Endocrine and molecular mechanisms involved in the sexual differentiation of Medaka (Oryzias latipes) under conditions of thermal stress

• Grant number: 18/10265-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2019
• End date: April 30, 2021
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Inland Water Fishery Resources
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Rafael Henrique Nóbrega
• Grantee: Ivana Felipe da Rosa
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 14/07620-7 - Spermatogonial stem cell bank to preserve the genotype of endangered and valuable teleost species, AP.JP

Abstract

Among the vertebrates, the fish present mechanisms of determination and sexual differentiation, both as a genetic and environmental factor, such as temperature variations. These variations may influence the endocrine control of various hormones, such as thyroid hormones and cortisol, which are important modulators of the sex determination and differentiation process in fish. Thus, our objective is to test whether the increase in temperature could modulate endocrine mechanisms dependent on glucocorticoids and thyroid hormones, influencing the expression of genes involved in sexual differentiation in Medaka. For this, we will induce sexual reversion in medaka embryos and larvae in order to generate reversed males (XX) by increasing the temperature. To test whether heat-induced sexual reversal is mediated by cortisol and thyroid hormones specific inhibitors will be used for these hormones. In addition, the expression pattern of gsdf and differentially expressed genes during the period of male and female sexual differentiation in the different experimental groups (temperature, cortisol and THs) will be evaluated. Animals that overexpress gsdf will also be generated to evaluate the phenotype of these. These results will provide support for a better understanding between factors in the genetic - environmental - endocrine axis during sexual differentiation in this important biological model, expanding our knowledge about the regulatory genes of the sex determination/differentiation cascade in vertebrates.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PADILLA, LUISA F. ARIAS; CASTANEDA-CORTES, DIANA C.; ROSA, IVANA F.; ACOSTA, OMAR D. MORENO; HATTORI, RICARDO S.; NOBREGA, RAFAEL H.; FERNANDINO, I, JUAN. Cystic proliferation of germline stem cells is necessary to reproductive success and normal mating behavior in medaka. eLIFE, v. 10, MAR 1 2021. (18/10265-5, 14/07620-7)

MARTINEZ-BENGOCHEA, A.; DORETTO, L.; ROSA, I. F.; OLIVEIRA, M. A.; SILVA, C.; SILVA, D. M. Z. A.; SANTOS, G. R.; SANTOS, J. S. F.; AVELAR, M. M.; SILVA, V, L.; et al. Effects of 17 beta-estradiol on early gonadal development and expression of genes implicated in sexual differentiation of a South American teleost, Astyanax altiparanae. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, v. 248, OCT-NOV 2020. (14/07620-7, 16/12101-4, 18/10265-5, 14/25313-4)