Molecular identification and phylogenetic analysis of baculoviruses from Lepidoptera

Abstract

PCR amplification of the highly conserved baculovirus genes late expression factor 8 (lef-8), late expression factor 9 (lef-9) and polyhedrin/granulin (polh/gran) combined with molecular phylogenetic analyses provide a powerful tool to identify lepidopteran-specific baculoviruses and to study their diversity. In the present investigation, we have improved the degenerate oligonucleotides and corroborated the approach that was recently described by Lange et al. (Lange, M., Wang, H., Zhihong, H., Jehle, J.A., 2004. Towards a molecular identification and classification system of lepidopteran-specific baculoviruses. Virology 325, 36-47.). Baculovirus DNA was isolated from 71 uncharacterized historic baculovirus samples, and partial gene sequences were amplified by using gene-specific degenerate PCR primers. The obtained PCR products were directly sequenced, and the deduced amino acid sequences were compiled and aligned with published sequences of these target genes. A phylogenetic tree of 117 baculoviruses was inferred using maximum parsimony and distance methods. Based on the comprehensive phylogenetic analysis of the partial lef-8, lef-9 and polh/gran genes, we propose a phylogenetic species criterion for lepidopteran-specific baculoviruses that uses the genetic distances of these genes for species demarcation.

Genomic sequence analysis of a fast-killing isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus

“…2a), and (ii) the concatenated aligned partial amino acid sequences of polyhedrin and late expression factors 8 and 9 (polh, lef-8 and lef-9; Fig. 2b) for SfMNPV-3AP2, other completely sequenced group II NPVs, a selection of group II NPV sequences produced by Jehle et al (2006b), AcMNPV-C6 and CpGV. The first dataset included all of the genes in common among all baculoviruses sequenced as of 2006 (Jehle et al, 2006a) except for p6.9, which was not identified in the annotation for the Clanis bilineata NPV (ClbiNPV) genome sequence (GenBank accession no.…”

Free-living pathogens: Life-history constraints and strain competition

“…The Baculoviruses are probably the largest and most diverse group of DNA viruses; more than 600 have been identified as insect pathogens (Jehle et al, 2006). A number of these viruses have been deployed as biological controls in forestry or agriculture (Godfray et al, 1997).…”

“…Baculoviral virions are embedded in a paracrystalline matrix of proteins (Zhou et al, 1998). The resulting structure is usually termed an occlusion body (Jehle et al, 2006). GV occlusion bodies are small and usually contain only a single virion.…”

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“…The Lepidopteran NPVs were separated into two groups, group I and II, based on the conserved gene, polyhedron, which encoded the major occlusion body protein required for producing viral progeny 3,5 . Later, the phylogenetics of NPVs were generated with other conserved genes, www.scienceasia.org for example lef-2 33 , lef-8, lef-9 34,35 , and ecdysteroid UBP-glycosyl transferase (egt) 4 . Recently, many phylogenetics of NPVs have been established by means of the combination of several conserved gene sequences and whole genome sequences 7,36,37 .…”