TGF-β superfamily: how does it regulate testis development.

Testis development is a highly regulated sequence of developmental process that spans from the establishment of germ cell lineage during embryonic development to the periodic wave of spermatogenesis in adulthood. The normal development of testes and the fertility of male animals require specific cell types to respond correctly at a specific time point, the process of which is precisely regulated by various factors. Several members of the transforming growth factor-β superfamily are shown to be the key mediators. They act as the extracellular ligand of signaling transduction that regulates the proliferation, differentiation, apoptosis and other cell behaviors to help coordinate the physiology of the cells to the overall development of the testis and the organism. This paper reviews the current understanding of some of TGF-βs' major regulatory roles in the overall process of testis development, analyzes the current studies and their limitations and points out the research areas that need further investigation.