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Fredericton, Canada

Lucarotti C.J.,Natural Resources Canada | Lucarotti C.J.,University of New Brunswick | Whittome-Waygood B.H.,University of Victoria | Lapointe R.,Sylvar Technologies Inc. | And 2 more authors.
Psyche (New York) | Year: 2012

The Neodiprion abietis Gammabaculovirus (Baculoviridae: NeabNPV) is virulent, highly contagious, and infects only midgut epithelial cells of balsam fir sawfly larvae, but infections can carry through to adult sawflies in the midgut. Larval infections are characterized by hypertrophy of midgut epithelial cell nuclei, where virogenic stromata develop to produce nucleocapsids that are singly enveloped before occlusion into occlusion bodies. Infected, occlusion body-laden cells slough from the midgut epithelium as a result of a dissolution of the basal lamina. Infected cells undergo lysis, and viral occlusion bodies exit affected larvae in a watery diarrhea to infect other balsam fir sawfly larvae. A budded virus stage was not observed, but nucleocapsid and occlusion body formation resembled the development of occlusion-derived virions and occlusion bodies in lepidopteran alphabaculoviruses. © 2012 Christopher J. Lucarotti et al.

Brodersen G.,University of New Brunswick | Johns R.,Natural Resources Canada | Lapointe R.,Sylvar Technologies Inc. | Thumbi D.,Sylvar Technologies Inc. | And 3 more authors.
Canadian Entomologist | Year: 2012

Food quality can influence the performance of immature insects and their interactions with pathogens, such as viruses. In manipulative field studies, virus-free caterpillars of the whitemarked tussock moth (WMTM) (Orgyia leucostigma (Smith)) had higher survival, more female-biased sex ratios, and were larger when feeding on white birch (Betula papyrifera Marshall) versus balsam fir (Abies balsamea (Linnaeus) Miller) or red spruce (Picea rubens Sargent). Subsequent laboratory studies with two nucleopolyhedroviruses, derived from WMTMs and Douglas-fir tussock moths, indicated that caterpillars fed high quality food (i.e., artificial diet) prior to infection had less mortality associated with virus infection than those feeding on lower quality foliage (i.e., birch). In field studies, caterpillars fed birch following infection had significantly lower mortality than those feeding on relatively lower quality foliage (i.e., balsam fir). We postulate that higher nutritional quality in artificial diet relative to birch (previrus-ingestion nutrition) and in birch relative to balsam fir foliage (postvirus-ingestion nutrition) has a positive effect on the ability of tussock moth caterpillars to resist or recover from viral infections, although the specific mechanisms responsible for observed resistance remain unclear. © 2012 Entomological Society of Canada.

Zhang J.,Sylvar Technologies Inc. | Lapointe R.,Sylvar Technologies Inc. | Thumbi D.,Sylvar Technologies Inc. | Morin B.,Natural Resources Canada | Lucarotti C.J.,Natural Resources Canada
Canadian Entomologist | Year: 2010

Gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), multicapsid nucleo-polyhedrovirus (LdMNPV) has been registered as a microbial pest-control product in the United States (Gypchek®) and Canada (Disparvirus®). Similarly, Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae), multicapsid nucleopolyhedrovirus (OpMNPV) is registered in the United States and Canada as TM BioControl-1® and a product derived from TM BioControl-1 (Virtuss®) is also registered in Canada. To determine changes that may have occurred in these products over time, we compared DNA from Gypchek with Disparvirus and DNA from TM BioControl-1 with Virtuss using restriction fragment length polymorphism (RFLP) analysis. Gypchek and Disparvirus showed the same RFLP banding patterns when viral genomic DNA was digested with BamH I, EcoR V, and Hind III and only a single band difference at approximately 1.6 kilobase (kb) when digested with Bgl II. TM BioControl-1 and Virtuss showed no differences in genomic DNA when digested with Bgl II, Sam I or Hind III. Twelve viral open reading frames (ORFs) were amplified from Gypchek and Disparvirus and nine from TM BioControl-1 and Virtuss by polymerase chain reactions (PCR). The amplified ORFs ranged from highly conserved (polyhedrin) to least conserved (vp91 capsid associated protein). The products were sequenced and the deduced protein products compared. Amino acid sequences deduced from the sequenced PCR products indicated that 8 of the 12 proteins were identical in the two LdMNPV products. The four proteins showing minor sequence variations were DNA polymerase, LEF-8, P74 envelope protein, and VP 91 capsid associated protein. No differences were detected in the protein products deduced from the nine sequenced ORFs from TM BioControl-1 and Virtuss. Comparative RFLP and protein phylogenetic analyses of Gypchek with Disparvirus and TM BioControl-1 with Virtuss revealed little difference between the respective LdMNPV and OpMNPV populations that make up these product pairs. © 2010 Entomological Society of Canada.

Thumbi D.K.,Sylvar Technologies Inc. | Eveleigh R.J.M.,Sylvar Technologies Inc. | Lucarotti C.J.,Natural Resources Canada | Lapointe R.,Sylvar Technologies Inc. | And 4 more authors.
Viruses | Year: 2011

The complete genome of the Orgyia leucostigma nucleopolyhedrovirus (OrleNPV) isolated from the whitemarked tussock moth (Orgyia leucostigma, Lymantridae: Lepidoptera) was sequenced, analyzed, and compared to other baculovirus genomes. The size of the OrleNPV genome was 156,179 base pairs (bp) and had a G+C content of 39%. The genome encoded 135 putative open reading frames (ORFs), which occupied 79% of the entire genome sequence. Three inhibitor of apoptosis (ORFs 16, 43 and 63), and five baculovirus repeated ORFs (bro-a through bro-e) were interspersed in the OrleNPV genome. In addition to six direct repeat (drs), a common feature shared among most baculoviruses, OrleNPV genome contained three homologous regions (hrs) that are located in the latter half of the genome. The presence of an F-protein homologue and the results from phylogenetic analyses placed OrleNPV in the genus Alphabaculovirus, group II. Overall, OrleNPV appears to be most closely related to group II alphabaculoviruses Ectropis obliqua (EcobNPV), Apocheima cinerarium (ApciNPV), Euproctis pseudoconspersa (EupsNPV), and Clanis bilineata (ClbiNPV). © 2011 2011 by the authors; licensee MDPI, Basel, Switzerland.

Thumbi D.K.,Natural Resources Canada | Thumbi D.K.,Sylvar Technologies Inc. | Beliveau C.,Natural Resources Canada | Cusson M.,Natural Resources Canada | And 2 more authors.
PLoS ONE | Year: 2013

The complete genome sequences of Choristoneura occidentalis and C. rosaceana nucleopolyhedroviruses (ChocNPV and ChroNPV, respectively) (Baculoviridae: Alphabaculovirus) were determined and compared with each other and with those of other baculoviruses, including the genome of the closely related C. fumiferana NPV (CfMNPV). The ChocNPV genome was 128,446 bp in length (1147 bp smaller than that of CfMNPV), had a G+C content of 50.1%, and contained 148 open reading frames (ORFs). In comparison, the ChroNPV genome was 129,052 bp in length, had a G+C content of 48.6% and contained 149 ORFs. ChocNPV and ChroNPV shared 144 ORFs in common, and had a 77% sequence identity with each other and 96.5% and 77.8% sequence identity, respectively, with CfMNPV. Five homologous regions (hrs), with sequence similarities to those of CfMNPV, were identified in ChocNPV, whereas the ChroNPV genome contained three hrs featuring up to 14 repeats. Both genomes encoded three inhibitors of apoptosis (IAP-1, IAP-2, and IAP-3), as reported for CfMNPV, and the ChocNPV IAP-3 gene represented the most divergent functional region of this genome relative to CfMNPV. Two ORFs were unique to ChocNPV, and four were unique to ChroNPV. ChroNPV ORF chronpv38 is a eukaryotic initiation factor 5 (eIF-5) homolog that has also been identified in the C. occidentalis granulovirus (ChocGV) and is believed to be the product of horizontal gene transfer from the host. Based on levels of sequence identity and phylogenetic analysis, both ChocNPV and ChroNPV fall within group I alphabaculoviruses, where ChocNPV appears to be more closely related to CfMNPV than does ChroNPV. Our analyses suggest that it may be appropriate to consider ChocNPV and CfMNPV as variants of the same virus species. © 2013 Thumbi et al.

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