1
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Harders EP, Charboneau C, Paitz RT. Extraembryonic metabolism of corticosterone protects against effects of exposure. Gen Comp Endocrinol 2024; 347:114439. [PMID: 38158163 DOI: 10.1016/j.ygcen.2023.114439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/21/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
When females experience stress during reproduction, developing embryos can be exposed to elevated levels of glucocorticoids, which can permanently affect offspring development, physiology, and behavior. However, the embryo can regulate exposure to glucocorticoids. In placental species, the placenta regulates embryonic exposure to maternal steroids via metabolism. In a comparable way, recent evidence has shown the extraembryonic membranes of avian species also regulate embryonic exposure to a number of maternal steroids deposited in the yolk via metabolism early in development. However, despite the known effects of embryonic exposure to glucocorticoids, it is not yet understood how glucocorticoids are metabolized early in development. To address this knowledge gap, we injected corticosterone into freshly laid chicken (Gallus gallus) eggs and identified corticosterone metabolites, located metabolomic enzyme transcript expression, tracked metabolomic enzyme transcript expression during the first six days of development, and determined the effect of corticosterone and metabolites on embryonic survival. We found that yolk corticosterone was metabolized before day four of development into two metabolites: 5β-corticosterone and 20β-corticosterone. The enzymes, AKR1D1 and CBR1 respectively, were expressed in the extraembryonic membranes. Expression was dynamic during early development, peaking on day two of development. Finally, we found that corticosterone exposure is lethal to the embryos, yet exposure to the metabolites is not, suggesting that metabolism protects the embryo. Ultimately, we show that the extraembryonic membranes of avian species actively regulate their endocrine environment very early in development.
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Affiliation(s)
- Emily P Harders
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | | | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
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2
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Harders EP, Agustin M, Paitz RT. Avian extraembryonic membranes respond to yolk corticosterone early in development. Biol Open 2024; 13:bio060131. [PMID: 38156650 PMCID: PMC10836647 DOI: 10.1242/bio.060131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
During times of maternal stress, developing embryos can be exposed to elevated levels of glucocorticoids, which can affect development and permanently alter offspring phenotype. In placental species, the placenta mediates fetal exposure to maternal glucocorticoids via metabolism, yet the placenta itself responds to glucocorticoids to regulate offspring growth and development. In oviparous species, maternal glucocorticoids can be deposited into the egg yolk and are metabolized early in development. This metabolism is mediated by the extraembryonic membranes, but it is unknown if the extraembryonic membranes also respond to maternal glucocorticoids in a way comparable to the placenta. In this study, we quantified the expression of acyl-CoA thioesterase 13 (Acot13) as an initial marker of the membrane's response to corticosterone in chicken (Gallus gallus) eggs. Acot13 regulates fatty acid processing in the embryo, to potentially regulate resource availability during development. We addressed the following questions using Acot13 expression: 1) Do the extraembryonic membranes respond to yolk corticosterone early in development? 2) Is the response to corticosterone dependent on the dose of corticosterone? 3) What is the duration of the response to corticosterone? 4) Does a metabolite of corticosterone (5β-corticosterone) elicit the same response as corticosterone? We found that corticosterone significantly induces the expression of Acot13 on day four of development and that expression of Acot13 increases with the dose of corticosterone. Further, we found expression of Acot13 is significantly elevated by corticosterone on days four and six of development compared to oil treated eggs, but not on days eight and ten. Although this response is transient, it occurs during a critical period of development and could initiate a cascade of events that ultimately alter offspring phenotype. Finally, we found that 5β-corticosterone does not increase the expression of Acot13, indicating that metabolism inactivates corticosterone. Ultimately, this study provides insight into the mechanisms underlying how maternally deposited glucocorticoids can affect embryonic development.
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Affiliation(s)
- Emily P. Harders
- Illinois State University, School of Biological Sciences, Campus Box 4120, Normal, IL 61790, USA
| | - Mitch Agustin
- Illinois State University, School of Biological Sciences, Campus Box 4120, Normal, IL 61790, USA
| | - Ryan T. Paitz
- Illinois State University, School of Biological Sciences, Campus Box 4120, Normal, IL 61790, USA
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3
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Biesek J. The physicochemical features of eggshell, thick albumen, amniotic fluid, and yolk during chicken embryogenesis. Poult Sci 2023; 102:103119. [PMID: 37832191 PMCID: PMC10585332 DOI: 10.1016/j.psj.2023.103119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 10/15/2023] Open
Abstract
The study aimed to analyze the hatching egg and physiochemical features of eggshells, thick albumen, amniotic fluid, and yolk during the incubation of Ross 308 chicken eggs. Eggs (n = 755) were incubated for 21 d. Quality analysis of fresh eggs was performed. Eggshells, albumen, and yolk were collected from fresh eggs and incubation d 1, 7, and 14. Eggshell thickness and strength, pH, vitelline membrane strength, fatty acid (FA) in the yolk, pH, viscosity, lysozyme activity, and crude protein content in thick albumen and amniotic fluid were analyzed. Hatching parameters were calculated. Egg weight loss was constant (8.04% overall). Lower egg surface temperature was found on d 7 compared to d 4, 14, and 18. A lower thickness of posthatch eggshells was found. The strength of the vitelline membrane significantly decreased within 24 h (by over 58%). During incubation, there was a decrease in thick albumen/amniotic fluid pH; an opposite trend was found in yolk pH. The vitelline membrane strength was negatively correlated with the albumen pH. Lysozyme activity was higher in fresh thick albumen and up to 2 wk of incubation. On d 7, the lowest activity was found in the amniotic fluid. On d 14, lysozyme activity increased in amniotic fluid. The higher viscosity of the thick albumen was demonstrated on d 7 and 14 of incubation. The lowest viscosity in amniotic fluid was found on the same days. Crude protein content was higher in thick albumen (d 7 and 14) and lowest in amniotic fluid on d 7. The FA content changed between d 0 and 14. The results indicate different use of FA, where PUFA decreased. Eggshell is used in the last week of incubation. The thick albumen is reduced, while the biological value of amniotic fluid is increasing. Lysozyme activity, viscosity, and crude protein content may be interdependent. It may indicate the flow of substances and the transfer of functions from the thick albumen to the amniotic fluid during chicken embryogenesis.
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Affiliation(s)
- Jakub Biesek
- Department of Animal Breeding and Nutrition, Faculty of Animal Breeding and Biology, Bydgoszcz University of Science and Technology, 85-084 Bydgoszcz, Poland.
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4
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Murray BA, Soos C, Machin KL. The effects of pre-hatch elevated corticosterone and post-hatch restrictive food availability on the HPA axis development of mallard ducks (Anas platyrhynchos). Gen Comp Endocrinol 2023; 342:114339. [PMID: 37369328 DOI: 10.1016/j.ygcen.2023.114339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 06/29/2023]
Abstract
Environmental changes can be stressors (altered habitat and food supply, climate change, etc.) to wild animals. Stressors trigger the hypothalamic pituitary adrenal (HPA) axis to release corticosterone (CORT) which modifies energy homeostasis. During nesting, stressed females can deposit increased concentrations of CORT into eggs, altering egg viability and offspring characteristics, constituting a significant mechanism regulating population productivity in subsequent generations. In this study, increased maternal disposition of CORT was mimicked through a 15 ng/g in ovo injection of CORT into mallard duck eggs. Growth and HPA axis function were measured during post-hatch development. For growth, changes in mass were compared at hatch, 7 weeks and 11 weeks. The HPA axis was assessed at seven weeks by measuring CORT at baseline, followed by restraint stress, dexamethasone (negative feedback) and ACTH (maximal adrenal capacity) challenges. At eleven weeks of age, ducks were subjected to a 6-day 25% feed reduction to simulate a poor quality environment to evaluate response to a chronic stressor by comparing CORT at baseline and after restraint stress. Growth and CORT concentration did not differ between treatments at seven weeks or after feed restriction (11 weeks). The CORT dosage administered did not appear to affect HPA axis development in ducklings. Mallards are a highly adaptable species and may have overcome any early alterations to their phenotype. Further research is needed to determine the effects of increased maternal CORT on growth and the development of the HPA axis in ducks. SUMMARY STATEMENT: This study examines how maternal stress (simulated through elevated corticosterone in ovo) and post-hatch chronic stressors (food restriction) affect the development of the HPA axis in a precocial bird.
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Affiliation(s)
- Breanne A Murray
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Catherine Soos
- Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, 115 Perimeter Road, Saskatoon, Saskatchewan S7N 0X4, Canada
| | - Karen L Machin
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada.
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5
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Reyes-Contreras M, de Vries B, van der Molen JC, Groothuis TGG, Taborsky B. Egg-mediated maternal effects in a cooperatively breeding cichlid fish. Sci Rep 2023; 13:9759. [PMID: 37328515 PMCID: PMC10276030 DOI: 10.1038/s41598-023-35550-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 05/19/2023] [Indexed: 06/18/2023] Open
Abstract
Mothers can influence offspring phenotype through egg-mediated maternal effects, which can be influenced by cues mothers obtain from their environment during offspring production. Developing embryos use these components but have mechanisms to alter maternal signals. Here we aimed to understand the role of mothers and embryos in how maternal effects might shape offspring social phenotype. In the cooperatively breeding fish Neolamprologus pulcher different social phenotypes develop in large and small social groups differing in predation risk and social complexity. We manipulated the maternal social environment of N. pulcher females during egg laying by allocating them either to a small or a large social group. We compared egg mass and clutch size and the concentration of corticosteroid metabolites between social environments, and between fertilized and unfertilized eggs to investigate how embryos deal with maternal signalling. Mothers in small groups produced larger clutches but neither laid smaller eggs nor bestowed eggs differently with corticosteroids. Fertilized eggs scored lower on a principal component representing three corticosteroid metabolites, namely 11-deoxycortisol, cortisone, and 11-deoxycorticosterone. We did not detect egg-mediated maternal effects induced by the maternal social environment. We discuss that divergent social phenotypes induced by different group sizes may be triggered by own offspring experience.
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Affiliation(s)
- Maria Reyes-Contreras
- Division of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50A, 3032, Hinterkappelen, Switzerland
| | - Bonnie de Vries
- The Groningen Institute for Evolutionary Life Science, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - J C van der Molen
- Laboratorium Bijzondere Chemie, Cluster Endocrinologie and Metabole Ziekten, University Medical Center Groningen, 9700 RB, Groningen, The Netherlands
| | - T G G Groothuis
- The Groningen Institute for Evolutionary Life Science, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Barbara Taborsky
- Division of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50A, 3032, Hinterkappelen, Switzerland.
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6
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Angove J, Willson NL, Barekatain R, Rosenzweig D, Forder R. In ovo corticosterone exposure does not influence yolk steroid hormone relative abundance or skeletal muscle development in the embryonic chicken. Poult Sci 2023; 102:102735. [PMID: 37209653 DOI: 10.1016/j.psj.2023.102735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 05/22/2023] Open
Abstract
In ovo corticosterone (CORT) exposure reportedly reduces growth and alters body composition traits in meat-type chickens. However, the mechanisms governing alterations in growth and body composition remain unclear but could involve myogenic stem cell commitment, and/or the presence of yolk steroid hormones. This study investigated whether in ovo CORT exposure influenced yolk steroid hormone content, as well as embryonic myogenic development in meat-type chickens. Fertile eggs were randomly divided at embryonic day (ED) 11 and administered either a control (CON; 100 µL of 10 mM PBS) or CORT solution (100 µL of 10 mM PBS containing 1 µg CORT) into the chorioallantoic membrane. Yolk samples were collected at ED 0 and ED 5. At ED 15 and hatch, embryos were humanely killed, and yolk and breast muscle (BM) samples were collected. The relative abundance of 15 steroid hormones, along with total lipid content was measured in yolk samples collected at ED 0, ED 5, ED 15, and ED 21. Muscle fiber number, cross-sectional area, and fascicle area occupied by muscle fibers were measured in BM samples collected at hatch. Relative expression of MyoD, MyoG, Pax7, PPARγ, and CEBP/β, and the sex steroid receptors were measured in BM samples collected at hatch. The administration of CORT had a limited effect on yolk steroid hormones. In ovo CORT significantly reduced fascicle area occupied by muscle fibers and CEBP/β expression was increased in CORT exposed birds at hatch. In addition, the quantity of yolk lipid was significantly reduced in CORT-treated birds. In conclusion, in ovo exposure to CORT does not appear to influence early muscle development through yolk steroid hormones in embryonic meat-type chickens however, the results provide a comprehensive analysis of the composition of yolk steroid hormones in ovo at different developmental time points. The findings may suggest increased mesenchymal stem cell commitment to the adipogenic lineage during differentiation and requires further investigation.
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Affiliation(s)
- J Angove
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, SA, Australia
| | - N-L Willson
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, SA, Australia
| | - R Barekatain
- South Australian Research and Development Institute, Roseworthy, SA, Australia
| | - D Rosenzweig
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, SA, Australia
| | - R Forder
- School of Animal and Veterinary Sciences, the University of Adelaide, Roseworthy, SA, Australia.
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7
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Heppner JJ, Krause JS, Ouyang JQ. Urbanization and maternal hormone transfer: Endocrine and morphological phenotypes across ontogenetic stages. Gen Comp Endocrinol 2023; 333:114166. [PMID: 36402244 DOI: 10.1016/j.ygcen.2022.114166] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 10/11/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022]
Abstract
The phenotypes observed in urban and rural environments are often distinct; however, it remains unclear how these novel urban phenotypes arise. Hormone-mediated maternal effects likely play a key role in shaping developmental trajectories of offspring in different environments. Thus, we measured corticosterone (Cort) and testosterone (T) concentrations in eggs across the laying sequence in addition to Cort concentrations in nestling and adult female house wrens (Troglodytes aedon) at one urban and one rural site. We found that egg T concentrations were not different between birds from urban and rural sites. However, across all life stages (egg, nestling, and adult female), Cort concentrations were higher at the urban site. Additionally, urban nestling Cort concentrations, but not rural, correlated with fine-scale urban density scores. Furthermore, rural egg volume increased over the laying sequence, but urban egg volume leveled off mid-sequence, suggesting either that urban mothers are resource limited or that they are employing a different brood development strategy than rural mothers. Our study is one of the first to show that egg hormone concentrations differ in an urban environment with differences persisting in chick development and adult life stages. We suggest that maternal endocrine programing may shape offspring phenotypes in urban environments and are an overlooked yet important aspect underlying mechanisms of urban evolution.
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Affiliation(s)
| | - Jesse S Krause
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
| | - Jenny Q Ouyang
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
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8
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Hakala SM, Fujioka H, Gapp K, De Gasperin O, Genzoni E, Kilner RM, Koene JM, König B, Linksvayer TA, Meurville MP, Negroni MA, Palejowski H, Wigby S, LeBoeuf AC. Socially transferred materials: why and how to study them. Trends Ecol Evol 2022; 38:446-458. [PMID: 36543692 DOI: 10.1016/j.tree.2022.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022]
Abstract
When biological material is transferred from one individual's body to another, as in ejaculate, eggs, and milk, secondary donor-produced molecules are often transferred along with the main cargo, and influence the physiology and fitness of the receiver. Both social and solitary animals exhibit such social transfers at certain life stages. The secondary, bioactive, and transfer-supporting components in socially transferred materials have evolved convergently to the point where they are used in applications across taxa and type of transfer. The composition of these materials is typically highly dynamic and context dependent, and their components drive the physiological and behavioral evolution of many taxa. Our establishment of the concept of socially transferred materials unifies this multidisciplinary topic and will benefit both theory and applications.
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9
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Mouton JC, Duckworth RA, Paitz RT, Martin TE. Nest predation risk and deposition of yolk steroids in a cavity nesting songbird: an experimental test. J Exp Biol 2022; 225:274901. [PMID: 35352809 DOI: 10.1242/jeb.243047] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/22/2022] [Indexed: 11/20/2022]
Abstract
Maternal hormones can shape offspring development and increase survival when predation risk is elevated. In songbirds, yolk androgens influence offspring growth and begging behaviors which can help mitigate offspring predation risk in the nest. Other steroids may also be important for responding to nest predation risk, but non-androgen steroids have been poorly studied. We used a nest predator playback experiment and liquid chromatography with tandem mass spectrometry (LC-MS-MS) to assess whether nest predation risk influences deposition of 10 yolk steroids. We found no clear evidence that yolk androgen deposition changed when perception of nest predation risk was experimentally increased. However, elevated nest predation risk led to decreased yolk progesterone deposition. Overall, our results suggest yolk progesterone may be more important than yolk androgens in responses to offspring predation risk and highlight new avenues for research.
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Affiliation(s)
- James C Mouton
- Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT 59812, USA.,Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
| | - Renée A Duckworth
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Thomas E Martin
- Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT 59812, USA
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10
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De Haas EN, Newberry RC, Edgar J, Riber AB, Estevez I, Ferrante V, Hernandez CE, Kjaer JB, Ozkan S, Dimitrov I, Rodenburg TB, Janczak AM. Prenatal and Early Postnatal Behavioural Programming in Laying Hens, With Possible Implications for the Development of Injurious Pecking. Front Vet Sci 2021; 8:678500. [PMID: 34336975 PMCID: PMC8323009 DOI: 10.3389/fvets.2021.678500] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/27/2021] [Indexed: 11/25/2022] Open
Abstract
Injurious pecking (IP) represents a serious concern for the welfare of laying hens (Gallus gallus domesticus). The risk of IP among hens with intact beaks in cage-free housing prompts a need for solutions based on an understanding of underlying mechanisms. In this review, we explore how behavioural programming via prenatal and early postnatal environmental conditions could influence the development of IP in laying hens. The possible roles of early life adversity and mismatch between early life programming and subsequent environmental conditions are considered. We review the role of maternal stress, egg conditions, incubation settings (temperature, light, sound, odour) and chick brooding conditions on behavioural programming that could be linked to IP. Brain and behavioural development can be programmed by prenatal and postnatal environmental conditions, which if suboptimal could lead to a tendency to develop IP later in life, as we illustrate with a Jenga tower that could fall over if not built solidly. If so, steps taken to optimise the environmental conditions of previous generations and incubation conditions, reduce stress around hatching, and guide the early learning of chicks will aid in prevention of IP in commercial laying hen flocks.
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Affiliation(s)
- Elske N De Haas
- Division of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands.,Flanders Research Institute for Agriculture, Fisheries, and Food, Melle, Belgium
| | - Ruth C Newberry
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Joanne Edgar
- Bristol Veterinary School, University of Bristol, Langford, United Kingdom
| | - Anja B Riber
- Aarhus University, Department of Animal Science, Tjele, Denmark
| | - Inma Estevez
- Department of Animal Production, Neiker, Vitoria-Gasteiz, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Valentina Ferrante
- Department of Environmental Science and Policy, Università degli Studi di Milano, Milan, Italy
| | - Carlos E Hernandez
- Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Joergen B Kjaer
- Institute of Animal Welfare and Animal Husbandry, Friedrich-Loeffler-Institut, Celle, Germany
| | - Sezen Ozkan
- Department of Animal Science, Faculty of Agriculture, Ege University, Izmir, Turkey
| | - Ivan Dimitrov
- Agricultural Institute - Stara Zagora, Stara Zagora, Bulgaria
| | - T Bas Rodenburg
- Division of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Andrew M Janczak
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
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11
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Mouton JC, Duckworth RA. Maternally derived hormones, neurosteroids and the development of behaviour. Proc Biol Sci 2021; 288:20202467. [PMID: 33499795 DOI: 10.1098/rspb.2020.2467] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In a wide range of taxa, there is evidence that mothers adaptively shape the development of offspring behaviour by exposing them to steroids. These maternal effects have major implications for fitness because, by shaping early development, they can permanently alter how offspring interact with their environment. However, theory on parent-offspring conflict and recent physiological studies showing that embryos rapidly metabolize maternal steroids have placed doubt on the adaptive significance of these hormone-mediated maternal effects. Reconciling these disparate perspectives requires a mechanistic understanding of the pathways by which maternal steroids can influence neural development. Here, we highlight recent advances in developmental neurobiology and psychiatric pharmacology to show that maternal steroid metabolites can have direct neuro-modulatory effects potentially shaping the development of neural circuitry underlying ecologically relevant behavioural traits. The recognition that maternal steroids can act through a neurosteroid pathway has critical implications for our understanding of the ecology and evolution of steroid-based maternal effects. Overall, compared to the classic view, a neurosteroid mechanism may reduce the evolutionary lability of hormone-mediated maternal effects owing to increased pleiotropic constraints and frequently influence long-term behavioural phenotypes in offspring.
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Affiliation(s)
- James C Mouton
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA.,Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, MRC 5503, Washington, DC 20013-7012, USA
| | - Renée A Duckworth
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
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12
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Explaining discrepancies in the study of maternal effects: the role of context and embryo. Curr Opin Behav Sci 2020. [DOI: 10.1016/j.cobeha.2020.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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13
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Peixoto MRLV, Karrow NA, Newman A, Widowski TM. Effects of Maternal Stress on Measures of Anxiety and Fearfulness in Different Strains of Laying Hens. Front Vet Sci 2020; 7:128. [PMID: 32292791 PMCID: PMC7118700 DOI: 10.3389/fvets.2020.00128] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/20/2020] [Indexed: 01/21/2023] Open
Abstract
Maternal stress can affect the offspring of birds, possibly due to hormone deposition in the egg. Additionally, phenotypic diversity resulting from domestication and selection for productivity has created a variety of poultry lines that may cope with stress differently. In this study, we investigated the effects of maternal stress on the behavior of different strains of laying hens and the role of corticosterone as its mediator. For this, fertilized eggs of five genetic lines-two brown (Brown 1 and 2), two white (White 1 and 2), and one pure line White Leghorn-were reared identically as four flocks of 27 birds (24F: 3M) per strain. Each strain was equally separated into two groups: Maternal Stress ("MS"), where hens were subjected to a series of daily acute psychological stressors for 8 days before egg collection, and "Control," which received routine husbandry. Fertile eggs from both treatments were collected at three different ages forming different offspring groups that were treated as replicates; additional eggs from Control were injected either with corticosterone diluted in a vehicle solution ("CORT") or just "Vehicle." Eggs from each replicate were incubated and hatched, and offspring (N = 1,919) were brooded under identical conditions. To measure the effects of maternal stress on anxiety and fear-like behavior, offspring were subjected to a social isolation test (SI) between 5 and 10 days of age and a tonic immobility test (TI) at 9 weeks of age. Compared to Control, MS decreased the number of distress vocalizations emitted by White 2 in SI. No effects of MS were observed in TI, and no effects of CORT were observed in any tests. Overall, brown lines vocalized more in SI and remained in TI for a longer duration than white strains, suggesting genetic differences in fear behavior. Females vocalized more than males in TI and showed a trend toward significance for the same trait in SI. Overall, results suggest that the effects of maternal stress on fearfulness are not directly mediated by corticosterone. Moreover, it highlights behavioral differences across various strains of laying hens, suggesting that fear responses are highly dependent on genotype.
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Affiliation(s)
| | - Niel A. Karrow
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Amy Newman
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Tina M. Widowski
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
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14
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Nechaeva M, Alekseeva T, Dobretsov M, Kubasov I. Chicken embryos can maintain heart rate during hypoxia on day 4 of incubation. J Comp Physiol B 2020; 190:361-370. [PMID: 32198537 DOI: 10.1007/s00360-020-01274-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 12/18/2019] [Accepted: 03/05/2020] [Indexed: 11/24/2022]
Abstract
Acute exposure to hypoxic conditions is a frequent natural event during the development of bird eggs. However, little is known about the effect of such exposure on the ability of young embryos in which cardiovascular regulation is not yet developed to maintain a normal heart rate (HR). To address this question, we studied the effect of 10-20 min of exposure to moderate or severe acute hypoxia (10% or 5% O2, respectively) on the HR of day 4 (D4) chicken embryos. In ovo, video recording of the beating embryo heart inside the egg revealed that severe, but not moderate, hypoxia resulted in significant HR changes. The HR response to severe hypoxia consisted of two phases: the first phase, consisting of an initial decrease in HR, was followed by a phase of partial HR recovery. Upon the restoration of normoxia, after an overshoot period of a few minutes, the HR completely recovered to its basal level. In vitro (isolated heart preparation), the first phase of the HR response to severe hypoxia was strengthened (nearly complete heart silencing) compared to that in ovo, and the HR recovery phase was greatly attenuated. Furthermore, neither an overshoot period nor complete HR recovery after hypoxia was observed. Thus, the D4 chicken embryo heart can partially maintain its rhythm during hypoxia in ovo, but not in vitro. Some factors from the egg, such as catecholamines, are likely to be critical for avian embryo responding to hypoxic condition and survival.
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Affiliation(s)
- Marina Nechaeva
- Institute of Developmental Biology RAS, Vavilov Str. 26, Moscow, 119334, Russia.
| | - Tatyana Alekseeva
- Institute of Developmental Biology RAS, Vavilov Str. 26, Moscow, 119334, Russia
| | - Maxim Dobretsov
- Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg, Russia
| | - Igor Kubasov
- Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg, Russia
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15
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Campbell NA, Angles R, Bowden RM, Casto JM, Paitz RT. Characterizing the timing of yolk testosterone metabolism and the effects of etiocholanolone on development in avian eggs. J Exp Biol 2020; 223:jeb210427. [PMID: 32001543 DOI: 10.1242/jeb.210427] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 01/23/2020] [Indexed: 12/21/2022]
Abstract
Maternal transfer of steroids to eggs can elicit permanent effects on offspring phenotype. Although testosterone was thought to be a key mediator of maternal effects in birds, we now know that vertebrate embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites, not testosterone, may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling (Sturnus vulgaris) eggs to characterize the timing of testosterone metabolism and determine whether etiocholanolone, a prominent metabolite of testosterone in avian embryos, is capable of affecting early embryonic development. Tritiated testosterone was injected into freshly laid eggs to characterize steroid movement and metabolism during early development. Varying levels of etiocholanolone were also injected into eggs, with incubation for either 3 or 5 days, to test whether etiocholanolone influences the early growth of embryonic tissues. The conversion of testosterone to etiocholanolone was initiated within 12 h of injection, but the increase in etiocholanolone was transient, indicating that etiocholanolone is also subject to metabolism, and that exposure to maternal etiocholanolone is limited to a short period during early development. Exogenous etiocholanolone manipulation had no significant effect on the growth rate of the embryos or extra-embryonic membranes early in development. Thus, the conversion of testosterone to etiocholanolone may be an inactivation pathway that buffers the embryo from maternal steroids, with any effects of yolk testosterone resulting from testosterone that escapes metabolism; alternatively, etiocholanolone may influence processes other than growth or take additional time to manifest.
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Affiliation(s)
- Nicole A Campbell
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rachel Angles
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Joseph M Casto
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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16
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Paitz RT, Angles R, Cagney E. In ovo metabolism of estradiol to estrone sulfate in chicken eggs: Implications for how yolk estradiol influences embryonic development. Gen Comp Endocrinol 2020; 287:113320. [PMID: 31715137 DOI: 10.1016/j.ygcen.2019.113320] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/19/2019] [Accepted: 11/08/2019] [Indexed: 12/11/2022]
Abstract
The steroid 17β-estradiol (herein "estradiol") is a potent regulator of sexual differentiation that exerts wide-ranging effects on the developing brain and other tissues. The developing gonads are an important source of estradiol but most, if not all, vertebrate embryos are also exposed to maternally derived estradiol during development. In birds, this maternally derived estradiol is present in the egg at the time of oviposition but very little is known about how this source of estradiol influences development. A critical aspect of understanding yolk estradiol effects is deciphering how steroid metabolism may regulate embryonic exposure to yolk estradiol. In this study, we examine the metabolic fate of estradiol during the first five days of incubation in chicken (Gallus gallus) eggs. Using tritiated estradiol to trace the movement and metabolism of estradiol, we demonstrate that estradiol is metabolized to estrone, which is subsequently conjugated to estrone sulfate as the primary metabolite. Estrone sulfate then accumulates in the albumen by day five of incubation. Overall, these findings have important implications for how yolk estradiol may influence development and alter offspring phenotype. Mechanisms through which estradiol, as well as estrone sulfate, might elicit effects are discussed.
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Affiliation(s)
- Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
| | - Rachel Angles
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Erin Cagney
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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17
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Paitz RT, Cagney E. In ovo metabolism of progesterone to 5β-pregnanedione in chicken eggs: Implications for how yolk progesterone influences embryonic development. Gen Comp Endocrinol 2019; 282:113221. [PMID: 31301283 DOI: 10.1016/j.ygcen.2019.113221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 07/09/2019] [Accepted: 07/09/2019] [Indexed: 01/30/2023]
Abstract
Progesterone has received substantial attention for the essential role it plays in establishing and maintaining pregnancy in placental vertebrates. Despite the prevalence of progesterone during development, relatively little is known about how embryos respond to progesterone. This is true of placental vertebrates as well as egg-laying vertebrates where levels of progesterone in the yolk tend to be higher than most other steroids in the yolk. Bird eggs provide an opportunity to investigate the effects of progesterone on embryonic development because progesterone can be easily manipulated without any confounding effects on maternal physiology. To understand how progesterone might influence embryonic development, it is important to characterize the metabolic fate of progesterone given its potential to be converted to a wide range of steroids. We investigated the metabolic fate of tritiated progesterone over the first four days of development using chicken eggs (Gallus gallus) and identified 5β-pregnanedione as the primary metabolite during this period. After only one day of development, 5β-pregnanedione could be detected within the yolk. Levels of 5β-pregnanedione in both the yolk and albumen tended to rise early in development but conjugated metabolites began to accumulate towards the end of our sampling period. Additionally, in vitro assays using embryo homogenates collected after 72 h of development demonstrated that embryos were capable of carrying out the conversion of progesterone to 5β-pregnanedione. Overall these results have important implications for deciphering the mechanisms through which yolk progesterone might influence embryonic development. Effects could arise via progesterone receptors or receptors capable of binding 5β-pregnanedione but we found no evidence that progesterone is serving as a precursor for androgen or estrogen production.
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Affiliation(s)
- Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
| | - Erin Cagney
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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18
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Groothuis TGG, Hsu BY, Kumar N, Tschirren B. Revisiting mechanisms and functions of prenatal hormone-mediated maternal effects using avian species as a model. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180115. [PMID: 30966885 PMCID: PMC6460091 DOI: 10.1098/rstb.2018.0115] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2018] [Indexed: 12/16/2022] Open
Abstract
Maternal effects can adaptively modulate offspring developmental trajectories in variable but predictable environments. Hormone synthesis is sensitive to environmental factors, and maternal hormones are thus a powerful mechanism to transfer environmental cues to the next generation. Birds have become a key model for the study of hormone-mediated maternal effects because the embryo develops outside the mother's body, facilitating the measurement and manipulation of prenatal hormone exposure. At the same time, birds are excellent models for the integration of both proximate and ultimate approaches, which is key to a better understanding of the evolution of hormone-mediated maternal effects. Over the past two decades, a surge of studies on hormone-mediated maternal effects has revealed an increasing number of discrepancies. In this review, we discuss the role of the environment, genetic factors and social interactions in causing these discrepancies and provide a framework to resolve them. We also explore the largely neglected role of the embryo in modulating the maternal signal, as well as costs and benefits of hormone transfer and expression for the different family members. We conclude by highlighting fruitful avenues for future research that have opened up thanks to new theoretical insights and technical advances in the field. This article is part of the theme issue 'Developing differences: early-life effects and evolutionary medicine'.
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Affiliation(s)
- Ton G. G. Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Bin-Yan Hsu
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
- Department of Biology, University of Turku, Turku, Finland
| | - Neeraj Kumar
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Barbara Tschirren
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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19
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Vassallo BG, Litwa HP, Haussmann MF, Paitz RT. In ovo metabolism and yolk glucocorticoid concentration interact to influence embryonic glucocorticoid exposure patterns. Gen Comp Endocrinol 2019; 272:57-62. [PMID: 30500372 PMCID: PMC7480747 DOI: 10.1016/j.ygcen.2018.11.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 11/21/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022]
Abstract
Vertebrates release glucocorticoids during stressful events. If stress occurs during reproduction, the resulting offspring can show altered phenotypes that are thought to arise from increased exposure to maternal glucocorticoids. Developing offspring can metabolize maternal glucocorticoids, which can alter the pattern of exposure they encounter. For egg laying vertebrates, we are just beginning to understand how embryonic steroid metabolism impacts embryonic exposure to maternal glucocorticoids. Here we injected three doses of radioactive corticosterone into Japanese quail (Coturnix japonica) eggs to determine the degree of embryonic exposure at days six and nine of development. We found that increasing injection dose increased the amount of radioactivity found in the embryo at day six but by day nine the effect of injection dose disappeared as the amount of radioactivity within the embryo dropped to equivalent levels for all three doses. Interestingly, when examined as a percentage of initial dose, there were no differences between treatment groups at any time points. Importantly, using thin-layer chromatography we characterized that some free steroid, putatively identified as corticosterone, does reach the developing embryo. Together, our data suggest that the in ovo metabolism of maternal corticosterone can eventually eliminate it from the egg, but before this happens, embryos developing in eggs with elevated amounts of maternal corticosterone are exposed to higher levels early in development. This has important implications for how we understand the developmental steroid environment and the mechanisms underlying maternal stress effects.
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Affiliation(s)
- Brian G Vassallo
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - Hannah P Litwa
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - Mark F Haussmann
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
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20
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Kumar N, van Dam A, Permentier H, van Faassen M, Kema I, Gahr M, Groothuis TGG. Avian yolk androgens are metabolized instead of taken up by the embryo during the first days of incubation. J Exp Biol 2019; 222:jeb.193961. [DOI: 10.1242/jeb.193961] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/05/2019] [Indexed: 11/20/2022]
Abstract
Several studies show effects of yolk androgens in avian eggs on the phenotype of the offspring. Yolk hormone concentrations decline strongly already in the first few days of incubation. Although early embryonic uptake of yolk androgens is suggested by the presence of radioactivity in the embryo when eggs are injected with radiolabelled androgens, these studies do not verify the chemical identity of radioactive compound(s), while it is known that these androgens can be metabolized substantially. By using stable isotope labelled testosterone and androstenedione in combination with mass spectrometry, enabling verification of the exact molecular identity of labelled compounds in the embryo, we found that after five days of incubation the androgens are not taken up by the embryo. Yet their concentrations in the entire yolk-albumen homogenates decline strongly, even when corrected for dilution by albumen and water. Our results indicate metabolism of maternal androgens, very likely to 5β-androstane-3α,17β-diol, etiocholanolone, and their conjugated forms. The results imply that the effects of increased exposure of the embryo to maternal androgens either take place before this early conversion or are mediated by these metabolites with a so far unknown function, opening new avenues for understanding hormone mediated maternal effects in vertebrates.
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Affiliation(s)
- Neeraj Kumar
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
- Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Annie van Dam
- Interfaculty Mass Spectrometry Center, University of Groningen, the Netherlands
| | - Hjalmar Permentier
- Interfaculty Mass Spectrometry Center, University of Groningen, the Netherlands
| | - Martijn van Faassen
- Laboratory Medicine, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Ido Kema
- Laboratory Medicine, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Manfred Gahr
- Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Ton G. G. Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
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21
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Parent-embryo acoustic communication: a specialised heat vocalisation allowing embryonic eavesdropping. Sci Rep 2018; 8:17721. [PMID: 30532029 PMCID: PMC6286336 DOI: 10.1038/s41598-018-35853-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/30/2018] [Indexed: 11/13/2022] Open
Abstract
Sound is arguably the external cue most accessible to embryos of many species, and as such may constitute an unrivalled source of early information. Recent evidence shows that prenatal sounds, similarly to maternal effects, may shape developmental trajectories. Establishing whether parental vocalisations are signals directed at embryos, or parental cues on which embryos eavesdrop, can elucidate whether parents or embryos control developmental outcomes. Prenatal exposure to a characteristic heat-related parental call was recently shown to alter zebra finch growth and fitness. Here, we test the ecological context of this behaviour in the wild, and assess the information value and specificity of this vocalisation for an embryonic audience. We show that wild zebra finches also produce this characteristic call, only at high temperatures. In addition, in the lab, we demonstrate experimentally that calling is specifically triggered by high air temperatures, can occur without an embryonic audience, and importantly, is predicted by individuals’ body mass. Overall, our findings reveal a specialised heat vocalisation that enables embryonic eavesdropping, by indicating high ambient temperatures, and parents’ capacity to cope with such conditions. This challenges the traditional view of embryos as passive agents of their development, and opens exciting research avenues on avian adaptation to extreme heat.
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22
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Kumar N, van Faassen M, Kema I, Gahr M, Groothuis TGG. Early embryonic modification of maternal hormones differs systematically among embryos of different laying order: A study in birds. Gen Comp Endocrinol 2018; 269:53-59. [PMID: 30110617 DOI: 10.1016/j.ygcen.2018.08.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 08/07/2018] [Accepted: 08/07/2018] [Indexed: 12/17/2022]
Abstract
Vertebrate embryos are exposed to maternal hormones that can profoundly affect their later phenotype. Although it is known that the embryo can metabolize these maternal hormones, the metabolic outcomes, their quantitative dynamics and timing are poorly understood. Moreover, it is unknown whether embryos can adjust their metabolic activity to, for example, hormones or other maternal signals. We studied the dynamics of maternal steroids in fertilized and unfertilized rock pigeon eggs during early incubation. Embryos of this species are naturally exposed to different amounts of maternal steroids in the egg according to their laying position, which provides a natural context to study differential embryonic regulation of the maternal signals. We used mass spectrometric analyses to map changes in the androgen and estrogen pathways of conversion. We show that the active hormones are heavily metabolized only in fertilized eggs, with a corresponding increase in supposedly less potent metabolites already within one-fourth of total incubation period. Interestingly, the rate of androgen metabolism was different between embryos in different laying positions. The results also warrant a re-interpretation of the timing of hormone mediated maternal effects and the role of the supposedly biologically inactive metabolites. Furthermore, the results also provide a potential solution as to how the embryo can prevent maternal steroids in the egg from interfering with its sexual differentiation processes as we show that the embryo can metabolize most of the maternal steroids before sexual differentiation starts.
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Affiliation(s)
- Neeraj Kumar
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands; Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany.
| | - Martijn van Faassen
- Laboratory Medicine, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Ido Kema
- Laboratory Medicine, University Medical Center Groningen, University of Groningen, the Netherlands
| | - Manfred Gahr
- Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Ton G G Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, the Netherlands
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23
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Carter AW, Bowden RM, Paitz RT. Evidence of embryonic regulation of maternally derived yolk corticosterone. J Exp Biol 2018; 221:jeb182600. [PMID: 30266787 PMCID: PMC6262762 DOI: 10.1242/jeb.182600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 09/24/2018] [Indexed: 12/31/2022]
Abstract
In recent years, the potential for maternal stress effects to adaptively alter offspring phenotype has received considerable attention. This research has identified offspring traits that are labile in response to maternal stress; however, an understanding of the mechanisms underlying these effects is lagging and is crucial to appreciating the significance of this maternal effect. In the present study, we sought to better understand maternal stress effects by examining the potential for embryonic regulation of corticosterone exposure, determining the phenotypic consequences of elevated corticosterone during development, and characterizing the levels of maternally transferred corticosterone in unmanipulated eggs using Trachemys scripta By dosing eggs with tritiated corticosterone and tracking the steroid throughout development, we found that most corticosterone is metabolized, and less than 1% of the corticosterone dose reaches the embryo as free corticosterone. We also found that exogenous dosing of corticosterone, in concentrations sufficient to overwhelm embryonic metabolism, reduces embryonic survival and negatively impacts hatchling traits important to fitness. Our results demonstrate that concentrations of maternal corticosterone in the yolks of unmanipulated eggs are low and are significantly lower than the doses of corticosterone required to elicit phenotypic effects in hatchlings. Taken together, these results provide evidence that both the embryo and the female may minimize corticosterone accumulation in the embryo to avoid reductions in embryonic survival and negative impacts on offspring phenotype and fitness.
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Affiliation(s)
- Amanda W Carter
- School of Biological Sciences, Illinois State University, Normal, IL 61761, USA
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61761, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61761, USA
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24
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Gonadal steroid levels in rock pigeon eggs do not represent adequately maternal allocation. Sci Rep 2018; 8:11213. [PMID: 30046065 PMCID: PMC6060151 DOI: 10.1038/s41598-018-29478-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 07/06/2018] [Indexed: 12/04/2022] Open
Abstract
Maternal hormones deposited in the egg can provide a powerful model for the study of maternal effects. The differential amount of maternal hormones in the yolk of freshly laid eggs is assumed to represent differential maternal allocation. However, some evidence suggests that these amounts do not reflect maternal allocation that in fact takes place before ovulation. We compared the amounts of a wide array of gonadal steroids and their metabolites in the yolk of pre-ovulatory follicles with those of freshly laid eggs of rock pigeons using mass spectrometry. We found that between the follicle and egg stages the levels of progesterone increase whereas androstenedione and testosterone decrease in which the strength of decrease was dependent on the laying order of the egg. For conjugated estrone the change between follicle and egg differed in direction for first and second laying position yielding a significant interaction effect. For conjugated testosterone the interaction did not reach but was close to significance. This extremely early steroid metabolism was not due to maternal enzymes in the yolk as indicated by incubation of pre-ovulatory yolks treated with proteinase-K, a protein digesting enzyme. The results have significant consequences for the functional and evolutionary interpretation as well as experimental manipulation of hormone-mediated maternal effects.
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25
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Podmokła E, Drobniak SM, Rutkowska J. Chicken or egg? Outcomes of experimental manipulations of maternally transmitted hormones depend on administration method - a meta-analysis. Biol Rev Camb Philos Soc 2018; 93:1499-1517. [PMID: 29573376 DOI: 10.1111/brv.12406] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 01/28/2018] [Accepted: 02/13/2018] [Indexed: 12/25/2022]
Abstract
Steroid hormones are important mediators of prenatal maternal effects in animals. Despite a growing number of studies involving experimental manipulation of these hormones, little is known about the impact of methodological differences among experiments on the final results expressed as offspring traits. Using a meta-analytical approach and a representative sample of experimental studies performed on birds, we tested the effect of two types of direct hormonal manipulations: manipulation of females (either by implantation of hormone pellets or injection of hormonal solutions) and manipulation of eggs by injection. In both types of manipulation we looked at the effects of two groups of hormones: corticosterone and androgens in the form of testosterone and androstenedione. We found that the average effect on offspring traits differed between the manipulation types, with a well-supported positive effect of egg manipulation and lack of a significant effect of maternal manipulation. The observed average positive effect for egg manipulation was driven mainly by androgen manipulations, while corticosterone manipulations exerted no overall effect, regardless of manipulation type. Detailed analyses revealed effects of varying size and direction depending on the specific offspring traits; e.g., egg manipulation positively affected physiology and behaviour (androgens), and negatively affected future reproduction (corticosterone). Effect size was negatively related to the dose of androgen injected into the eggs, but unrelated to timing of manipulation, offspring developmental stage at the time of measuring their traits, solvent type, the site of egg injection and maternal hormone delivery method. Despite the generally acknowledged importance of maternal hormones for offspring development in birds, the overall effect of their experimental elevation is rather weak, significantly heterogeneous and dependent on the hormone and type of manipulation. We conclude by providing general recommendations as to how hormonal manipulations should be performed in order to standardize their impact and the results achieved. We also emphasize the need for research on free-living birds with a focus on fitness-related and other long-term effects of maternal hormones.
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Affiliation(s)
- Edyta Podmokła
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Szymon M Drobniak
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Joanna Rutkowska
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
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26
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Della Costa NS, Navarro JL, Busso JM, Marin RH, Martella MB. Distribution and concentration of maternal progesterone in the yolk of Greater Rhea eggs (Rhea americana). JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 327:143-148. [PMID: 29356448 DOI: 10.1002/jez.2073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 04/04/2017] [Accepted: 04/05/2017] [Indexed: 01/28/2023]
Abstract
Progesterone is the most concentrated maternal yolk steroid characterized to date in birds; however, no information about it is available in ratite eggs. We collected freshly laid eggs from zoo-housed Greater Rhea females (Rhea americana) bred under similar rearing conditions during two breeding seasons to characterize concentration and distribution of maternal yolk progesterone. After high-performance liquid chromatography analysis, yolk hormone was measured using a commercial electrochemiluminescence immunoassay. Progesterone concentrations were found to vary significantly among the yolk layers, supporting a follicular origin for this steroid in Greater Rhea eggs. Additionally, highly similar mean absolute yolk progesterone concentrations were detected between 2013 and 2015 breeding seasons (1,332.98 ± 82.59 and 1,313.59 ± 85.19 ng/g, respectively). These values are also comparable to those found in some domestic carinate species. Findings suggest that at population level, when rearing conditions are similar, mean absolute yolk maternal progesterone concentrations also appear bounded. Future research on the factors and mechanisms that regulate progesterone deposition in Greater Rhea eggs is needed to better understand whether its levels depend on different rearing conditions.
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Affiliation(s)
- Natalia Soledad Della Costa
- Instituto de Diversidad y Ecología Animal (IDEA, CONICET-UNC) and Centro de Zoología Aplicada, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Joaquín Luis Navarro
- Instituto de Diversidad y Ecología Animal (IDEA, CONICET-UNC) and Centro de Zoología Aplicada, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Juan Manuel Busso
- Instituto de Investigaciones Biológicas y Tecnológicas, Instituto de Ciencia y Tecnología de los Alimentos (IIBYT, CONICET-UNC), Córdoba, Argentina
| | - Raúl Héctor Marin
- Instituto de Investigaciones Biológicas y Tecnológicas, Instituto de Ciencia y Tecnología de los Alimentos (IIBYT, CONICET-UNC), Córdoba, Argentina.,Cátedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba
| | - Mónica Beatriz Martella
- Instituto de Diversidad y Ecología Animal (IDEA, CONICET-UNC) and Centro de Zoología Aplicada, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina
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27
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Paitz RT, Duffield KR, Bowden RM. Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated? J Exp Biol 2017; 220:4567-4570. [PMID: 29074704 DOI: 10.1242/jeb.167031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/20/2017] [Indexed: 11/20/2022]
Abstract
All vertebrate embryos are exposed to maternally derived steroids during development. In placental vertebrates, metabolism of maternal steroids by the placenta modulates embryonic exposure, but how exposure is regulated in oviparous vertebrates is less clear. Recent work in oviparous vertebrates has demonstrated that steroids are not static molecules, as they can be converted to more polar steroid sulfates by sulfotransferase enzymes. Importantly, these steroid sulfates can be converted back to the parent compound by the enzyme steroid sulfatase (STS). We investigated when and where STS was present during embryonic development in the red-eared slider turtle, Trachemys scripta We report that STS is present during all stages of development and in all tissues we examined. We conclude that STS activity may be particularly important for regulating maternal steroid exposure in oviparous vertebrates.
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Affiliation(s)
- Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Kristin R Duffield
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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Parolini M, Romano A, Possenti CD, Caprioli M, Rubolini D, Saino N. Contrasting effects of increased yolk testosterone content on development and oxidative status in gull embryos. J Exp Biol 2017; 220:625-633. [DOI: 10.1242/jeb.145235] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 11/25/2016] [Indexed: 01/13/2023]
Abstract
ABSTRACT
Hormone-mediated maternal effects generate variation in offspring phenotype. In birds, maternal egg testosterone (T) exerts differential effects on offspring traits after hatching, suggesting that mothers experience a trade-off between contrasting T effects. However, there is very little information on T pre-natal effects. In the yellow-legged gull (Larus michahellis), we increased yolk T concentration within physiological limits and measured the effects on development and oxidative status of late-stage embryos. T-treated embryos had a larger body size but a smaller brain than controls. Males had a larger brain than females, controlling for overall size. T treatment differentially affected brain mass and total amount of pro-oxidants in the brain depending on laying order. T-treatment effects were not sex dependent. For the first time in the wild, we show contrasting T pre-natal effects on body mass and brain size. Hence, T may enforce trade-offs between different embryonic traits, but also within the same trait during different developmental periods.
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Affiliation(s)
- Marco Parolini
- Department of Biosciences, University of Milan, via Celoria 26, Milan I-20133, Italy
| | - Andrea Romano
- Department of Biosciences, University of Milan, via Celoria 26, Milan I-20133, Italy
| | | | - Manuela Caprioli
- Department of Biosciences, University of Milan, via Celoria 26, Milan I-20133, Italy
| | - Diego Rubolini
- Department of Biosciences, University of Milan, via Celoria 26, Milan I-20133, Italy
| | - Nicola Saino
- Department of Biosciences, University of Milan, via Celoria 26, Milan I-20133, Italy
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Muriel J, Pérez-Rodríguez L, Ortiz-Santaliestra ME, Puerta M, Gil D. Sex-Specific Effects of High Yolk Androgen Levels on Constitutive and Cell-Mediated Immune Responses in Nestlings of an Altricial Passerine. Physiol Biochem Zool 2017; 90:106-117. [DOI: 10.1086/688445] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Paitz RT, Bukhari SA, Bell AM. Stickleback embryos use ATP-binding cassette transporters as a buffer against exposure to maternally derived cortisol. Proc Biol Sci 2016; 283:20152838. [PMID: 26984623 DOI: 10.1098/rspb.2015.2838] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Offspring from females that experience stressful conditions during reproduction often exhibit altered phenotypes and many of these effects are thought to arise owing to increased exposure to maternal glucocorticoids. While embryos of placental vertebrates are known to regulate exposure to maternal glucocorticoids via placental steroid metabolism, much less is known about how and whether egg-laying vertebrates can control their steroid environment during embryonic development. We tested the hypothesis that threespine stickleback (Gasterosteus aculeatus) embryos can regulate exposure to maternal steroids via active efflux of maternal steroids from the egg. Embryos rapidly (within 72 h) cleared intact steroids, but blocking ATP-binding cassette (ABC) transporters inhibited cortisol clearance. Remarkably, this efflux of cortisol was sufficient to prevent a transcriptional response of embryos to exogenous cortisol. Taken together, these findings suggest that, much like their placental counterparts, developing fish embryos can actively regulate their exposure to maternal cortisol. These findings highlight the fact that even in egg-laying vertebrates, the realized exposure to maternal steroids is mediated by both maternal and embryonic processes and this has important implications for understanding how maternal stress influences offspring development.
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Affiliation(s)
- Ryan T Paitz
- School of Integrative Biology, University of Illinois, Urbana, IL 61801, USA School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, IL 61790, USA
| | - Syed Abbas Bukhari
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA Illinois Informatics Institute, University of Illinois, Urbana, IL 61801, USA
| | - Alison M Bell
- School of Integrative Biology, University of Illinois, Urbana, IL 61801, USA Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, USA
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31
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Hu SX. Age-related change of hepatic uridine diphosphate glucuronosyltransferase and sulfotransferase activities in male chickens and pigs. J Vet Pharmacol Ther 2016; 40:270-278. [PMID: 27593531 DOI: 10.1111/jvp.12355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/25/2016] [Indexed: 02/04/2023]
Abstract
The hepatic activities of uridine diphosphate glucuronosyltransferase (UGT) and sulfotransferase (SULT) of male Ross 708 broiler chickens at the age of 1, 7, 14, 28, and 56 days and male Camborough-29 pigs at the age of 1 day and 2, 5, 10, and 20 weeks were investigated. Glucuronidation and sulfation of 4-nitrophenol were used to evaluate the activities. Porcine hepatic UGT and SULT activities were low at birth, peaked at around 5-10 weeks, and then declined. Both hepatic UGT and SULT activities of chickens were high at hatch and declined. Chicken hepatic UGT activity had a peak at the age of 28 days. Affinity of hepatic SULT to 4-nitrophenol is similar in chickens and pigs, but the affinity of hepatic UGT in pigs was about 10 times higher than that in chickens. 4-nitrophenol was predominantly conjugated by SULT instead of UGT in chicken livers from hatch to day 56. Conversely, hepatic UGT contributed predominantly in 4-nitrophenol conjugation than the SULT in pigs from birth to 20 weeks. Therefore, age has significant impact on hepatic activities of UGT and SULT, and the importance of UGT and SULT on conjugation is different in chickens and pigs.
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Affiliation(s)
- S X Hu
- Veterinary Medicine Research and Development, Zoetis, Inc., Kalamazoo, MI, USA
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Dean KM, Baltos LD, Carro T, Iwaniuk AN, Bohannon MEB, Ottinger MA. Comparison of vehicle mortality followingin ovoexposure of Japanese quail (Coturnix japonica) eggs to corn oil, triolein and a fatty acid mix. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/23273747.2016.1224022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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33
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Tilgar V, Mägi M, Lind M, Lodjak J, Moks K, Mänd R. Acute embryonic exposure to corticosterone alters physiology, behaviour and growth in nestlings of a wild passerine. Horm Behav 2016; 84:111-20. [PMID: 27374762 DOI: 10.1016/j.yhbeh.2016.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/08/2016] [Accepted: 06/26/2016] [Indexed: 11/27/2022]
Abstract
Maternally-derived glucocorticoids can modify the normal development of young animals. To date, little is known about maternal effects that are mediated by acute embryonic exposure to glucocorticoids. In birds, elevated maternal transmission of corticosterone (CORT) to egg albumen is mainly dependent on acute stress. In this study, we increased CORT levels in the egg albumen of a wild passerine, the great tit (Parus major), breeding in favourable deciduous and less suitable coniferous habitat. Subsequently we measured the somatic growth, baseline and acute glucocorticoid responses, immunity and behaviour of prenatally manipulated offspring with respect to control siblings. We found that prenatally CORT-exposed nestlings had lower baseline CORT levels, a more rapid decline in CORT during recovery from a standardized stressor, and a reduced heterophil/lymphocyte ratio compared with controls. Although stress-induced total CORT levels remained unchanged, free CORT levels were significantly lower and the levels of corticosteroid binding globulins (CBG) significantly higher in experimental offspring. Prenatally CORT-exposed offspring begged longer after hatching than controls. Stress-induced behavioural activity of fledglings did not differ between treatments, while its association with baseline CORT levels was significant in the control group only. The body mass and tarsus length of fledglings was positively affected by manipulation in unfavourable coniferous habitat only. We conclude that maternal effects related to elevated levels of albumen CORT modify diverse aspects of offspring phenotype and potentially increase offspring performance in resource poor environments. Moreover, our results indicate that maternal glucocorticoids may suppress the effect of hormones on behavioural responses.
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Affiliation(s)
- Vallo Tilgar
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Marko Mägi
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Marianne Lind
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Jaanis Lodjak
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Kadri Moks
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
| | - Raivo Mänd
- Department of Zoology, Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, Tartu 51014, Estonia.
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34
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Bentz AB, Sirman AE, Wada H, Navara KJ, Hood WR. Relationship between maternal environment and DNA methylation patterns of estrogen receptor alpha in wild Eastern Bluebird (Sialia sialis) nestlings: a pilot study. Ecol Evol 2016; 6:4741-52. [PMID: 27547309 PMCID: PMC4979703 DOI: 10.1002/ece3.2162] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/18/2022] Open
Abstract
There is mounting evidence that, across taxa, females breeding in competitive environments tend to allocate more testosterone to their offspring prenatally and these offspring typically have more aggressive and faster‐growing phenotypes. To date, no study has determined the mechanisms mediating this maternal effect's influence on offspring phenotype. However, levels of estrogen receptor alpha (ERα) gene expression are linked to differences in early growth and aggression; thus, maternal hormones may alter gene regulation, perhaps via DNA methylation, of ERα in offspring during prenatal development. We performed a pilot study to examine natural variation in testosterone allocation to offspring through egg yolks in wild Eastern Bluebirds (Sialia sialis) in varying breeding densities and percent DNA methylation of CG dinucleotides in the ERα promoter in offspring brain regions associated with growth and behavior. We hypothesized that breeding density would be positively correlated with yolk testosterone, and prenatal exposure to maternal‐derived yolk testosterone would be associated with greater offspring growth and decreased ERα promoter methylation. Yolk testosterone concentration was positively correlated with breeding density, nestling growth rate, and percent DNA methylation of one out of five investigated CpG sites (site 3) in the diencephalon ERα promoter, but none in the telencephalon (n = 10). Percent DNA methylation of diencephalon CpG site 3 was positively correlated with growth rate. These data suggest a possible role for epigenetics in mediating the effects of the maternal environment on offspring phenotype. Experimentally examining this mechanism with a larger sample size in future studies may help elucidate a prominent way in which animals respond to their environment. Further, by determining the mechanisms that mediate maternal effects, we can begin to understand the potential for the heritability of these mechanisms and the impact that maternal effects are capable of producing at an evolutionary scale.
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Affiliation(s)
- Alexandra B Bentz
- Poultry Science Department University of Georgia 203 Poultry Science Bldg. Athens Georigia 30602
| | - Aubrey E Sirman
- Department of Biological Sciences Auburn University 101 Life Science Building Auburn Alabama 36849
| | - Haruka Wada
- Department of Biological Sciences Auburn University 101 Life Science Building Auburn Alabama 36849
| | - Kristen J Navara
- Poultry Science Department University of Georgia 203 Poultry Science Bldg. Athens Georigia 30602
| | - Wendy R Hood
- Department of Biological Sciences Auburn University 101 Life Science Building Auburn Alabama 36849
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35
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Strange MS, Bowden RM, Thompson CF, Sakaluk SK. Pre- and Postnatal Effects of Corticosterone on Fitness-Related Traits and the Timing of Endogenous Corticosterone Production in a Songbird. ACTA ACUST UNITED AC 2016; 325:347-59. [PMID: 27279255 DOI: 10.1002/jez.2022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 12/18/2022]
Abstract
Maternally derived corticosterone in the egg and corticosterone produced endogenously by altricial nestling birds play essential roles during development. Although persistently high corticosterone levels can be harmful, moderately elevated levels above baseline can lead to reallocation of resources between growth and maintenance to ensure immediate survival or to enhance the development of fitness-related traits. We tested two hypotheses concerning the fitness consequences of elevated corticosterone during prenatal and postnatal development in altricial house wrens: (1) elevated corticosterone shifts resources away from growth and immune function and (2) elevated corticosterone serves as a signal to allocate resources to fitness-related traits. We also explored the development of the stress response, hypothesizing that early-stage nestlings have little endogenously produced corticosterone, but that their baseline and stress-induced corticosterone levels increase with age. Nestlings hatching from corticosterone-injected eggs were lighter at hatching, but through compensatory growth, ended up heavier than controls near the time of fledging, an important, fitness-related trait. Nestlings that hatched from corticosterone-injected eggs and those given oral doses of corticosterone did not differ from controls in three other fitness-related traits: immunoresponsiveness, size, or haematocrit. Early- and late-stage nestlings had similar baseline corticosterone levels, and all nestlings increased their plasma corticosterone levels in response to a capture-and-restraint protocol, with older nestlings mounting a stronger stress-induced response than younger nestlings. These results suggest that prenatal exposure to corticosterone is important in shaping offspring phenotype and are consistent with the hypothesis that maternally derived corticosterone in the egg can have long-term, fitness-related effects on offspring phenotype.
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Affiliation(s)
- Meghan S Strange
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences, Illinois State University, Normal, Illinois
| | - Rachel M Bowden
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences, Illinois State University, Normal, Illinois
| | - Charles F Thompson
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences, Illinois State University, Normal, Illinois
| | - Scott K Sakaluk
- Behavior, Ecology, Evolution and Systematics Section, School of Biological Sciences, Illinois State University, Normal, Illinois
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36
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Herrington JA, Rodriguez Y, Lickliter R. Elevated yolk progesterone moderates prenatal heart rate and postnatal auditory learning in bobwhite quail (Colinus virginianus). Dev Psychobiol 2016; 58:784-8. [PMID: 27108924 DOI: 10.1002/dev.21419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/31/2016] [Indexed: 11/07/2022]
Abstract
Previous studies have established that yolk hormones of maternal origin can influence physiology and behavior in birds. However, few studies have examined the effects of maternal gestagens, like progesterone, on chick behavior and physiology. We tested the effects of experimentally elevated egg yolk progesterone on embryonic heart rate and postnatal auditory learning in bobwhite quail hatchlings. Quail chicks were passively exposed to an individual maternal assembly call for 10 min/hr during the 24 hr following hatching. Preference for the familiarized call was tested at 48 hr following hatching in three experimental groups: chicks that received artificially elevated yolk progesterone (P) prior to incubation, vehicle-only controls (V), and non-manipulated controls (C). Resting heart rate of P, V, and C embryos were also measured on prenatal day 17. The resting heart rate of P embryos was significantly higher than both the V and C embryos. Chicks from the P group also showed an enhanced preference for the familiarized bobwhite maternal call when compared to chicks from the C and V groups. Our results indicate that elevated yolk progesterone in pre-incubated bobwhite quail eggs can influence arousal level in bobwhite embryos and postnatal perceptual learning in bobwhite neonates.
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Affiliation(s)
| | - Yvette Rodriguez
- Department of Psychology, Florida International University, Miami, Florida
| | - Robert Lickliter
- Department of Psychology, Florida International University, Miami, Florida
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37
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Possenti CD, Romano A, Caprioli M, Rubolini D, Spiezio C, Saino N, Parolini M. Yolk testosterone affects growth and promotes individual-level consistency in behavioral lateralization of yellow-legged gull chicks. Horm Behav 2016; 80:58-67. [PMID: 26836770 DOI: 10.1016/j.yhbeh.2016.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 02/02/2023]
Abstract
Behavioral lateralization is common in animals and may be expressed at the individual- and at the population-level. The ontogenetic processes that control lateralization, however, are largely unknown. Well-established sex-dependence in androgen physiology and sex-dependent variation in lateralization have led to the hypothesis that testosterone (T) has organizational effects on lateralization. The effects of T exposure in early life on lateralization can be efficiently investigated by manipulating T levels in the cleidoic eggs of birds, because the embryo is isolated from maternal and sibling physiological interference, but this approach has been adopted very rarely. In the yellow-legged gull (Larus michahellis) we increased yolk T concentration within the physiological limits and tested the effects on the direction of lateralization in two functionally fundamental behaviors (begging for parental care and escape to cover) of molecularly sexed hatchlings. We also speculated that T may intervene in regulating consistency, rather than direction of lateralization, and therefore tested if T affected the 'repeatability' of lateral preference in consecutive behavioral trials. T treatment had no effect on the direction of lateralization, but enhanced the consistency of lateral preference in escape responses. Sex did not predict lateralization. Neither behavior was lateralized at the population-level. We therefore showed for the first time in any species an effect of egg T on consistency in lateralization. The implications of the effect of T for the evolution of trade-offs in maternal allocation of egg hormones, and the evolutionary interpretations of findings from our studies on lateralization among unmanipulated birds are discussed.
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Affiliation(s)
| | - Andrea Romano
- Department of Biosciences, University of Milan, via Celoria 26, Milan, Italy.
| | - Manuela Caprioli
- Department of Biosciences, University of Milan, via Celoria 26, Milan, Italy
| | - Diego Rubolini
- Department of Biosciences, University of Milan, via Celoria 26, Milan, Italy
| | - Caterina Spiezio
- Research and Conservation Department, Parco Natura Viva, Verona, Italy
| | - Nicola Saino
- Department of Biosciences, University of Milan, via Celoria 26, Milan, Italy
| | - Marco Parolini
- Department of Biosciences, University of Milan, via Celoria 26, Milan, Italy.
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38
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Ruuskanen S. Hormonally-mediated maternal effects in birds: Lessons from the flycatcher model system. Gen Comp Endocrinol 2015; 224:283-93. [PMID: 26393309 DOI: 10.1016/j.ygcen.2015.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/09/2015] [Accepted: 09/17/2015] [Indexed: 11/20/2022]
Abstract
Maternal effects are a crucial mechanism in many taxa in generating phenotypic variation, affecting offspring development and fitness and thereby potentially adapting them to their expected environments. Androgen hormones in bird eggs have attracted considerable interest in past years, and it is frequently assumed that their concentrations in eggs are shaped by Darwinian selection. Currently, however, the data is scattered over species with very different life-history strategies, environments and selection pressures, making it difficult to draw any firm conclusions as to their functional significance for a given system. I review the evidence available as to the function, variation and potential adaptive value of yolk androgens (testosterone, T and androstenedione, A4) using one well-studied wild bird model system, the European flycatchers Ficedula hypoleuca and Ficedula albicollis. These species both show genetic and environmental variation in yolk androgen levels, along with fitness correlations for the female, suggesting the potential for selection. However, variation in yolk T and A4 seem to be differentially affected, suggesting that maternal constraints/costs shape the transfer of the yolk steroids differently. Most of the environmental variation is consistent with the idea of high yolk androgen levels under poor rearing conditions, although the effect sizes in relation to environmental variation are rather small in relation to genetic among-female variation. Importantly, within-clutch patterns too vary in relation to environmental conditions. Yolk androgens seem to have multiple short- and long-term effects on phenotype and behavior; importantly, they are also correlated with the fitness of offspring and mothers. However, the effects are often sex-dependent, and not universally beneficial for the offspring. Unfortunately, conclusive data as to the adaptive benefits of clutch mean androgen levels or within clutch-patterns in different environmental conditions is still lacking.
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Affiliation(s)
- Suvi Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Finland.
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39
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Groothuis TGG, Taborsky B. Introducing biological realism into the study of developmental plasticity in behaviour. Front Zool 2015; 12 Suppl 1:S6. [PMID: 26816523 PMCID: PMC4722348 DOI: 10.1186/1742-9994-12-s1-s6] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
There is increasing attention for integrating mechanistic and functional approaches to the study of (behavioural) development. As environments are mostly unstable, it is now often assumed that genetic parental information is in many cases not sufficient for offspring to become optimally adapted to the environment and that early environmental cues, either indirectly via the parents or from direct experience, are necessary to prepare them for a specific environment later in life. To study whether these early developmental processes are adaptive and through which mechanism, not only the early environmental cues but also how they impinge on the later-life environmental context has therefore to be taken into account when measuring the animal's performance. We first discuss at the conceptual level six ways in which interactions between influences of different time windows during development may act (consolidation, cumulative information gathering and priming, compensation, buffering, matching and mismatching, context dependent trait expression). In addition we discuss how different environmental factors during the same time window may interact in shaping the phenotype during development. Next we discuss the pros and cons of several experimental designs for testing these interaction effects, highlighting the necessity for full, reciprocal designs and the importance of adjusting the nature and time of manipulation to the animal's adaptive capacity. We then review support for the interaction effects from both theoretical models and animal experiments in different taxa. This demonstrates indeed the existence of interactions at multiple levels, including different environmental factors, different time windows and between generations. As a consequence, development is a life-long, environment-dependent process and therefore manipulating only the early environment without taking interaction effects with other and later environmental influences into account may lead to wrong conclusions and may also explain inconsistent results in the literature.
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Affiliation(s)
- Ton G G Groothuis
- Behavioural Biology, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG, Groningen, the Netherlands
| | - Barbara Taborsky
- Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
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40
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Paitz RT, Mommer BC, Suhr E, Bell AM. Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus). JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL GENETICS AND PHYSIOLOGY 2015; 323:422-9. [PMID: 26036752 PMCID: PMC5977982 DOI: 10.1002/jez.1937] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/12/2015] [Accepted: 04/09/2015] [Indexed: 11/07/2022]
Abstract
Embryonic exposure to steroids often leads to long-term phenotypic effects. It has been hypothesized that mothers may be able to create a steroid environment that adjusts the phenotypes of offspring to current environmental conditions. Complicating this hypothesis is the potential for developing embryos to modulate their early endocrine environment. This study utilized the threespined stickleback (Gasterosteus aculeatus) to characterize the early endocrine environment within eggs by measuring four steroids (progesterone, testosterone, estradiol, and cortisol) of maternal origin. We then examined how the concentrations of these four steroids changed over the first 12 days post fertilization (dpf). Progesterone, testosterone, estradiol, and cortisol of maternal origin could be detected within unfertilized eggs and levels of all four steroids declined in the first 3 days following fertilization. While levels of progesterone, testosterone, and estradiol remained low after the initial decline, levels of cortisol rose again by 8 dpf. These results demonstrate that G. aculeatus embryos begin development in the presence of a number of maternal steroids but levels begin to change quickly following fertilization. This suggests that embryonic processes change the early endocrine environment and hence influence the ability of maternal steroids to affect development. With these findings, G. aculeatus becomes an intriguing system in which to study how selection may act on both maternal and embryonic processes to shape the evolutionary consequence of steroid-mediated maternal effects.
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Affiliation(s)
- Ryan Thomas Paitz
- School of Integrative Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois
- School of Biological Sciences, Illinois State University, Normal, Illinois
| | - Brett Christian Mommer
- School of Integrative Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois
- GIGA Neurosciences, University of Liege, Liège, Belgium
| | - Elissa Suhr
- School of Integrative Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois
| | - Alison Marie Bell
- School of Integrative Biology, Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois
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41
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Vassallo BG, Paitz RT, Fasanello VJ, Haussmann MF. Glucocorticoid metabolism in the in ovo environment modulates exposure to maternal corticosterone in Japanese quail embryos (Coturnix japonica). Biol Lett 2015; 10:20140502. [PMID: 25392311 DOI: 10.1098/rsbl.2014.0502] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Maternal effects have gained attention as a method by which mothers may alter the physiological condition and phenotype of their offspring based upon current environmental conditions. The physiological and phenotypic outcomes of glucocorticoid-mediated maternal effects have been extensively studied in a variety of vertebrates; however, the underlying mechanism is currently unclear. Here, we injected tritiated corticosterone into the yolks of freshly laid Japanese quail eggs (Coturnix japonica) and traced its movement and metabolism through the in ovo development period. We found that corticosterone was extensively conjugated throughout the egg by the end of development, and while minimal corticosterone was detected within the embryo during development, accumulation of a conjugated metabolite in the embryo started to occur on day 6 of development. Because no movement and metabolism of corticosterone occurred in infertile eggs, our findings suggest that embryos are not passive recipients of maternal steroids, but instead appear to possess extensive metabolic capabilities, which may modulate their exposure to maternal steroids.
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Affiliation(s)
- Brian G Vassallo
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
| | - Ryan T Paitz
- School of Integrative Biology, University of Illinois, Urbana, IL 61801, USA
| | | | - Mark F Haussmann
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
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Muriel J, Pérez-Rodríguez L, Puerta M, Gil D. Diverse dose-response effects of yolk androgens on embryo development and nestling growth in a wild passerine. ACTA ACUST UNITED AC 2015; 218:2241-9. [PMID: 25987739 DOI: 10.1242/jeb.118257] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 05/06/2015] [Indexed: 11/20/2022]
Abstract
Avian egg yolks contain various amounts of maternally derived androgens that can modify offspring phenotype and adjust their development to the post-hatching environment. Seemingly adaptive variation in yolk androgen levels with respect to breeding density conditions or male attractiveness has been found in numerous studies. One important consideration that has been overlooked in previous research is the likely non-linear nature of hormone effects. To examine possible complex dose-response effects of maternal androgens on chick development, we experimentally administered three different androgen doses of the naturally occurring mixture of yolk testosterone and androstenedione to spotless starling eggs (Sturnus unicolor). We found that yolk androgens induce a non-linear dose-response pattern in several traits. Androgens had a stimulatory effect on hatchling body mass and nestling skeletal growth, but maximum values were found at intermediate doses, whereas our highest dose resulted in a decrease. However, the opposite U-shaped effect was found on nestling body mass. We also detected linear negative and positive effects on embryonic development period and nestling gape width, respectively. Our results suggest differential tissue responsiveness to yolk androgens, which may result in compromises in maternal allocation to produce adapted phenotypes. Because of the non-linear dose-response pattern, future investigations should carefully consider a wide range of concentrations, as the balance of costs and benefits may strongly differ depending on concentration.
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Affiliation(s)
- Jaime Muriel
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain
| | - Lorenzo Pérez-Rodríguez
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain Departamento de Ecología Evolutiva, Estación Biológica de Doñana (EBD-CSIC), Avda. Américo Vespucio, s/n, Isla de la Cartuja, Sevilla 41092, Spain
| | - Marisa Puerta
- Departamento de Fisiología Animal II, Facultad de Ciencias Biológicas, Universidad Complutense, José Antonio Novais, 2 Ciudad Universitaria, Madrid 28040, Spain
| | - Diego Gil
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, Madrid E-28006, Spain
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43
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Bowers EK, Bowden RM, Sakaluk SK, Thompson CF. Immune activation generates corticosterone-mediated terminal reproductive investment in a wild bird. Am Nat 2015; 185:769-83. [PMID: 25996862 DOI: 10.1086/681017] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Despite classical expectations of a trade-off between immune activity and reproduction, an emergent view suggests that individuals experiencing activation of their immune system actually increase reproductive effort and allocation to offspring as a form of terminal investment in response to reduced survival probability. However, the components and mechanisms of increased parental investment following immunostimulation are currently unknown. We hypothesize that increased glucocorticoid production following immunostimulation modulates the increase in reproductive effort that constitutes terminal investment. We activated the immune system of breeding female house wrens (Troglodytes aedon) with an immunogen and cross-fostered the eggs that they subsequently produced to separate prenatal and postnatal components of maternal investment. Cross-fostering revealed an increase in both pre- and postnatal allocation from immunostimulated females, which was confirmed by quantification of egg constituents and maternal provisioning behavior. The increase in maternal provisioning was mediated, at least in part, by increased corticosterone in these females. Offspring immune responsiveness was also enhanced through transgenerational immune priming via the egg. Thus, our results indicate that maternal immunostimulation induces transgenerational effects on offspring through both pre- and postnatal parental effects and support an important role for corticosterone in mediating parental investment.
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Affiliation(s)
- E Keith Bowers
- Behavior, Ecology, Evolution, and Systematics Section, School of Biological Sciences, Illinois State University, Normal, Illinois 61790
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44
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Paitz RT, Bowden RM. The in ovo conversion of oestrone to oestrone sulfate is rapid and subject to inhibition by Bisphenol A. Biol Lett 2015; 11:20140946. [PMID: 25904318 PMCID: PMC4424608 DOI: 10.1098/rsbl.2014.0946] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 03/31/2015] [Indexed: 01/06/2023] Open
Abstract
Vertebrate embryos develop in the presence of maternally derived steroids. While these steroids can influence development, embryonic enzymes are thought to buffer some steroid sensitive processes, such as gonadal differentiation, from the effects of maternal steroids. Many of these same enzymes may also buffer the embryo from chemicals present in the environment, but this may alter their capacity to metabolize maternal steroids. Here, we characterized the ability of red-eared slider (Trachemys scripta) embryos to metabolize oestrone immediately following oviposition and tested whether a prevalent environmental chemical, Bisphenol A (BPA), would affect the in ovo conversion of oestrone to oestrone sulfate. We found that tritiated oestrone applied at the time of oviposition is mostly converted to oestrone sulfate within 6 h. However, when BPA is present, that conversion is inhibited, resulting in elevated oestrone levels. Our finding of rapid in ovo metabolism of steroids suggests that maternally derived enzymes are present in the egg and can alter embryonic exposure to exogenous chemicals. The disruption of this metabolism by BPA demonstrates how environmental chemicals might change embryonic exposure to endogenous substances within the egg. Taken together, these findings highlight the dynamic nature of the early endocrine environment in developing vertebrates.
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Affiliation(s)
- Ryan T Paitz
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, IL 61790-4120, USA
| | - Rachel M Bowden
- School of Biological Sciences, Illinois State University, Campus Box 4120, Normal, IL 61790-4120, USA
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45
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De Baere S, Rosendahl Larsen T, Devreese M, De Backer P, De Neve L, Fairhurst G, Lens L, Croubels S. Use of LC–MS–MS as an alternative to currently available immunoassay methods to quantitate corticosterone in egg yolk and albumen. Anal Bioanal Chem 2014; 407:4351-62. [DOI: 10.1007/s00216-014-8269-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/12/2014] [Accepted: 10/13/2014] [Indexed: 01/19/2023]
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46
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Schweitzer C, Schwabl H, Baran NM, Adkins-Regan E. Pair disruption in female zebra finches: consequences for offspring phenotype and sensitivity to a social stressor. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.01.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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47
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Muriel J, Pérez-Rodríguez L, Puerta M, Gil D. Differential effects of yolk testosterone and androstenedione in embryo development and nestling growth in the spotless starling (Sturnus unicolor). Gen Comp Endocrinol 2013; 194:175-82. [PMID: 24090611 DOI: 10.1016/j.ygcen.2013.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 09/05/2013] [Accepted: 09/16/2013] [Indexed: 11/18/2022]
Abstract
Yolk androgens in avian eggs play a significant role in embryo and nestling development. However, few studies have examined the differential effect of two of the main yolk androgens, testosterone (T) and androstenedione (A4). Here, we injected eggs of spotless starlings with physiological levels of either T, A4, the combination T+A4 or vehicle substance (control), to examine the differential ability of these steroids to influence nestling development. We found that the duration of the embryonic period was increased by T, and less so by A4, but not by the combination T+A4. Body condition was reduced in all experimental treatments where A4 was present, particularly so in the combination T+A4. Tarsus length was increased in males by A4, and in a lower degree by T, whereas the combination T+A4 inhibited growth. However, these differences in tarsus length between groups disappeared at the end of the nestling period. Cell-mediated immune responsiveness was marginally affected by the interaction between treatment and sex. These patterns suggest that in this species, T has a stronger influence during embryo development than A4, whereas during nestling development the capacities of both androgens to influence growth are similar. The combination T+A4 showed non-additive effects, suggesting either some kind of inhibition between the two androgens, or else an excessive effect due to a bell-shaped pattern of response. Our results suggest a complex picture of sex and age-dependent effects of T and A4, and underline the necessity of further research in the metabolism and action of egg androgens.
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Affiliation(s)
- Jaime Muriel
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), José Gutiérrez Abascal 2, E-28006 Madrid, Spain.
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48
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Benowitz-Fredericks ZM, Hodge M. Yolk androstenedione in domestic chicks (Gallus gallus domesticus): uptake and sex-dependent alteration of growth and behavior. Gen Comp Endocrinol 2013; 193:48-55. [PMID: 23871777 DOI: 10.1016/j.ygcen.2013.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/01/2013] [Accepted: 07/04/2013] [Indexed: 11/22/2022]
Abstract
In birds, causes and consequences of variation in maternally-derived steroids in egg yolk have been the subject of intense experimentation. Many studies have quantified or manipulated testosterone ("T") and one of its immediate precursors, androstenedione ("A4") - often lumping the two steroids as "androgens" and treating them as functionally equivalent. However, yolk A4 is deposited in substantially higher concentrations than T, binds only weakly to the androgen receptor, and is readily converted into either T or estrone by steroidogenic enzymes present during embryonic development. Thus it may not be appropriate to assume that A4 has the same effect as T. In addition, A4's metabolic fate is likely to differ between females and males. The goals of this study were to examine the sex-specific uptake and metabolism of yolk A4 and consequences of elevated levels of yolk A4 on development and behavior of domestic chicks. Eggs were injected with 2μ Ci of tritiated androstenedione; radioactivity was detected in all tissues of day 7 and day 16 embryos and found in both aqueous and organics phases of day 7 yolk, with no difference between sexes. A second set of eggs was injected with 125ng of A4. A4 increased growth of morphological traits (tarsus, beak) in females, but not males. A4 males had smaller combs than controls; there was no treatment effect in females. A4 reduced tonic immobility behavior in both sexes. The results of this study illustrate the importance of distinguishing both between androgens and between sexes when investigating avian endocrine maternal effects.
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Rubolini D, Fusani L, Bonisoli-Alquati A, Canoine V, Caprioli M, Romano M, Ambrosini R, Dessì-Fulgheri F, Saino N. Effects of Egg and Circulating Testosterone on Ring-Necked Pheasant (Phasianus colchicus) Male Traits and Combat Outcome. Ethology 2013. [DOI: 10.1111/eth.12179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Diego Rubolini
- Dipartimento di Bioscienze; Università degli Studi di Milano; Milan Italy
| | - Leonida Fusani
- Dipartimento di Scienze della Vita e Biotecnologie; Università degli Studi di Ferrara; Ferrara Italy
| | | | - Virginie Canoine
- Department of Biological Sciences; University of South Carolina; Columbia SC USA
| | - Manuela Caprioli
- Dipartimento di Bioscienze; Università degli Studi di Milano; Milan Italy
| | - Maria Romano
- Dipartimento di Bioscienze; Università degli Studi di Milano; Milan Italy
| | - Roberto Ambrosini
- Dipartimento di Biotecnologie e Bioscienze; Università degli Studi di Milano-Bicocca; Milan Italy
| | | | - Nicola Saino
- Dipartimento di Bioscienze; Università degli Studi di Milano; Milan Italy
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50
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Treidel LA, Whitley BN, Benowitz-Fredericks ZM, Haussmann MF. Prenatal exposure to testosterone impairs oxidative damage repair efficiency in the domestic chicken (Gallus gallus). Biol Lett 2013; 9:20130684. [PMID: 24046877 DOI: 10.1098/rsbl.2013.0684] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Elevated levels of maternal androgens in avian eggs affect numerous traits, including oxidative stress. However, current studies disagree as to whether prenatal androgen exposure enhances or ameliorates oxidative stress. Here, we tested how prenatal testosterone exposure affects oxidative stress in female domestic chickens (Gallus gallus) during the known oxidative challenge of an acute stressor. Prior to incubation, eggs were either injected with an oil vehicle or 5 ng testosterone. At either 17 or 18 days post-hatch, several oxidative stress markers were assessed from blood taken before and after a 20 min acute stressor, as well as following a 25 min recovery from the stressor. We found that, regardless of yolk treatment, during both stress and recovery all individuals were in a state of oxidative stress, with elevated levels of oxidative damage markers accompanied by a reduced total antioxidant capacity. In addition, testosterone-exposed individuals exhibited poorer DNA damage repair efficiencies in comparison with control individuals. Our work suggests that while yolk androgens do not alter oxidative stress directly, they may impair mechanisms of oxidative damage repair.
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Affiliation(s)
- L A Treidel
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
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