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Rocha ELB, da Silva LGVP, Barreto INR, Magalhães MDS, Dias LC, Matias de Oliveira RE, Braz JKFDS, de Oliveira MF, de Moura CEB. Gonadal Morphology of Stillborn Hawksbill Sea Turtle (Eretmochelys imbricata) Hatchlings. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2024; 30:169-177. [PMID: 38252589 DOI: 10.1093/micmic/ozae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/20/2023] [Accepted: 01/06/2024] [Indexed: 01/24/2024]
Abstract
This study aimed to investigate sexual dimorphism in stillborn hawksbill sea turtles (Eretmochelys imbricata) through gonadal morphological characterizations. Macroscopic, light microscopy, and transmission electron analyses were performed for 30 gonad-mesonephros complexes. Female gonads were spindle-shaped and present a translucent whitish appearance with a grainy texture. Male gonads were approximately ovoid with a smooth opaque white surface. A primary sexual difference concerns different marrow structures, with females presenting organized cellularity featuring oocytes, lacunae, and blood vessels, while males presented a distinct organizational medulla pattern marked by testicular cords extending throughout the gonad length. Ultrastructurally, female's stroma presented interstitial cells and an abundant cytoplasm rich in electrodense droplets and large oval germline cells, with a conspicuous and noncentral nucleus. Males, on the other hand, presented testicular cord cells containing small amounts of heterochromatin and approximately triangular apical and basal cytoplasms with an evident nucleolus characteristic of support cells. Additionally, there were cells with a large spherical nucleus compared with the cell size and a relatively scarce cytoplasm, identified as gonocytes. These findings indicate that macroscopic, microscopic, and ultrastructural evaluations are effective and reliable techniques for the sexual identification of stillborn E. imbricata hatchlings.
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Affiliation(s)
- Emanuel Lucas Bezerra Rocha
- Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Avenida Francisco Mota, 572, Costa e Silva, Mossoró, Rio Grande do Norte 59625-900, Brazil
| | - Lucas Gabriel Verissimo Pinheiro da Silva
- Instituto Federal do Rio Grande do Norte (IFRN), Avenida Senador Salgado Filho, 1559, Tirol, Natal, Rio Grande do Norte 59015-000, Brazil
- Associação de Proteção e Conservação Ambiental Cabo de São Roque (APC Cabo de São Roque), Rua da Praia de Caraúbas, 150, Praia de Caraúbas, Maxaranguape, Rio Grande do Norte 59580-000, Brazil
| | - Isadora Natália Rocha Barreto
- Instituto Federal do Rio Grande do Norte (IFRN), Avenida Senador Salgado Filho, 1559, Tirol, Natal, Rio Grande do Norte 59015-000, Brazil
- Associação de Proteção e Conservação Ambiental Cabo de São Roque (APC Cabo de São Roque), Rua da Praia de Caraúbas, 150, Praia de Caraúbas, Maxaranguape, Rio Grande do Norte 59580-000, Brazil
| | - Marcela Dos Santos Magalhães
- Department of Morphology, Universidade Federal do Amazonas, Avenida General Octávio Jordão Ramos, 1200, Campus Universitário Setor Norte, Coroado, Manaus 69067-005, Brazil
| | - Lucas Castanhola Dias
- Department of Morphology, Universidade Federal do Amazonas, Avenida General Octávio Jordão Ramos, 1200, Campus Universitário Setor Norte, Coroado, Manaus 69067-005, Brazil
| | - Radan Elvis Matias de Oliveira
- Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Avenida Francisco Mota, 572, Costa e Silva, Mossoró, Rio Grande do Norte 59625-900, Brazil
| | - Janine Karla França da Silva Braz
- Multicampi School of Medical Sciences, Universidade Federal do Rio Grande do Norte (UFRN), Rua José Evaristo, s/n, Penedo, Caicó, Rio Grande do Norte 59300-000, Brazil
| | - Moacir Franco de Oliveira
- Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Avenida Francisco Mota, 572, Costa e Silva, Mossoró, Rio Grande do Norte 59625-900, Brazil
| | - Carlos Eduardo Bezerra de Moura
- Department of Animal Sciences, Universidade Federal Rural do Semi-Árido (UFERSA), Avenida Francisco Mota, 572, Costa e Silva, Mossoró, Rio Grande do Norte 59625-900, Brazil
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2
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Carsia RV, McIlroy PJ, John-Alder HB. Invited review: Adrenocortical function in avian and non-avian reptiles: Insights from dispersed adrenocortical cells. Comp Biochem Physiol A Mol Integr Physiol 2023; 281:111424. [PMID: 37080352 DOI: 10.1016/j.cbpa.2023.111424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/07/2023] [Accepted: 04/08/2023] [Indexed: 04/22/2023]
Abstract
Herein we review our work involving dispersed adrenocortical cells from several lizard species: the Eastern Fence Lizard (Sceloporus undulatus), Yarrow's Spiny Lizard (Sceloporus jarrovii), Striped Plateau Lizard (Sceloporus virgatus) and the Yucatán Banded Gecko (Coleonyx elegans). Early work demonstrated changes in steroidogenic function of adrenocortical cells derived from adult S. undulatus associated with seasonal interactions with sex. However, new information suggests that both sexes operate within the same steroidogenic budget over season. The observed sex effect was further explored in orchiectomized and ovariectomized lizards, some supported with exogenous testosterone. Overall, a suppressive effect of testosterone was evident, especially in cells from C. elegans. Life stage added to this complex picture of adrenal steroidogenic function. This was evident when sexually mature and immature Sceloporus lizards were subjected to a nutritional stressor, cricket restriction/deprivation. There were divergent patterns of corticosterone, aldosterone, and progesterone responses and associated sensitivities of each to corticotropin (ACTH). Finally, we provide strong evidence that there are multiple, labile subpopulations of adrenocortical cells. We conclude that the rapid (days) remodeling of adrenocortical steroidogenic function through fluctuating cell subpopulations drives the circulating corticosteroid profile of Sceloporus lizard species. Interestingly, progesterone and aldosterone may be more important with corticosterone serving as essential supportive background. In the wild, the flux in adrenocortical cell subpopulations may be adversely susceptible to climate-change related disruptions in food sources and to xenobiotic/endocrine-disrupting chemicals. We urge further studies using native lizard species as bioindicators of local pollutants and as models to examine the broader eco-exposome.
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Affiliation(s)
- Rocco V Carsia
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, United States.
| | - Patrick J McIlroy
- Department of Biology and Center for Computational and Integrative Biology, Rutgers University, 311 North Fifth Street, Camden, NJ 08102, United States
| | - Henry B John-Alder
- Department of Ecology, Evolution, and Natural Resources, The Pinelands Field Station Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, United States
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Pewhom A, Supapakorn T, Srakaew N. Male reproductive cycle in a population of the endemic butterfly lizard, Leiolepis ocellata Peters, 1971 (Squamata: Agamidae) from northern Thailand. BMC ZOOL 2022; 7:45. [PMID: 37170386 PMCID: PMC10127433 DOI: 10.1186/s40850-022-00145-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/18/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Fundamental knowledge on the seasonal reproductive microanatomy and endocrinology of reptiles has been collected from several studies of various species. The present study was to determine annual changes in hormonal profiles, and detailed histomorphometric and histochemical characteristics of the entire male reproductive system of the tropical agamid lizard, Leiolepis ocellata.
Results
Male L. ocellata individuals (n = 75) collected from the territory of two provinces (Lampang and Tak) in northern Thailand exhibited annual variation in sex hormonal, histomorphometric, and histochemical characteristics of the male reproductive system. The reproductive cycle was subdivided into eight reproductive periods (early first active, first active, resting, second recrudescent, second active, regressive, quiescent, and first recrudescent), thus displaying a bimodal pattern with two actively reproductive periods. Circulating sex hormones (testosterone, estradiol, and progesterone) peaked in the first active (February) and the second active (June–July) periods. Likewise, gonadosomatic index (GSI) and histomorphometric variables of the testes and of the genital ducts (rete testis, ductuli efferentes, ductus epididymis, and ductus deferens) revealed their highest values in the first active period. Marked increase in protein and carbohydrate production was detectable in the ductuli efferentes during the active periods.
Conclusions
The male reproductive cycle of L. ocellata showed a biannual pattern of the hormonal profile, and detailed histomorphometric and histochemical characteristics of the entire reproductive system. Hence, the present study provides improved basic knowledge on the reptilian reproductive biology with comparative viewpoints to other reptiles.
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Mason AK, Lee J, Perry SM, Boykin KL, Del Piero F, Lierz M, Mitchell MA. Determining the Effects of Serial Injections of Pregnant Mare Serum Gonadotropin on Plasma Testosterone Concentrations, Testicular Dynamics, and Semen Production in Leopard Geckos ( Eublepharis macularius). Animals (Basel) 2021; 11:2477. [PMID: 34573443 PMCID: PMC8470321 DOI: 10.3390/ani11092477] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 11/18/2022] Open
Abstract
Reptiles are highly susceptible to anthropogenic activities as a result of their narrow geographical ranges and habitat specialization, making them a conservation concern. Geckos represent one of the mega-diverse reptile lineages under pressure; however, limited assisted reproductive technologies currently exist for these animals. Exogenous pregnant mare serum gonadotropin (PMSG) has been found to exhibit follicle stimulating hormone-like action and has been routinely used to alter reproductive hormones of vertebrates in assisted reproductive protocols. The purpose of this study was to determine the effects of serial injections of 20 IU and 50 IU PMSG on circulating testosterone concentrations, testicular dynamics, and semen production in a model species of gecko. Twenty-four captive-bred, adult, male leopard geckos (Eublepharis macularius) were divided into three treatment groups and administered a once-weekly injection of either PMSG or saline for a total of nine weeks. Ultrasonographic testicular measurements, electrostimulation for semen collection, and venipuncture were performed on days 0, 21, 42, and 63. Right unilateral orchidectomies and epididymectomies were performed in all animals on day 63; tissues were submitted for histopathology. PMSG treated geckos had significantly higher testicular volumes and weights, spermatozoa motility, and spermatozoa concentrations compared with controls. However, there were no significant differences in testosterone concentrations by treatment or time. Under the conditions outlined, PMSG is effective at stimulating spermatogenesis and increasing testicular size, but not effective at increasing testosterone concentrations in the leopard gecko between October-December in the Northern hemisphere.
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Affiliation(s)
- Alexandra K. Mason
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (A.K.M.); (K.L.B.)
| | - Jeongha Lee
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (J.L.); (F.D.P.)
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | | | - Kimberly L. Boykin
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (A.K.M.); (K.L.B.)
| | - Fabio Del Piero
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (J.L.); (F.D.P.)
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Michael Lierz
- Clinic for Birds, Reptiles, Amphibians, and Fish, Justus Liebig University Giessen, 35392 Giessen, Germany;
| | - Mark A. Mitchell
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA; (A.K.M.); (K.L.B.)
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5
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Motta CM, Tammaro S, Di Lorenzo M, Panzuto R, Verderame M, Migliaccio V, Simoniello P. Spring and Fall recrudescence in Podarcis siculus ovaries: A role for progesterone. Gen Comp Endocrinol 2020; 290:113393. [PMID: 31982398 DOI: 10.1016/j.ygcen.2020.113393] [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: 09/26/2019] [Revised: 01/04/2020] [Accepted: 01/15/2020] [Indexed: 11/18/2022]
Abstract
In the lacertid Podarcis siculus the reproductive cycle is typically biphasic, with alternate recrudescence (Spring and Fall) and resting (Summer and Winter) phases. This study aimed to shed some light on the role exerted by progesterone during the two recrudescence periods; to this purpose, exogenous progesterone was administered intraperitoneally and the effects on oogonial proliferation, oocyte recruitment, and follicle cells apoptosis were determined. The presence and distribution of progesterone receptors was also investigated by immunohistochemistry and western blotting. Results indicate that progesterone would play different roles and follow different route of action in the two recrudescence periods thus confirming the complexity of the mechanisms controlling oogenesis in this species of vertebrate.
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Affiliation(s)
- C M Motta
- Department of Biology, University of Naples Federico II, Italy
| | - S Tammaro
- Department of Biology, University of Naples Federico II, Italy
| | - M Di Lorenzo
- Department of Biology, University of Naples Federico II, Italy
| | - R Panzuto
- Department of Biology, University of Naples Federico II, Italy
| | - M Verderame
- Department of Biology, University of Naples Federico II, Italy
| | - V Migliaccio
- Department of Biology, University of Naples Federico II, Italy
| | - P Simoniello
- Department of Sciences and Technologies, University of Naples Parthenope, Italy.
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6
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Melo GC, Nascimento LB, Galdino CAB. Lizard reproductive biology beyond the gonads: An investigation of sperm storage structures and renal sexual segments. ZOOLOGY 2019; 135:125690. [PMID: 31383295 DOI: 10.1016/j.zool.2019.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/17/2019] [Accepted: 05/14/2019] [Indexed: 11/25/2022]
Abstract
In this study, we investigated the reproductive biology of the small lizard Eurolophosaurus nanuzae based on evidence of sperm storage by females and variations of the renal sexual segment (RSS) in males. We found a remarkable occurrence of crypts containing bundles of sperm and secretions in the epithelium of E. nanuzae oviducts. The chemical composition of the secretions associated with the sperm within the crypts was similar to secretions from the oviductal epithelium, which suggests that females can produce substances involved in the maintenance of stored sperm. Female sperm storage does not occur over the span of years for long-term reproduction; the majority of females with stored sperm occurred during the peak and late periods of the reproductive season. We discuss this result in relation to post-copulatory sexual selection strategies in the context of sperm competition for restricted successful fertilisation. In males, testicular activity was continuous, while RSS activity varied seasonally, in synchrony with female reproductive activity. Throughout the reproductive season, the RSS was hypertrophied, with maximum activity during the peak of the reproductive season. The lowest RSS activity occurred when females were not reproductive (non-reproductive season). Considering that RSS secretions are essential for reproduction, an absence or reduction of these secretions during the non-reproductive season may imply the reduced functionality of sperm during this period. Since sperm production continues throughout the whole reproductive cycle in E. nanuzae males, RSS activity could be an important indicator of reproduction, beyond testicular activity.
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Affiliation(s)
- Gabriela C Melo
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil; Neotropical Lizard Behavioural Ecology Research Group (NeoLiBE), Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil.
| | - Luciana B Nascimento
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil
| | - Conrado A B Galdino
- Programa de Pós-graduação em Biologia de Vertebrados, Pontifícia Universidade Católica de Minas Gerais, Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil; Neotropical Lizard Behavioural Ecology Research Group (NeoLiBE), Av. Dom José Gaspar, 500, 30535-901, Minas Gerais, Brazil
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7
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Zena LA, Dillon D, Hunt KE, Navas CA, Bícego KC, Buck CL. Seasonal changes in plasma concentrations of the thyroid, glucocorticoid and reproductive hormones in the tegu lizard Salvator merianae. Gen Comp Endocrinol 2019; 273:134-143. [PMID: 29913170 DOI: 10.1016/j.ygcen.2018.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/16/2018] [Accepted: 06/15/2018] [Indexed: 12/21/2022]
Abstract
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 (T4) and triiodothyronine (T3)] 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. T4 gradually increased from an annual nadir during pre-hibernation and hibernation to high concentrations during spring in both sexes. In contrast, T3 did not vary seasonally in males, but females showed a two-fold increase in T3 during the spring reproductive season. T3 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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Affiliation(s)
- Lucas A Zena
- Department of Physiology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, SP, Brazil; Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900, Jaboticabal, São Paulo, Brazil; National Institute of Science and Technology in Comparative Physiology (INCT Fisiologia Comparada), Brazil.
| | - Danielle Dillon
- Department of Biological Sciences, Center for Bioengineering Innovation, Northern Arizona University, Flagstaff, AZ, USA
| | - Kathleen E Hunt
- Department of Biological Sciences, Center for Bioengineering Innovation, Northern Arizona University, Flagstaff, AZ, USA
| | - Carlos A Navas
- Department of Physiology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, SP, Brazil
| | - Kênia C Bícego
- Department of Animal Morphology and Physiology, College of Agricultural and Veterinary Sciences, São Paulo State University, 14884-900, Jaboticabal, São Paulo, Brazil; National Institute of Science and Technology in Comparative Physiology (INCT Fisiologia Comparada), Brazil
| | - C Loren Buck
- Department of Biological Sciences, Center for Bioengineering Innovation, Northern Arizona University, Flagstaff, AZ, USA.
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Peña‐Herrera E, Villagrán‐SantaCruz M, Hernández‐Gallegos O, Rheubert JL, Gribbins KM, Granados‐González G. Reproductive activity in males of
Sceloporus variabilis
: Little time to rest, long time to breed. ACTA ZOOL-STOCKHOLM 2018. [DOI: 10.1111/azo.12275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eric Peña‐Herrera
- Laboratorio de Morfofisiología de la Reproducción, Facultad de Ciencias Universidad Autónoma del Estado de México Toluca Estado de México México
| | - Maricela Villagrán‐SantaCruz
- Laboratorio de Biología Tisular y Reproductora, Departamento de Biología Comparada, Facultad de Ciencias Universidad Nacional Autónoma de México Ciudad de México México
| | - Oswaldo Hernández‐Gallegos
- Laboratorio de Herpetología, Facultad de Ciencias Universidad Autónoma del Estado de México Toluca Estado de México México
| | | | - Kevin M. Gribbins
- Department of Biology University of Indianapolis Indianapolis Indiana
| | - Gisela Granados‐González
- Laboratorio de Morfofisiología de la Reproducción, Facultad de Ciencias Universidad Autónoma del Estado de México Toluca Estado de México México
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Carsia RV, McIlroy PJ, John-Alder HB. Modulation of adrenal steroidogenesis by testosterone in the lizard, Coleonyx elegans. Gen Comp Endocrinol 2018; 259:93-103. [PMID: 29155264 DOI: 10.1016/j.ygcen.2017.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/09/2017] [Accepted: 11/15/2017] [Indexed: 10/18/2022]
Abstract
Our previous work with adrenocortical cells from several Sceloporus lizard species suggests that gonadal hormones influence the steroidogenic capacity and the sensitivity to ACTH. However, there are discrepancies in these cellular response parameters suggesting that the effects of gonadal hormones on adrenocortical function vary with species, sex, age, season, and environmental/experimental conditions. To gain further insight into these complex interactions, here we report studies on Coleonyx elegans, Eublepharidae (Yucatán Banded Gecko), which is only distantly related to Sceloporus lizards via a basal common ancestor and in captivity, reproduces throughout the year. We hypothesized that a more constant reproductive pattern would result in less variable effects of gonadal hormones on adrenocortical function. Reproductively mature male geckos were orchiectomized with and without replacement of testosterone (300 μg) via an implanted Silastic® tube. Reproductively mature intact female geckos received implants with and without testosterone. After 11 weeks, adrenocortical cells were isolated from these lizards and incubated with corticotropin (ACTH) for 3 h at 28 °C. Three adrenocortical steroids, progesterone, corticosterone and aldosterone, were measured by highly specific radioimmunoassays. The production rate of each steroid was statistically analyzed using established software and net maximal rate (by subtracting the basal rate) in response to ACTH was determined. In general, corticosterone predominated and comprised ∼83% of the total net maximal rate, followed by progesterone (∼14%) and aldosterone (∼3%). Compared to the functional responses of adrenocortical cells derived from other lizards thus far, adrenocortical cells from C. elegans exhibited a depressed steroid response to ACTH and this depressed response was more pronounced in male cells. In addition, other sex differences in cellular response were apparent. In female cells, the net maximal rates of progesterone, corticosterone and aldosterone were, respectively, 161, 122 and 900% greater than those in intact-male cells. In contrast, cellular sensitivity to ACTH, as determined by the half-maximally effective steroidogenic concentration (EC50) of ACTH, did not differ between intact-male and intact-female adrenocortical cells. Treatment effects were most striking for corticosterone, the putative, major glucocorticoid in lizards. Orchiectomy caused an increase in the net maximal corticosterone rate equivalent to that of intact-female cells. Testosterone maintenance in orchiectomized lizards completely suppressed the stimulatory effect of orchiectomy. However, orchiectomy with or without testosterone maintenance did not alter cellular sensitivity to ACTH. The effect of testosterone supplementation in intact females, although suppressive, was notably different from its effect in orchiectomized males. Its effect on the net maximal corticosterone rate was relatively modest and did not completely "masculinize" the greater rate seen in intact-female cells. However, testosterone supplementation dramatically suppressed the basal corticosterone rate (by 82%) and enhanced the overall cellular sensitivity to ACTH by 150%, two effects not seen in cells derived from testosterone-treated orchiectomized lizards. Collectively, these findings clearly indicating that the gonad directly or indirectly regulates lizard adrenocortical cell function. Whereas other gonadal or extra-gonadal factors may play a role, testosterone appears to be an essential determinant of the observed sex differences in adrenocortical function.
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Affiliation(s)
- Rocco V Carsia
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA; Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA.
| | - Patrick J McIlroy
- Department of Biology and Center for Computational and Integrative Biology, Rutgers University, 311 North Fifth Street, Camden, NJ 08102, USA.
| | - Henry B John-Alder
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901, USA.
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10
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Granados-González G, Rheubert JL, Villagrán-SantaCruz M, González-Herrera ME, Dávila-Cedillo JV, Gribbins KM, Hernández-Gallegos O. Male reproductive cycle inAspidoscelis costata costata(Squamata: Teiidae) from Tonatico, Estado de México, México. ACTA ZOOL-STOCKHOLM 2013. [DOI: 10.1111/azo.12057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gisela Granados-González
- Facultad de Ciencias; Universidad Autónoma del Estado de México; Instituto Literario 100 Toluca Centro C.P. 50000 México
| | - Justin L. Rheubert
- Department of Biology; Saint Louis University; 3507 Laclede Ave St. Louis MO 63103 USA
| | - Maricela Villagrán-SantaCruz
- Laboratorio de Biología de la Reproducción Animal; Departamento de Biología Comparada; Facultad de Ciencias; Universidad Nacional Autónoma de México; Distrito Federal C.P. 04510 México
| | - María E. González-Herrera
- Facultad de Ciencias; Universidad Autónoma del Estado de México; Instituto Literario 100 Toluca Centro C.P. 50000 México
| | - Jessica V. Dávila-Cedillo
- Facultad de Ciencias; Universidad Autónoma del Estado de México; Instituto Literario 100 Toluca Centro C.P. 50000 México
| | - Kevin M. Gribbins
- Department of Biology; Wittenberg University; P.O. Box 720 Springfield OH 45501 USA
| | - Oswaldo Hernández-Gallegos
- Facultad de Ciencias; Universidad Autónoma del Estado de México; Instituto Literario 100 Toluca Centro C.P. 50000 México
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