Bacteriophage WO Can Mediate Horizontal Gene Transfer in Endosymbiotic Wolbachia Genomes.

Guan H Wang,Tuan L Xiong,Yan K Wang,Kristen E Murfin,Bao F Sun,Jin H Xiao,Da W Huang

doi:10.3389/fmicb.2016.01867

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 Wolbachia. The Wolbachia-infecting temperate phage WO can actively shift among Wolbachia genomes and has the potential to mediate HGT between Wolbachia 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 Wolbachia and phage WO genomes. Our results show that the phage WO can mediate HGT between Wolbachia strains, regardless of whether the transferred genes originate from Wolbachia or other unrelated bacteria.

Highlights

Horizontal gene transfer (HGT), or lateral gene transfer, is the exchange of genetic elements across species
The WO phage WOVitA1 can transfer between Wolbachia wVitA and wVitB strains hosted in N. vitripennis, and interestingly, the transfer seems to involve the phage region and the flanking bacterial region (Kent et al, 2011b)
ANKs are rare in bacteria but common in eukaryotes and viruses (Bork, 1993; Li et al, 2006), while these genes are overrepresented in Wolbachia bacteria

Summary

Introduction

Horizontal gene transfer (HGT), or lateral gene transfer, is the exchange of genetic elements across species. The genes acquired by HGT can provide new activities to a bacterial host (Waldor and Mekalanos, 1996; Brüssow et al, 2004; Rodriguez-Valera et al, 2009; Modi et al, 2013). These genes can play a significant role in the ecological and evolutionary adaptation to a new host (Ochman et al, 2000). Bacteriophages, plasmids, and transposons are the typical genetic vehicles that mediate HGT (Brüssow et al, 2004). The global rate of phage-mediated HGT events is estimated to be as much as 2 × 1016 per second (Bushman, 2002). The role of phage in such transfers has not been thoroughly investigated and is considered likely to be rare due to the constraints of an intracellular lifestyle (Fineran et al, 2009)

Methods

Results

Conclusion