseline surface water concentrations, elevated concentrations were generally observed at sampling stations located near the launch complexes and from sites isolated from major water systems. While there could be several natural and anthropogenic sources for metal deposition at KSC, the data in this report indicate that shuttle launch events are a significant source.
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Affiliation(s)
- John A Bowden
- National Institute of Standards and Technology (NIST) , Hollings Marine Laboratory, Charleston, South Carolina 29412, United States
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48
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Schwacke LH, Smith CR, Townsend FI, Wells RS, Hart LB, Balmer BC, Collier TK, De Guise S, Fry MM, Guillette LJ, Lamb SV, Lane SM, McFee WE, Place NJ, Tumlin MC, Ylitalo GM, Zolman ES, Rowles TK. Response to comment on health of common bottlenose dolphins (Tursiops truncatus) in Barataria Bay, Louisiana following the deepwater horizon oil spill. Environ Sci Technol 2014; 48:4209-4211. [PMID: 24625036 DOI: 10.1021/es5009278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Lori H Schwacke
- National Centers for Coastal Ocean Science, National Oceanic and Atmospheric Administration, 331 Fort Johnson Road, Charleston, South Carolina 29412, United States
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49
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Parrott BB, Bowden JA, Kohno S, Cloy-McCoy JA, Hale MD, Bangma JT, Rainwater TR, Wilkinson PM, Kucklick JR, Guillette LJ. Influence of tissue, age, and environmental quality on DNA methylation in Alligator mississippiensis. Reproduction 2014; 147:503-13. [DOI: 10.1530/rep-13-0498] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epigenetic modifications are key mediators of the interactions between the environment and an organism's genome. DNA methylation represents the best-studied epigenetic modification to date and is known to play key roles in regulating transcriptional activity and promoting chromosome stability. Our laboratory has previously demonstrated the utility of the American alligator (Alligator mississippiensis) as a sentinel species to investigate the persistent effects of environmental contaminant exposure on reproductive health. Here, we incorporate a liquid chromatography–tandem mass spectrometry method to directly measure the total (global) proportion of 5-methyl-2′-deoxycytidine (5mdC) in ovarian and whole blood DNA from alligators. Global DNA methylation in ovaries was significantly elevated in comparison with that of whole blood. However, DNA methylation appeared similar in juvenile alligators reared under controlled laboratory conditions but originating from three sites with dissimilar environmental qualities, indicating an absence of detectable site-of-origin effects on persistent levels of global 5mdC content. Analyses of tissues across individuals revealed a surprising lack of correlation between global methylation levels in blood and ovary. In addition, global DNA methylation in blood samples from juvenile alligators was elevated compared with those from adults, suggesting that age, as observed in mammals, may negatively influence global DNA methylation levels in alligators. To our knowledge, this is the first study examining global levels of DNA methylation in the American alligator and provides a reference point for future studies examining the interplay of epigenetics and environmental factors in a long-lived sentinel species.
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Parrott BB, Kohno S, Cloy-McCoy JA, Guillette LJ. Differential incubation temperatures result in dimorphic DNA methylation patterning of the SOX9 and aromatase promoters in gonads of alligator (Alligator mississippiensis) embryos. Biol Reprod 2014; 90:2. [PMID: 24227754 DOI: 10.1095/biolreprod.113.111468] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Environmental factors are known to influence sex determination in many nonmammalian vertebrates. In all crocodilians studied thus far, temperature is the only known determinant of sex. However, the molecular mechanisms mediating the effect of temperature on sex determination are not known. Aromatase (CYP19A1) and SOX9 play critical roles in vertebrate sex determination and gonadogenesis. Here, we used a variety of techniques to investigate the potential roles of DNA methylation patterning on CYP19A1 and SOX9 expression in the American alligator, an organism that relies on temperature-dependent sex determination. Our findings reveal that developing gonads derived from embryos incubated at a male-producing temperature (MPT) show elevated CYP19A1 promoter methylation and decreased levels of gene expression relative to incubation at a female-producing temperature (FPT). The converse was observed at the SOX9 locus, with increased promoter methylation and decreased expression occurring in embryonic gonads resulting from incubation at FPT relative to that of MPT. We also examined the gonadal expression of the three primary, catalytically active DNA methyltransferase enzymes and show that they are present during critical stages of gonadal development. Together, these data strongly suggest that DNA methylation patterning is a central component in coordinating the genetic cascade responsible for sexual differentiation. In addition, these data raise the possibility that DNA methylation could act as a key mediator integrating temperature into a molecular trigger that determines sex in the alligator.
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Affiliation(s)
- Benjamin B Parrott
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Hollings Marine Laboratory, Charleston, South Carolina
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