Sequence Analysis of the Genome of the Neodiprion sertifer Nucleopolyhedrovirus

Abstract

The genome of the Neodiprion sertifer nucleopolyhedrovirus (NeseNPV), which infects the European pine sawfly, N. sertifer (Hymenoptera: Diprionidae), was sequenced and analyzed. The genome was 86,462 bp in size. The C؉G content of 34% was lower than that of the majority of baculoviruses. A total of 90 methionineinitiated open reading frames (ORFs) with more than 50 amino acids and minimal overlapping were found. From those, 43 ORFs were homologous to other baculovirus ORFs, and 29 of these were from the 30 conserved core genes among all baculoviruses. A NeseNPV homolog to the ld130 gene, which is present in all other baculovirus genomes sequenced to date, could not be identified. Six NeseNPV ORFs were similar to non-baculovirus-related genes, one of which was a trypsin-like gene. Only one iap gene, containing a single BIR motif and a RING finger, was found in NeseNPV. Two NeseNPV ORFs (nese18 and nese19) were duplicates transcribed in opposite orientations from each other. NeseNPV did not have an AcMNPV ORF 2 homolog characterized as the baculovirus repeat ORF (bro). Six homologous regions (hrs) were located within the NeseNPV genome, each containing small palindromes embedded within direct repeats. A phylogenetic analysis was done to root the tree based upon the sequences of DNA polymerase genes of NeseNPV, 23 other baculoviruses, and other phyla. Baculovirus phylogeny was then constructed with 29 conserved genes from 24 baculovirus genomes. Culex nigripalpus nucleopolyhedrovirus (CuniNPV) was the most distantly related baculovirus, branching to the hymenopteran NeseNPV and the lepidopteran nucleopolyhedroviruses and granuloviruses.

On the classification and nomenclature of baculoviruses: A proposal for revision

“…This indicates that the phylogenetic distance between CuniNPV and lepidoperan NPVs is much greater than between lepidopteran NPVs and GVs (Table 2). Our current picture of baculovirus genome diversity was further advanced by the genome characterization of two viruses infecting hymenopteran hosts, the Neodiprion lecontei NPV (NeleNPV) and N. sertifer NPV (NeseNPV) [23,10]. These two viruses have relatively small genomes of only 82-86 kbp encoding about 90 ORFs.…”

Genomic and host range studies of Maruca vitrata nucleopolyhedrovirus

“…All 126 MaviNPV ORFs have an assigned function or homologues in other baculoviruses. The 29 genes shared by all baculovirus genomes, including the dipteran and hymenopteran baculoviruses (Herniou et al, 2003;Garcia-Maruniak et al, 2004), were also found in the MaviNPV genome. The 126 predicted ORFs are encoded by 92 % of the MaviNPV genome; the rest is made up of intergenic spaces and hrs.…”

“…Based on the polyhedrin (polh) gene, NPVs are further subdivided into group I and group II (Bulach et al, 1999;Herniou et al, 2001Herniou et al, , 2003. Recent evidence shown from the comparison of 29 baculovirus genomes indicates that baculovirus phylogeny is aligned with the classification of the hosts more closely than with morphological traits (Afonso et al, 2001;Garcia-Maruniak et al, 2004;Lauzon et al, 2004;Jehle et al, 2006). An updated classification of the family Baculoviridae, which includes four generaAlphabaculovirus (lepidopteran-specific NPV), Betabaculovirus (lepidopteran-specific GV), Gammabaculovirus (hymenopteran-specific NPV) and Deltabaculovirus (dipteran-specific NPV) -was thus proposed (Lauzon et al, 2004;Jehle et al, 2006).…”

Recent Advances in Our Knowledge of Baculovirus Molecular Biology and Its Relevance for the Registration of Baculovirus-Based Products for Insect Pest Population Control

“…In mosquito hosts, following the primary infection of the gastric caeca and posterior midgut by ODVs, deltabaculovirus BVs also spread the infection further from cell to cell but only to these same tissues (Moser et al, 2001). Sawfly gammabaculoviruses do not appear to have a BV phenotype (Duffy et al, 2006;Garcia-Maruniak et al, 2004;Lauzon et al, 2004) and OBs are only produced in the nuclei of midgut epithelial cells (Federici, 1997).…”