The Evolutionary Genetics of the Parasitic Wasp Nasonia

The presence of symbionts is ubiquitous amongst eukaryotes. They form an integral part of the evolutionary forces acting on their hosts and are inextricably linked with the host's evolutionary history. The present study investigates the evolutionary genetics of such an association between the parasitoid wasp genus, Nasonia and its endosymbiont, Wolbachia. The study finds a rich diversity of Wolbachia infections amongst the four host species. In all, eleven different Wolbachia infections occur in the genus and have been acquired through very different biological processes. One such process is co-divergence with the host and is the basis of the first enumeration of the rates of evolution of the bacteria and its host. The study finds that the nature of the cytoplasmic incompatibility between two closely related Wolbachia strains is dependant upon the host genotype and reports the first case of a switch from bi-directional to unidirectional cytoplasmic incompatibility due to host genotypic effects. The present study also finds that the phylogeographic pattern of one of the host species, N. vitripennis, is influenced by either a mitochondrial and/or Wolbachia sweep. Finally, it describes a serendipitous discovery of a new species in the genus and characterizes its genetics, behavior and Wolbachia infections.