Germ plasm assembly and germ cell migration in Drosophila.

Many aspects of germ cell behavior, migration, and gonad formation are shared between vertebrate and invertebrate species. For example, a specialized germ plasm has been observed in many species including Caenorhabditis elegans and Xenopus. Furthermore, the fact that Vasa marks germ cells in many species suggests that even certain molecular aspects of germ cells may be common between different organisms. In most organisms, germ cells initially form at a location away from their target mesodermal tissues and have to migrate to reach the mesoderm. Further genetic studies will reveal the extent to which molecular aspects of germ cell migration and gonad formation are conserved.