Sex determination is the set of mechanisms that lead a fetal indiffere
nciated gonad to commit into the development of either a testis or an
ovary. This pathway is a very complex developmental cascade that requi
res interaction of many genes. The SRY gene (sex determining region, Y
chromosome) has been identified as being the testis ,determining fact
or which is the primary signal triggering testis formation. Thanks to
the analysis of sex reversed patients or animal models, some other gen
es are shown to play a role in sex determination. However, many steps
of the cascade are unknown and remain to be identified.