Pristionchus pacificus: a satellite organism in evolutionary developmentalbiology

Pristionchus pacificus has been described as a satellite organism, for func tional comparative studies with Caenorhabditis elegans. Like C. elegans, P. pacificus is also easily cultured in the laboratory on a lawn of E. coli b acteria. P. pacificus is a hermaphroditic species with a 4-day life cycle, but unlike most nematodes which pass through four juvenile stages during th eir development, P. pacificus has only three juvenile stages. The combinati on of genetic, molecular and cell-biological studies have made P. pacificus a model system in the new field of evolutionary developmental biology. One process that has been studied in detail is the development of the vulva. G enetic and molecular studies revealed that the function of several genes in volved in vulva development differs between P. pacificus and C. elegans. He re, we review our genetic and molecular studies of P. pacificus. We show th at P. pacificus is well-suited as a satellite organism not only for underst anding the cellular and genetic aspects of evolutionary change, but also fo r addressing questions of molecular evolution at the genomic level.