Evolutionary Determinants of Host Range in Parasitic Nematodes

University Of Arizona, Tucson AZ

Investigators

Abstract

0074141 Jaenike The proposed research will examine the evolution of associations between Drosophila and nematode parasites, encompassing time scales of evolutionary change from of millions of years down to changes ongoing within present-day populations. Experimental infections will be conducted with 8 nematode species and 24 Drosophila species. These experiments, in conjunction with molecular phylogenetic analyses, will allow a determination of the extent to which a parasite's host range is determined by host phylogeny, as well as determination of how host range evolves in these parasites. Closely related Drosophila species will be crossed to uncover the genetic basis of interspecific differences in resistance to parasites. These hybridization experiments will also reveal whether resistance to one parasite species is genetically correlated with resistance to others. Parasites are ubiquitous - but generally overlooked - components of natural communities, often having major effects on the individuals and populations of their host species. The potential host range of a parasite is relevant to the issue of emerging diseases, the use of parasites in biological control programs, and the effect of invading parasites on endangered species. The proposed studies of the evolutionary determinants of parasite host range will contribute to the development of a comprehensive theory of host-parasite interactions.