Putative biological functions of the DAZ family.

The Deleted in Azoospermia (DAZ) gene belongs to a gene family that consists of three members: BOULE, DAZ-Like (DAZL) and DAZ. Members of the DAZ family are expressed exclusively in the germ cells, and their protein products contain a highly conserved RNA-binding motif and a unique DAZ repeat. Null mutations of the DAZ family members affect the fertility of either male or female, or both sexes. DAZ and DAZL are expressed throughout most of the life of germ cells and are required for the development of primordial germ cells and the differentiation and maturation of the germ cells. BOULE is expressed around the time of meiosis and has a more limited function. The DAZ proteins bind to RNAs in vitro and in vivo and are probably involved in the post-transcriptional regulation of mRNA expression. Their downstream RNA targets remain largely unknown, although members of the CDC25 gene family are potential candidates.