Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.ygcen.2018.06.006 http://hdl.handle.net/11449/185489 |
Resumo: | The tegu lizard Salvator merianae is a large, widely distributed teiid lizard endemic to South America that exhibits annual cycles of high activity during the spring and summer, and hibernation during winter. This pattern of activity and hibernation is accompanied by profound seasonal changes in physiology and behavior, including endothermy during the austral spring. The unusual combination of seasonal endothermy, hibernation and oviparity, in a non-avian, non-mammalian species, makes S. merianae an interesting subject for study of comparative aspects of endocrine regulation of seasonal changes in physiology. In the present study, we first validated commercially available immunoassay kits for quantification of hormone concentrations of the reproductive (testosterone, estradiol and progesterone), adrenal (corticosterone), and thyroid [thyroxine (T-4) and triiodothyronine (T-3)] axes in plasma of an outdoor, captive adult male and female S. merianae in southeastern Brazil. All assays exhibited parallelism and accuracy with S. merianae plasma. We next assessed patterns of concentration of these hormones across the annual cycle of S. merianae. Testosterone in males and estradiol in females peaked in spring coincident with the peak in reproductive behavior. Progesterone in females was significantly elevated in October coincident with putative ovulation when gravid females build nests. Thyroid hormones, known for regulating energy metabolism, varied seasonally with some sex-dependent differences. T-4 gradually increased from an annual nadir during pre-hibernation and hibernation to high concentrations during spring in both sexes. In contrast, T-3 did not vary seasonally in males, but females showed a two-fold increase in T-3 during the spring reproductive season. T-3 may be involved in energy investment during the seasonal production of large clutches of eggs. Corticosterone was significantly elevated during the active season in both sexes, suggesting its involvement in mobilization of energy stores and modulation of behavior (territoriality) and physiology. Ours is the first investigation of concurrent changes in reproductive, thyroid and adrenal hormone concentrations in this endemic and physiologically unique South American lizard. Our findings set the stage for future investigations to determine the extent to which these hormones influence activity and thermoregulation in S. merianae. |
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Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianaeHibernationEndothermyThyroid hormonesGonadal steroidsCorticosteroidsCircannual rhythmsThe tegu lizard Salvator merianae is a large, widely distributed teiid lizard endemic to South America that exhibits annual cycles of high activity during the spring and summer, and hibernation during winter. This pattern of activity and hibernation is accompanied by profound seasonal changes in physiology and behavior, including endothermy during the austral spring. The unusual combination of seasonal endothermy, hibernation and oviparity, in a non-avian, non-mammalian species, makes S. merianae an interesting subject for study of comparative aspects of endocrine regulation of seasonal changes in physiology. In the present study, we first validated commercially available immunoassay kits for quantification of hormone concentrations of the reproductive (testosterone, estradiol and progesterone), adrenal (corticosterone), and thyroid [thyroxine (T-4) and triiodothyronine (T-3)] axes in plasma of an outdoor, captive adult male and female S. merianae in southeastern Brazil. All assays exhibited parallelism and accuracy with S. merianae plasma. We next assessed patterns of concentration of these hormones across the annual cycle of S. merianae. Testosterone in males and estradiol in females peaked in spring coincident with the peak in reproductive behavior. Progesterone in females was significantly elevated in October coincident with putative ovulation when gravid females build nests. Thyroid hormones, known for regulating energy metabolism, varied seasonally with some sex-dependent differences. T-4 gradually increased from an annual nadir during pre-hibernation and hibernation to high concentrations during spring in both sexes. In contrast, T-3 did not vary seasonally in males, but females showed a two-fold increase in T-3 during the spring reproductive season. T-3 may be involved in energy investment during the seasonal production of large clutches of eggs. Corticosterone was significantly elevated during the active season in both sexes, suggesting its involvement in mobilization of energy stores and modulation of behavior (territoriality) and physiology. Ours is the first investigation of concurrent changes in reproductive, thyroid and adrenal hormone concentrations in this endemic and physiologically unique South American lizard. Our findings set the stage for future investigations to determine the extent to which these hormones influence activity and thermoregulation in S. merianae.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)University of Alaska Anchorage's Environment and Natural Resources InstituteNorthern Arizona University's Center for Bioengineering InnovationUniv Sao Paulo, Inst Biosci, Dept Physiol, BR-05508090 Sao Paulo, SP, BrazilSao Paulo State Univ, Coll Agr & Vet Sci, Dept Anim Morphol & Physiol, BR-14884900 Jaboticabal, SP, BrazilNatl Inst Sci & Technol Comparat Physiol, INCT Fisiol Comparada, Jaboticabal, BrazilNo Arizona Univ, Dept Biol Sci, Ctr Bioengn Innovat, Box 5640, Flagstaff, AZ 86011 USASao Paulo State Univ, Coll Agr & Vet Sci, Dept Anim Morphol & Physiol, BR-14884900 Jaboticabal, SP, BrazilFAPESP: 2017/01652-2FAPESP: 2015/04849-6FAPESP: 2014/16320-7Elsevier B.V.Universidade de São Paulo (USP)Universidade Estadual Paulista (Unesp)Natl Inst Sci & Technol Comparat PhysiolNo Arizona UnivZena, Lucas A. [UNESP]Dillon, DanielleHunt, Kathleen E.Navas, Carlos A.Bicego, Kenia C. [UNESP]Buck, C. Loren2019-10-04T12:35:58Z2019-10-04T12:35:58Z2019-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article134-143http://dx.doi.org/10.1016/j.ygcen.2018.06.006General And Comparative Endocrinology. San Diego: Academic Press Inc Elsevier Science, v. 273, p. 134-143, 2019.0016-6480http://hdl.handle.net/11449/18548910.1016/j.ygcen.2018.06.006WOS:000459951600015Web of Sciencereponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengGeneral And Comparative Endocrinologyinfo:eu-repo/semantics/openAccess2024-06-06T18:41:54Zoai:repositorio.unesp.br:11449/185489Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T19:21:47.911613Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
title |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
spellingShingle |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae Zena, Lucas A. [UNESP] Hibernation Endothermy Thyroid hormones Gonadal steroids Corticosteroids Circannual rhythms |
title_short |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
title_full |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
title_fullStr |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
title_full_unstemmed |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
title_sort |
Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae |
author |
Zena, Lucas A. [UNESP] |
author_facet |
Zena, Lucas A. [UNESP] Dillon, Danielle Hunt, Kathleen E. Navas, Carlos A. Bicego, Kenia C. [UNESP] Buck, C. Loren |
author_role |
author |
author2 |
Dillon, Danielle Hunt, Kathleen E. Navas, Carlos A. Bicego, Kenia C. [UNESP] Buck, C. Loren |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
Universidade de São Paulo (USP) Universidade Estadual Paulista (Unesp) Natl Inst Sci & Technol Comparat Physiol No Arizona Univ |
dc.contributor.author.fl_str_mv |
Zena, Lucas A. [UNESP] Dillon, Danielle Hunt, Kathleen E. Navas, Carlos A. Bicego, Kenia C. [UNESP] Buck, C. Loren |
dc.subject.por.fl_str_mv |
Hibernation Endothermy Thyroid hormones Gonadal steroids Corticosteroids Circannual rhythms |
topic |
Hibernation Endothermy Thyroid hormones Gonadal steroids Corticosteroids Circannual rhythms |
description |
The tegu lizard Salvator merianae is a large, widely distributed teiid lizard endemic to South America that exhibits annual cycles of high activity during the spring and summer, and hibernation during winter. This pattern of activity and hibernation is accompanied by profound seasonal changes in physiology and behavior, including endothermy during the austral spring. The unusual combination of seasonal endothermy, hibernation and oviparity, in a non-avian, non-mammalian species, makes S. merianae an interesting subject for study of comparative aspects of endocrine regulation of seasonal changes in physiology. In the present study, we first validated commercially available immunoassay kits for quantification of hormone concentrations of the reproductive (testosterone, estradiol and progesterone), adrenal (corticosterone), and thyroid [thyroxine (T-4) and triiodothyronine (T-3)] axes in plasma of an outdoor, captive adult male and female S. merianae in southeastern Brazil. All assays exhibited parallelism and accuracy with S. merianae plasma. We next assessed patterns of concentration of these hormones across the annual cycle of S. merianae. Testosterone in males and estradiol in females peaked in spring coincident with the peak in reproductive behavior. Progesterone in females was significantly elevated in October coincident with putative ovulation when gravid females build nests. Thyroid hormones, known for regulating energy metabolism, varied seasonally with some sex-dependent differences. T-4 gradually increased from an annual nadir during pre-hibernation and hibernation to high concentrations during spring in both sexes. In contrast, T-3 did not vary seasonally in males, but females showed a two-fold increase in T-3 during the spring reproductive season. T-3 may be involved in energy investment during the seasonal production of large clutches of eggs. Corticosterone was significantly elevated during the active season in both sexes, suggesting its involvement in mobilization of energy stores and modulation of behavior (territoriality) and physiology. Ours is the first investigation of concurrent changes in reproductive, thyroid and adrenal hormone concentrations in this endemic and physiologically unique South American lizard. Our findings set the stage for future investigations to determine the extent to which these hormones influence activity and thermoregulation in S. merianae. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-10-04T12:35:58Z 2019-10-04T12:35:58Z 2019-03-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1016/j.ygcen.2018.06.006 General And Comparative Endocrinology. San Diego: Academic Press Inc Elsevier Science, v. 273, p. 134-143, 2019. 0016-6480 http://hdl.handle.net/11449/185489 10.1016/j.ygcen.2018.06.006 WOS:000459951600015 |
url |
http://dx.doi.org/10.1016/j.ygcen.2018.06.006 http://hdl.handle.net/11449/185489 |
identifier_str_mv |
General And Comparative Endocrinology. San Diego: Academic Press Inc Elsevier Science, v. 273, p. 134-143, 2019. 0016-6480 10.1016/j.ygcen.2018.06.006 WOS:000459951600015 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
General And Comparative Endocrinology |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
134-143 |
dc.publisher.none.fl_str_mv |
Elsevier B.V. |
publisher.none.fl_str_mv |
Elsevier B.V. |
dc.source.none.fl_str_mv |
Web of Science reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808129059098460160 |