Stasiak Karine, Demattei Marie-Véronique, Federici Brian A, Bigot Yves
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.
J Gen Virol. 2000 Dec;81(Pt 12):3059-3072. doi: 10.1099/0022-1317-81-12-3059.
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.
杆状DNA病毒科：是一类大型双链（ds）DNA昆虫病毒家族，包含四个种，即草地贪夜蛾杆状DNA病毒（SfAV1）、粉纹夜蛾杆状DNA病毒（TnAV2）、烟芽夜蛾杆状DNA病毒（HvAV3）和美丽潜蝇茧蜂杆状DNA病毒（DpAV4）。这些病毒在昆虫病毒中独具特色，因为它们在鳞翅目宿主之间的主要传播方式通常是通过膜翅目寄生蜂进行机械传播。杆状DNA病毒在病毒粒子结构上相似，但它们与寄生蜂载体的关系从机会性到专性各不相同。然而，关于这些病毒彼此之间以及与其他大型dsDNA病毒的亲缘关系，人们知之甚少。因此，我们克隆并测序了DpAV4的δDNA聚合酶基因，对其进行了表征，并将其与59种真核生物和病毒的δ和εDNA聚合酶进行了比较。基于这些基因的系统发育分析表明，杆状DNA病毒DpAV4和SfAV1形成了一组与虹彩病毒科物种不同但密切相关的病毒种：基于保守的δDNA聚合酶基序对杆状DNA病毒种间亲缘关系的详细分析显示，杆状DNA病毒科内有两个组，一组包含DpAV4，另一组包含SfAV1、TnAV2和HvAV3，这与它们的宿主-载体关系一致。尽管杆状DNA病毒和虹彩病毒在衣壳对称性上存在显著差异，但这些结果表明这些病毒可能起源于一种共同的祖先病毒。
