The taxonomy of developmental control in Caenorhabditis elegans

The Caenorhabditis elegans genome sequence was surveyed for transcription f actor and signaling gene families that have been shown to regulate developm ent in a variety of species. About 10 to 25 percent of the genes in most of the gene families already have been genetically analyzed in C. elegans, ab out half of the genes detect probable orthologs in other species, and about 10 to 25 percent of the genes are, at present, unique to C. elegans. Caeno rhabditis elegans is also missing genes that are found in vertebrates and o ther invertebrates. Thus the genome sequence reveals universals in developm ental control that are the Legacy of metazoan complexity before the Cambria n explosion, as well as genes that have been more recently invented or Lost in particular phylogenetic lineages.