Wolbachia Induces Epigenetic and Transcriptional Modifications in the Orthopteran Chorthippus parallelus (Acrididae: Gomphocerinae)

Wolbachia is an obligate endosymbiotic alphaproteobacterium that is widely distributed among insects. It also infects the European orthopteran Chorthippus parallelus parallelus (Cpp). In this subspecies, Wolbachia induces a reproductive barrier through uni- and bidirectional cytoplasmic incompatibilities. Recently, we found that it also modifies the expression of genes related to essential physiological pathways in Cpp. Here, we have analysed the influence of Wolbachia infection on the epigenetic profiles in Cpp gonads of infected and uninfected males and females, since they constitute Wolbachia’s main target. We characterised de novo nine genes related to epigenetic mechanisms and their transcriptional activity, together with global DNA methylation levels. The results indicate that Wolbachia influences the epigenetic mechanisms in Cpp mainly in females, inducing the expression of genes related to histone deacetylation and reducing the global DNA methylation percentage. This study provides the first evidence of Wolbachia’s ability to alter epigenetic processes in Cpp, increasing our understanding of this symbiotic relationship, with potential implications for the induced reproductive isolation within and between subspecies of C. parallelus. It also offers new insights into the molecular basis of host–symbiont biology in a group for which this information is rather scarce.