Vasa homolog genes in mammalian germ cell development.

Many vasa homologue genes to Drosophila vasa have been isolated in various animal species. They provide specific molecular probes to analyze the establishment and the differentiation of germ cell lineage. In mammals, the expression of VASA protein becomes detectable in PGCs at the late migrating stage. Interestingly, during spermatogenesis the intracellular localization of VASA protein is closely associated with the chromatoid body.