FERNANDINO Juan Ignacio
congresos y reuniones científicas
Cortisol-induced masculinization: Does stress play rolein temperature-dependent sex determination?
HATTORI, R.S.; JUAN IGNACIO FERNANDINO; KISHII, AI; HIROYUKI KIMURA; KINNO, TOMOMI; OURA, M.; GUSTAVO MANUEL SOMOZA; YOKATA, M; CARLOS AUGUSTO STRÜSSMANN; WATANABE, S
Hong Kong, China
Congreso; 16th International Congress of Comparative Endocrinology; 2009
University of Hong Kong
Gonadal fate in many reptiles, fish, and amphibians is modulated by the temperature experienced during a critical period early in life (temperature-dependent sex determination; TSD). Several molecular processes involved in TSD have been described but how the animals sense environmental temperature remains unknown. We examined whether the stress-related hormone cortisol mediates between temperature and sex differentiation of pejerrey (Odontesthes bonariensis), a teleost fish with marked TSD, and the possibility that it involves glucocorticoid receptor- and/or steroid biosynthesis-modulation. Larvae maintained during the period of gonadal sex differentiation at a masculinizing temperature (29ºC; 100% males) consistently had higher cortisol, 11-ketotestoterone (11-KT), and testosterone (T) levels than those at a feminizing temperature (17ºC; 100% females). Cortisol-treated animals had elevated 11-KT and T, and showed a typical molecular signature of masculinization including amh upregulation, cyp19a1a downregulation, and higher incidence of gonadal apoptosis during sex differentiation. Administration of cortisol and a non-metabolizable glucocorticoid receptor (GR) agonist (Dexamethasone) to larvae at a sexually neutral temperature (24ºC) caused significant increases in the proportion of males. All results are consistent with a role of cortisol in the masculinization process of pejerrey and provide a direct link between stress and testicular differentiation in a TSD species. The cortisol roles or role during TSD seem(s) to involve both androgen biosynthesis- and GR-mediated processes. Stress responses are common among lower vertebrates and could be the mediator between the environment (stressor) and gonadal sex differentiation in other forms of environmental sex determination besides TSD.