Wolbachia genomics: accelerating our understanding of a pervasive symbiosis

The completion of numerous whole genome projects in recent years has led to a surge of new DNA sequence data for researchers. This is especially the case for bacteria, where small genome sizes make them especially suited to sequencing at relatively low cost. A number of medically important pathogens have now been completed, and this data is providing new insights into infection and possible ways to combat disease (Pallen, 2004). Similarly, a growing number of bacterial endosymbiont genomes of insects have been completed (Shigenobu et al., 2000; Akman et al., 2002; Gil et al., 2003), thus greatly advancing our understanding of hosta??symbiont co-evolution, as well as the mechanistic basis of bacteriala??insect interactions. The genomes of two Wolbachia strains can now be added to this list, as well as the genomes of some closely related pathogenic Rickettsia (Andersson et al., 1998; Ogawa and Hirai, 2000; McLeod et al., 2004; Wu et al., 2004; Foster et al., 2005; Ogata et al., 2005a). Taken together, this data provides new tools to understand the population biology of Wolbachia, new approaches to investigate current paradoxes in Wolbachia research, and generates candidate genes that may explain the mechanisms Wolbachia uses to orchestrate its well-described, but poorly understood, host manipulations.