Crossover between stress and thyroid hormone axes in stress-induced sex reversal

CASTAÑEDA CORTES DIANA CAROLINA; BOAN AGUSTÍN FERNANDO; ZHANG JING; LANGLOIS VALERY; FERNANDINO JUAN IGNACIO

Buenos Aires

Congreso; X Latin American Society for Developmental Biology Meeting; 2019

Sociedad Latinoamericana de Biología del Desarrollo

In many fish species, environmental stressors, like high temperatures (HT), induces sexreversal of genotypic females (GF) to phenotypic male. In a previous study, weelucidate that all begins in the brain with the early increase of crhb and the concomitantwhole body cortisol level raise in respond to environmental stress. However, themechanism of how the brain regulates the gonadal sex determination directing the testisdevelopment has not been fully elucidated. Recent studies showed that exposure tothyroid hormones (THs) can induce sex reversion in fish. Besides, in non-mammalianspecies CRH can induce the thyroid-stimulating hormone (TSH) secretion in thepituitary of adults through the CRH type 2 receptor (CRHR2) in thyrotrope cells, linkingthe stress and thyroid endocrine axes. Firstly we performed a microarray after exposureembryos to HT, showing a whole effects of stress , e.i. crhb, gr2, and the up-regulationof thyroid axes, e.i. tsh, tg, and iyd. To corroborate the participation of TSH in the stressinduced sex reversal we performed biallelic mutant embryos for both crhrs by CRISPR/Cas9 exposed to HT, observing a down-regulation of tsh that phenocopied the controlgroup. Finally, we corroborate that both axes contribute to the synthesis of androgens,the final inductor of testis development. In this study, we provide clear evidence of thecrosstalk between stress and THs axes in the stress-induced female-to-male sexreversal.