Sequence Analysis of the Spodoptera litura Multicapsid Nucleopolyhedrovirus Genome

Six clones of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) were plaquepurified from field isolates collected in Missouri, USA. In bioassays, four of the plaque-purified isolates killed neonate S. frugiperda larvae more rapidly than the field isolates from which they were derived, with LT 50 values (mean time to kill 50 % of the test larvae) ranging from 34.4 to 49.7 h post-infection. The complete genomic sequence of one of these isolates, SfMNPV-3AP2, was determined and analysed. The SfMNPV-3AP2 genome was 131 330 bp with a G+C content of 40.2 %. A total of 144 open reading frames (ORFs) was identified and examined, including the set of 62 genes in common among lepidopteran nucleopolyhedrovirus genomes. Comparisons of ORF content, order and predicted amino acid sequences with other nucleopolyhedoviruses indicated that SfMNPV is part of a cluster of viruses within NPV group II that includes NPVs isolated from Spodoptera, Agrotis and Mamestra host species. SfMNPV-3AP2 shared a high degree of nucleotide sequence similarity with partial sequences from other SfMNPV isolates. Comparison of the SfMNPV-3AP2 genome sequence with a partial sequence from a Brazilian isolate of SfMNPV revealed that SfMNPV-3AP2 contained a deletion that removed parts of ORF sf27 and the gene encoding ecdysteroid UDP-glucosyltransferase (egt). An examination of the egt region in the other isolates revealed that the other five SfMNPV clones also contained deletions of varying length in this region. Variant genotypes with deletions extending around the egt gene have been reported previously from a Nicaraguan field isolate of SfMNPV, suggesting that the presence of such variants is a common feature of SfMNPV populations.

Section: Gene Content and Ordermentioning

confidence: 99%

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

Harrison

Puttler

Popham

2008

“…AAD00095); ManeNPV, Malacosoma neustria NPV (accession no. AAB31529); MbMNPV, Mamestra brassicae MNPV ; OpMNPV, Orgyia pseudotsugata MNPV (Ahrens et al, 1997); OpSNPV, Orgyia pseudotsugata SNPV (Leisy et al, 1986); PaflMNPV, Panolis flammea MNPV (Oakey et al, 1989); PenuNPV, Perina nuda NPV (Chou et al, 1996); RoMNPV, Rachiplusia ou MNPV (Harrison & Bonning, 1999); SeMNPV, Spodoptera exigua MNPV (IJkel et al, 1999); SfMNPV, Spodoptera frugiperda MNPV (Gonzalez et al, 1989); SpltMNPV, Spodoptera litura MNPV (Pang et al, 2001); ThorMNPV, Thysanoplusia orichalcea MNPV (accession no. AF169480); ThorSNPV, Thysanoplusia orichalcea SNPV (Cheng et al, 1998); TnSNPV, Trichoplusia ni SNPV (Fielding & Davison, 1999); WisiNPV, Wiseana signata NPV (accession no.…”

Section: Comparison Of Romnpv and Acmnpv Orfsmentioning

confidence: 99%

Comparative analysis of the genomes of Rachiplusia ou and Autographa californica multiple nucleopolyhedroviruses

Harrison

Bonning

2003

The Rachiplusia ou multiple nucleopolyhedrovirus (RoMNPV) is a variant of Autographa californica MNPV (AcMNPV) but is significantly more virulent against several major agricultural pests. The genome sequence of the R1 strain of RoMNPV was determined and compared to that of AcMNPV strain C6. The RoMNPV genome is approximately 131?5 kbp with a G+C content of 39?1 %. The homologous repeat regions (hrs) described for AcMNPV-C6 are present in RoMNPV-R1 but the hrs of RoMNPV have fewer palindromic repeats. The RoMNPV-R1 nucleotide sequence is almost completely collinear with the sequence of AcMNPV-C6 and contains homologues of 150 of the 155 ORFs described for AcMNPV-C6. Deletions, insertions and substitutions have resulted in the loss of homologues for AcMNPV ORFs ac2 (bro), ac3 (ctl), ac97, ac121 and ac140 from the RoMNPV genome. The average amino acid sequence identity between RoMNPV and AcMNPV ORFs is 96?1 % and there are differences in promoter motif composition for 23 of these ORFs. Maximum-likelihood analysis of selection pressures on AcMNPV and RoMNPV ORFs indicate that ORFs ro18/ac20-ac21 (arif-1) and ro135/ac143 (odv-e18) have undergone positive selection.

“…It has been shown to block apoptosis in diverse systems and to substitute for the p35 gene in blocking AcMNPV-induced apoptosis in Sf21 cells (Crook et al, 1993). p35 genes have only been identified in AcMNPV, BmNPV, Spodoptera litura MNPV and Maruca vitrata MNPV (Ayres et al, 1994;Gomi et al, 1999;Pang et al, 2001). Whereas, all baculoviruses have been found to contain IAP homologues.…”

Section: Inhibitors Of Apoptosismentioning

confidence: 99%

Genomic sequence and biological characterization of a nucleopolyhedrovirus isolated from the summer fruit tortrix, Adoxophyes orana

Hilton

Winstanley

2008

Adoxophyes orana nucleopolyhedrovirus (AdorNPV) was isolated from overwintering larvae from an orchard in the UK. The nucleotide sequence of the AdorNPV DNA genome was determined and analysed. The genome contains 111724 bp and has a G+C content of 35.0 mol%. The analysis predicted 121 ORFs of 150 nt or larger. Of these putative genes, 118 were homologous to genes identified previously in the Adoxophyes honmai nucleopolyhedrovirus (AdhoNPV) genome (83.3-100 % aa identity), and three AdorNPV ORFs were unique. There were four small homologous regions that consisted of a similar core sequence and at the same relative positions in the genome as AdhoNPV, but they differed in the number of repeats and orientation. Some genes that have been reported to have major roles in baculovirus biology were either absent or truncated in the AdorNPV genome. These included chitinase, which is involved in the liquefaction of the host, and the C-terminal of the ecdysteroid UDP-glucosyltransferase (egt) protein, which was truncated by 149 aa compared with AdhoNPV, with essential amino acids absent. The AdorNPV genome encoded two inhibitor of apoptosis (iap) genes compared with three in AdhoNPV and three bro genes compared with four in AdhoNPV. The susceptibility of A. orana larvae to AdorNPV was evaluated in laboratory bioassays using inoculation by microdroplet feeding and applied dose assays. LD 50 for neonates was 56 occlusion bodies rising to 2.3¾10 4 for fifth instar larvae. Median survival time values using an LD 80 dose were 8.8 days for neonates and 7.0 days for fifth instar larvae. INTRODUCTIONThe family Baculoviridae consists of invertebrate viruses with large circular, covalently closed, double-stranded DNA genomes with enveloped nucleocapsids and an occluded form of the virus embedded in proteinaceous occlusion bodies (OBs) . There are two genera of baculovirus, the Nucleopolyhedrovirus (NPV) and the Granulovirus (GV) based on OB morphology . The NPVs are further classed into group I and II NPVs (Bulach et al., 1999;Zanotto et al., 1993). The majority of the sequenced NPVs infect insects of the Lepidopteran order, but NPVs that infect dipteran or hymenopteran insect species like the mosquito-infecting Culex nigripalpus NPV, or the NPVs from three Neodiprion species, have been sequenced (Afonso et al., 2001;Garcia-Maruniak et al., 2004;Lauzon et al., 2004; Duffy et al., 2006). Baculoviruses are used worldwide as biological control agents of agricultural and forest pests. The summer fruit tortrix moth (Adoxophyes orana) is a pest of apples and pears in most of Europe and Japan.During the past 25 years, there has been increased interest in the use of a naturally occurring GV as a control agent for the summer fruit tortrix (Cross et al., 1999). Recently, a mixture of baculoviruses was recovered from larvae in the UK (Hilton & Winstanley, 2008). These were separated and found to comprise an NPV and a GV. The GV (Adoxophyes orana GV) has been characterized and completely sequenced (Wormleaton et al., 2003;Hilton & Winstanley, 2...