Eukaryotic association module in phage WO genomes from Wolbachia

Area of Science:

• Virology
• Genomics
• Microbial Ecology

Background:

• Viruses are classified into eukaryotic, archaeal, and bacterial categories, typically reflecting their host's genetic material.
• Bacteriophages, viruses infecting bacteria, usually contain bacterial genes.
• The obligate intracellular nature of some bacteria, like Wolbachia, within eukaryotic hosts presents opportunities for inter-domain gene transfer.

Purpose of the Study:

• To investigate the genetic makeup of the WO bacteriophage, a virus that infects Wolbachia bacteria.
• To identify any eukaryotic genetic material within the WO bacteriophage genome.
• To explore the implications of eukaryotic gene presence for viral evolution and host-bacterium interactions.

Main Methods:

• Metagenomic analysis of purified WO bacteriophage particles.
• Whole-genome sequencing of the WO bacteriophage.
• Bioinformatic analysis to identify and characterize novel genes and domains.
• Phylogenetic analysis to infer the origin and distribution of identified genes.

Main Results:

• A novel eukaryotic association module was identified within the complete WO bacteriophage genome.
• This module includes predicted domains, such as the black widow latrotoxin C-terminal domain, previously unreported in bacteriophages.
• These eukaryotic-like domains are unusually large, enriched with eukaryotic protease cleavage sites, and show evidence of lateral gene transfer from animal genomes.
• Attachment sites within the WO genome were identified.

Conclusions:

• The WO bacteriophage genome contains eukaryotic-like genes, indicating horizontal gene transfer between animals and bacteriophages.
• These findings challenge the traditional view of strict domain-specific gene content in viruses.
• The identified WO genome sequences and attachment sites offer potential for advancing genetic manipulation of Wolbachia bacteria.