Bacteriophage WO Can Mediate Horizontal Gene Transfer in Endosymbiotic Wolbachia Genomes

Abstract

Phage-mediated horizontal gene transfer (HGT) is common in free-living bacteria, and many transferred genes can play a significant role in their new bacterial hosts. However, there are few reports concerning phage-mediated HGT in endosymbionts (obligate intracellular bacteria within animal or plant hosts), such as <i>Wolbachia</i>. The <i>Wolbachia</i>-infecting temperate phage WO can actively shift among <i>Wolbachia</i> genomes and has the potential to mediate HGT between <i>Wolbachia</i> strains. In the present study, we extend previous findings by validating that the phage WO can mediate transfer of non-phage genes. To do so, we utilized bioinformatic, phylogenetic, and molecular analyses based on all sequenced <i>Wolbachia</i> and phage WO genomes. Our results show that the phage WO can mediate HGT between <i>Wolbachia</i> strains, regardless of whether the transferred genes originate from <i>Wolbachia</i> or other unrelated bacteria.