Complete Sequence, Analysis and Organization of the Orgyia leucostigma Nucleopolyhedrovirus Genome

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)

Sequence and Organization of the Neodiprion lecontei Nucleopolyhedrovirus Genome

All fully sequenced baculovirus genomes, with the exception of the dipteran Culex nigripalpus nucleopolyhedrovirus (CuniNPV), have previously been from Lepidoptera. This study reports the sequencing and characterization of a hymenopteran baculovirus, Neodiprion lecontei nucleopolyhedrovirus (NeleNPV), from the redheaded pine sawfly. NeleNPV has the smallest genome so far published (81,755 bp) and has a GC content of only 33.3%. It contains 89 potential open reading frames, 43 with baculovirus homologues, 6 identified by conserved domains, and 1 with homology to a densovirus structural protein. Average amino acid identity of homologues ranged from 19.7% with CuniNPV to 24.9% with Spodoptera exigua nucleopolyhedrovirus. The conserved set of baculovirus genes has dropped to 29, since NeleNPV lacks an F protein homologue (ac23/ld130). NeleNPV contains 12 conserved lepidopteran baculovirus genes, including that for DNA binding protein, late expression factor 11 (lef-11), polyhedrin, occlusion derived virus envelope protein-18 (odv-e18), p40, and p45, but lacks 21 others, including lef-3, me53, immediate early gene-1, lef-6, pp31, odv-e66, few polyhedra 25k, odv-e25, protein kinase-1, fibroblast growth factor, and ubiquitin. The lack of identified baculovirus homologues may be due to difficulties in identification, differences in host-virus interactions, or other genes performing similar functions. Gene parity plots showed limited colinearity of NeleNPV with other baculoviruses, and phylogenetic analysis indicates that NeleNPV may have existed before the lepidopteran nucleopolyhedrovirus and granulovirus divergence. The creation of two new Baculoviridae genera to fit hymenopteran and dipteran baculoviruses may be necessary

The Putative LEF-1 Proteins From Two Distinct Choristoneura fumiferana Multiple Nucleopolyhedroviruses Share Domain Homology to Eukaryotic Primases

peer reviewedWe have identified the lef-1 genes from two multiple nucleopolyhedroviruses that infect natural populations of Choristoneura fumiferana. The lef-I genes in both viruses are directly upstream and in the opposite orientation of their respective ecdysteroid UDP-glucosyltransferase (egt) genes. This gene organization pattern is similar to that found in the genomes of AcMNPV and of OpMNPV. As well, the coding regions and putative protein sequences share a high degree of similarity. Alignment of the predicted amino acid sequences of all known baculovirus lef-1 genes suggests that the LEF-1 proteins have a relatively high degree of conservation, particularly at four identified and distinct domains. Moreover, LEF-I proteins bear clear similarity to some eukaryotic primases, predominately at three of the four domains where certain amino acids are absolutely conserved

Proteomics Analysis of Helicoverpa armigera Single Nucleocapsid Nucleopolyhedrovirus Identified Two New Occlusion-Derived Virus-Associated Proteins, HA44 and HA100▿

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry were used to analyze the structural proteins of the occlusion-derived virus (ODV) of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV), a group II NPV. Twenty-three structural proteins of HearNPV ODV were identified, 21 of which have been reported previously as structural proteins or ODV-associated proteins in other baculoviruses. These include polyhedrin, P78/83, P49, ODV-E18, ODV-EC27, ODV-E56, P74, LEF-3, HA66 (AC66), DNA polymerase, GP41, VP39, P33, ODV-E25, helicase, P6.9, ODV/BV-C42, VP80, ODV-EC43, ODV-E66, and PIF-1. Two proteins encoded by HearNPV ORF44 (ha44) and ORF100 (ha100) were discovered as ODV-associated proteins for the first time. ha44 encodes a protein of 378 aa with a predicted mass of 42.8 kDa. ha100 encodes a protein of 510 aa with a predicted mass of 58.1 kDa and is a homologue of the gene for poly(ADP-ribose) glycohydrolase (parg). Western blot analysis and immunoelectron microscopy confirmed that HA44 is associated with the nucleocapsid and HA100 is associated with both the nucleocapsid and the envelope of HearNPV ODV. HA44 is conserved in group II NPVs and granuloviruses but does not exist in group I NPVs, while HA100 is conserved only in group II NPVs