Item

Abstract

Extending knowledge gained from classical model organisms to other organisms has been one of the major objectives of evolutionary systems biology. Our lab has been focused on understanding the basis of phenotypic divergence by comparing the developmental systems of our focal organism Pristionchus pacificus to Caenorhabditis elegans and linking these with their population genetics and ecology. A recent study on natural variation in dauer formation in P. pacificus demonstrated that this evolutionary conserved developmental decision is regulated by a novel gene dauerless which lacks homology in any other nematode genome. The co-option of existing regulatory networks to control the development of novel traits such as the plasticity of feeding structures in Pristionchus nematodes, forms another example of developmental systems drift in P. pacificus. However, the evolutionary distance between P. pacificus and C. elegans is over 200 million years and thus to better understand how developmental systems drift is manifested at the genomic level, we have sequenced the genomes of 8 Pristionchus species and 2 outgroup species. Along with a general characterization of evolutionary dynamics within the Pristionchus genome, we carried out a detailed analysis of the eud-1 locus , which controls the feeding structure plasticity in Pristionchus. In combination with knock-out experimentswe show that the developmentally plastic mouth-form in Pristionchus species is regulated by a syntenic gene cluster that is conserved only within Pristionchus genus but not in the outgroup species.