Project description:Pristionchus pacificus has emerged as a valuable model system for comparative and evolutionary-developmental biology (evo-devo) studies alongside the classic model nematode C. elegans. Previous studies have identified a lack of conservation of genetic networks underlying conserved traits, referred to as developmental systems drift. However, the conservation – or lack thereof – of epigenetic pathways which regulate development have not been investigated. In the manuscript associated with this study, we present an “epigenetic toolkit” for P. pacificus and C. elegans to compare and contrast epigenetic pathways. Assembly of this toolkit was done by identifying orthologous genes, including the “writers” and “erasers” of histone modifications. To complement this evolutionary approach, here we produce a data set of the suite of histone modifications present in P. pacificus.
Project description:The geographical mosaic theory of coevolution predicts that different local species interactions will shape population traits, but little is known about the molecular factors involved in mediating the specificity of these interactions. Pristionchus nematodes associate with different scarab beetles around the world, with Pristionchus pacificus isolated primarily from the oriental beetle in Japan. In particular, the constituent populations of P. pacificus represent a rare opportunity to study multiple specialized interactions and the mechanisms that influence population traits at the genetic level. We identified a component of the cGMP signaling pathway to be involved in the natural variation for sensing the insect pheromone ETDA, using targeted introgression lines, exogenous cGMP treatment, and a null egl-4 allele. Our data strongly implicate egl-4 as one of several loci involved in behavioral variation in P. pacificus populations. That EGL-4 homologs have been independently implicated for behavioral variations in other invertebrate models suggests that EGL-4 may act as a modulator for interspecies behavioral repertoires across large phylogenetic distances.