Sequence and organization of the Spodoptera exigua multicapsid nucleopolyhedrovirus genome

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.

Section: Comparison Of Romnpv and Acmnpv Orfsmentioning

confidence: 99%

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 Spodoptera exigua cell line Se301 (Hara et al, 1995) was cultured at 27 uC in plastic tissue-culture flasks (Nunc) in Grace's insect medium, pH 5.9-6.1 (Invitrogen), supplemented with 10 % fetal bovine serum (FBS). The SeMNPV isolate (Gelernter & Federici, 1986) (IJkel et al, 1999). The reverse primer was 59-ATACATTATATATTGTT-TTATTTTACTCTACTACTATTACAATCAATCGGCCTAAGGTTC-CTGTGCGACGGTTAC-39, with viral flanking sequences (39 UTR) from nt 14545 to 14496.…”

Section: Methodsmentioning

confidence: 99%

GP64 of group I nucleopolyhedroviruses cannot readily rescue infectivity of group II f-null nucleopolyhedroviruses

Westenberg

Vlak

2008

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The genus Nucleopolyhedrovirus (NPV) of the family Baculoviridae can be subdivided phylogenetically into two groups. The same division can be made on the basis of their budded virus (BV) envelope fusion protein. Group I NPVs are characterized by the presence of a GP64-like major envelope fusion protein, which is involved in viral attachment and the fusion of virus and cell membrane, and is required for budding of progeny nucleocapsids. Group II NPVs have an envelope fusion protein unrelated to GP64, named F. In contrast to GP64, F proteins are found in all baculoviruses, but they are not functional as envelope fusion proteins in group I NPVs. Autographa californica multiple NPV (AcMNPV) lacking GP64 can be pseudotyped by the F protein of Spodoptera exigua multiple NPV (SeMNPV), suggesting that F proteins are functionally analogous to GP64. GP64 homologues are thought to have been acquired by group I NPVs during evolution, thereby giving these viruses a selective advantage and obviating the need for a functional F protein. To address this supposition experimentally, attempts were made to pseudotype a group II NPV, SeMNPV, with GP64. Transfection of an f-null SeMNPV bacmid into Se301 cells did not result in the production of infectious BVs. This defect was rescued by insertion of SeMNPV f, but not by insertion of AcMNPV gp64. This suggests that the functional analogy between GP64 and F is not readily reciprocal and that F proteins from group II NPVs may provide additional functions in BV formation that are lacking in the GP64 type of fusion protein.

“…The average amino acid sequence identity between AdorNPV and AdhoNPV, Mamestra configurata NPV-A (MacoNPV-A) (Q.J. , Spodoptera exigua MNPV (SeMNPV) (IJkel et al, 1999), Lymantria dispar MNPV (LdMNPV) (Kuzio et al, 1999) and Autographa californica MNPV (AcMNPV) (Ayres et al, 1994) were 93.9, 45.4, 45.3, 44.2 and 41.8 %, respectively. The most conserved ORFs are polyhedrin/granulin (ORF1), ubiquitin (ORF16), sod (ORF101), lef-9 (ORF33) and lef-8 (ORF46) (Supplementary Table S1).…”

Section: Comparison Of Adornpv Gene Content With That Of Other Baculomentioning

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...