1
|
Currylow AFT, Rafeliarisoa TH, Louis EE, Stanford CB, Randrianjafizanaka ST, Chinn SM, Crocker DE. Characterization of seasonal reproductive and stress steroid hormones in wild Radiated Tortoises, Astrochelys radiata. Gen Comp Endocrinol 2017; 253:70-78. [PMID: 28888695 DOI: 10.1016/j.ygcen.2017.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 08/29/2017] [Accepted: 09/03/2017] [Indexed: 10/18/2022]
Abstract
The critically endangered Radiated Tortoise (Astrochelys radiata) is endemic to the southern coastlines of Madagascar. Once common, wild populations of this tortoise have undergone dramatic declines in recent years. Although there have been studies documenting reproductive activities, reproductive physiological parameters are unknown yet may be crucial in the recovery of the species. Over four research seasons in remote field locations native to A. radiata, we surveyed for, radio-tracked, and sampled wild, free ranging tortoises. We sampled and measured stress and reproductive parameters (corticosterone [CORT], testosterone [T], estradiol-17β [E2], and progesterone [P]) in 311 plasma samples from 203 wild A. radiata, capturing their active period. Generally, hormone concentrations were associated with body condition, temperature, and humidity. There was wide variation in CORT that varied monthly and by group. Juvenile tortoises maintained more than twice the mean basal CORT concentrations than either adult sex, with the most dramatic distinctions in the middle of the wet season. For adult sex hormones, the last months of the dry season and into the wet season when ground humidities are low and just begin to rise prior to temperature declines, male T concentrations gradually increased to a peak before returning to near undetectable values into the dry season. We had limited data for T concentrations in females, but found average T concentrations were much lower than in males and positively correlated with larger female home range sizes. For female hormone cycles, E2 also peaked in the early 1/3 of the wet season along with male T, and was followed by an uptick in P which correlates to the putative ovulatory cycle. Females tracked over four years showed variation in patterns of P, indicating that number and frequency of clutches vary. Our results suggest that 1) there is high species plasticity in response to stress; 2) A. radiata reproductive cycling is somewhat dissociated with courtship timing and is instead triggered by environmental cues; and 3) individual female reproductive output is irregular. This study is oone of the first to document and describe multi-year seasonal stress and reproductive hormones in a free-ranging Malagasy chelonian. These data may be used to identify key high-production habitats for conservation, and aide in captive management and reproduction in assurance colonies for species health and survival.
Collapse
Affiliation(s)
- Andrea F T Currylow
- Integrative and Evolutionary Biology, University of Southern California, Los Angeles, CA, USA.
| | - Tsilavo H Rafeliarisoa
- Animal Biology Department, University of Antananarivo, Antananarivo, Madagascar; Madagascar Biodiversity Partnership; Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, NE, USA
| | - Edward E Louis
- Madagascar Biodiversity Partnership; Conservation Genetics Department, Omaha's Henry Doorly Zoo and Aquarium, Omaha, NE, USA
| | - Craig B Stanford
- Integrative and Evolutionary Biology, University of Southern California, Los Angeles, CA, USA; Herpetology Section, Los Angeles County Natural History Museum, Los Angeles, CA, USA
| | | | - Sarah M Chinn
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| |
Collapse
|
2
|
Bhandari RK, Deem SL, Holliday DK, Jandegian CM, Kassotis CD, Nagel SC, Tillitt DE, Vom Saal FS, Rosenfeld CS. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species. Gen Comp Endocrinol 2015; 214:195-219. [PMID: 25277515 DOI: 10.1016/j.ygcen.2014.09.014] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 08/08/2014] [Accepted: 09/20/2014] [Indexed: 12/12/2022]
Abstract
Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered.
Collapse
Affiliation(s)
- Ramji K Bhandari
- Biological Sciences, University of Missouri, Columbia, MO 65211, USA; Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA
| | - Sharon L Deem
- Institute for Conservation Medicine, Saint Louis Zoo, Saint Louis, MO 63110, USA; Veterinary Clinical Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Dawn K Holliday
- Department of Biology and Environmental Science, Westminster College, Fulton, MO 65251, USA; Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Caitlin M Jandegian
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA; Institute for Conservation Medicine, Saint Louis Zoo, Saint Louis, MO 63110, USA; Masters in Public Health Program, University of Missouri, Columbia, MO 65211, USA
| | | | - Susan C Nagel
- Biological Sciences, University of Missouri, Columbia, MO 65211, USA; Obstetrics, Gynecology, & Women's Health, University of Missouri, Columbia, MO 65211, USA
| | - Donald E Tillitt
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA
| | | | - Cheryl S Rosenfeld
- Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Genetics Area Program Faculty Member, University of Missouri, Columbia, MO 65211, USA.
| |
Collapse
|
3
|
Graham SP, Ward CK, Shelby Walker J, Sterrett S, Mendonça MT. Sexual Dimorphism and Seasonal Variation of Reproductive Hormones in the Pascagoula Map Turtle,Graptemys gibbonsi. COPEIA 2015. [DOI: 10.1643/cp-13-157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
4
|
Plumel MI, Wasselin T, Plot V, Strub JM, Van Dorsselaer A, Carapito C, Georges JY, Bertile F. Mass spectrometry-based sequencing and SRM-based quantitation of two novel vitellogenin isoforms in the leatherback sea turtle (Dermochelys coriacea). J Proteome Res 2013; 12:4122-35. [PMID: 23837631 DOI: 10.1021/pr400444m] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
No biomarker has yet been discovered to identify the reproductive status of the endangered leatherback sea turtle (Dermochelys coriacea). Although vitellogenin (VTG) could be used for this, its sequence is not known in D. coriacea and no quantitative assay has been carried out in this species to date. Using de novo sequencing-based proteomics, we unambiguously characterized sequences of two different VTG isoforms that we named Dc-VTG1 and Dc-VTG2. To our knowledge, this is the first clear evidence of different VTG isoforms and the structural characterization of derived yolk proteins in reptiles. This work illustrates how massive de novo sequencing can characterize novel sequences when working on "exotic" nonmodel species in which even nucleotide sequences are not available. We developed assays for absolute quantitation of these two isoforms using selected reaction monitoring (SRM) mass spectrometry, thus providing the first SRM assays developed specifically for a nonsequenced species. Plasma levels of Dc-VTG1 and Dc-VTG2 decreased as the nesting season proceeded, and were closely related to the increased levels of reproductive effort. The SRM assays developed here therefore provide an original and efficient approach for the reliable monitoring of reproduction cycles not only in D. coriacea, but potentially in other turtle species.
Collapse
Affiliation(s)
- Marine I Plumel
- Département Sciences Analytiques, Université de Strasbourg, IPHC, 25 rue Becquerel, 67087 Strasbourg, France
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Currylow AF, Tift MS, Meyer JL, Crocker DE, Williams RN. Seasonal variations in plasma vitellogenin and sex steroids in male and female Eastern Box Turtles, Terrapene carolina carolina. Gen Comp Endocrinol 2013; 180:48-55. [PMID: 23174697 DOI: 10.1016/j.ygcen.2012.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 11/08/2012] [Accepted: 11/09/2012] [Indexed: 11/29/2022]
Abstract
The Eastern Box Turtle (Terrapene carolina carolina) is a widespread species that has recently experienced precipitous declines throughout its range. Although many studies have documented aspects of reproduction in box turtles, reproductive physiology of free-ranging animals is unknown and can be crucial in this species' recovery. Over a two-year period, we measured reproductive parameters, (vitellogenin [Vtg], estradiol-17β [E2], and total testosterone [TT]), in plasma of 116 free-ranging Eastern Box Turtles across their active season. We found similar seasonal variations of Vtg and E2 within females. Mid-season, females showed a sharp peak in E2 that correlates with the putative beginning of the ovarian cycle. Individual females lacking these expected peaks of both Vtg and E2 suggest that some female T. c. carolina may not reproduce annually. Females typically expressed undetectable levels of TT, yet there was a small peak in TT early in the active season. Male Eastern Box Turtles exhibited a dual peak in TT. Elevated TT in males was significantly associated with observed sexual behaviors and smaller home ranges. Body condition had no effect on the concentration of TT or E2 in either sex. This is the first study to (1) document Vtg and sex steroid hormones in free-ranging animals of this genus, and (2) relate those metrics to individuals, the population, the purported annual cycle, and to other chelonian species.
Collapse
Affiliation(s)
- Andrea F Currylow
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA.
| | | | | | | | | |
Collapse
|