Canadian Forest Service Publications
Sequence analysis of the Choristoneura occidentalis granulovirus genome. 2006. Escasa, S.R.; Lauzon, H.A.M.; Mathur, A.C.; Krell, P.J.; Arif, B.M. Journal of General Virology 87: 1917-1933.
Issued by: Great Lakes Forestry Centre
Catalog ID: 26426
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The genome of the Choristoneura occidentalis granulovirus (ChocGV) isolated from the western spruce budworm, Choristoneura occidentalis, was sequenced completely. It was 104 710 bp long, with a 67.3 % A+T content and contained 116 potential open reading frames (ORFs) covering 88.4 % of the genome. Of these, 29 ORFs were conserved in all fully sequenced baculovirus genomes, 30 were GV-specific, 53 were present in some nucleopolyhedroviruses (NPVs) and/or GVs, three were common to ChocGV and Choristoneura fumiferana GV (ChfuGV) and one was so far unique. To date, ChocGV is the only GV identified that contains a homologue of the apoptosis inhibitor protein P35/P49, present in some group I NPVs. It is also the first GV without a Xestia c-nigrum GV ORF 26 homologue. Five homologous regions (hrs)/repeat regions, lacking typical NPV hr palindromes were identified. ChocGV hrs were similar to each other but not to other GV hrs. A 1.8 kb repeat region with a high A+T content (81 %) and multiple repeats of 21–210 bp was found between choc36 and 37. This area resembled the non-homologous region origin of DNA replication (non-hr ori) identified in Cryptophlebia leucotreta GV (CrleGV) and Cydia pomonella GV (CpGV). Based on the mean amino acid identities of homologous proteins, ChocGV was closest to fully sequenced genomes CpGV (52.3 %) and CrleGV (52.1 %). The closest amino acid identity was to individual ORFs from the partially sequenced ChfuGV genome (97.2 % in 38 ORFs). Phylogenetic analysis placed ChocGV in a clade with CrleGV and CpGV.