Effects of 5alpha-dihydrotestosterone on expression of genes related to steroidogenesis and spermatogenesis during the sex determination and differentiation periods of the pejerrey, Odontesthes bonariensis.

GONZALEZ, A.; FERNANDINO, J.I.; SOMOZA, G.M.

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2015 vol. 182 p. 1 - 7

1095-6433

Sex steroid hormones are important players in the control of sex differentiation by regulating gonadal development in teleosts. Although estrogens are clearly associated with the ovarian differentiation, the effects of androgens on early gonadal development are still a matter of debate in teleosts. Traditionally, it has been considered that 11-ketotestosterone (11-KT) is the major androgen in fish; however, 5α-dihydrotestosterone (5α-DHT), the most potent androgen in tetrapods, was recently found in fish testis and plasma, but its physiological role is still unknown. In this context, the expression of steroidogenic and spermatogenetic related genes, body growth and sex ratio were assessed in Odontesthes bonariensis larvae fed with food supplemented with two doses of 5α-DHT (0.1 and 10 µg/g of food) during 6 weeks from hatching. At the lowest dose, 5α-DHT showed an estrogenic gene expression pattern, with low hsd11b2 and high cyp19a1a and er2 expression levels with no differences in sex ratio. At the highest dose, 5α-DHT produced a male-shifted sex ratio and exhibited a gene expression profile characteristic of an advancement of spermatogenesis in larvae, with inhibition of amh and stimulation of ndrg3. No differences were observed in somatic growth. These results suggest that 5α-DHT could have a role on sex differentiation in fish and its effects can differ according to the dose.