Sexual Differentiation of the Mammalian Ovary

During the early embryonic life the gonadal primordia of vertebrates usually exhibit intersexuality. At a certain stage of development the sex of the individual becomes obvious as the gonad differentiates into a testis or an ovary. In contrast to many other vertebrates, the sex of the mammalian gonad is very stable. When the gonad becomes a testis or an ovary, a fixed sex-related pattern of development is imposed on the germ cells as well as on the somatic elements. Until now it has not been possible to change this pattern to such an extent that a functional sex-reversed individual could be obtained (Burns 1961).