Genomic and morphological features of a banchine polydnavirus: comparison with bracoviruses and ichnoviruses.
Many ichneumonid and braconid endoparasitoids inject a polydnavirus (PDV) into their caterpillar hosts during oviposition. The viral entities carried by wasps of these families are referred to as "ichnoviruses" (IVs) and "bracoviruses" (BVs), respectively. All IV genomes characterized to date are found in wasps of the subfamily Campopleginae; consequently, little is known about PDVs found in wasps of the subfamily Banchinae, the only other ichneumonid taxon thus far shown to carry these viruses. Here we report on the genome sequence and virion morphology of a PDV carried by the banchine parasitoid Glypta fumiferanae. With an aggregate genome size of approximately 290 kb and 105 genome segments, this virus displays a degree of genome segmentation far greater than that reported for BVs or IVs. The size range of its genome segments is also lower than those in the latter two groups. As reported for other PDVs, the predicted open reading frames of this virus cluster into gene families, including the protein tyrosine phosphatase (PTP) and viral ankyrin (ank) families, but phylogenetic analysis indicates that ank genes of the G. fumiferanae virus are not embedded within the IV lineage, while its PTPs and those of BVs form distinct clusters. The banchine PDV genome also encodes a novel family of NTPase-like proteins displaying a pox-D5 domain. The unique genomic features of the first banchine virus examined, along with the morphological singularities of its virions (IV-like nucleocapsids, but enveloped in groups like some of the BVs), suggest that they could have an origin distinct from those of IVs and BVs.
Lapointe
Renée
R
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, P.O. Box 10380, Stn. Ste-Foy, Quebec G1V 4C7, Canada.
Tanaka
Kohjiro
K
Barney
Walter E
WE
Whitfield
James B
JB
Banks
Jonathan C
JC
Béliveau
Catherine
C
Stoltz
Don
D
Webb
Bruce A
BA
Cusson
Michel
M
D000595:Amino Acid Sequence; D000818:Animals; D001499:Bayes Theorem; D015139:Blotting, Southern; D004279:DNA, Viral; D004587:Electrophoresis, Agar Gel; D016679:Genome, Viral; D008969:Molecular Sequence Data; D005810:Multigene Family; D016366:Open Reading Frames; D010802:Phylogeny; D018071:Polydnaviridae / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014863:Wasps
D004279:DNA, Viral