Taxon-specific maternal factors for germline specification

Despite the great diversity of animal forms, many genetic networks controlling developmental processes are remarkably conserved across animal species, such as between flies and mice. In many cases, conserved genetic networks rely on the use of homologous genes, such as Hox genes for the anterior-posterior patterning and NK-class genes for heart development. However, in the case of germline development, although the process itself including global repression of zygotic gene expression is conserved, participating components are often variable and taxon specific. Here I present our recent findings on germline development of the Japanese ascidian Halocynthia roretzi, as an example of conserved genetic mechanisms that do not rely on conserved genes.