. Sex hormone-binding globulin expression during early gonadal development and ovarian cycle in pejerrey.

ANELISA GONZÁLEZ; JUAN I. FERNANDINO; TOMÁS CHALDE; MARIANO ELISIO ; MARÍA E. SCHARRIG; LEANDRO A. MIRANDA; GUSTAVO M. SOMOZA

Chascomus

Congreso; XVI Jornadas Anuales de la Sociedad Argentina de Biología; 2014

Sociedad Argentina de Biología

Sex hormone-binding globulin (SHBG) is a serum protein that transports steroids in the blood of all vertebrate. Its function is to regulate the bioavailability and metabolic clearance of serum steroids. In teleost fishes the main expression site of SHBG is the liver. In the present study, SHBG gene expression was evaluated during the pejerrey gonadal sex differentiation period at female- and male-producing temperatures, and also during adult ovarian cycle. The present results showed that SHBG was expressed early during gonadal development since week 3 after hatching, being higher at male than at female. Besides, the SHBG mRNA abundance varied throughout pejerrey ovarian cycle, with higher levels at pre-vitellogenesis and decreasing as vitellogenesis progresses. These results suggest that the SHBG gene expression rises before the increase of sex steroids in plasma, and is inhibited after a significant increase of these hormones, probably involving a negative feedback mechanism.