Résumé
Coupling methylome and transcriptome analysis to identify possible epignetic regulations in an entomopathogenic bacterium In bacteria, the main epigenetic regulatory mechanism involves DNA methylation, which is carried out by DNA-methyltransferases. When this methylation is located in a promoter region, it can modify the affinity of certain regulatory proteins for their binding site, making it possible to regulate the activity of a gene. The transcriptional regulator OxyR, widely conserved in Gram-negative bacteria, is involved in the virulence of several bacterial pathogens It is known to have a differential affinity for methylated and unmethylated DNA, and is therefore involved in epigenetic regulations, leading to the coexistence of distinct bacterial subpopulations in the same clonal culture. Bacteria of the genus Xenorhabdus are insect pathogenic Gram-negative bacteria, mutualists of soilnematodes. The nematobacterial complex is parasitic for a broad spectrum of insects. In Xenorhabdus, phenotypic heterogeneity is frequently observed, and this could be explained by epigenetic mechanisms. By coupling methylomic and transcriptomic data, we will investigate the differentially expressed genes in an oxyR-mutant strain that may show particular methylated pattern. This prospective study would represent a first description of epigenetic regulation in an insect pathogenic bacterium.