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Martín J, Rodríguez-Ruiz G, Navarro-Castilla Á, Barja I, López P. Blind date: female fossorial amphisbaenians prefer scent marks of large and healthy males. Integr Zool 2024. [PMID: 38247017 DOI: 10.1111/1749-4877.12802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Selecting a good mate is a decision with important fitness consequences. For this reason, mate choice has promoted the evolution of sexual ornaments signaling the quality of an individual. In fossorial animals, inhabiting visually restricted underground environments, chemical senses should be very important for mate choice. We examined whether sexual chemical signals (substrate scent marks) produced by males of the Iberian worm lizard, Blanus cinereus, a strictly fossorial blind amphisbaenian, provide information to females on morphological traits and health state. We administered corticosterone (CORT) to males simulating a continuous stressor affecting their health. Females preferred settling at sites scent-marked by males in comparison with similar sites with female scent or unmarked sites, but the attractiveness of males' scent differed between individuals. Females preferred scent marks of larger/older males and with a higher immune response, while their body condition and CORT treatment were unrelated to female preferences. Chemical analyses showed that proportions of some compounds in precloacal secretions of males (used to produce scent marks) were correlated with the morphological (body size) and health state (immune response and body condition, but not CORT treatment) of these males. These results suggest that females may make site-selection decisions based on assessing the chemical characteristics of males' scent marks, which were reliably related to some of the traits of the male that produced the scent. Therefore, females might use chemical senses to increase the opportunities to find and mate with males of high quality, coping with the restrictions of the subterranean environment.
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Affiliation(s)
- José Martín
- Departmento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Gonzalo Rodríguez-Ruiz
- Departmento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Álvaro Navarro-Castilla
- Etho-Physiology Group, Unit of Zoology, Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Autonomous University of Madrid, Madrid, Spain
| | - Isabel Barja
- Etho-Physiology Group, Unit of Zoology, Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Autonomous University of Madrid, Madrid, Spain
| | - Pilar López
- Departmento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
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Palacios MG, Bronikowski AM, Amer A, Gangloff EJ. Transgenerational effects of maternal corticosterone across early life in a viviparous snake. Gen Comp Endocrinol 2023; 331:114162. [PMID: 36356645 DOI: 10.1016/j.ygcen.2022.114162] [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: 08/19/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Glucocorticoids (GCs) are central mediators of vertebrate responses to intrinsic and extrinsic stimuli. Among the sources of variation in circulating GCs are transgenerational effects mediated by mothers. Here we studied potential maternal effects mediated by GCs on offspring phenotype in a live-bearing reptile, the western terrestrial garter snake (Thamnophis elegans). We evaluated the association between baseline corticosterone (CORT) levels during gestation (i.e., preparturition) in field-captured mothers and 1) reproductive success and offspring sex ratios, 2) birth phenotypic traits of offspring born under common-garden laboratory conditions, and 3) neonate (age 3 months) and juvenile (age 12 months) traits of offspring raised under two thermal regimes ('warm' and 'cool') during their first year of life. Reproductive success and offspring sex ratios were not associated with preparturition maternal CORT, but pregnant snakes with higher CORT levels gave birth to smaller, lighter offspring, which tended to grow faster to age three months. Neonate baseline CORT varied with preparturition maternal CORT in a sex-specific manner (positive trend for females, negative for males). Maternal CORT effects on offspring phenotype were no longer detectable in juveniles at age one year. Instead, juvenile phenotypes were most influenced by rearing environment, with offspring raised under the cool regime showing higher baseline CORT and slower growth than those raised under warmer conditions. Our findings support the notion that offspring phenotype might be continuously adjusted in response to environmental cues -both pre- and post-natal- and that the strength of maternal CORT effects declines as offspring develop and experience unique environmental challenges. Our results contribute to a growing literature on transgenerational effects of hormones and help to fill a gap in our knowledge of these effects in ectothermic amniotes.
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Affiliation(s)
- Maria G Palacios
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA; Centro Para el Estudio de Sistemas Marinos, CCT CONICET-CENPAT, Blvd. Brown 2915, Puerto Madryn, Chubut, Argentina.
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA; Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
| | - Ali Amer
- Department of Biological Sciences, Ohio Wesleyan University, Delaware, OH, USA
| | - Eric J Gangloff
- Department of Biological Sciences, Ohio Wesleyan University, Delaware, OH, USA
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Martín J, Barja I, Rodríguez-Ruiz G, Recio P, Cuervo JJ. Hidden but Potentially Stressed: A Non-Invasive Technique to Quantify Fecal Glucocorticoid Levels in a Fossorial Amphisbaenian Reptile. Animals (Basel) 2022; 13:ani13010109. [PMID: 36611718 PMCID: PMC9817767 DOI: 10.3390/ani13010109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/22/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022] Open
Abstract
To understand wildlife responses to the changing environment, it is useful to examine their physiological responses and particularly their endocrine status. Here, we validated an enzyme immunoassay (EIA) to non-invasively quantify fecal corticosterone metabolites (FCM) in the fossorial amphisbaenian reptile Trogonophis wiegmanni from North Africa. We supplemented animals assigned to the treatment group with corticosterone dissolved in oil applied non-invasively on the skin for several days, while control groups received the oil-alone solution. Fresh feces were collected at the end of the supplementation period, and FCM levels were quantified by an EIA. Basal FCM levels were similar for both treatments and increased at the end of the test, but FCM increased significantly more in corticosterone-treated animals. A further examination of FCM levels in a wild population of this amphisbaenian did not find overall sexual, size or seasonal differences but showed a high range of variation among individuals. This suggests that different uncontrolled intrinsic or local environmental variables might increase the circulating glucocorticoid levels of different individuals. Our results confirmed the suitability of EIA for analyzing physiological changes in FCM in this amphisbaenian species. This technique may be useful for understanding and remediating the little-explored potential stressors of the soil environment that may negatively affect the health state of fossorial reptiles.
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Affiliation(s)
- José Martín
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C/José Gutiérrez Abascal 2, 28006 Madrid, Spain
- Correspondence:
| | - Isabel Barja
- Etho-Physiology Group, Unit of Zoology, Department of Biology, Faculty of Sciences, Autonomous University of Madrid, 28049 Madrid, Spain
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Autonomous University of Madrid, C/Darwin 2, 28049 Madrid, Spain
| | - Gonzalo Rodríguez-Ruiz
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C/José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Pablo Recio
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C/José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - José Javier Cuervo
- Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C/José Gutiérrez Abascal 2, 28006 Madrid, Spain
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4
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Gangloff EJ, Leos-Barajas V, Demuth G, Zhang H, Kelly CD, Bronikowski AM. Movement modeling and patterns of within- and among-individual behavioral variation across time scales in neonate garter snakes (Thamnophis elegans). Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03099-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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MacLeod KJ, Langkilde T, Venable CP, Ensminger DC, Sheriff MJ. The influence of maternal glucocorticoids on offspring phenotype in high- and low-risk environments. Behav Ecol 2021; 32:1330-1338. [PMID: 34949960 PMCID: PMC8691550 DOI: 10.1093/beheco/arab099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/06/2021] [Accepted: 08/11/2021] [Indexed: 11/12/2022] Open
Abstract
Elevated maternal glucocorticoid levels during gestation can lead to phenotypic changes in offspring via maternal effects. Although such effects have traditionally been considered maladaptive, maternally derived glucocorticoids may adaptively prepare offspring for their future environment depending upon the correlation between maternal and offspring environments. Nevertheless, relatively few studies test the effects of prenatal glucocorticoid exposure across multiple environments. We tested the potential for ecologically relevant increases in maternal glucocorticoids in the eastern fence lizard (Sceloporus undulatus) to induce adaptive phenotypic changes in offspring exposed to high or low densities of an invasive fire ant predator. Maternal treatment had limited effects on offspring morphology and behavior at hatching, but by 10 days of age, we found maternal treatment interacted with offspring environment to alter anti-predator behaviors. We did not detect differences in early-life survival based on maternal treatment or offspring environment. Opposing selection on anti-predator behaviors from historic and novel invasive predators may confound the potential of maternal glucocorticoids to adaptively influence offspring behavior. Our test of the phenotypic outcomes of transgenerational glucocorticoid effects across risk environments provides important insight into the context-specific nature of this phenomenon and the importance of understanding both current and historic evolutionary pressures.
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Affiliation(s)
- Kirsty 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, 223 62, Lund, Sweden
| | - Tracy Langkilde
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA, 16802, USA
- Intercollege Graduate Degree Program in Ecology, The Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
- Center for Brain, Behavior and Cognition, Pennsylvania State University, University Park, PA, 16802, USA
| | - Cameron P Venable
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA, 16802, USA
| | - David C Ensminger
- 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 Biological Sciences, San Jose State University, One Washington Square, San José, CA, 95192, USA
| | - Michael J Sheriff
- Biology Department, University of Massachusetts Dartmouth, Dartmouth, MA, 02747, USA
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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.
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Brusch GA, DeNardo DF, Lourdais O. Reproductive state and water deprivation increase plasma corticosterone in a capital breeder. Gen Comp Endocrinol 2020; 288:113375. [PMID: 31874136 DOI: 10.1016/j.ygcen.2019.113375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 11/29/2022]
Abstract
Plasma corticosterone (CORT) concentrations fluctuate in response to homeostatic demands. CORT is widely recognized as an important hormone related to energy balance. However, far less attention has been given to the potential role of CORT in regulating salt and water balance or responding to osmotic imbalances. We examined the effects of reproductive and hydric states on CORT levels in breeding Children's pythons (Antaresia childreni), a species with substantial energetic and hydric costs associated with egg development. Using a 2 × 2 experimental design, we examined how reproduction and water deprivation, both separately and combined, impact CORT levels and how these changes correlate with hydration (plasma osmolality) and energy levels (blood glucose). We found that reproduction leads to increased CORT levels, as does dehydration induced by water deprivation. The combined impact of reproduction and water deprivation led to the largest increases in CORT levels. Additionally, we found significant positive relationships among CORT levels, plasma osmolality, and blood glucose. Our results provide evidence that both reproductive activity and increased plasma osmolality can lead to increased plasma CORT in an ectotherm, which could be explained by either CORT having a role as a mineralocorticoid or CORT being elevated as part of a stress response to resource imbalances.
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Affiliation(s)
- George A Brusch
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85281, USA; Centre d'Etudies Biologiques de Chizé, CNRS, 79360 Villiers en Bois, France.
| | - Dale F DeNardo
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ 85281, USA
| | - Olivier Lourdais
- Centre d'Etudies Biologiques de Chizé, CNRS, 79360 Villiers en Bois, France
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8
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Hanover AM, Husak JF, Lovern M. Corticosterone in Lizard Egg Yolk Is Reduced by Maternal Diet Restriction but Unaltered by Maternal Exercise. Physiol Biochem Zool 2019; 92:573-578. [PMID: 31584858 DOI: 10.1086/705708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
When females face adverse environmental conditions, physiological changes, such as elevated corticosterone levels, to cope with the stressors may also impact their offspring. Such maternal effects are often considered adaptive and may "prime" the offspring for the same adverse environment, but maternal corticosterone levels do not always match that of the eggs produced. We examined how diet restriction and increased locomotor activity, via exercise training, affected steroid hormone levels of female green anole lizards, as well as the hormone levels in the yolk of their eggs. Diet restriction did not affect female hormone levels, but training increased corticosterone levels. Despite this, training did not affect yolk steroid levels, but eggs from females with diet restriction had lower corticosterone levels in yolk. This suggests that two common stressors, food shortage and increased locomotor activity, impact female physiology in a way that is not translated to her offspring.
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Holden KG, Reding DM, Ford NB, Bronikowski AM. Effects of early nutritional stress on physiology, life-histories and their trade-offs in a model ectothermic vertebrate. J Exp Biol 2019; 222:jeb.200220. [DOI: 10.1242/jeb.200220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/14/2019] [Indexed: 12/21/2022]
Abstract
Early-life experiences can have far-reaching consequences for phenotypes into adulthood. The effect of early-life experiences on fitness, particularly under adverse conditions, is mediated by resource allocation to particular life-history traits. Reptiles exhibit great variation in life-histories (e.g., indeterminate growth) thus selective pressures often mitigate the effects of early-life stress, particularly on growth and maturation. We examined the effects of early-life food restriction on growth, adult body size, physiology and reproduction in the checkered garter snake. Animals were placed on one of two early-life diet treatments: normal-diet (approximating ad libitum feeding) or low-diet (restricted to 20% of body mass in food weekly). At 15 weeks of age low-diet animals were switched to the normal-diet treatment. Individuals fed a restricted diet showed reduced growth rates, depressed immunocompetence and a heightened glucocorticoid response. Once food restriction was lifted, animals experiencing nutritional stress early in life (low-diet) caught up to the normal-diet group by increasing their growth, and were able to recover from the negative effects of nutritional stress on immune function and physiology. Growth restriction and the subsequent allocation of resources into increasing growth rates, however, had a negative effect on fitness. Mating success was reduced in low-diet males, while low-diet females gave birth to smaller offspring. In addition, although not a direct goal of our study, we found a sex-specific effect of early-life nutritional stress on median age of survival. Our study demonstrates both immediate and long-term effects of nutritional stress on physiology and growth, reproduction, and trade-offs among them.
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Affiliation(s)
- Kaitlyn G. Holden
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Department of Biology, University of Texas at Tyler, Tyler, TX 75799, USA
| | - Dawn M. Reding
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Department of Biology, Luther College, Decora, IA 52101, USA
| | - Neil B. Ford
- Department of Biology, University of Texas at Tyler, Tyler, TX 75799, USA
| | - Anne M. Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
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Adedeji TG, Fasanmade A, Olapade-Olaopa E. Multigenerational effects of dietary macronutrient intake on the metabolic phenotype of male Wistar rats. Nutrition 2018; 58:125-133. [PMID: 30391691 DOI: 10.1016/j.nut.2018.06.008] [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: 11/30/2017] [Revised: 06/10/2018] [Accepted: 06/21/2018] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Gene-nutrient interactions are implicated in metabolic phenotypes like metabolic syndrome. The aim of this study was to examine the effects of diet-induced metabolic phenotypes in rats and investigate the effects of these phenotypes in three successive generations. METHODS Three generations of rats were fed on different diets and mated. Blood glucose, adiposity, lipid profile, insulin, adipocytokines, ghrelin, and corticosterone concentrations were determined in F0, F1, and F2 generations using standard methods. RESULTS In comparison with control across generations, glucose (32%), triacylglycerols (52%), and insulin (10%) were significantly elevated in the high-fat diet (HFD)-fed rats; total cholesterol was higher in HFD and high-carbohydrate diet (HCD)-fed groups; whereas high density lipoprotein was higher in the HFD rats but lower in the HPD rats. Adipocytokines were significantly higher in the HCD and HFD groups but lower in the high-protein diet group, whereas ghrelin only declined in HFD rats. CONCLUSION This study revealed that different dietary macronutrients induced distinctive metabolic phenotypes, which had variable effects in different generations.
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Swierk L, Langkilde T. Does repeated human handling of study animals during the mating season affect their offspring? JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:80-86. [PMID: 29806245 DOI: 10.1002/jez.2177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 05/04/2018] [Indexed: 11/07/2022]
Abstract
Minimizing disturbance of study animals is a major consideration in ethological and ecological research design. One nearly universal type of disturbance is the handling of study animals as a component of trial setup. Even low to moderate levels of handling can be a substantial stressor to study animals, which may negatively affect their offspring via maternal effects. Understanding how routine human handling and manipulation may affect the outcome of research studies is therefore critical for interpreting study outcomes. We tested whether repeatedly handling and manipulating (i.e., manually disengaging) amplexed pairs of wood frogs (Rana sylvatica [Lithobates sylvaticus]), which have an explosive breeding season, would affect their reproductive output and offspring fitness. Handling and manipulation did not alter any parameter that we measured: reproductive timing, hatching success, and offspring larval duration, survival, and size at metamorphosis. These results suggest that handling and manipulation by researchers may have a negligible effect on wood frog reproduction and offspring fitness. It is possible that many species that are commonly used in reproductive studies because they suppress behavioral and physiological responses during the mating season are likewise unaffected by human handling. Nevertheless, researchers should examine possible consequences of methodological interventions on their study species in order to determine any potential influence on their results. Having a broad understanding of these effects on species that have robust or dampened stress responsiveness during the breeding season would be useful for making generalizations about potential effects.
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Affiliation(s)
- Lindsey Swierk
- Department of Biology, Intercollege Graduate Program in Ecology, and Center for Brain, Behavior and Cognition, The Pennsylvania State University, University Park, Pennsylvania
| | - Tracy Langkilde
- Department of Biology, Intercollege Graduate Program in Ecology, and Center for Brain, Behavior and Cognition, The Pennsylvania State University, University Park, Pennsylvania
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12
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Baxter-Gilbert J, Riley JL, Whiting MJ. Runners and fighters: clutch effects and body size drive innate antipredator behaviour in hatchling lizards. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2505-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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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.
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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.
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15
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Tamilselvan P, Sloman K. Developmental social experience of parents affects behaviour of offspring in zebrafish. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.09.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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16
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Gangloff EJ, Sparkman AM, Bronikowski AM. Among-individual heterogeneity in maternal behaviour and physiology affects reproductive allocation and offspring life-history traits in the garter snakeThamnophis elegans. OIKOS 2017. [DOI: 10.1111/oik.04204] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Eric J. Gangloff
- Dept. of Ecology; Evolution and Organismal Biology, Iowa State Univ.; Ames IA USA
- Station d'Ecologie Théorique et Expérimentale du CNRS; FR-09200 Moulis France
| | | | - Anne M. Bronikowski
- Dept. of Ecology; Evolution and Organismal Biology, Iowa State Univ.; Ames IA USA
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17
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Mohammadi S, French SS, Neuman-Lee LA, Durham SL, Kojima Y, Mori A, Brodie ED, Savitzky AH. Corticosteroid responses of snakes to toxins from toads (bufadienolides) and plants (cardenolides) reflect differences in dietary specializations. Gen Comp Endocrinol 2017; 247:16-25. [PMID: 28347742 DOI: 10.1016/j.ygcen.2017.03.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/07/2017] [Accepted: 03/22/2017] [Indexed: 01/24/2023]
Abstract
Toads are chemically defended by cardiotonic steroids known as bufadienolides. Resistance to the acute effects of bufadienolides in snakes that prey on toads is conferred by target-site insensitivity of the toxin's target enzyme, the Na+/K+-ATPase. Previous studies have focused largely on the molecular mechanisms of resistance but have not investigated the physiological mechanisms or consequences of exposure to the toxins. Adrenal enlargement in snakes often is associated with specialization on a diet of toads. These endocrine glands are partly composed of interrenal tissue, which produces the corticosteroids corticosterone and aldosterone. Corticosterone is the main hormone released in response to stress in reptiles, and aldosterone plays an important role in maintaining ion balance through upregulation of Na+/K+-ATPase. We tested the endocrine response of select species of snakes to acute cardiotonic steroid exposure by measuring circulating aldosterone and corticosterone concentrations. We found that Rhabdophis tigrinus, which specializes on a diet of toads, responds with lower corticosterone and higher aldosterone compared to other species that exhibit target-site resistance to the toxins but do not specialize on toads. We also found differences between sexes in R. tigrinus, with males generally responding with higher corticosterone and aldosterone than females. This study provides evidence of physiological adaptations, beyond target-site resistance, associated with tolerance of bufadienolides in a specialized toad-eating snake.
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Affiliation(s)
- Shabnam Mohammadi
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, United States.
| | - Susannah S French
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, United States
| | - Lorin A Neuman-Lee
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States
| | - Susan L Durham
- Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, United States
| | - Yosuke Kojima
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Akira Mori
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Edmund D Brodie
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, United States
| | - Alan H Savitzky
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, United States
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18
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Geographic variation and within-individual correlations of physiological stress markers in a widespread reptile, the common garter snake (Thamnophis sirtalis). Comp Biochem Physiol A Mol Integr Physiol 2017; 205:68-76. [DOI: 10.1016/j.cbpa.2016.12.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/16/2016] [Accepted: 12/16/2016] [Indexed: 01/14/2023]
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19
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Neuman-Lee L, Greives T, Hopkins GR, French SS. The role of the kisspeptin system in regulation of the reproductive endocrine axis and territorial behavior in male side-blotched lizards (Uta stansburiana). Horm Behav 2017; 89:48-54. [PMID: 28017596 DOI: 10.1016/j.yhbeh.2016.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/23/2016] [Accepted: 12/12/2016] [Indexed: 11/18/2022]
Abstract
The neuropeptide kisspeptin and its receptor are essential for activation of the hypothalamic-pituitary-gonadal (HPG) axis and regulating reproduction. While the role of kisspeptin in regulating the HPG axis in mammals has been well established, little is known about the functional ability of kisspeptins to activate the HPG axis and associated behavior in non-mammalian species. Here we experimentally examined the effects of kisspeptin on downstream release of testosterone and associated aggression and display behaviors in the side-blotched lizard (Uta stansburiana). We found that exogenous treatment with kisspeptin resulted in an increase in circulating testosterone levels, castration blocked the kisspeptin-induced increase in testosterone, and testosterone levels in kisspeptin-treated animals were positively related to frequency of aggressive behaviors. This evidence provides a clear link between kisspeptin, testosterone, and aggressive behavior in lizards. Thus, it is likely that kisspeptin plays an important role more broadly in non-mammalian systems in the regulation of reproductive physiology and related behaviors.
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Affiliation(s)
- Lorin Neuman-Lee
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA
| | - Timothy Greives
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58106, USA
| | - Gareth R Hopkins
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA
| | - Susannah S French
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA; The Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5205, USA.
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20
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Cusaac JPW, Kremer V, Wright R, Henry C, Otter RR, Bailey FC. Effects of Maternally-Transferred Methylmercury on Stress Physiology in Northern Water Snake (Nerodia sipedon) Neonates. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 96:725-731. [PMID: 26886428 DOI: 10.1007/s00128-016-1757-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/12/2016] [Indexed: 06/05/2023]
Abstract
Biomagnification of methylmercury in aquatic systems can cause elevated tissue mercury (Hg) and physiological stress in top predators. Mercury is known to affect stress hormone levels in mammals, birds and fish. In this study, the effects of maternally-transferred methylmercury on the stress physiology of Northern Water Snake (Nerodia sipedon) neonates were tested. Gravid females were dosed via force-fed capsules during late gestation with 0, 0.01, or 10 µg methylmercury per gram of body mass. Plasma corticosterone levels and leukocyte differentials were analyzed in baseline and confinement-stressed neonates from all dose levels. Neither Hg nor confinement stress had a significant effect on leukocyte differentials nor was Hg related to corticosterone levels. However, stress group neonates showed lower heterophil/lymphocyte ratios and this study was the first to show that neonate N. sipedon can upregulate CORT in response to stress. These results indicate that N. sipedon may be somewhat tolerant to Hg contamination.
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Affiliation(s)
- J Patrick W Cusaac
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
- Department of Zoology, Oklahoma State University, Stillwater, OK, 74075, USA
| | - Victoria Kremer
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Raymond Wright
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Cassandra Henry
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Ryan R Otter
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
| | - Frank C Bailey
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
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21
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Polich RL. Stress hormone levels in a freshwater turtle from sites differing in human activity. CONSERVATION PHYSIOLOGY 2016; 4:cow016. [PMID: 27293763 PMCID: PMC4892809 DOI: 10.1093/conphys/cow016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/14/2016] [Accepted: 04/09/2016] [Indexed: 05/26/2023]
Abstract
Glucocorticoids, such as corticosterone (CORT), commonly serve as a measure of stress levels in vertebrate populations. These hormones have been implicated in regulation of feeding behaviour, locomotor activity, body mass, lipid metabolism and other crucial behaviours and physiological processes. Thus, understanding how glucocorticoids fluctuate seasonally and in response to specific stressors can yield insight into organismal health and the overall health of populations. I compared circulating CORT concentrations between two similar populations of painted turtle, Chrysemys picta, which differed primarily in the level of exposure to human recreational activities. I measured basal CORT concentrations as well as the CORT stress response and did not find any substantive difference between the two populations. This similarity may indicate that painted turtles are not stressed by the presence of humans during the nesting season. The results of this study contribute to our understanding of CORT concentrations in freshwater reptiles, a group that is historically under-represented in studies of circulating hormone concentrations; specifically, studies that seek to use circulating concentrations of stress hormones, such as CORT, as a measure of the effect of human activities on wild populations. They also give insight into how these species as a whole may respond to human recreational activities during crucial life-history stages, such as the nesting season. Although there was no discernable difference between circulating CORT concentrations between the urban and rural populations studied, I did find a significant difference in circulating CORT concentrations between male and female C. picta. This important finding provides better understanding of the sex differences between male and female painted turtles and adds to our understanding of this species and other species of freshwater turtle.
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Affiliation(s)
- Rebecca L. Polich
- Corresponding author: Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA. Tel: +1 818 585 9763.
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22
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Gangloff EJ, Holden KG, Telemeco RS, Baumgard LH, Bronikowski AM. Hormonal and metabolic responses to upper temperature extremes in divergent life-history ecotypes of a garter snake. J Exp Biol 2016; 219:2944-2954. [DOI: 10.1242/jeb.143107] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/15/2016] [Indexed: 01/03/2023]
Abstract
Extreme temperatures constrain organismal physiology and impose both acute and chronic effects. Additionally, temperature-induced hormone-mediated stress response pathways and energetic trade-offs are important drivers of life-history variation. This study employs an integrative approach to quantify acute physiological responses to high temperatures in divergent life-history ecotypes of the western terrestrial garter snake (Thamnophis elegans). Using wild-caught animals, we measured oxygen consumption rate and physiological markers of hormonal stress response, energy availability, and anaerobic respiration in blood plasma across five ecologically relevant temperatures (24, 28, 32, 35, and 38° C; 3-hour exposure). Corticosterone, insulin, and glucose concentrations all increased with temperature, but with different thermal response curves, suggesting that high temperatures differently affect energy-regulation pathways. Additionally, oxygen consumption rate increased without plateau and lactate concentration did not increase with temperature, challenging the recent hypothesis that oxygen limitation sets upper thermal tolerance limits. Finally, animals had similar physiological thermal responses to high-temperature exposure regardless of genetic background, suggesting that local adaptation has not resulted in fixed differences between ecotypes. Together, these results identify some of the mechanisms by which higher temperatures alter hormonal-mediated energy balance in reptiles and potential limits to the flexibility of this response.
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Affiliation(s)
- Eric J. Gangloff
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Kaitlyn G. Holden
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Rory S. Telemeco
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Present Address: Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Lance H. Baumgard
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Anne M. Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
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23
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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.
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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
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24
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Halliday WD, Gilmour KM, Blouin-Demers G. Faecal corticosterone metabolite concentrations are not a good predictor of habitat suitability for common gartersnakes. CONSERVATION PHYSIOLOGY 2015; 3:cov047. [PMID: 27293731 PMCID: PMC4778491 DOI: 10.1093/conphys/cov047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/02/2015] [Accepted: 09/11/2015] [Indexed: 06/06/2023]
Abstract
Measuring habitat suitability is important in conservation and in wildlife management. Measuring the abundance or presence-absence of a species in various habitats is not sufficient to measure habitat suitability because these metrics can be poor predictors of population success. Therefore, having some measure of population success is essential in assessing habitat suitability, but estimating population success is difficult. Identifying suitable proxies for population success could thus be beneficial. We examined whether faecal corticosterone metabolite (fCM) concentrations could be used as a proxy for habitat suitability in common gartersnakes (Thamnophis sirtalis). We conducted a validation study and confirmed that fCM concentrations indeed reflect circulating corticosterone concentrations. We estimated abundance, reproductive output and growth rate of gartersnakes in field and in forest habitat and we also measured fCM concentrations of gartersnakes from these same habitats. Common gartersnakes were more abundant and had higher reproductive outputs and higher growth rates in field habitat than in forest habitat, but fCM concentrations did not differ between the same two habitats. Our results suggest either that fCM concentrations are not a useful metric of habitat suitability in common gartersnakes or that the difference in suitability between the two habitats was too small to induce changes in fCM concentrations. Incorporating fitness metrics in estimates of habitat suitability is important, but these metrics of fitness have to be sensitive enough to vary between habitats.
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Affiliation(s)
- William D Halliday
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Gabriel Blouin-Demers
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5
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25
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Mitochondrial divergence between slow- and fast-aging garter snakes. Exp Gerontol 2015; 71:135-46. [PMID: 26403677 DOI: 10.1016/j.exger.2015.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/03/2015] [Accepted: 09/04/2015] [Indexed: 01/26/2023]
Abstract
Mitochondrial function has long been hypothesized to be intimately involved in aging processes--either directly through declining efficiency of mitochondrial respiration and ATP production with advancing age, or indirectly, e.g., through increased mitochondrial production of damaging free radicals with age. Yet we lack a comprehensive understanding of the evolution of mitochondrial genotypes and phenotypes across diverse animal models, particularly in species that have extremely labile physiology. Here, we measure mitochondrial genome-types and transcription in ecotypes of garter snakes (Thamnophis elegans) that are adapted to disparate habitats and have diverged in aging rates and lifespans despite residing in close proximity. Using two RNA-seq datasets, we (1) reconstruct the garter snake mitochondrial genome sequence and bioinformatically identify regulatory elements, (2) test for divergence of mitochondrial gene expression between the ecotypes and in response to heat stress, and (3) test for sequence divergence in mitochondrial protein-coding regions in these slow-aging (SA) and fast-aging (FA) naturally occurring ecotypes. At the nucleotide sequence level, we confirmed two (duplicated) mitochondrial control regions one of which contains a glucocorticoid response element (GRE). Gene expression of protein-coding genes was higher in FA snakes relative to SA snakes for most genes, but was neither affected by heat stress nor an interaction between heat stress and ecotype. SA and FA ecotypes had unique mitochondrial haplotypes with amino acid substitutions in both CYTB and ND5. The CYTB amino acid change (Isoleucine → Threonine) was highly segregated between ecotypes. This divergence of mitochondrial haplotypes between SA and FA snakes contrasts with nuclear gene-flow estimates, but correlates with previously reported divergence in mitochondrial function (mitochondrial oxygen consumption, ATP production, and reactive oxygen species consequences).
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26
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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: 54] [Impact Index Per Article: 6.0] [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.
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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
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27
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Maternal investment influences development of behavioural syndrome in swordtail fish, Xiphophorus multilineatus. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.02.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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28
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Neuman-Lee LA, Stokes AN, Greenfield S, Hopkins GR, Brodie ED, French SS. The role of corticosterone and toxicity in the antipredator behavior of the Rough-skinned Newt (Taricha granulosa). Gen Comp Endocrinol 2015; 213:59-64. [PMID: 25556312 DOI: 10.1016/j.ygcen.2014.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 01/26/2023]
Abstract
A variety of mechanisms are responsible for enabling an organism to escape a predatory attack, including behavioral changes, alterations in hormone levels, and production and/or secretion of toxins. However, these mechanisms are rarely studied in conjunction with each other. The Rough-skinned Newt (Taricha granulosa) is an ideal organism to examine the relationships between these mechanisms because its behavioral displays and toxin secretion during a predator attack are well documented and readily characterized. While we found no direct relationship between antipredator behavior and endogenous levels of corticosterone (CORT), antipredator behavior was inhibited when exogenous CORT and adrenocorticotropic hormone (ACTH) were administered, resulting in high circulating concentrations of CORT, indicating that CORT may play a role in mediating the behavior. There was no correlation between the animal's toxicity and either CORT or behavior. The results of this study provide evidence that CORT plays an important, yet complex, role in the antipredator response of these amphibians.
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Affiliation(s)
- Lorin A Neuman-Lee
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States.
| | - Amber N Stokes
- Department of Biology, California State University, 9001 Stockdale Highway, Bakersfield, CA 93311-1022, United States.
| | - Sydney Greenfield
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States.
| | - Gareth R Hopkins
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5305, United States.
| | - Edmund D Brodie
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5305, United States.
| | - Susannah S French
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States; Ecology Center, Utah State University, 5205 Old Main Hill, Logan, UT 84322-5305, United States.
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29
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Refsnider JM, Palacios MG, Reding DM, Bronikowski AM. Effects of a novel climate on stress response and immune function in painted turtles (Chrysemys picta). ACTA ACUST UNITED AC 2015; 323:160-8. [DOI: 10.1002/jez.1902] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 10/06/2014] [Indexed: 01/25/2023]
Affiliation(s)
- Jeanine M. Refsnider
- Department of Ecology; Evolution and Organismal Biology; Iowa State University; Ames Iowa
| | - Maria G. Palacios
- Department of Ecology; Evolution and Organismal Biology; Iowa State University; Ames Iowa
| | - Dawn M. Reding
- Department of Ecology; Evolution and Organismal Biology; Iowa State University; Ames Iowa
| | - Anne M. Bronikowski
- Department of Ecology; Evolution and Organismal Biology; Iowa State University; Ames Iowa
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30
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Telemeco RS, Addis EA. Temperature has species-specific effects on corticosterone in alligator lizards. Gen Comp Endocrinol 2014; 206:184-92. [PMID: 25019656 DOI: 10.1016/j.ygcen.2014.07.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 07/03/2014] [Accepted: 07/06/2014] [Indexed: 11/26/2022]
Abstract
In response to conditions that threaten homeostasis and/or life, vertebrates generally increase production of glucocorticoid hormones, such as corticosterone (CORT), which induces an emergency physiological state referred to as the stress response. Given that extreme temperatures pose a threat to performance and survival, glucocorticoid upregulation might be an important component of a vertebrate ectotherm's response to extreme thermal conditions. To address this hypothesis, we experimentally examined the effects of body temperature (10, 20, 28, and 35°C; 5-h exposure) on CORT in two congeneric species of lizard naturally exposed to different thermal environments, northern and southern alligator lizards (Elgaria coerulea and Elgaria multicarinata, respectively). In both species, CORT was similarly elevated at medium and high temperatures (28 and 35°C, respectively), but CORT was only elevated at low temperatures (10°C) in southern alligator lizards. We also examined CORT before and after adrenocorticotrophic hormone (ACTH) challenge. In both species, ACTH induced higher CORT levels than any temperature, suggesting that these animals could respond to further stressors at all experimental temperatures. Finally, we compared our laboratory results to measurements of CORT in field-active southern alligator lizards. Plasma CORT concentrations from our laboratory experiment had the same mean and less variance than the field lizards, suggesting that our laboratory lizards displayed CORT within natural levels. Our results demonstrate that body temperature directly affects CORT in alligator lizards. Moreover, the CORT response of these lizards appears to be adapted to their respective thermal environments. Species-specific differences in the thermal CORT response might be common in vertebrate ectotherms and have implications for species' biogeography and responses to climate change.
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Affiliation(s)
- Rory S Telemeco
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.
| | - Elizabeth A Addis
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA; Department of Biology, Gonzaga University, Spokane, WA, USA.
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31
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Neuman-Lee LA, Gaines KF, Baumgartner KA, Voorhees JR, Novak JM, Mullin SJ. Assessing multiple endpoints of atrazine ingestion on gravid Northern Watersnakes (Nerodia sipedon) and their offspring. ENVIRONMENTAL TOXICOLOGY 2014; 29:1072-1082. [PMID: 23436772 DOI: 10.1002/tox.21837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/07/2012] [Indexed: 06/01/2023]
Abstract
Ecotoxicological studies that focus on a single endpoint might not accurately and completely represent the true ecological effects of a contaminant. Exposure to atrazine, a widely used herbicide, disrupts endocrine function and sexual development in amphibians, but studies involving live-bearing reptiles are lacking. This study tracks several effects of atrazine ingestion from female Northern Watersnakes (Nerodia sipedon) to their offspring exposed in utero. Twenty-five gravid N. sipedon were fed fish dosed with one of the four levels of atrazine (0, 2, 20, or 200 ppb) twice weekly for the entirety of their gestation period. Endpoints for the mothers included blood estradiol levels measured weekly and survival more than 3 months. Endpoints for the offspring included morphometrics, clutch sex ratio, stillbirth, and asymmetry of dorsal scales and jaw length. Through these multiple endpoints, we show that atrazine ingestion can disrupt estradiol production in mothers, increase the likelihood of mortality from infection, alter clutch sex ratio, cause a higher proportion of stillborn offspring, and affect scale symmetry. We emphasize the need for additional research involving other reptile species using multiple endpoints to determine the full range of impacts of contaminant exposure.
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Affiliation(s)
- Lorin A Neuman-Lee
- Department of Biological Sciences, Eastern Illinois University, Charleston, Illinois 61920, USA
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McCormick GL, Langkilde T. Immune responses of eastern fence lizards (Sceloporus undulatus) to repeated acute elevation of corticosterone. Gen Comp Endocrinol 2014; 204:135-40. [PMID: 24852352 DOI: 10.1016/j.ygcen.2014.04.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 04/15/2014] [Accepted: 04/23/2014] [Indexed: 01/03/2023]
Abstract
Prolonged elevations of glucocorticoids due to long-duration (chronic) stress can suppress immune function. It is unclear, however, how natural stressors that result in repeated short-duration (acute) stress, such as frequent agonistic social encounters or predator attacks, fit into our current understanding of the immune consequences of stress. Since these types of stressors may activate the immune system due to increased risk of injury, immune suppression may be reduced at sites where individuals are repeatedly exposed to potentially damaging stressors. We tested whether repeated acute elevation of corticosterone (CORT, a glucocorticoid) suppresses immune function in eastern fence lizards (Sceloporus undulatus), and whether this effect varies between lizards from high-stress (high baseline CORT, invaded by predatory fire ants) and low-stress (low baseline CORT, uninvaded) sites. Lizards treated daily with exogenous CORT showed higher hemagglutination of novel proteins by their plasma (a test of constitutive humoral immunity) than control lizards, a pattern that was consistent across sites. There was no significant effect of CORT treatment on bacterial killing ability of plasma. These results suggest that repeated elevations of CORT, which are common in nature, produce immune effects more typical of those expected at the acute end of the acute-chronic spectrum and provide no evidence of modulated consequences of elevated CORT in animals from high-stress sites.
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Affiliation(s)
- Gail L McCormick
- Intercollege Graduate Degree Program in Ecology, Department of Biology, and The Center for Brain, Behavior and Cognition, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802, USA.
| | - Tracy Langkilde
- Intercollege Graduate Degree Program in Ecology, Department of Biology, and The Center for Brain, Behavior and Cognition, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802, USA
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Sparkman AM, Bronikowski AM, Williams S, Parsai S, Manhart W, Palacios MG. Physiological indices of stress in wild and captive garter snakes: Correlations, repeatability, and ecological variation. Comp Biochem Physiol A Mol Integr Physiol 2014; 174:11-7. [DOI: 10.1016/j.cbpa.2014.03.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 11/26/2022]
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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.
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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.
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Palacios MG, Cunnick JE, Bronikowski AM. Complex interplay of body condition, life history, and prevailing environment shapes immune defenses of garter snakes in the wild. Physiol Biochem Zool 2013; 86:547-58. [PMID: 23995485 DOI: 10.1086/672371] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The immunocompetence "pace-of-life" hypothesis proposes that fast-living organisms should invest more in innate immune defenses and less in adaptive defenses compared to slow-living ones. We found some support for this hypothesis in two life-history ecotypes of the snake Thamnophis elegans; fast-living individuals show higher levels of innate immunity compared to slow-living ones. Here, we optimized a lymphocyte proliferation assay to assess the complementary prediction that slow-living snakes should in turn show stronger adaptive defenses. We also assessed the "environmental" hypothesis that predicts that slow-living snakes should show lower levels of immune defenses (both innate and adaptive) given the harsher environment they live in. Proliferation of B- and T-lymphocytes of free-living individuals was on average higher in fast-living than slow-living snakes, opposing the pace-of-life hypothesis and supporting the environmental hypothesis. Bactericidal capacity of plasma, an index of innate immunity, did not differ between fast-living and slow-living snakes in this study, contrasting the previously documented pattern and highlighting the importance of annual environmental conditions as determinants of immune profiles of free-living animals. Our results do not negate a link between life history and immunity, as indicated by ecotype-specific relationships between lymphocyte proliferation and body condition, but suggest more subtle nuances than those currently proposed.
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Affiliation(s)
- Maria G Palacios
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011, USA.
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Citadini JM, Navas CA. Inter-individual variation and temperature-dependent antipredator behavior in the snake Tomodon dorsatus (Dipsadidae). Behav Processes 2013; 97:11-7. [PMID: 23548560 DOI: 10.1016/j.beproc.2013.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/14/2013] [Indexed: 11/17/2022]
Abstract
Although many studies assessed the influence of temperature on the behavior of ectotermic vertebrates, little attention has been given to interindividual variation in the defensive responses of reptiles. In the present study we investigated the defensive behavior of the snake Tomodon dorsatus, in order to test the hypotheses that (1) individuals differ in their antipredator behavior consistently with the concept of behavioral syndromes, (2) temperature influences the defensive behavior, and (3) these two factors interact with each other. There was significant interindividual variation in defensive behavior, as well as consistently aggressive, passive or evasive behaviors. Temperature influenced aggressiveness, which was slightly higher when body temperature was lower, but this trend was only evident in animals with aggressive disposition. Our results corroborate the hypothesis of interaction between individuality of behavior and temperature-dependent defensive behavior in T. dorsatus. These results, together with results from previous studies, suggest that the evolution of temperature-dependent defensive behavior differs among lineages of ectothermic tetrapods. This article is part of a Special Issue entitled: insert SI title.
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Affiliation(s)
- Jessyca Michele Citadini
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav. 14, n° 321, Cidade Universitária, CEP: 05508-090 São Paulo, SP, Brazil
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Schwartz TS, Bronikowski AM. Dissecting molecular stress networks: identifying nodes of divergence between life-history phenotypes. Mol Ecol 2012; 22:739-56. [DOI: 10.1111/j.1365-294x.2012.05750.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 06/08/2012] [Accepted: 06/28/2012] [Indexed: 11/29/2022]
Affiliation(s)
- Tonia S. Schwartz
- Ecology, Evolution and Organismal Biology Department; 251 Bessey Hall Iowa State, University; Ames; Iowa; 50011
| | - Anne M. Bronikowski
- Ecology, Evolution and Organismal Biology Department; 251 Bessey Hall Iowa State, University; Ames; Iowa; 50011
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Meylan S, Miles DB, Clobert J. Hormonally mediated maternal effects, individual strategy and global change. Philos Trans R Soc Lond B Biol Sci 2012; 367:1647-64. [PMID: 22566673 DOI: 10.1098/rstb.2012.0020] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A challenge to ecologists and evolutionary biologists is predicting organismal responses to the anticipated changes to global ecosystems through climate change. Most evidence suggests that short-term global change may involve increasing occurrences of extreme events, therefore the immediate response of individuals will be determined by physiological capacities and life-history adaptations to cope with extreme environmental conditions. Here, we consider the role of hormones and maternal effects in determining the persistence of species in altered environments. Hormones, specifically steroids, are critical for patterning the behaviour and morphology of parents and their offspring. Hence, steroids have a pervasive influence on multiple aspects of the offspring phenotype over its lifespan. Stress hormones, e.g. glucocorticoids, modulate and perturb phenotypes both early in development and later into adulthood. Females exposed to abiotic stressors during reproduction may alter the phenotypes by manipulation of hormones to the embryos. Thus, hormone-mediated maternal effects, which generate phenotypic plasticity, may be one avenue for coping with global change. Variation in exposure to hormones during development influences both the propensity to disperse, which alters metapopulation dynamics, and population dynamics, by affecting either recruitment to the population or subsequent life-history characteristics of the offspring. We suggest that hormones may be an informative index to the potential for populations to adapt to changing environments.
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Affiliation(s)
- Sandrine Meylan
- Laboratoire Ecologie-Evolution, CNRS UMR 7625, Université Pierre et Marie Curie-Paris 6, 7 quai Saint Bernard, 75252 Paris cedex 05, France
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Smith CF, Schuett GW, Hoss SK. Reproduction in female copperhead snakes (Agkistrodon contortrix): plasma steroid profiles during gestation and post-birth periods. Zoolog Sci 2012; 29:273-9. [PMID: 22468838 DOI: 10.2108/zsj.29.273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated levels of plasma progesterone (P4), 17β-estradiol (E2), testosterone (T), and corticosterone (CORT) during gestation and post-birth periods in wild-collected female copperhead snakes (Viperidae; Agkistrodon contortrix). We also sought to determine whether CORT levels at (or near) birth dramatically increase and were correlated with duration of labor and litter size. Specifically, pregnant subjects (N = 14) were collected during early- to mid-gestation, held in the laboratory, and repeatedly bled to obtain plasma for steroid analyses. Progesterone showed significant changes during gestation, with the highest levels at the onset of sampling (circa 50 days prior to birth); P4 progressively declined up to parturition, and basal levels were observed thereafter. At the onset of sampling, E2 was at peak levels and fell sharply at circa 30 days prior to birth, a trend observed throughout the post-birth sampling period. Throughout the entire sampling period, T was undetectable. Although CORT showed no significant changes during gestation and several days following parturition, there was a highly significant peak at the time of birth. Our findings mirror the results of previous studies on pregnancy and steroid hormones of other live-bearing snakes, lizards, and mammals. As expected, there was a significant relationship between duration of labor and litter size; however, although levels of CORT did not achieve significance, there was a positive trend with litter size. We suggest that elevation of CORT at birth is involved in the mobilization and regulation of energy stores necessary for the physiological process of parturition and as a possible mechanism to trigger birth.
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Affiliation(s)
- Charles F Smith
- Department of Ecology and Evolutionary Biology, The University of Connecticut, Storrs, Connecticut 06269-3043, USA.
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40
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Palacios MG, Sparkman AM, Bronikowski AM. Corticosterone and pace of life in two life-history ecotypes of the garter snake Thamnophis elegans. Gen Comp Endocrinol 2012; 175:443-8. [PMID: 22178432 DOI: 10.1016/j.ygcen.2011.11.042] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 11/21/2011] [Accepted: 11/24/2011] [Indexed: 11/29/2022]
Abstract
Glucocorticoids are main candidates for mediating life-history trade-offs by regulating the balance between current reproduction and survival. It has been proposed that slow-living organisms should show higher stress-induced glucocorticoid levels that favor self-maintenance rather than current reproduction when compared to fast-living organisms. We tested this hypothesis in replicate populations of two ecotypes of the garter snake (Thamnophis elegans) that exhibit slow and fast pace of life strategies. We subjected free-ranging snakes to a capture-restraint protocol and compared the stress-induced corticosterone levels between slow- and fast-living snakes. We also used a five-year dataset to assess whether baseline corticosterone levels followed the same pattern as stress-induced levels in relation to pace of life. In accordance with the hypothesis, slow-living snakes showed higher stress-induced corticosterone levels than fast-living snakes. Baseline corticosterone levels showed a similar pattern with ecotype, although differences depended on the year of study. Overall, however, levels of glucocorticoids are higher in slow-living than fast-living snakes, which should favor self-maintenance and survival at the expense of current reproduction. The results of the present study are the first to relate glucocorticoid levels and pace of life in a reptilian system and contribute to our understanding of the physiological mechanisms involved in life-history evolution.
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Affiliation(s)
- Maria G Palacios
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA.
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41
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Blood corticosterone levels and intersexual selection games: best-of-bad-job strategies of male common lizards. Behav Ecol Sociobiol 2011. [DOI: 10.1007/s00265-011-1278-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Trompeter WP, Langkilde T. Invader danger: lizards faced with novel predators exhibit an altered behavioral response to stress. Horm Behav 2011; 60:152-8. [PMID: 21549122 DOI: 10.1016/j.yhbeh.2011.04.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 04/08/2011] [Accepted: 04/14/2011] [Indexed: 01/30/2023]
Abstract
Animals respond to stressors by producing glucocorticoid stress hormones, such as corticosterone (CORT). CORT acts too slowly to trigger immediate behavioral responses to a threat, but can change longer-term behavior, facilitating an individual's survival to subsequent threats. To be adaptive, the nature of an animal's behavior following elevated CORT levels should be matched to the predominant threats that they face. Seeking refuge following a stressful encounter could be beneficial if the predominant predator is a visual hunter, but may prove detrimental when the predominant predator is able to enter these refuge sites. As a result, an individual's behavior when their CORT levels are high may differ among populations of a single species. Invasive species impose novel pressures on native populations, which may select for a shift in their behavior when CORT levels are high. We tested whether the presence of predatory invasive fire ants (Solenopsis invicta) at a site affects the behavioral response of native eastern fence lizards (Sceloporus undulatus) to elevated CORT levels. Lizards from an uninvaded site were more likely to hide when their CORT levels were experimentally elevated; a response that likely provides a survival advantage for lizards faced with native predatory threats (e.g. birds and snakes). Lizards from a fire ant invaded site showed the opposite response; spending more time moving and up on the basking log when their CORT levels were elevated. Use of the basking log likely reflects a refuge-seeking behavior, rather than thermoregulatory activity, as selected body temperatures were not affected by CORT. Fleeing off the ground may prove more effective than hiding for lizards that regularly encounter small, terrestrially-foraging fire ant predators. This study suggests that invasive species may alter the relationship between the physiological and behavioral stress response of native species.
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Henriksen R, Rettenbacher S, Groothuis TG. Prenatal stress in birds: Pathways, effects, function and perspectives. Neurosci Biobehav Rev 2011; 35:1484-501. [DOI: 10.1016/j.neubiorev.2011.04.010] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 04/10/2011] [Accepted: 04/13/2011] [Indexed: 02/04/2023]
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Palacios MG, Sparkman AM, Bronikowski AM. Developmental plasticity of immune defence in two life-history ecotypes of the garter snake, Thamnophis elegans - a common-environment experiment. J Anim Ecol 2010; 80:431-7. [DOI: 10.1111/j.1365-2656.2010.01785.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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45
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A garter snake transcriptome: pyrosequencing, de novo assembly, and sex-specific differences. BMC Genomics 2010; 11:694. [PMID: 21138572 PMCID: PMC3014983 DOI: 10.1186/1471-2164-11-694] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 12/07/2010] [Indexed: 12/19/2022] Open
Abstract
Background The reptiles, characterized by both diversity and unique evolutionary adaptations, provide a comprehensive system for comparative studies of metabolism, physiology, and development. However, molecular resources for ectothermic reptiles are severely limited, hampering our ability to study the genetic basis for many evolutionarily important traits such as metabolic plasticity, extreme longevity, limblessness, venom, and freeze tolerance. Here we use massively parallel sequencing (454 GS-FLX Titanium) to generate a transcriptome of the western terrestrial garter snake (Thamnophis elegans) with two goals in mind. First, we develop a molecular resource for an ectothermic reptile; and second, we use these sex-specific transcriptomes to identify differences in the presence of expressed transcripts and potential genes of evolutionary interest. Results Using sex-specific pools of RNA (one pool for females, one pool for males) representing 7 tissue types and 35 diverse individuals, we produced 1.24 million sequence reads, which averaged 366 bp in length after cleaning. Assembly of the cleaned reads from both sexes with NEWBLER and MIRA resulted in 96,379 contigs containing 87% of the cleaned reads. Over 34% of these contigs and 13% of the singletons were annotated based on homology to previously identified proteins. From these homology assignments, additional clustering, and ORF predictions, we estimate that this transcriptome contains ~13,000 unique genes that were previously identified in other species and over 66,000 transcripts from unidentified protein-coding genes. Furthermore, we use a graph-clustering method to identify contigs linked by NEWBLER-split reads that represent divergent alleles, gene duplications, and alternatively spliced transcripts. Beyond gene identification, we identified 95,295 SNPs and 31,651 INDELs. From these sex-specific transcriptomes, we identified 190 genes that were only present in the mRNA sequenced from one of the sexes (84 female-specific, 106 male-specific), and many highly variable genes of evolutionary interest. Conclusions This is the first large-scale, multi-organ transcriptome for an ectothermic reptile. This resource provides the most comprehensive set of EST sequences available for an individual ectothermic reptile species, increasing the number of snake ESTs 50-fold. We have identified genes that appear to be under evolutionary selection and those that are sex-specific. This resource will assist studies on gene expression and comparative genomics, and will facilitate the study of evolutionarily important traits at the molecular level.
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Wack CL, Lovern MB, Woodley SK. Transdermal delivery of corticosterone in terrestrial amphibians. Gen Comp Endocrinol 2010; 169:269-75. [PMID: 20850442 DOI: 10.1016/j.ygcen.2010.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/17/2010] [Accepted: 09/09/2010] [Indexed: 11/27/2022]
Abstract
Stressors elicit allostatic responses that allow animals to cope with changing and challenging environments and also cause release of glucocorticoid hormones (GCs). Compared to other vertebrate classes, relatively little is known about amphibian behavioral and physiological responses to GCs. To understand the effects of elevated plasma GCs in amphibians, exogenous application of GCs is necessary, but traditional methods to elevate GCs require handling and/or anesthesia which themselves are stressors. A less invasive alternative successfully used in birds and reptiles utilizes transdermal delivery by applying GCs via a dermal patch. We asked whether dermal patches containing corticosterone (CORT, the main GC in amphibians) would elevate plasma CORT in terrestrial salamanders and frogs. We explored the use of the dermal patch to deliver CORT in an acute, sustained, and repeated manner. Patches adhered well to the amphibians' moist skin and were easily removed to regulate the time course of CORT delivery. Application of CORT treated patches elevated plasma CORT concentrations compared to vehicle patches in all species. Patches delivered physiological levels of plasma CORT in ecologically relevant time frames. Repeated application and removal of CORT patches were used to simulate exposure to repeated stressors. Application of patches did not represent a stressor because plasma CORT concentrations were similar between animals that received vehicle patches and untreated animals. Thus, transdermal delivery of GCs represents a potentially useful tool to better understand amphibian allostatic responses to stressors, and perhaps amphibian population declines.
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Affiliation(s)
- Corina L Wack
- Department of Biological Sciences, Duquesne University, 201 Mellon Hall, Pittsburgh, PA 15282, USA.
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47
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Bronikowski A, Vleck D. Metabolism, body size and life span: a case study in evolutionarily divergent populations of the garter snake (Thamnophis elegans). Integr Comp Biol 2010; 50:880-7. [PMID: 21558247 DOI: 10.1093/icb/icq132] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a case study of metabolism, life history and aging in the western terrestrial garter snake (Thamnophis elegans). Early research in the field supported the rate-of-living hypothesis as an explanation of aging, which was based on an apparent negative relationship between mass-specific metabolic rate and lifespan in endotherms. This hypothesis in its original form has not withstood additional tests and comparisons between the two main lineages of endotherms-birds and mammals, but there is still much to be discovered of the causative links among rate of oxygen consumption, physiology and life history, particularly in ectothermic reptiles. We present data that show adult short-lived snakes, from naturally occurring ecotypes of garter snakes, have higher mass-specific resting metabolic rates at any given body mass (metabolic intensity) across a series of normal activity temperatures (15-32°C). The short-lived ecotype in this geographic region reaches a larger body size, and has life-history traits that place it at the fast end of a pace-of-life continuum (fast growth, early maturation, high reproductive output) relative to individuals of the small-bodied long-lived ecotype. The difference between ecotypes in metabolic intensity, even after acclimation to identical conditions, may reflect evolutionary divergence and genetic differences between ecotypes. The difference in metabolic intensity is not, however, present at birth, so an alternative is that developmental environment may permanently influence metabolic rate and life history. Such developmental canalization could lead to altered gene expression via environmental influences on the epigenome and result in altered metabolic trajectories in the snakes' natural habitats.
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Affiliation(s)
- Anne Bronikowski
- Ecology, Evolution and Organismal Biology, 253 Bessey Hall, Iowa State University, Ames, IA 50011, USA.
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48
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Hare KM, Cree A. Incidence, causes and consequences of pregnancy failure in viviparous lizards: implications for research and conservation settings. Reprod Fertil Dev 2010; 22:761-70. [PMID: 20450828 DOI: 10.1071/rd09195] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 11/21/2009] [Indexed: 11/23/2022] Open
Abstract
Research on the causes of pregnancy failure in vertebrates has historically been mammal-focussed. However, live-birth (viviparity) has evolved multiple times, and is present in all other vertebrate taxa except Aves and Agnatha. Viviparous lizards (O. Squamata, excluding snakes and amphisbaenians) provide a valuable experimental group when studying major evolutionary events and some are also species of high conservation value. Consequently, both researchers and herpetoculturists often require high reproductive output from captive-held lizards. We reviewed the literature to determine potential or known causes of pregnancy failure for captive lizards. Pregnancy success across species averages approximately 86%, but varies extensively and does not appear to be related to embryonic stage when brought into captivity or level of placentation. Causes of pregnancy failure also vary among species, but correct thermal environments are vital to success, and providing adequate nutrition before vitellogenesis increases the number of viable offspring. A coordinated sequence of hormonal changes involving both pro-pregnancy and pro-labour factors is important for successful pregnancies, although uncertainty remains around the maternal concentrations of corticosterone that allow successful development. Several research areas commonly studied in mammals have yet to be explored or fully addressed in pregnant lizards, including impacts of toxins, parasites, UV light and nutritional quality. As viviparity has evolved over 100 times in lizards, and many different levels of placentation exist, pregnant lizards provide valuable models for studies in ecology and evolution and offer a useful comparison for studies on other viviparous vertebrates.
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Affiliation(s)
- Kelly M Hare
- Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
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49
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Robert K, Bronikowski A. Evolution of Senescence in Nature: Physiological Evolution in Populations of Garter Snake with Divergent Life Histories. Am Nat 2010; 175:147-59. [DOI: 10.1086/649595] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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50
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Barry M, Cockrem JF, Brunton DH. Seasonal variation in plasma corticosterone concentrations in wild and captive adult Duvaucel's geckos (Hoplodactylus duvaucelii) in New Zealand. AUST J ZOOL 2010. [DOI: 10.1071/zo10023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Most of New Zealand’s herpetofauna species are threatened and in decline. Yet, little is known about their basic physiology and endocrinology. This study examined plasma corticosterone (CORT) concentrations in a threatened endemic New Zealand reptile, the Duvaucel’s gecko, in relation to season, sex, body temperature, body condition and female reproductive condition (pregnant versus non-pregnant). In addition, seasonal plasma CORT concentrations were compared between captive geckos from a breeding facility and a wild population to determine whether concentrations of CORT were chronically elevated in captive lizards. Plasma CORT concentrations showed significant seasonal variation, but were not related to sex, body temperature, body condition or female reproductive condition. Geckos, which successfully bred in captivity each year, did not exhibit chronically elevated plasma CORT levels but showed an elevation of plasma CORT concentrations in summer compared with wild geckos. Information on basal CORT concentrations in species of conservation concern can be beneficial for improving their management and can aid in identifying and evaluating stress-related changes in hormone patterns of individuals and chronic stress, which is particularly relevant for threatened species breeding programs.
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