Fig. 5.—

Comparison between wVitA and wUni in the upstream untranslated regions of orthologous genes (total of 880 compared). The 50 bp regions upstream of orthologous genes were compared using BLASTn and percent identity calculated. The vast majority of these sequences are syntenic in the two genomes (809/880) and therefore the level of divergence between the two strains represents the accumulation of nucleotide substitutions rather than intergenic recombination. Nevertheless, there is a striking bimodal distribution, with a second peak around 50% dissimilarity. This suggests that either some genes have very rapidly evolving 5′-intergenic regions, or that they were laterally transferred from other Wolbachia with divergent intergenic sequences. A gene ontology examination of those genes with divergent 5′-intergenic regions did not reveal significant enrichments in terms of function.