Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae

Detalhes bibliográficos
Autor(a) principal: Zena, Lucas A. [UNESP]
Data de Publicação: 2019
Outros Autores: Dillon, Danielle, Hunt, Kathleen E., Navas, Carlos A., Bicego, Kenia C. [UNESP], Buck, C. Loren
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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spelling 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
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