[Progress in the knowledge on the genetic process of sexual differentiation in humans].

In humans, the first stage of sex differentiation is determined by the sex chromosomal constitution and the genes required in the pathway leading gonadal organogenesis. The interaction of SRY, ZFY and several autosomic and X-linked genes in this process is analyzed. It has been suggested that sex-differences are present immediately after fertilization. Sex differentiation depends on a cascade of complex molecular and morphological events that occur at the appropriate time and in the correct sequence during ontogeny.