TGFβ superfamily members in spermatogenesis: setting the stage for fertility in mouse and Drosophila

Abstract
Male germ cell development involves a tightly controlled sequence of differentiation switches, from the time that this lineage is specified in the embryo to the moment of sperm release for transport from the testis. Recent research findings and technological advances have allowed key mediators of developmental switches to be identified, and several members of the TGFβ superfamily of ligands have been implicated at distinct points of male gamete formation and spermatogenesis. This paper reviews the multiple points of control mediated by TGFβ superfamily signalling molecules during differentiation of the mammalian male germ cell. Comparisons have been made with the Drosophila testis for which genetic analysis has yielded new information concerning the roles of TGFβ signalling in early germ cell differentiation.