Nucleotide composition shapes gene expression in <i>Wolbachia pipientis</i> : a role for MidA methyltransferase?

<i>Wolbachia pipientis</i> is one of the most common intracellular bacteria in insects, and it is currently utilized as a tool for the control of vector-borne diseases. As for many other endosymbiont bacteria, <i>Wolbachia</i> experienced important genome rearrangements, gene content changes, and the loss of several regulatory sequences, affecting the integrity of operons and promoters. Nevertheless, experimental studies have shown that <i>Wolbachia</i> gene expression is coordinated with the host physiology (e.g., developmental stages), although the underlying mechanism remains unclear. In this work, based on <i>in silico</i> analyses and an experimental study on wOo methyltransferase, we propose that bacterial DNA methylation could be a key mechanism regulating <i>Wolbachia</i> gene expression. Additionally, we found evidence suggesting that the DNA methylation process in <i>Wolbachia</i> can be activated by the host.