Expression profiles of dmrt1, sox9 and AMH during the thermolabile sex differentiation period in the pejerrey, Odontesthes bonariensis.

JUAN FERNANDINO,; CARLOS STRÜSSMANN; GUSTAVO M SOMOZA

Kona, Hawaii

Congreso; Fourth Internacional Symposium on the Biology of Vertebrate Sex Determination.; 2006

Much of the information on the molecular mechanism of temperature-dependent sex determination (TSD) has been obtained from reptiles, where many genes were found to be up- or down-regulated during sex determination/differentiation. For example dmrt1, a transcription factor containing a DM domain plays an important role in male sex differentiation. In TSD reptiles, dmrt1 has been cloned from different species, where it is highly expressed at male-producing temperatures (MPT). Sox9 is a transcription factor involved in the differentiation of Sertoli cells of the vertebrate testis and it has been shown to be down-regulated at female-producing temperatures in reptiles. AMH, also known as MIS, a glycoprotein member of TGF-â superfamily, shows a high expression level in MPT, preceding Sox9 expression in the American alligator. In comparison to reptiles, there is little information on the behavior of these genes in teleost species with TSD. Thus, the main objective of this study was to follow the expression patterns of dmrt1, Sox9 and AMH in a fish with TSD. We chose for this study the pejerrey, a species whereby the proportion of females decreases gradually from 100% at 19°C to 50% around 23-25°C 100%, and to 0% at 29°C.