Gonadotropin subunits of the characiform Astyanax altiparanae: Molecular characterization, spatiotemporal expression and their possible role on female reproductive dysfunction in captivity

Autor(es)

de Jesus, Lazaro Wender O. ; Bogerd, Jan ; Vieceli, Felipe M. ; Branco, Giovana S. ; Camargo, Marilia P. ; Cassel, Monica ; Moreira, Renata G. ; Yan, Chao Y. I. ; Borella, Maria I.

• Tipo de documento: Artigo Científico
• Fonte: General and Comparative Endocrinology; v. 246, p. 150-163, MAY 15 2017.
• Citações Web of Science: 4

Resumo

To better understand the endocrine control of reproduction in Characiformes and the reproductive dysfunctions that commonly occur in migratory fish of this order when kept in captivity, we chose Astyanax altiparanae, which has asynchronous ovarian development and multiple spawning events, as model species. From A. altiparanae pituitary total RNA, we cloned the full-length cDNAs coding for the follicle stimulating hormone beta subunit (fshb), the luteinizing hormone beta subunit (lhb), and the common gonadotropin cc subunit (gpha). All three sequences showed the highest degree of amino acid identity with other homologous sequences from Siluriformes and Cypriniformes. Real-time, quantitative PCR analysis showed that gpha, fshb and lhb mRNAs were restricted to the pituitary gland. In situ hybridization and immunofluorescence, using specific-developed and characterized polyclonal antibodies, revealed that both gonadotropin beta subunits mRNAs/proteins are expressed by distinct populations of gonadotropic cells in the proximal pars distalis. No marked variations for lhb transcripts levels were detected during the reproductive cycle, and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one plasma levels were also constant, suggesting that the reproductive dysfunction seen in A. altiparanae females in captivity are probably due to a lack of increase of Lh synthesis during spawning season. In contrast, fshb transcripts changed significantly during the reproductive cycle, although estradiol-17 beta (E-2) levels remained constant during the experiment, possibly due to a differential regulation of E-2 synthesis. Taken together, these data demonstrate the putative involvement of gonadotropin signaling on the impairment of the reproductive function in a migratory species when kept in captivity. Future experimental studies must be carried to clarify this hypothesis. All these data open the possibility for further basic and applied studies related to reproduction in this fish model. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 14/23451-0 - Caracterização molecular e atividade do eixo hipotálamo-hipófise-gônadas em Astyanax altiparanae (Teleostei, Characiformes) durante o ciclo reprodutivo em cativeiro
• Beneficiário: Maria Ines Borella
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/19268-8 - Clonagem molecular e expressão dos hormônios folículo estimulante (FSH) e luteinizante (LH) e perfil dos esteróides sexuais durante a diferenciação gonadal e ciclo reprodutivo do Characiforme Astyanax altiparanae
• Beneficiário: Lázaro Wender Oliveira de Jesus
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/18297-0 - Caracterização molecular, localização celular e estudos de expressão gênica dos mRNAs codificantes de gonadotropinas e seus receptores, e perfil plasmático de três esteróides sexuais em Astyanax altiparanae (Teleostei, Characiformes)
• Beneficiário: Lázaro Wender Oliveira de Jesus
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado