Drosophila melanogaster Transcriptome Response to Different Wolbachia Strains.

Wolbachia is a maternally inherited, intercellular bacterial symbiont of insects and some other invertebrates. Here, we investigated the effect of two different Wolbachia strains, differing in a large chromosomal inversion, on the differential expression of genes in D. melanogaster females. We revealed significant changes in the transcriptome of the infected flies compared to the uninfected ones, as well as in the transcriptome of flies infected with the Wolbachia strain, wMelPlus, compared to flies infected with the wMelCS(112) strain. We linked differentially expressed genes (DEGs) from two pairwise comparisons, "uninfected-wMelPlus-infected" and "uninfected-wMelCS(112)-infected", into two gene networks, in which the following functional groups were designated: "Proteolysis", "Carbohydrate transport and metabolism", "Oxidation-reduction process", "Embryogenesis", "Transmembrane transport", "Response to stress" and "Alkaline phosphatases". Our data emphasized similarities and differences between infections by different strains under study: a wMelPlus infection results in more than double the number of upregulated DEGs and half the number of downregulated DEGs compared to a wMelCS(112) infection. Thus, we demonstrated that Wolbachia made a significant contribution to differential expression of host genes and that the bacterial genotype plays a vital role in establishing the character of this contribution.