title: Phylogenetic position of the Diadromus pulchellus ascovirus DNA polymerase among viruses with large double-stranded DNA genomes.
abstract: The ASCOVIRIDAE: is a family of large double-stranded (ds) DNA insect viruses that contains four species, the Spodoptera frugiperda (SfAV1), Trichoplusia ni (TnAV2), Heliothis virescens (HvAV3) and Diadromus pulchellus (DpAV4) ascoviruses. These are unique among insect viruses in that the primary means of transmission among their lepidopteran hosts is generally by being vectored mechanically by hymenopteran parasitoids. Ascoviruses are similar in virion structure, but their relationships with their parasitoid vectors vary from being opportunistic to obligate. Little is known, however, about the relatedness of these viruses to one another or to other large dsDNA viruses. We therefore cloned and sequenced the delta DNA polymerase gene of DpAV4, characterized it and compared it to 59 eukaryotic and viral delta and epsilon DNA polymerases. Phylogenetic analyses based on these genes revealed that the ascoviruses DpAV4 and SfAV1 formed a group of virus species distinct from, but closely related to, species of the family IRIDOVIRIDAE: Detailed analyses of the relatedness of ascovirus species based on conserved delta DNA polymerase motifs showed two groups within the family ASCOVIRIDAE:, one containing DpAV4 and the other containing SfAV1, TnAV2 and HvAV3, which was consistent with their host-vector relationships. Despite significant differences in capsid symmetry between ascoviruses and iridoviruses, these results suggest that these viruses may have originated from a common ancestral virus.
authors.affiliation: Department of Entomology and Interdepartmental Graduate Program in Genetics, University of California, Riverside, CA 92521, USA2.|IRBI, Groupe d'Etude des Parasites Moléculaires, UPRESA CNRS 6035; Faculté des Sciences, Parc de Grandmont, 37200 Tours, France1.
authors.forename: Karine
authors.initials: K
authors.lastname: Stasiak
authors.affiliation: IRBI, Groupe d'Etude des Parasites Moléculaires, UPRESA CNRS 6035; Faculté des Sciences, Parc de Grandmont, 37200 Tours, France1.
authors.forename: Marie-Véronique
authors.initials: MV
authors.lastname: Demattei
authors.affiliation: Department of Entomology and Interdepartmental Graduate Program in Genetics, University of California, Riverside, CA 92521, USA2.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Federici
authors.affiliation: Department of Entomology and Interdepartmental Graduate Program in Genetics, University of California, Riverside, CA 92521, USA2.|IRBI, Groupe d'Etude des Parasites Moléculaires, UPRESA CNRS 6035; Faculté des Sciences, Parc de Grandmont, 37200 Tours, France1.
authors.forename: Yves
authors.initials: Y
authors.lastname: Bigot
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D017124:Conserved Sequence / Q000235:genetics; D004257:DNA Polymerase II / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004258:DNA Polymerase III / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004267:DNA Viruses / Q000201:enzymology* / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D019143:Evolution, Molecular; D005814:Genes, Viral / Q000235:genetics; D016679:Genome, Viral; D007304:Insect Viruses / Q000201:enzymology* / Q000235:genetics; D007497:Iridoviridae / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D017931:DNA Primers; D004279:DNA, Viral; D004257:DNA Polymerase II; D004258:DNA Polymerase III