The complete genome sequence and genetic analysis of phiCA82 a novel uncultured microphage from the turkey gastrointestinal system

Authors: Zsak, Laszlo; Day, James; Oakley, Brian; Seal, Bruce

Submitted to: Virology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2011
Publication Date: 6/29/2011
Citation: Zsak, L., Day, J.M., Oakley, B., Seal, B.S. 2011. The complete genome sequence and genetic analysis of phiCA82 a novel uncultured microphage from the turkey gastrointestinal system. Virology Journal. 8:331.

Interpretive Summary: Herein we report the complete nucleotide sequence of a novel uncultured microphage, phiCA82, which was identified in turkey enteric samples using metagenomics approaches. This is the first analysis of a full-length microphage genome from poultry gut. While the genome sequence analysis clearly indicates that phiCA82 belongs to the family of Microviridae, significant differences were found when either the full-length genome or individual open reading frame sequences were compared to other members of this microphage family. The distant genetic relationship between the genomes of our turkey microphage and microphages identified from other species suggests a potential unique evolutionary host specific pressures on the evolution of these phages in various microbiomes.

Technical Abstract: The genomic sequence of a novel enteric uncultured microphage, phiCA82 from a turkey gastrointestinal system was determined utilizing metagenomics techniques. The entire circular, single-stranded nucleotide sequence for the phiCA82 genome was 5,514 nucleotides. The phiCA82 genome is quite different from other microviruses as indicated by comparisons of nucleotide similarity, predicted protein similarity, and functional classifications. Only three genes showed significant similarity to microviral proteins as determined by local alignments using blast analysis. The phiCA82 genome open reading frame 1 encoded a predicted phage F capsid protein that was phylogenetically most similar to the Microviridae FMH2K member’s major coat protein. The phiCA82 genome also encoded a predicted minor capsid protein (open reading frame 2) and putative replication initiation protein (open reading frame 3) most similar to the microviral bacteriophage SpV4. The distant evolutionary relationship of phiCA82 suggests that the divergence of this novel turkey microvirus from other microviruses may reflect unique evolutionary pressures encountered within the turkey gastrointestinal system.