1
|
Bókony V, Kalina C, Ujhegyi N, Mikó Z, Lefler KK, Vili N, Gál Z, Gabor CR, Hoffmann OI. Does stress make males? An experiment on the role of glucocorticoids in anuran sex reversal. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:172-181. [PMID: 38155497 DOI: 10.1002/jez.2772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 12/30/2023]
Abstract
Environmentally sensitive sex determination may help organisms adapt to environmental change but also makes them vulnerable to anthropogenic stressors, with diverse consequences for population dynamics and evolution. The mechanisms translating environmental stimuli to sex are controversial: although several fish experiments supported the mediator role of glucocorticoid hormones, results on some reptiles challenged it. We tested this hypothesis in amphibians by investigating the effect of corticosterone on sex determination in agile frogs (Rana dalmatina). This species is liable to environmental sex reversal whereby genetic females develop into phenotypic males. After exposing tadpoles during sex determination to waterborne corticosterone, the proportion of genetic females with testes or ovotestes increased from 11% to up to 32% at 3 out of 4 concentrations. These differences were not statistically significant except for the group treated with 10 nM corticosterone, and there was no monotonous dose-effect relationship. These findings suggest that corticosterone is unlikely to mediate sex reversal in frogs. Unexpectedly, animals originating from urban habitats had higher sex-reversal and corticosterone-release rates, reduced body mass and development speed, and lower survival compared to individuals collected from woodland habitats. Thus, anthropogenic environments may affect both sex and fitness, and the underlying mechanisms may vary across ectothermic vertebrates.
Collapse
Affiliation(s)
- Veronika Bókony
- Department of Evolutionary Ecology, Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
- Department of Zoology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Csenge Kalina
- Department of Zoology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Nikolett Ujhegyi
- Department of Evolutionary Ecology, Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Zsanett Mikó
- Department of Evolutionary Ecology, Plant Protection Institute, HUN-REN Centre for Agricultural Research, Budapest, Hungary
| | - Kinga Katalin Lefler
- Department of Aquaculture, Institute of Agricultural and Environmental Safety, Hungarian University of Agriculture and Life Science, Gödöllő, Hungary
| | - Nóra Vili
- Department of Zoology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Zoltán Gál
- Department of Animal Biotechnology, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Science, Gödöllő, Hungary
| | - Caitlin R Gabor
- Department of Biology, Texas State University, San Marcos, Texas, USA
| | - Orsolya Ivett Hoffmann
- Department of Animal Biotechnology, Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Science, Gödöllő, Hungary
| |
Collapse
|
2
|
MacLeod KJ, English S, Ruuskanen SK, Taborsky B. Stress in the social context: a behavioural and eco-evolutionary perspective. J Exp Biol 2023; 226:jeb245829. [PMID: 37529973 PMCID: PMC10445731 DOI: 10.1242/jeb.245829] [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] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
The social environment is one of the primary sources of challenging stimuli that can induce a stress response in animals. It comprises both short-term and stable interactions among conspecifics (including unrelated individuals, mates, potential mates and kin). Social stress is of unique interest in the field of stress research because (1) the social domain is arguably the most complex and fluctuating component of an animal's environment; (2) stress is socially transmissible; and (3) stress can be buffered by social partners. Thus, social interactions can be both the cause and cure of stress. Here, we review the history of social stress research, and discuss social stressors and their effects on organisms across early life and adulthood. We also consider cross-generational effects. We discuss the physiological mechanisms underpinning social stressors and stress responses, as well as the potential adaptive value of responses to social stressors. Finally, we identify outstanding challenges in social stress research, and propose a framework for addressing these in future work.
Collapse
Affiliation(s)
| | - Sinead English
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Suvi K. Ruuskanen
- Department of Biological and Environmental Science, University of Jyväskylä, Survontie 9 C, FI-40014, Finland
- Department of Biology, University of Turku, Turku, FI-20014, Finland
| | - Barbara Taborsky
- Division of Behavioural Biology, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland
- Institute for Advanced Study, 14193 Berlin, Germany
| |
Collapse
|
3
|
Le Gal AS, Priol P, Georges JY, Verneau O. Population structure and dynamics of the Mediterranean Pond turtle Mauremys leprosa (Schweigger, 1812) in contrasted polluted aquatic environments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 330:121746. [PMID: 37137405 DOI: 10.1016/j.envpol.2023.121746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/18/2023] [Accepted: 04/28/2023] [Indexed: 05/05/2023]
Abstract
Pollution contributes to the degraded state of continental aquatic ecosystems and biodiversity. Some species appear to be tolerant to aquatic pollution, yet little is known about the effects of such pollution on population structure and dynamics. Here, we investigated how wastewater treatment plant (WWTP) effluents of the Cabestany City, in southern France, contribute to the pollution levels of the Fosseille River, and we tested how they could affect population structure and medium-term dynamics of the native freshwater turtle, the Mediterranean Pond Turtle Mauremys leprosa (Schweigger, 1812). Amongst the 68 pesticides surveyed from water samples collected along the river in 2018 and 2021, a total of 16 pesticides were detected, among which eight were found in the upstream section of the river, 15 in the river section located downstream of the WWTP, and 14 in the outfall of the WWTP, exhibiting the contribution of effluents to the river pollution. From 2013 to 2018 and in 2021, capture-mark-recapture protocols were carried out on the freshwater turtle population living in the river. Using robust design and multi-state models, we showed a stable population throughout the study period, with high year-dependent seniority, and a bidirectional transition occurring primarily from the upstream to the downstream river sections of the WWTP. The freshwater turtle population consisted mostly of adults, with a male biased sex ratio detected downstream of the WWTP neither related to sex-dependent survival, recruitment, nor transition, suggesting a male bias in the hatchlings or primary sex ratio. Also, the largest immatures and females were captured downstream of the WWTP, with females having the highest body condition, whereas no such differences were observed in males. This study highlights that population functioning of M. leprosa is driven primarily by effluents induced resources, at least over the medium-term.
Collapse
Affiliation(s)
- Anne-Sophie Le Gal
- Université de Perpignan Via Domitia, Centre de Formation et de Recherche sur Les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, F-66860, Perpignan Cedex, France; CNRS, Centre de Formation et de Recherche sur Les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, F-66860, Perpignan Cedex, France; Université de Strasbourg, CNRS, IPHC, UMR 7178, 23 Rue Du Lœss, 67000, Strasbourg, France.
| | - Pauline Priol
- StatiPop, Scientific Consulting, 34190, Cazilhac, France
| | - Jean-Yves Georges
- Université de Strasbourg, CNRS, IPHC, UMR 7178, 23 Rue Du Lœss, 67000, Strasbourg, France
| | - Olivier Verneau
- Université de Perpignan Via Domitia, Centre de Formation et de Recherche sur Les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, F-66860, Perpignan Cedex, France; CNRS, Centre de Formation et de Recherche sur Les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, F-66860, Perpignan Cedex, France; Unit for Environmental Sciences and Management, North-West University, Potchefstroom Campus, Private Bag X6001, 20520, Potchefstroom, South Africa
| |
Collapse
|
4
|
Goikoetxea A, Todd EV, Muncaster S, Lokman PM, Thomas JT, Robertson HA, De Farias e Moraes CE, Gemmell NJ. Effects of cortisol on female-to-male sex change in a wrasse. PLoS One 2022; 17:e0273779. [PMID: 36048785 PMCID: PMC9436091 DOI: 10.1371/journal.pone.0273779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
Sex change occurs as a usual part of the life cycle for many teleost fish and the modifications involved (behavioural, gonadal, morphological) are well studied. However, the mechanism that transduces environmental cues into the molecular cascade that underlies this transformation remains unknown. Cortisol, the main stress hormone in fish, is hypothesised to be a key factor linking environmental stimuli with sex change by initiating gene expression changes that shift steroidogenesis from oestrogens to androgens but this notion remains to be rigorously tested. Therefore, this study aimed to experimentally test the role of cortisol as an initiator of sex change in a protogynous (female-to-male) hermaphrodite, the New Zealand spotty wrasse (Notolabrus celidotus). We also sought to identify potential key regulatory factors within the head kidney that may contribute to the initiation and progression of gonadal sex change. Cortisol pellets were implanted into female spotty wrasses under inhibitory conditions (presence of a male), and outside of the optimal season for natural sex change. Histological analysis of the gonads and sex hormone analyses found no evidence of sex change after 71 days of cortisol treatment. However, expression analyses of sex and stress-associated genes in gonad and head kidney suggested that cortisol administration did have a physiological effect. In the gonad, this included upregulation of amh, a potent masculinising factor, and nr3c1, a glucocorticoid receptor. In the head kidney, hsd11b2, which converts cortisol to inactive cortisone to maintain cortisol balance, was upregulated. Overall, our results suggest cortisol administration outside of the optimal sex change window is unable to initiate gonadal restructuring. However, our expression data imply key sex and stress genes are sensitive to cortisol. This includes genes expressed in both gonad and head kidney that have been previously implicated in early sex change in several sex-changing species.
Collapse
Affiliation(s)
- Alexander Goikoetxea
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- * E-mail:
| | - Erica V. Todd
- School of Life and Environmental Sciences, Deakin University, Geelong, Australia
| | - Simon Muncaster
- Environmental Management Group, Toi Ohomai Institute of Technology, Tauranga, New Zealand
- School of Science, University of Waikato, Tauranga, New Zealand
| | - P. Mark Lokman
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Jodi T. Thomas
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Holly A. Robertson
- Environmental Management Group, Toi Ohomai Institute of Technology, Tauranga, New Zealand
| | | | - Neil J. Gemmell
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| |
Collapse
|
5
|
Goikoetxea A, Servili A, Houdelet C, Mouchel O, Hermet S, Clota F, Aerts J, Fernandino JI, Allal F, Vandeputte M, Blondeau-Bidet E, Geffroy B. Natural cortisol production is not linked to the sexual fate of European sea bass. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:1117-1135. [PMID: 35917042 DOI: 10.1007/s10695-022-01104-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
In this study, we aimed to investigate the relationship between cortisol and the determination of sexual fate in the commercially important European sea bass (Dicentrarchus labrax). To test our hypothesis, we designed two temperature-based experiments (19 ℃, 21 ℃ and 23 ℃, experiment 1; 16 ℃ and 21 ℃, experiment 2) to assess the effects of these thermal treatments on European sea bass sex determination and differentiation. In the fish from the first experiment, we evaluated whether blood cortisol levels and expression of stress key regulatory genes were different between differentiating (149 to 183 dph) males and females. In the second experiment, we assessed whether cortisol accumulated in scales over time during the labile period for sex determination as well as the neuroanatomical localisation of brain cells expressing brain aromatase (cyp19a1b) and corticotropin-releasing factor (crf) differed between males and females undergoing molecular sex differentiation (117 to 124 dph). None of the gathered results allowed to detect differences between males and females regarding cortisol production and regulatory mechanisms. Altogether, our data provide strong physiological, molecular and histochemical evidence, indicating that in vivo cortisol regulation has no major effects on the sex of European sea bass.
Collapse
Affiliation(s)
| | - Arianna Servili
- Ifremer, IFREMER, Univ Brest, CNRS, IRD, LEMAR, 29280, Plouzané, France
| | - Camille Houdelet
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France
| | - Olivier Mouchel
- Ifremer, IFREMER, Univ Brest, CNRS, IRD, LEMAR, 29280, Plouzané, France
| | - Sophie Hermet
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Montpellier, France
| | - Fréderic Clota
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | - Johan Aerts
- Stress Physiology Research Group, Faculty of Sciences, Ghent University, Ostend, Belgium
| | | | - François Allal
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France
| | - Marc Vandeputte
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | | | - Benjamin Geffroy
- MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France
| |
Collapse
|
6
|
Josimovich JM, Falk BG, Grajal-Puche A, Hanslowe EB, Bartoszek IA, Reed RN, Currylow AF. Clutch may predict growth of hatchling Burmese pythons better than food availability or sex. Biol Open 2021; 10:273482. [PMID: 34796905 PMCID: PMC8609237 DOI: 10.1242/bio.058739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 10/21/2021] [Indexed: 12/20/2022] Open
Abstract
Identifying which environmental and genetic factors affect growth pattern phenotypes can help biologists predict how organisms distribute finite energy resources in response to varying environmental conditions and physiological states. This information may be useful for monitoring and managing populations of cryptic, endangered, and invasive species. Consequently, we assessed the effects of food availability, clutch, and sex on the growth of invasive Burmese pythons (Python bivittatus Kuhl) from the Greater Everglades Ecosystem in Florida, USA. Though little is known from the wild, Burmese pythons have been physiological model organisms for decades, with most experimental research sourcing individuals from the pet trade. Here, we used 60 hatchlings collected as eggs from the nests of two wild pythons, assigned them to High or Low feeding treatments, and monitored growth and meal consumption for 12 weeks, a period when pythons are thought to grow very rapidly. None of the 30 hatchlings that were offered food prior to their fourth week post-hatching consumed it, presumably because they were relying on internal yolk stores. Although only two clutches were used in the experiment, we found that nearly all phenotypic variation was explained by clutch rather than feeding treatment or sex. Hatchlings from clutch 1 (C1) grew faster and were longer, heavier, in better body condition, ate more frequently, and were bolder than hatchlings from clutch 2 (C2), regardless of food availability. On average, C1 and C2 hatchling snout-vent length (SVL) and weight grew 0.15 cm d−1 and 0.10 cm d−1, and 0.20 g d−1 and 0.03 g d−1, respectively. Additional research may be warranted to determine whether these effects remain with larger clutch sample sizes and to identify the underlying mechanisms and fitness implications of this variation to help inform risk assessments and management. This article has an associated First Person interview with the first author of the paper. Summary: Hatchling pythons from an invasive population displayed substantial phenotypic variation in morphometrics, growth rates, and behaviors. This information may be useful for managing populations of cryptic, endangered, and invasive species.
Collapse
Affiliation(s)
- Jillian M Josimovich
- U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA
| | - Bryan G Falk
- U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA
| | - Alejandro Grajal-Puche
- U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA
| | - Emma B Hanslowe
- U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA
| | | | - Robert N Reed
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO 80526, USA
| | - Andrea F Currylow
- U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station, 40001 SR 9336, Homestead, FL 33034, USA
| |
Collapse
|
7
|
MacLeod KJ, Langkilde T, Heppner JJ, Howey CAF, Sprayberry K, Tylan C, Sheriff MJ. Compensating for a stressful pregnancy? Glucocorticoid treatment during gravidity reduces metabolic rate in female fence lizards post-parturition. Horm Behav 2021; 136:105072. [PMID: 34628291 DOI: 10.1016/j.yhbeh.2021.105072] [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: 12/14/2020] [Revised: 07/26/2021] [Accepted: 09/23/2021] [Indexed: 11/23/2022]
Abstract
Reproduction is a critical part of an animal's life history, but one which incurs significant costs to survival and future reproductive potential. These physiological consequences are likely to be influenced by context - for example, if an individual is subject to environmental stressors, physiological and behavioral changes associated with reproduction may be altered. Glucocorticoids, hormones produced as part of the physiological response to stressors, may alter how reproduction affects female physiology and behavior, and therefore the outcomes of reproductive trade-offs. Glucocorticoids prioritize immediate survival over reproduction, for example through changes in immune function, metabolic rate, and foraging, which may reduce energy expenditure or increase energy gain. However, we previously found that female eastern fence lizards (Sceloporus undulatus) experiencing elevated glucocorticoid levels during gestation were nevertheless able to maintain reproductive output and body condition. Here we investigate compensatory mechanisms by which eastern fence lizard females may maintain reproduction under experimental increases in a glucocorticoid, corticosterone (CORT). We found that, although CORT-treated females had similar immune function and behavior, they had reduced metabolic rates 3-5 days post-parturition compared to control females. Given that CORT-treated females spent a similar time basking and had equal food intake compared to control females, we suggest that the reduced metabolic rate is a mechanism by which CORT-treated females maintain their energy balance and reduce the energetic costs of gestation during periods of stress. This study suggests that physiological responses to reproduction may be context-dependent and could act to minimize costs of reproduction in situations where CORT is elevated (such as during periods of environmental stress).
Collapse
Affiliation(s)
- K J MacLeod
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA; Department of Biology, Lund University, Sölvegatan 37, Lund 223 62, Sweden.
| | - T Langkilde
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA
| | - J J Heppner
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Department of Biology, University of Nevada, Reno, Reno, NV 89557, USA
| | - C A F Howey
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA; Department of Biology, University of Scranton, Loyola Science Center, Scranton, PA 18510, USA
| | - K Sprayberry
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA
| | - C Tylan
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA
| | - M J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Biology Department, University of Massachusetts Dartmouth, Dartmouth, MA 02747, USA
| |
Collapse
|
8
|
Ensminger DC, Siegel SR, Owen DAS, Sheriff MJ, Langkilde T. Elevated glucocorticoids during gestation suggest sex-specific effects on offspring telomere lengths in a wild lizard. Comp Biochem Physiol A Mol Integr Physiol 2021; 257:110971. [PMID: 33933630 DOI: 10.1016/j.cbpa.2021.110971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 04/06/2021] [Accepted: 04/26/2021] [Indexed: 12/30/2022]
Abstract
The effects of maternal glucocorticoids (e.g. corticosterone, CORT) on offspring interest biologists due to increasing environmental perturbations. While little is known about the impact of maternal CORT on offspring fitness, it may modulate telomere length and compromise offspring health. Here, we use a modified real-time quantitative PCR assay to assess telomere length using small DNA quantities (<60 ng). We tested the hypothesis that increased maternal CORT during gestation decreases offspring telomere length. While CORT-driven telomere shortening is well established within individuals, cross-generational effects remain unclear. We treated wild-caught gravid female eastern fence lizards (Sceloporus undulatus) with daily transdermal applications of CORT, at ecologically relevant levels, from capture to laying. Maternal CORT treatment did not alter maternal telomere length, although baseline maternal CORT concentrations had a weak, negative correlation with maternal telomere length. There was no relation between mother and offspring telomere length. There was a trend for maternal CORT treatment to shorten telomeres of sons but not daughters. Our treatment replicated exposure to a single stressor per day, likely underestimating effects seen in the wild where stressors may be more frequent. Future research should further explore fitness consequences of maternal CORT effects.
Collapse
Affiliation(s)
- David C Ensminger
- Department of Ecosystem Science and Management, The Pennsylvania State University, Forest Resources Building, University Park, PA 16802, United States of America; Department of Biology, The Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, United States of America.
| | - Sue R Siegel
- Department of Biobehavioral Health, The Pennsylvania State University, Biomarker Core Lab, University Park, PA 16802, United States of America
| | - Dustin A S Owen
- Department of Ecosystem Science and Management, The Pennsylvania State University, Forest Resources Building, University Park, PA 16802, United States of America; Department of Biology, The Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, United States of America; Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Michael J Sheriff
- Biology Department, University of Massachusetts Dartmouth, Dartmouth, MA 02747, United States of America
| | - Tracy Langkilde
- Department of Biology, The Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, United States of America; Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802, United States of America
| |
Collapse
|
9
|
Bowden RM, Paitz RT. Is Thermal Responsiveness Affected by Maternal Estrogens in Species with Temperature-Dependent Sex Determination? Sex Dev 2021; 15:69-79. [PMID: 33902053 DOI: 10.1159/000515187] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/17/2021] [Indexed: 11/19/2022] Open
Abstract
In species with temperature-dependent sex determination (TSD), incubation temperatures regulate the expression of genes involved in gonadal differentiation and determine whether the gonads develop into ovaries or testes. For most species, natural incubation conditions result in transient exposure to thermal cues for both ovarian and testis development, but how individuals respond to this transient exposure varies and can drive variation in the resulting sex ratios. Here, we argue that variation in the timing to respond to temperature cues, or thermal responsiveness, is a trait needing further study. Recent work in the red-eared slider turtle (Trachemys scripta) has found that when embryos experience transient exposure to warm conditions (i.e., heatwaves), some embryos show high responsiveness, requiring only short exposures to commit to ovarian development, while others show low responsiveness, developing testes even after more extended exposures to warm conditions. We discuss how maternal estrogens might influence thermal responsiveness for organisms that develop under thermal fluctuations. Examining the interplay of molecular responses to more subtle thermal and endocrine environments may reveal significant insights into the process of sex determination in species with TSD.
Collapse
Affiliation(s)
- Rachel M Bowden
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Ryan T Paitz
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| |
Collapse
|
10
|
Hao X, Zou TT, Han XZ, Zhang FS, Du WG. Grow fast but don't die young: Maternal effects mediate life-history trade-offs of lizards under climate warming. J Anim Ecol 2021; 90:1550-1559. [PMID: 33713452 DOI: 10.1111/1365-2656.13475] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/16/2021] [Indexed: 11/28/2022]
Abstract
As postulated by life-history theory, not all life-history traits can be maximized simultaneously. In ectothermic animals, climate warming is predicted to increase growth rates, but at a cost to overall life span. Maternal effects are expected to mediate this life-history trade-off, but such effects have not yet been explicitly elucidated. To understand maternal effects on the life-history responses to climate warming in lizard offspring, we conducted a manipulative field experiment on a desert-dwelling viviparous lacertid lizard Eremias multiocellata, using open-top chambers in a factorial design (maternal warm climate and maternal present climate treatments × offspring warm climate and offspring present climate treatments). We found that the maternal warm climate treatment had little impact on the physiological and life-history traits of adult females (i.e. metabolic rate, reproductive output, growth and survival). However, the offspring warm climate treatment significantly affected offspring growth, and both maternal and offspring warm climate treatments interacted to affect offspring survival. Offspring from the warm climate treatment grew faster than those from the present climate treatment. However, the offspring warm climate treatment significantly decreased the survival rate of offspring from maternal present climate treatment, but not for those from the maternal warm climate treatment. Our study demonstrates that maternal effects mediate the trade-off between growth and survival of offspring lizards, allowing them to grow fast without a concurrent cost of low survival rate (short life span). These findings stress the importance of adaptive maternal effects in buffering the impact of climate warming on organisms, which may help us to accurately predict the vulnerability of populations and species to future warming climates.
Collapse
Affiliation(s)
- Xin Hao
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ting-Ting Zou
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xing-Zhi Han
- College of Wildlife Resources, Northeast Forestry University, Harbin, China
| | - Fu-Shun Zhang
- Institute of Grassland Research, Chinese Academy of Agriculture Sciences, Huhhot, China
| | - Wei-Guo Du
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| |
Collapse
|
11
|
Liu G, Cain K, Schwanz L. Maternal Temperature, Corticosterone, and Body Condition as Mediators of Maternal Effects in Jacky Dragons ( Amphibolurus muricatus). Physiol Biochem Zool 2021; 93:434-449. [PMID: 33104412 DOI: 10.1086/711955] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractTemperature is a crucial environmental component that imposes physiological constraints and ultimately produces variation in life-history traits. Temperatures experienced by mothers can influence offspring phenotypes, including growth and sex ratios, especially in ectothermic species. However, mechanisms by which thermal information can be passed onto offspring have been underexplored. Here, we investigated corticosterone as a potential mediator of thermal maternal effects. We held female jacky dragons (Amphibolurus muricatus) in two different thermal regimes (short [7 h] or long [11 h] basking treatments), then quantified plasma corticosterone levels and tested for correlations between the resulting corticosterone levels and reproductive outputs. Lizards in the long-bask treatment had significantly higher corticosterone levels than those in the short-bask treatment. Maternal corticosterone, in turn, had sex-dependent effects on offspring hatching size but was not associated with maternal reproductive effort or offspring sex or growth. In contrast, maternal body condition was strongly positively related to both reproductive output (including clutch size and total number of eggs) and offspring size at hatching but had no effect on offspring growth. Basking treatment also interacted with condition and corticosterone to affect egg mass and hatchling snout-vent length, respectively. When we tested for relationships between corticosterone levels and body condition, we found corticosterone to be negatively related to condition in long-bask lizards but only in the postbreeding season. These findings indicate that thermal opportunity alters physiology, with potential consequences for fitness. Moreover, the results suggest interactive influences of temperature, corticosterone, and condition as mediators of maternal effects.
Collapse
|
12
|
Castelli M, Georges A, Holleley CE. Corticosterone does not have a role in temperature sex reversal in the central bearded dragon (Pogona vitticeps). JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:301-310. [PMID: 33411403 DOI: 10.1002/jez.2441] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 11/30/2020] [Accepted: 12/18/2020] [Indexed: 12/29/2022]
Abstract
Environmental sex determination (ESD) is common among ectothermic vertebrates. The stress axis and production of stress hormones (corticosteroids) regulates ESD in fish, but evidence of a similar influence in reptiles is sparse and conflicting. The central bearded dragon (Pogona vitticeps) has a system of sex determination involving the interplay between sex chromosomes (ZZ/ZW female heterogamety) and the thermal environment. High egg incubation temperatures induce sex reversal of the ZZ genotype, feminizing chromosomally male individuals. Here we show that corticosterone elevation is not associated with sex reversal in the central bearded dragon, either during embryonic development or adulthood. We also demonstrate experimentally that sex determination is not affected by corticosterone injection into the yolk. This strongly suggests that stress axis upregulation by high temperature during incubation does not cause sex reversal in P. vitticeps. Our work is in general agreement with other research in reptiles, which suggests that the stress axis does not mediate sex in reptiles with ESD. Alternative biological systems may be responsible for capturing environmental conditions during reptile development, such as cellular calcium and redox regulation or the action of temperature-sensitive splicing factors.
Collapse
Affiliation(s)
- Meghan Castelli
- Institute for Applied Ecology, University of Canberra, Canberra, Australia.,Australian National Wildlife Collection, CSIRO, Canberra, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australia
| | - Clare E Holleley
- Institute for Applied Ecology, University of Canberra, Canberra, Australia.,Australian National Wildlife Collection, CSIRO, Canberra, Australia
| |
Collapse
|
13
|
Abstract
AbstractEvolution of adaptation requires predictability and recurrence of functional contexts. Yet organisms live in multifaceted environments that are dynamic and ever changing, making it difficult to understand how complex adaptations evolve. This problem is particularly apparent in the evolution of adaptive maternal effects, which are often assumed to require reliable and discrete cues that predict conditions in the offspring environment. One resolution to this problem is if adaptive maternal effects evolve through preexisting, generalized maternal pathways that respond to many cues and also influence offspring development. Here, we assess whether an adaptive maternal effect in western bluebirds is influenced by maternal stress pathways across multiple challenging environments. Combining 18 years of hormone sampling across diverse environmental contexts with an experimental manipulation of the competitive environment, we show that multiple environmental factors influenced maternal corticosterone levels, which, in turn, influenced a maternal effect on aggression of sons in adulthood. Together, these results support the idea that multiple stressors can induce a known maternal effect in this system. More generally, they suggest that activation of general pathways, such as the hypothalamic-pituitary-adrenal axis, may simplify and facilitate the evolution of adaptive maternal effects by integrating variable environmental conditions into preexisting maternal physiological systems.
Collapse
|
14
|
Straková B, Rovatsos M, Kubička L, Kratochvíl L. Evolution of Sex Determination in Amniotes: Did Stress and Sequential Hermaphroditism Produce Environmental Determination? Bioessays 2020; 42:e2000050. [DOI: 10.1002/bies.202000050] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 07/15/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Barbora Straková
- Department of Ecology, Faculty of Science Charles University Viničná 7 Praha 2 12844 Czech Republic
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science Charles University Viničná 7 Praha 2 12844 Czech Republic
| | - Lukáš Kubička
- Department of Ecology, Faculty of Science Charles University Viničná 7 Praha 2 12844 Czech Republic
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science Charles University Viničná 7 Praha 2 12844 Czech Republic
| |
Collapse
|
15
|
Murphy KM, Radder RS, Shine R, Warner DA. Lizard Embryos Prioritize Posthatching Energy Reserves over Increased Hatchling Body Size during Development. Physiol Biochem Zool 2020; 93:339-346. [PMID: 32692615 DOI: 10.1086/710053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Embryonic development in oviparous organisms is fueled by maternally allocated yolk, and many organisms hatch before that energy store is used completely; the resultant leftover (residual) yolk is internalized and may support early posthatching life. However, embryos that use most, or all, of their yolk supply before hatching should hatch at a larger size than those that do not exhaust those energy reserves, which could also have benefits for posthatching growth and survival. To examine the trade-off between residual yolk and offspring size, we experimentally reduced yolk quantity at oviposition in lizard eggs (Amphibolurus muricatus) and then quantified offspring size and the amount of internalized residual yolk. This design enabled us to determine whether embryos (1) exhaust yolk supply during development (thereby maximizing neonatal size) or (2) reduce neonatal size by retaining yolk reserves at hatching. Our data support the latter scenario. Eggs from the yolk-reduced treatment produced smaller offspring with a proportion of residual yolk similar to that of offspring from unmanipulated eggs, suggesting that the fitness benefits of posthatching energy stores outweigh those of larger neonatal size.
Collapse
|
16
|
Hara S, Furukawa F, Mukai K, Yazawa T, Kitano T. Peroxisome proliferator-activated receptor alpha is involved in the temperature-induced sex differentiation of a vertebrate. Sci Rep 2020; 10:11672. [PMID: 32669596 PMCID: PMC7363821 DOI: 10.1038/s41598-020-68594-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 06/30/2020] [Indexed: 11/09/2022] Open
Abstract
Medaka (Oryzias latipes) is a teleost fish with an XX/XY sex determination system, similar to that of mammals. However, under high temperature conditions, XX medaka is masculinised by elevation of cortisol, the major teleost glucocorticoid. In this study, to identify novel factors in the gonads acting downstream from cortisol during sexual differentiation, we performed RNA sequencing (RNA-seq) analysis using the gonadal regions of larvae reared at normal temperature with and without cortisol, and at high temperature. The RNA-seq and real-time PCR analyses showed that expression of some peroxisome proliferator-activated receptor α (PPARα) signalling-targeted genes was increased by cortisol. PPARα agonist treatment induced masculinisation of XX medaka in some cases, and co-treatment of the agonist with cortisol further induced masculinisation, whereas treatment of pparaa knockout medaka with cortisol or the agonist did not induce masculinisation. This study provides the first evidence that PPARα is involved in environmental sex determination in vertebrates.
Collapse
Affiliation(s)
- Seiji Hara
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Fumiya Furukawa
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Koki Mukai
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Takashi Yazawa
- Department of Biochemistry, Asahikawa Medical University, Asahikawa, Hokkaido, 078-8510, Japan
| | - Takeshi Kitano
- Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.
| |
Collapse
|
17
|
Castelli MA, Whiteley SL, Georges A, Holleley CE. Cellular calcium and redox regulation: the mediator of vertebrate environmental sex determination? Biol Rev Camb Philos Soc 2020; 95:680-695. [DOI: 10.1111/brv.12582] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Meghan A. Castelli
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Sarah L. Whiteley
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Arthur Georges
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Clare E. Holleley
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| |
Collapse
|
18
|
Dupoué A, Lourdais O, Meylan S, Brischoux F, Angelier F, Rozen‐Rechels D, Marcangeli Y, Decencière B, Agostini S, Le Galliard J. Some like it dry: Water restriction overrides heterogametic sex determination in two reptiles. Ecol Evol 2019; 9:6524-6533. [PMID: 31236241 PMCID: PMC6580259 DOI: 10.1002/ece3.5229] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 03/29/2019] [Accepted: 04/13/2019] [Indexed: 01/02/2023] Open
Abstract
ABSTRACT The evolution of sex determination is complex and yet crucial in our understanding of population stability. In ectotherms, sex determination involves a variety of mechanisms including genetic determination (GSD), environment determination (ESD), but also interactions between the two via sex reversal. In this study, we investigated whether water deprivation during pregnancy could override GSD in two heterogametic squamate reptiles. We demonstrated that water restriction in early gestation induced a male-biased secondary sex ratio in both species, which could be explained by water sex reversal as the more likely mechanism. We further monitored some long-term fitness estimates of offspring, which suggested that water sex determination (WSD) represented a compensatory strategy producing the rarest sex according to Fisher's assumptions of frequency-dependent selection models. This study provides new insights into sex determination modes and calls for a general investigation of mechanisms behind WSD and to examine the evolutionary implications. OPEN RESEARCH BADGES This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://doi.org/10.5061/dryad.mv06pv1.
Collapse
Affiliation(s)
- Andréaz Dupoué
- Station d'Ecologie Théorique et Expérimentale de MoulisCNRSUMR 5321Saint GironsFrance
| | - Olivier Lourdais
- Centre d'Etudes Biologiques de ChizeULR CNRSUMR 7372Beauvoir sur NiortFrance
| | - Sandrine Meylan
- iEES Paris, Sorbonne Université, CNRS, UMR 7618ParisFrance
- ESPE de ParisSorbonne UniversitéParisFrance
| | - François Brischoux
- Centre d'Etudes Biologiques de ChizeULR CNRSUMR 7372Beauvoir sur NiortFrance
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de ChizeULR CNRSUMR 7372Beauvoir sur NiortFrance
| | | | | | - Béatriz Decencière
- Département de biologie, Centre de recherche en écologie expérimentale et prédictive (CEREEP‐Ecotron IleDeFrance)Ecole normale supérieure, PSL Research University, CNRSSaint‐Pierre‐lès‐NemoursFrance
| | - Simon Agostini
- Département de biologie, Centre de recherche en écologie expérimentale et prédictive (CEREEP‐Ecotron IleDeFrance)Ecole normale supérieure, PSL Research University, CNRSSaint‐Pierre‐lès‐NemoursFrance
| | - Jean‐François Le Galliard
- iEES Paris, Sorbonne Université, CNRS, UMR 7618ParisFrance
- Département de biologie, Centre de recherche en écologie expérimentale et prédictive (CEREEP‐Ecotron IleDeFrance)Ecole normale supérieure, PSL Research University, CNRSSaint‐Pierre‐lès‐NemoursFrance
| |
Collapse
|
19
|
The Adaptive Sex in Stressful Environments. Trends Ecol Evol 2019; 34:628-640. [PMID: 30952545 DOI: 10.1016/j.tree.2019.02.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/18/2019] [Accepted: 02/19/2019] [Indexed: 01/10/2023]
Abstract
The impact of early stress on juvenile development has intrigued scientists for decades, but the adaptive significance of such effects remains an ongoing debate. This debate has largely ignored some characteristics of the offspring, such as their sex, despite strong evolutionary and demographic implications of sex-ratio variation. We review recent studies that examine associations between glucocorticoids (GCs), the main class of stress hormones, and offspring sex. Whereas exposure to GCs at around the time of sex determination in fish consistently produces males, the extent and direction of sex-ratio bias in response to stress vary in reptiles, birds, and mammals. We propose proximate and ultimate explanations for most of these trends.
Collapse
|
20
|
Ensminger DC, Langkilde T, Owen DAS, MacLeod KJ, Sheriff MJ. Maternal stress alters the phenotype of the mother, her eggs and her offspring in a wild-caught lizard. J Anim Ecol 2018; 87:1685-1697. [PMID: 30074248 DOI: 10.1111/1365-2656.12891] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/22/2018] [Indexed: 01/05/2023]
Abstract
While biomedical researchers have long appreciated the influence of maternally derived glucocorticoids (GCs) on offspring phenotype, ecologists have only recently begun exploring its impact in wild animals. Interpreting biomedical findings within an ecological context has posited that maternal stress, mediated by elevations of maternal GCs, may play an adaptive role preparing offspring for a stressful or rigorous environment. Yet, the influence of maternal stress on offspring phenotype has been little studied in wild animals. We experimentally elevated GCs to ecologically relevant levels (mimicking increases in maternal stress hormones following a nonlethal predator encounter, a heat challenge, or a chasing or confinement stressor) in female eastern fence lizards Sceloporus undulatus during gestation. We tested the hypothesis that maternally derived stress hormones themselves are sufficient to alter offspring phenotype. Specifically, we examined the effects of experimentally elevated maternal GCs on fitness-relevant traits of the mother, her eggs and her subsequent offspring. We found that daily maternal GC elevation: (a) increased maternal antipredator behaviours and postlaying glucose levels; (b) had no effect on egg morphology or caloric value, but altered yolk hormone (elevated GC) and nutrient content; and (c) altered offspring phenotype including stress-relevant physiology, morphology and behaviour. These findings reveal that maternally derived GCs alone can alter offspring phenotype in a wild animal, changes that may be mediated via maternal behaviour, and egg hormone and nutrient content. Understanding the ecological consequences of these effects under different environmental conditions will be critical for determining the adaptive significance of elevated maternal GCs for offspring.
Collapse
Affiliation(s)
- David C Ensminger
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Tracy Langkilde
- Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Dustin A S Owen
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Kirsty J MacLeod
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Michael J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| |
Collapse
|
21
|
Sex‐dependent effects of maternal stress: Stressed moms invest less in sons than daughters. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:317-322. [DOI: 10.1002/jez.2192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 05/22/2018] [Accepted: 05/24/2018] [Indexed: 12/29/2022]
|
22
|
While GM, Noble DW, Uller T, Warner DA, Riley JL, Du W, Schwanz LE. Patterns of developmental plasticity in response to incubation temperature in reptiles. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:162-176. [DOI: 10.1002/jez.2181] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/16/2018] [Accepted: 05/07/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Geoffrey M. While
- School of Biological Sciences University of Tasmania Hobart Australia
| | - Daniel W.A. Noble
- Evolution & Ecology Research Centre School of Biological, Earth, and Environmental Sciences University of New South Wales Sydney Australia
| | - Tobias Uller
- Department of Biology Lund University Lund Sweden
| | - Daniel A. Warner
- Department of Biological Sciences Auburn University Auburn Alabama
| | - Julia L. Riley
- Evolution & Ecology Research Centre School of Biological, Earth, and Environmental Sciences University of New South Wales Sydney Australia
- Department of Biological Sciences Macquarie University Sydney Australia
| | - Wei‐Guo Du
- Institute of Zoology Chinese Academy of Sciences Beijing China
| | - Lisa E. Schwanz
- Evolution & Ecology Research Centre School of Biological, Earth, and Environmental Sciences University of New South Wales Sydney Australia
| |
Collapse
|
23
|
|
24
|
Warner DA, Mitchell TS, Bodensteiner BL, Janzen FJ. The effect of hormone manipulations on sex ratios varies with environmental conditions in a turtle with temperature-dependent sex determination. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 327:172-181. [PMID: 29356364 DOI: 10.1002/jez.2085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 06/27/2017] [Indexed: 02/03/2023]
Abstract
Exogenous application of steroids and related substances to eggs affects offspring sex ratios in species with temperature-dependent sex determination (TSD). Laboratory studies demonstrate that this effect is most pronounced near the constant temperature that produces 1:1 sex ratios (i.e., pivotal temperature). However, the impact of such chemicals on sex determination under natural nest temperatures (which fluctuate daily) is unknown, but could provide insight into the relative contributions of these two factors under natural conditions. We applied estradiol (E2) and an aromatase inhibitor (fadrozole) to eggs of the painted turtle (Chrysemys picta), a species with TSD, and allowed eggs to incubate under natural conditions during two field seasons (in 2012 and 2013). Exogenous E2, fadrozole, and nest temperature contributed to variation in offspring sex ratio, but the relative contributions of these factors differed between years. In 2012, a much hotter than average season, sex ratios were heavily female biased regardless of nest temperature and chemical treatment. However, in 2013, a milder season, both nest temperature and chemical treatment were important. Moreover, a significant interaction between nest temperature and treatment demonstrated that exogenous estradiol induces female development regardless of nest temperature, but aromatase inhibition widens the range of temperatures that produces both sexes.
Collapse
Affiliation(s)
- Daniel A Warner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa.,Department of Biological Sciences, Auburn University, Auburn, Alabama
| | - Timothy S Mitchell
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa.,Department of Biological Sciences, Auburn University, Auburn, Alabama
| | - Brooke L Bodensteiner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa
| | - Fredric J Janzen
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa
| |
Collapse
|
25
|
Polich RL, Bodensteiner BL, Adams CIM, Janzen FJ. Effects of augmented corticosterone in painted turtle eggs on offspring development and behavior. Physiol Behav 2018; 183:1-9. [PMID: 29031544 DOI: 10.1016/j.physbeh.2017.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/31/2017] [Accepted: 10/04/2017] [Indexed: 01/09/2023]
Abstract
Maternal stressors can play an integral role in offspring development and ultimate behaviors in many vertebrates. Increased circulating stress avoidance hormones can be reflected in elevated concentrations in ova, thus providing a potential mechanism for maternal stress to be transmitted to offspring even in taxa without parental care. In this study, we assessed the potential impacts of augmented stress avoidance hormones on offspring development and anti-predator behaviors in a freshwater turtle, Chrysemys picta. We exposed C. picta eggs to biologically relevant amounts of the stress avoidance hormone, corticosterone, as a proxy for maternal stressors. We allowed the eggs to incubate in the field, then measured offspring phenotypes, conducted performance trials, and simulated nest emergence in a field experiment. Exogenous corticosterone reduced survivorship to hatch, but did not affect incubation duration, offspring size, overwinter survival, or size after hibernation. In performance trials, this hormone treatment reduced the frequency of righting, yet enhanced the righting speed of neonates. Regardless, these performance differences did not detectably alter survivorship in the nest emergence experiment. These results lend insight into the potential effects of maternal stress levels on offspring phenotypes, as well as the robustness of offspring fitness to altered levels of maternal stress in freshwater turtles.
Collapse
Affiliation(s)
- Rebecca L Polich
- Department of Human Physiology, Gonzaga University, Spokane, WA, USA.
| | - Brooke L Bodensteiner
- Department of Biological Sciences, Virginia Polytechnic University and State University, Blacksburg, VA, USA.
| | - Clare I M Adams
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.
| | - Fredric J Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.
| |
Collapse
|
26
|
Gruber J, Cunningham GD, While GM, Wapstra E. Disentangling sex allocation in a viviparous reptile with temperature-dependent sex determination: a multifactorial approach. J Evol Biol 2017; 31:267-276. [PMID: 29194826 DOI: 10.1111/jeb.13219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 11/26/2017] [Accepted: 11/27/2017] [Indexed: 11/30/2022]
Abstract
Females are predicted to alter sex allocation when ecological, physiological and behavioural variables have different consequences on the fitness of male and female offspring. Traditionally, tests of sex allocation have examined single causative factors, often ignoring possible interactions between multiple factors. Here, we used a multifactorial approach to examine sex allocation in the viviparous skink, Niveoscincus ocellatus. We integrated a 16-year observational field study with a manipulative laboratory experiment to explore whether the effects of the maternal thermal environment interact with the resources available to females for reproduction to affect sex allocation decisions. We found strong effects of temperature on sex allocation in the field, with females born in warm conditions and males in cold conditions; however, this was not replicated in the laboratory. In contrast, we found no effect of female resource availability on sex allocation, either independently, or in interaction with temperature. These results corresponded with an overall lack of an effect of resource availability on any of the life history traits that we predicted would mediate the benefits of differential sex allocation in this system, suggesting that selection for sex allocation in response to resource availability may be relatively weak. Combined, these results suggest that temperature may be the predominant factor driving sex allocation in this system.
Collapse
Affiliation(s)
- J Gruber
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
| | - G D Cunningham
- School of Biological Sciences, The University of Tasmania, Hobart, Tas., Australia
| | - G M While
- School of Biological Sciences, The University of Tasmania, Hobart, Tas., Australia
| | - E Wapstra
- School of Biological Sciences, The University of Tasmania, Hobart, Tas., Australia
| |
Collapse
|
27
|
Deveson IW, Holleley CE, Blackburn J, Marshall Graves JA, Mattick JS, Waters PD, Georges A. Differential intron retention in Jumonji chromatin modifier genes is implicated in reptile temperature-dependent sex determination. SCIENCE ADVANCES 2017; 3:e1700731. [PMID: 28630932 PMCID: PMC5470834 DOI: 10.1126/sciadv.1700731] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In many vertebrates, sex of offspring is determined by external environmental cues rather than by sex chromosomes. In reptiles, for instance, temperature-dependent sex determination (TSD) is common. Despite decades of work, the mechanism by which temperature is converted into a sex-determining signal remains mysterious. This is partly because it is difficult to distinguish the primary molecular events of TSD from the confounding downstream signatures of sexual differentiation. We use the Australian central bearded dragon, in which chromosomal sex determination is overridden at high temperatures to produce sex-reversed female offspring, as a unique model to identify TSD-specific features of the transcriptome. We show that an intron is retained in mature transcripts from each of two Jumonji family genes, JARID2 and JMJD3, in female dragons that have been sex-reversed by temperature but not in normal chromosomal females or males. JARID2 is a component of the master chromatin modifier Polycomb Repressive Complex 2, and the mammalian sex-determining factor SRY is directly regulated by an independent but closely related Jumonji family member. We propose that the perturbation of JARID2/JMJD3 function by intron retention alters the epigenetic landscape to override chromosomal sex-determining cues, triggering sex reversal at extreme temperatures. Sex reversal may then facilitate a transition from genetic sex determination to TSD, with JARID2/JMJD3 intron retention preserved as the decisive regulatory signal. Significantly, we also observe sex-associated differential retention of the equivalent introns in JARID2/JMJD3 transcripts expressed in embryonic gonads from TSD alligators and turtles, indicative of a reptile-wide mechanism controlling TSD.
Collapse
Affiliation(s)
- Ira W. Deveson
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales (UNSW), Sydney, New South Wales, Australia
| | - Clare E. Holleley
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
- Australian National Wildlife Collection, National Research Collections Australia, CSIRO, Canberra, Australian Capital Territory, Australia
| | - James Blackburn
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St. Vincent’s Clinical School, UNSW, Sydney, New South Wales, Australia
| | - Jennifer A. Marshall Graves
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
- School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - John S. Mattick
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales (UNSW), Sydney, New South Wales, Australia
- St. Vincent’s Clinical School, UNSW, Sydney, New South Wales, Australia
- Neuroscience Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Paul D. Waters
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales (UNSW), Sydney, New South Wales, Australia
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
- Corresponding author.
| |
Collapse
|
28
|
Hsu BY, Dijkstra C, Darras VM, de Vries B, Groothuis TGG. Maternal thyroid hormones enhance hatching success but decrease nestling body mass in the rock pigeon (Columba livia). Gen Comp Endocrinol 2017; 240:174-181. [PMID: 27793722 DOI: 10.1016/j.ygcen.2016.10.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/20/2016] [Accepted: 10/24/2016] [Indexed: 11/22/2022]
Abstract
Thyroid hormones (THs) - triiodothyronine (T3) and thyroxine (T4) - are essential for embryonic development in vertebrates. All vertebrate embryos are exposed to THs from maternal origin. As maternal TH levels are known to be essential to embryonic development, the natural variation of maternal THs probably represents a pathway of maternal effects that can modify offspring phenotype. However, potential fitness consequences of variation of maternal TH exposure within the normal physiological range and without confounding effects of the mother have never been experimentally investigated. We experimentally manipulated the levels of yolk T3 and T4 within the physiological range in a species in which the embryo develops outside the mother's body, the Rock Pigeon (Columba livia) eggs. Making use of the natural difference of yolk testosterone between the two eggs of pigeon clutches, we were also able to investigate the potential interaction between THs and testosterone. Elevated yolk TH levels enhanced embryonic development and hatching success, and reduced body mass but not tarsus length between day 14 and fledging. The yolk hormones increased plasma T4 concentrations in females but reduced it in males, in line with the effect on metabolic rate at hatching. Plasma concentrations of T3 and testosterone were not significantly affected. The effects of treatment did not differ between eggs with high or low testosterone levels. Our data indicate that natural variation in maternal yolk TH levels affects offspring phenotype and embryonic survival, potentially influencing maternal and chick fitness.
Collapse
Affiliation(s)
- Bin-Yan Hsu
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
| | - Cor Dijkstra
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Veerle M Darras
- Laboratory of Comparative Endocrinology, Section of Animal Physiology and Neurobiology, KU Leuven, Naamsestraat 61, B-3000 Leuven, Belgium
| | - Bonnie de Vries
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Ton G G Groothuis
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| |
Collapse
|
29
|
Martínez-Caballero Y, Bock B, Pérez I, Ortega-León Á, Páez V. Incubation temperature and clutch effects on initial body sizes and growth rates in green iguana hatchlings (Iguana iguana). ANIM BIOL 2017. [DOI: 10.1163/15707563-00002535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Large initial body size and rapid early growth rate are important in many species, both because predation rates decline as individuals grow and because females that attain a larger adult body size are more fecund. To identify possible factors contributing to size and growth rate variation in hatchling green iguanas, we artificially incubated six clutches at three constant temperatures to test for effects of incubation temperature and/or clutch effects on initial size and growth rate. Higher incubation temperatures resulted in significantly shorter incubation periods but did not influence initial body size. There were significant differences among clutches in egg size, and also in initial hatchling body size, even after correcting for differences in egg size among clutches. A subset of hatchlings from each nest was reared in semi-natural conditions for four months, with individuals from the high incubation temperature condition exhibiting the slowest longer-term growth rates. No clutch effects were detected in the growth rate analyses. The observed variation in early growth rate of juvenile iguanas seems to be selectively important and this variation may be due in part to the conditions the eggs experience during incubation, but clutch effects in this study were limited to egg size and initial hatchling body size variation, but were not found for subsequent growth rates.
Collapse
Affiliation(s)
| | - Brian C. Bock
- 2Instituto de Biología, Universidad de Antioquia, Calle 70, No. 52-21, Medellín, Colombia
| | - Isabel Pérez
- 2Instituto de Biología, Universidad de Antioquia, Calle 70, No. 52-21, Medellín, Colombia
| | - Ángela M. Ortega-León
- 1Departamento de Biología, Universidad de Córdoba, Carrera 6, No. 76-103, Montería, Colombia
| | - Vivian P. Páez
- 2Instituto de Biología, Universidad de Antioquia, Calle 70, No. 52-21, Medellín, Colombia
| |
Collapse
|
30
|
Lorioux S, Angelier F, Lourdais O. Are glucocorticoids good indicators of pregnancy constraints in a capital breeder? Gen Comp Endocrinol 2016; 232:125-33. [PMID: 27090427 DOI: 10.1016/j.ygcen.2016.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 03/31/2016] [Accepted: 04/09/2016] [Indexed: 12/24/2022]
Abstract
Pregnancy imposes a substantial energetic demand on the mother (i.e. metabolic costs of pregnancy) and is often associated with modified maternal behavior and increased physical burdens that make females more vulnerable to predation. The Hypothalamic-Pituitary-Adrenal axis plays a fundamental role in reproduction through hormonal control of energy regulation and parental care. Therefore, evaluating the changes in baseline and stress-induced glucocorticoid levels in response to pregnancy may provide a robust tool to assess not only the constraints of gestation but also the way females may adjust to these constraints. In this study, we measured baseline and stress-induced corticosterone (CORT) concentrations in pregnant and non-pregnant aspic vipers (Vipera aspis), which are capital breeders. We also measured muscle condition (tail width) and locomotion performance (traction force) because these are robust proxies of protein mobilization associated with fasting. Baseline CORT concentration increased significantly over time in pregnant females, while they were lower and stable in non-reproductive females. Pregnant females had lower muscle condition at the onset of the study and tail width was negatively correlated with CORT concentration in this group. Contrary to our prediction, the stress response was not attenuated in pregnant females, but was proportional to baseline CORT concentration. Our results suggest that baseline CORT variations are closely related to energy constraints and structural protein mobilization in this capital breeder.
Collapse
Affiliation(s)
- Sophie Lorioux
- Centre d'Etudes Biologiques de Chizé, CNRS UPR 1934, 79360 Villiers en Bois, France; Université de Poitiers, 40 Avenue du recteur Pineau, 85022 Poitiers, France; School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA.
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de Chizé, CNRS UPR 1934, 79360 Villiers en Bois, France
| | - Olivier Lourdais
- Centre d'Etudes Biologiques de Chizé, CNRS UPR 1934, 79360 Villiers en Bois, France; School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| |
Collapse
|
31
|
Schwanz LE. Parental thermal environment alters offspring sex ratio and fitness in an oviparous lizard. ACTA ACUST UNITED AC 2016; 219:2349-57. [PMID: 27229475 DOI: 10.1242/jeb.139972] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/23/2016] [Indexed: 01/18/2023]
Abstract
The environment experienced by parents can impact the phenotype of their offspring (parental effects), a critical component of organismal ecology and evolution in variable or changing environments. Although temperature is a central feature of the environment for ectotherms, its role in parental effects has been little explored until recently. Here, parental basking opportunity was manipulated in an oviparous lizard with temperature-dependent sex determination, the jacky dragon (Amphibolurus muricatus). Eggs were incubated at a temperature that typically produces a 50:50 sex ratio, and hatchlings were reared in a standard thermal environment. Offspring of parents in short bask conditions appeared to have better fitness outcomes in captive conditions than those of parents in long bask conditions - they had greater growth and survival as a function of their mass. In addition, the sex of offspring (male or female) depended on the interaction between parental treatment and egg mass, and treatment impacted whether sons or daughters grew larger in their first season. The interactive effects of treatment on offspring sex and growth are consistent with adaptive explanations for the existence of temperature-dependent sex determination in this species. Moreover, the greater performance recorded in short bask offspring may represent an anticipatory parental effect to aid offspring in predicted conditions of restricted thermal opportunity. Together, these responses constitute a crucial component of the population response to spatial or temporal variation in temperature.
Collapse
Affiliation(s)
- Lisa E Schwanz
- Research School of Biology, The Australian National University, Bruce, ACT 2601, Australia
| |
Collapse
|
32
|
Yatsu R, Miyagawa S, Kohno S, Parrott BB, Yamaguchi K, Ogino Y, Miyakawa H, Lowers RH, Shigenobu S, Guillette LJ, Iguchi T. RNA-seq analysis of the gonadal transcriptome during Alligator mississippiensis temperature-dependent sex determination and differentiation. BMC Genomics 2016; 17:77. [PMID: 26810479 PMCID: PMC4727388 DOI: 10.1186/s12864-016-2396-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 01/14/2016] [Indexed: 11/26/2022] Open
Abstract
Background The American alligator (Alligator mississippiensis) displays temperature-dependent sex determination (TSD), in which incubation temperature during embryonic development determines the sexual fate of the individual. However, the molecular mechanisms governing this process remain a mystery, including the influence of initial environmental temperature on the comprehensive gonadal gene expression patterns occurring during TSD. Results Our characterization of transcriptomes during alligator TSD allowed us to identify novel candidate genes involved in TSD initiation. High-throughput RNA sequencing (RNA-seq) was performed on gonads collected from A. mississippiensis embryos incubated at both a male and a female producing temperature (33.5 °C and 30 °C, respectively) in a time series during sexual development. RNA-seq yielded 375.2 million paired-end reads, which were mapped and assembled, and used to characterize differential gene expression. Changes in the transcriptome occurring as a function of both development and sexual differentiation were extensively profiled. Forty-one differentially expressed genes were detected in response to incubation at male producing temperature, and included genes such as Wnt signaling factor WNT11, histone demethylase KDM6B, and transcription factor C/EBPA. Furthermore, comparative analysis of development- and sex-dependent differential gene expression revealed 230 candidate genes involved in alligator sex determination and differentiation, and early details of the suspected male-fate commitment were profiled. We also discovered sexually dimorphic expression of uncharacterized ncRNAs and other novel elements, such as unique expression patterns of HEMGN and ARX. Twenty-five of the differentially expressed genes identified in our analysis were putative transcriptional regulators, among which were MYBL2, MYCL, and HOXC10, in addition to conventional sex differentiation genes such as SOX9, and FOXL2. Inferred gene regulatory network was constructed, and the gene-gene and temperature-gene interactions were predicted. Conclusions Gonadal global gene expression kinetics during sex determination has been extensively profiled for the first time in a TSD species. These findings provide insights into the genetic framework underlying TSD, and expand our current understanding of the developmental fate pathways during vertebrate sex determination. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2396-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ryohei Yatsu
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Shinichi Miyagawa
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Satomi Kohno
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Benjamin B Parrott
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Katsushi Yamaguchi
- National Institute for Basic Biology, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
| | - Yukiko Ogino
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, 350 Mine-machi, Utsunomiya, Tochigi, 321-8505, Japan.
| | - Russell H Lowers
- Innovative Health Applications, Kennedy Space Center, Merritt Island, FL, 32899, USA.
| | - Shuji Shigenobu
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,National Institute for Basic Biology, National Institutes of Natural Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
| | - Louis J Guillette
- Department of Obstetrics and Gynecology, Medical University of South Carolina, and Marine Biomedicine and Environmental Science Center, Hollings Marine Laboratory, Charleston, SC, 29412, USA.
| | - Taisen Iguchi
- Department of Basic Biology, Faculty of Life Science, SOKENDAI (Graduate University for Advanced Studies), 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
| |
Collapse
|
33
|
Dupoué A, Angelier F, Brischoux F, DeNardo DF, Trouvé C, Parenteau C, Lourdais O. Water deprivation increases maternal corticosterone levels and enhances offspring growth in the snake Vipera aspis. J Exp Biol 2016; 219:658-67. [DOI: 10.1242/jeb.132639] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 12/10/2015] [Indexed: 12/26/2022]
Abstract
Circulating glucocorticoids (GCs) levels may increase as a result of reproductive effort or in response to unpredictable events. However, the GCs secretion can vary with the availability of vital trophic resources such as energy. While water represents another critical resource, the impact of water deprivation on GCs secretion during reproduction has not yet been thoroughly investigated. Here, we examined the effects of water deprivation on plasma corticosterone (CORT) concentrations of female aspic vipers (Vipera aspis), and we determined the impacts of water deprivation on offspring traits. We exposed both pregnant and non-reproductive females to a 20-day water deprivation and compared their pre- and post-deprivation CORT levels to those of control females. At the end of the treatment, only water-deprived pregnant females showed a significant increase in CORT levels. In pregnant females, changes in baseline CORT level were correlated to changes in female hydration state. Changes in baseline CORT levels were also negatively influenced by maternal reproductive effort in pregnant control females, while such relationship was not apparent in pregnant water-deprived females. Finally, we found that offspring from water-deprived females had higher growth rates than offspring from control females. Offspring growth was also positively correlated to changes in both maternal osmolality and baseline CORT levels. Together, our results suggest that dehydration increases maternal CORT levels which may subsequently influence offspring development. Further long-term field studies are therefore required to assess whether there is an adaptive significance of this response.
Collapse
Affiliation(s)
- Andréaz Dupoué
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
- Université de Poitiers, 40 avenue du recteur Pinaud 86022 Poitiers, France
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
| | - François Brischoux
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
| | - Dale F. DeNardo
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Colette Trouvé
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
| | - Charline Parenteau
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
| | - Olivier Lourdais
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-ULR, 79360 Villiers en Bois, France
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| |
Collapse
|
34
|
Carter AW, Paitz RT, McGhee KE, Bowden RM. Turtle hatchlings show behavioral types that are robust to developmental manipulations. Physiol Behav 2015; 155:46-55. [PMID: 26657026 DOI: 10.1016/j.physbeh.2015.11.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/16/2015] [Accepted: 11/28/2015] [Indexed: 11/17/2022]
Abstract
There can be substantial variation among individuals within a species in how they behave, even under similar conditions; this pattern is found in many species and across taxa. However, the mechanisms that give rise to this behavioral variation are often unclear. This study investigated the influence of environmental manipulations during development on behavioral variation in hatchlings of the red-eared slider turtle (Trachemys scripta). First, we examined the effects of three manipulations during incubation (estrone sulfate exposure, corticosterone exposure, and thermal fluctuations) on hatchling righting response and exploration. Second, we determined whether hatchlings showed consistent differences (i.e. behavioral types) in their righting response and exploration across days and months, and whether these behaviors were correlated with one another. Finally, we examined whether righting response was predictive of ecologically relevant behaviors such as habitat choice and dispersal. Hatchling behavior was robust to our early manipulations; none of the pre-hatch treatments affected later behavior. There were significant clutch effects, which due to the split-clutch design suggests genetic underpinnings and/or maternal effects. We found evidence for behavioral types in turtles; both righting response and exploration were strongly repeatable and these behaviors were positively correlated. Righting response was not predictive of dispersal ability in the field, necessitating a revision in the general interpretations of righting response as a proxy for dispersal ability in turtles. Thus, turtle hatchlings show consistent behavioral differences that are robust to early developmental manipulations, and while not necessarily predictive of dispersal, these behavioral types can have important consequences throughout ontogeny.
Collapse
Affiliation(s)
- A W Carter
- School of Biological Sciences, Illinois State University, Julian Hall 210, Campus Box 4120, Normal, IL 61790, United States.
| | - R T Paitz
- School of Biological Sciences, Illinois State University, Julian Hall 210, Campus Box 4120, Normal, IL 61790, United States.
| | - K E McGhee
- School of Integrative Biology, University of Illinois, 286 Morrill Hall MC-120 505 S. Goodwin Ave., Urbana, IL 61801, United States; Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom.
| | - R M Bowden
- School of Biological Sciences, Illinois State University, Julian Hall 210, Campus Box 4120, Normal, IL 61790, United States.
| |
Collapse
|
35
|
Reproduction as a Function of Living Conditions: The Breeding Biology of the Radiated Tortoise (Astrochelys radiata) under Natural and Captive Conditions in Southwest Madagascar. J HERPETOL 2015. [DOI: 10.1670/14-055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
36
|
Sopinka NM, Patterson LD, Redfern JC, Pleizier NK, Belanger CB, Midwood JD, Crossin GT, Cooke SJ. Manipulating glucocorticoids in wild animals: basic and applied perspectives. CONSERVATION PHYSIOLOGY 2015; 3:cov031. [PMID: 27293716 PMCID: PMC4778459 DOI: 10.1093/conphys/cov031] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/12/2015] [Accepted: 06/15/2015] [Indexed: 05/27/2023]
Abstract
One of the most comprehensively studied responses to stressors in vertebrates is the endogenous production and regulation of glucocorticoids (GCs). Extensive laboratory research using experimental elevation of GCs in model species is instrumental in learning about stressor-induced physiological and behavioural mechanisms; however, such studies fail to inform our understanding of ecological and evolutionary processes in the wild. We reviewed emerging research that has used GC manipulations in wild vertebrates to assess GC-mediated effects on survival, physiology, behaviour, reproduction and offspring quality. Within and across taxa, exogenous manipulation of GCs increased, decreased or had no effect on traits examined in the reviewed studies. The notable diversity in responses to GC manipulation could be associated with variation in experimental methods, inherent differences among species, morphs, sexes and age classes, and the ecological conditions in which responses were measured. In their current form, results from experimental studies may be applied to animal conservation on a case-by-case basis in contexts such as threshold-based management. We discuss ways to integrate mechanistic explanations for changes in animal abundance in altered environments with functional applications that inform conservation practitioners of which species and traits may be most responsive to environmental change or human disturbance. Experimental GC manipulation holds promise for determining mechanisms underlying fitness impairment and population declines. Future work in this area should examine multiple life-history traits, with consideration of individual variation and, most importantly, validation of GC manipulations within naturally occurring and physiologically relevant ranges.
Collapse
Affiliation(s)
- Natalie M. Sopinka
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada K1S 5B6
| | - Lucy D. Patterson
- Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Julia C. Redfern
- Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Naomi K. Pleizier
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada K1S 5B6
| | - Cassia B. Belanger
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada K1S 5B6
| | - Jon D. Midwood
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada K1S 5B6
| | - Glenn T. Crossin
- Department of Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2
| | - Steven J. Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada K1S 5B6
| |
Collapse
|
37
|
Sopinka NM, Hinch SG, Healy SJ, Harrison PM, Patterson DA. Egg cortisol treatment affects the behavioural response of coho salmon to a conspecific intruder and threat of predation. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
38
|
Iungman JL, Somoza GM, Piña CI. Are Stress-Related Hormones Involved in the Temperature-Dependent Sex Determination of the Broad-Snouted Caiman? SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2015. [DOI: 10.2994/sajh-d-14-00027.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
39
|
Marcó MVP, Piña CI, Somoza GM, Jahn GA, Pietrobon EO, Iungman JL. Corticosterone Plasma Levels of Embryo and Hatchling Broad-Snouted Caimans (Caiman latirostris) Incubated at Different Temperatures. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2015. [DOI: 10.2994/sajh-d-14-00026.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
40
|
Warner DA, Addis E, Du WG, Wibbels T, Janzen FJ. Exogenous application of estradiol to eggs unexpectedly induces male development in two turtle species with temperature-dependent sex determination. Gen Comp Endocrinol 2014; 206:16-23. [PMID: 24954686 DOI: 10.1016/j.ygcen.2014.06.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 05/28/2014] [Accepted: 06/08/2014] [Indexed: 11/23/2022]
Abstract
Steroid hormones affect sex determination in a variety of vertebrates. The feminizing effects of exposure to estradiol and the masculinizing effects of aromatase inhibition during development are well established in a broad range of vertebrate taxa, but paradoxical findings are occasionally reported. Four independent experiments were conducted on two turtle species with temperature-dependent sex determination (Chrysemys picta and Chelydra serpentina) to quantify the effects of egg incubation temperature, estradiol, and an aromatase inhibitor on offspring sex ratios. As expected, the warmer incubation temperatures induced female development and the cooler temperatures produced primarily males. However, application of an aromatase inhibitor had no effect on offspring sex ratios, and exogenous applications of estradiol to eggs produced male offspring across all incubation temperatures. These unexpected results were remarkably consistent across all four experiments and both study species. Elevated concentrations of estradiol could interact with androgen receptors or inhibit aromatase expression, which might result in relatively high testosterone concentrations that lead to testis development. These findings add to a short list of studies that report paradoxical effects of steroid hormones, which addresses the need for a more comprehensive understanding of the role of sex steroids in sexual development.
Collapse
Affiliation(s)
- Daniel A Warner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50014, USA; Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Elizabeth Addis
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50014, USA; Department of Biology, Gonzaga University, Spokane, WA 99258, USA.
| | - Wei-guo Du
- Key Lab of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Thane Wibbels
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Fredric J Janzen
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA 50014, USA.
| |
Collapse
|
41
|
Warner DA. Fitness Consequences of Maternal and Embryonic Responses to Environmental Variation: Using Reptiles as Models for Studies of Developmental Plasticity. Integr Comp Biol 2014; 54:757-73. [DOI: 10.1093/icb/icu099] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
42
|
Esquerré D, Keogh JS, Schwanz LE. Direct effects of incubation temperature on morphology, thermoregulatory behaviour and locomotor performance in jacky dragons (Amphibolurus muricatus). J Therm Biol 2014; 43:33-9. [DOI: 10.1016/j.jtherbio.2014.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/19/2014] [Accepted: 04/26/2014] [Indexed: 11/26/2022]
|
43
|
Anderson L, Cree A, Towns D, Nelson N. Modulation of corticosterone secretion in tuatara (Sphenodon punctatus): Evidence of a dampened stress response in gravid females. Gen Comp Endocrinol 2014; 201:45-52. [PMID: 24713446 DOI: 10.1016/j.ygcen.2014.03.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 03/08/2014] [Accepted: 03/11/2014] [Indexed: 11/15/2022]
Abstract
Baseline and stress response glucocorticoid (GC) secretion can be modulated by individuals to support activities and physiological functions connected with reproduction (migration, mating, oviposition and/or parturition, care of young). Corticosterone (CORT) is the primary GC in reptiles and, in accordance with other vertebrates, an adrenocortical stress response is observed. Modulation of CORT secretion occurs in several reptile species, such that elevated baseline CORT concentration and/or a dampened CORT response are common during reproductive life-history events. We investigated CORT secretion after 24 h capture-restraint in the oviparous tuatara (Sphenodon punctatus), the last living rhynchocephalian, and tested whether gravid females have a dampened CORT response compared with non-gravid females. We also included males as a comparison. We confirmed that gravid females have significantly higher baseline plasma CORT concentrations than non-gravid females, suggesting increased CORT secretion during nesting. Furthermore, we found that gravid females exhibit a dampened CORT response compared to non-gravid females and males. Our results demonstrate that female reproductive condition influences CORT secretion in tuatara, and suggest that gravid females modulate CORT secretion during nesting to maintain homeostasis, effectively increasing chances of reproductive success and promoting overall fitness.
Collapse
Affiliation(s)
- Lindsay Anderson
- Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand.
| | - Alison Cree
- Department of Zoology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
| | - David Towns
- Ecosystem Development Team, Science and Technical Group, Department of Conservation, Private Bag 68-908 Newton, Auckland 1145, New Zealand.
| | - Nicola Nelson
- Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand.
| |
Collapse
|
44
|
Schwanz LE, Robert KA. Proximate and ultimate explanations of mammalian sex allocation in a marsupial model. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1720-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
45
|
Warner DA, Lovern MB. The maternal environment affects offspring viability via an indirect effect of yolk investment on offspring size. Physiol Biochem Zool 2014; 87:276-87. [PMID: 24642545 DOI: 10.1086/674454] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Environmental conditions that reproductive females experience can influence patterns of offspring provisioning and fitness. In particular, prey availability can influence maternal reproduction and, in turn, affect the viability of their offspring. Although such maternal effects are widespread, the mechanisms by which these effects operate are poorly understood. We manipulated the amount of prey available to female brown anole lizards (Anolis sagrei) to evaluate how this factor affects patterns of reproductive investment (total egg output, egg size, yolk steroids) and offspring viability (morphology, growth, survival). Experimental reduction of yolk in a subset of eggs enabled us to evaluate a potential causal mechanism (yolk investment) that mediates the effect of maternal prey availability on offspring viability. We show that limited prey availability significantly reduced egg size, which negatively influenced offspring size, growth, and survival. Experimental yolk removal from eggs directly reduced offspring size, which, in turn, negatively affected offspring growth and survival. These findings show that maternal environments (i.e., low prey) can affect offspring fitness via an indirect effect of yolk investment on offspring size and highlight the complex set of indirect effects by which maternal effects can operate.
Collapse
Affiliation(s)
- Daniel A Warner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa 50011; 2Department of Zoology, Oklahoma State University, Stillwater, Oklahoma 74078
| | | |
Collapse
|
46
|
Shilton C, Brown GP, Chambers L, Benedict S, Davis S, Aumann S, Isberg SR. Pathology of Runting in Farmed Saltwater Crocodiles (Crocodylus porosus) in Australia. Vet Pathol 2014; 51:1022-34. [DOI: 10.1177/0300985813516642] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Extremely poor growth of some individuals within a birth cohort (runting) is a significant problem in crocodile farming. We conducted a pathological investigation to determine if infectious disease is associated with runting in farmed saltwater crocodiles ( Crocodylus porosus) and to look for evidence of other etiologies. In each of 2005 and 2007, 10 normal and 10 runt crocodiles, with an average age of 5.5 months and reared under identical conditions, were sampled. Laboratory testing included postmortem; histological examination of a wide variety of tissues (with quantitation of features that were noted subjectively to be different between groups); hematology; serum biochemistry (total protein, albumin, globulins, total calcium, phosphorus, and iron); bacterial culture of liver and spleen (2005 only); viral culture of liver, thymus, tonsil, and spleen using primary crocodile cell lines (2007 only); and serum corticosterone (2007 only). The only evidence of infectious disease was mild cutaneous poxvirus infection in 45% of normal and 40% of runt crocodiles and rare intestinal coccidia in 5% of normal and 15% of runt crocodiles. Bacterial and viral culture did not reveal significant differences between the 2 groups. However, runt crocodiles exhibited significant ( P < .05) increases in adrenocortical cell cytoplasmic vacuolation and serum corticosterone, decreased production of bone (osteoporosis), and reduced lymphoid populations in the spleen, tonsil, and thymus. Runts also exhibited moderate anemia, hypoalbuminemia, and mild hypophosphatemia. Taken together, these findings suggest an association between runting and a chronic stress response (hyperactivity of the hypothalamic-pituitary-adrenal axis).
Collapse
Affiliation(s)
- C. Shilton
- Berrimah Veterinary Laboratories, Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
| | - G. P. Brown
- The University of Sydney, Sydney, New South Wales, Australia
| | - L. Chambers
- Berrimah Veterinary Laboratories, Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
| | - S. Benedict
- Berrimah Veterinary Laboratories, Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
| | - S. Davis
- Berrimah Veterinary Laboratories, Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
| | - S. Aumann
- Berrimah Veterinary Laboratories, Department of Primary Industry and Fisheries, Northern Territory Government, Berrimah, Northern Territory, Australia
| | - S. R. Isberg
- The University of Sydney, Sydney, New South Wales, Australia
- Porosus Pty. Ltd., Noonamah, Northern Territory, Australia
| |
Collapse
|
47
|
Abstract
The ability to adjust sex ratios at the individual level exists among all vertebrate groups studied to date. In many cases, there is evidence for facultative adjustment of sex ratios in response to environmental and/or social cues. Because environmental and social information must be first transduced into a physiological signal to influence sex ratios, hormones likely play a role in the adjustment of sex ratio in vertebrates, because the endocrine system acts as a prime communicator that directs physiological activities in response to changing external conditions. This symposium was developed to bring together investigators whose work on adjustment of sex ratio represents a variety of vertebrate groups in an effort to draw comparisons between species in which the sex-determination process is well-established and those in which more work is needed to understand how adjustments in sex ratio are occurring. This review summarizes potential hormone targets that may underlie the mechanisms of adjustment of sex ratio in humans, non-human mammals, birds, reptiles, and fishes.
Collapse
Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
48
|
Weiss SL, Mulligan EE, Wilson DS, Kabelik D. Effect of stress on female-specific ornamentation. ACTA ACUST UNITED AC 2013; 216:2641-7. [PMID: 23531828 DOI: 10.1242/jeb.080937] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Signal honesty is theorized to be maintained by condition-dependent trait expression. However, the mechanisms mediating the condition dependence of sexually selected traits are often unknown. New work suggests that elevated glucocorticoid levels during physiological stress may play a role in maintaining signal honesty. Here, we experimentally examine the effect of both chronic and acute stress on the expression of the condition-dependent ornamentation of female striped plateau lizards, Sceloporus virgatus. Females were stressed either chronically via corticosterone implants or relatively acutely via autotomy, were sham manipulated or were left unmanipulated. Both stressors resulted in elevations in corticosterone within physiologically relevant levels, though the implants resulted in significantly higher levels than did autotomy. Corticosterone-implanted females were less likely to produce a clutch of eggs, but those individuals that did reproduce had reproductive output similar to that of females from other treatment groups. Compared with females in other groups, the corticosterone-implanted females tended to develop smaller ornaments that had less UV and orange-to-red wavelength reflectance relative to medium wavelength reflectance. The sex steroid hormones testosterone and estradiol were correlated to corticosterone levels, but did not appear to underlie the effect on ornament expression; of the steroids measured, only corticosterone levels were negatively related to ornament size and coloration. Thus, the condition-dependent ornamentation of female lizards is sensitive to chronic elevations in stress hormones, supporting their importance in the maintenance of signal honesty.
Collapse
Affiliation(s)
- Stacey L Weiss
- University of Puget Sound, 1500 N Warner Street, Tacoma, WA 98416-1088, USA
| | | | | | | |
Collapse
|
49
|
Offspring sex in a TSD gecko correlates with an interaction between incubation temperature and yolk steroid hormones. Naturwissenschaften 2012; 99:999-1006. [PMID: 23086395 DOI: 10.1007/s00114-012-0981-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/05/2012] [Accepted: 10/10/2012] [Indexed: 02/03/2023]
Abstract
We incubated eggs of the Japanese gecko Gekko japonicus at three temperatures, and measured yolk testosterone (T) and 17β-estradiol (E2) levels at three time points in embryonic development (oviposition, 1/3 of incubation, and 2/3 of incubation), to examine whether maternal influence on offspring sex via yolk steroid hormone deposition is significant in the species. Eggs incubated at 24 °C and 32 °C produced mostly females, and eggs incubated at 28 °C almost a 50:50 sex ratio of hatchlings. Female-producing eggs were larger than male-producing eggs. Clutches in which eggs were incubated at the same temperature produced mostly same-sex siblings. Yolk T level at laying was negatively related to eggs mass, and yolk E2/T ratio was positively related to egg mass. Results of two-way ANOVA with incubation temperature and stage as the factors show that: yolk E2 level was higher at 32 °C than at 24 °C; yolk T level was higher, whereas yolk E2/T ratio was smaller, at 28 °C than at 24 °C; yolk E2 and T levels were higher at 2/3 than at 1/3 of incubation. Our data in G. japonucus show that: (1) maternal influence on offspring sex via yolk steroid hormone deposition is significant; (2) incubation temperature affects the dynamics of developmental changes in yolk steroid hormones; (3) influences of yolk steroid hormones on offspring sex are secondary relative to incubation temperature effects; and (4) offspring sex correlates with an interaction between incubation temperature and yolk steroid hormones.
Collapse
|
50
|
Helle S, Laaksonen T, Huitu O. Sex-specific offspring growth according to maternal testosterone, corticosterone, and glucose levels. Behav Ecol 2012. [DOI: 10.1093/beheco/ars155] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|