Expression of 11beta-hsd2 during the temperature-dependent masculinization process in pejerrey

FERNANDINO, J.I.; HATTORI, R.S.; KISHII, AI; KAMIOKA, H; STRÜSSMANN, C.A.; SOMOZA, G.M.

Buenos Aires

Workshop; Twelfth´s Multidisciplinary Workshop; 2010

Sociedad Argentina de Biología

Recently, our group has associated cortisol (a stress hormone) with masculinization by warm temperature (MPT, 29ºC) in the pejerrey, Odontesthes bonariensis. In this species, all larvae exposed to MPT during 4 weeks after hatching develop as males. Moreover, a significant increase in 11-ketotestosterone (11-KT, the main bioactive androgen in fish) levels is observed during the same period. In order to clarify the role of stress on masculinization, the expression of the stereodogenic enzyme 11β-hsd2, and the glucocorticoid receptors gr1 and gr2 was analyzed by Real Time PCR and ISH in larvae reared at MPT, FPT (female promoting temperature, 17°C), and MixPT [with our without cortisol (50 mg/kg food) supplemented food] during the sex determination period. In addition, an in vitro experiment with adult testicular explants was done. Both MPT and cortisol treatments showed significant increases in gene transcription levels, mainly in 11β-hsd2, whose mRNAs in larval gonads were restricted to somatic cells, presumably Leydig cells The administration of increasing doses of cortisol in vitro induced an increase in both hsd11b2 expression and 11-KT levels. Overall, these results suggest that cortisol may increase 11-KT production through the action of 11β-hsd2 during the masculinization process by warm temperature.