Characterization of new baculovirus genotypes arising from inoculation of Pieris brassicae with granulosis viruses

Abstract

Previous studies have shown that of 15 Artogeia (Pieris) rapae granulosis virus isolates (ArGV1 to ArGV15) only two, ArGV1 and ArGV2, gave a normal dose-mortality response in larvae from an established colony of Pieris brassicae. We report here that at extremely high doses, approaching 10000 times the LDs0 for ArGV1 and ArGV2, three other ArGV isolates caused low and irregular levels of mortality in P. brassicae. At similar doses Agrotis segetum GV caused 43 % mortality in one infection, but no deaths ensued from other inoculations with this virus. Restriction endonuclease analysis of viral DNA recovered from individual larval cadavers revealed that, in most cases, progeny virus differed from the inoculum and consisted either of ArGV1 or of novel genotypes explicable as recombinants between genomes of the inoculum and of ArGV1. Field-collected P. brassicae inoculated with ArGV8 yielded a similar range of progeny genotypes. Physical maps were constructed for two such recombinants, based on comparative restriction analysis with reference to the published map of ArGVl and to those of ArGV5 and ArGV8, which are presented. Replication of the inoculum genotype was observed in only two infections. The origin of ArGV1 DNA appearing among progeny from these infections and the relevance of our results to identifying ArGV DNA sequences that modulate pathogenicity for P. brassicae are discussed.

Characterization of a Granulovirus Isolated from Epinotia aporema Wals. (Lepidoptera: Tortricidae) Larvae

“…The restriction patterns of EpapGV DNA were distinct from those published for other GVs (3,4,5,7,11,14,31,33,37,39) (Fig. 2B and C).…”

Molecular characterization and genetic organization of the inhibitor of apoptosis gene (iap-5) region of the Pieris rapae granulovirus

“…The original granulovirus used in this study was isolated from P. rapae larvae collected in the field in Nanning, China in 2001, and was propagated in laboratory stocks of P. rapae larvae as described previously [8]. Single genotype of this virus was obtained by three successive rounds of in vivo cloning using the limiting dilution method [15].…”

“…Genomes of several PiraGV isolates from different geological locations have been mapped previously with restriction enzymes [8][9][10]. Digestion of PiraGV-E3 with BamHI resulted in 12 fragments, and all of them were cloned into pUC19.…”

“…Based on the restriction pattern of viral genome, isolates of PiraGV could be grouped into three subtypes [7]. The genome size of PiraGV was estimated to be 106.5-110 kb [8][9][10]. In China, PiraGV has been used as a biological insecticide for the control of P. rapae (Pieridae, Lepidoptera), but the molecular biology knowledge about this GV is very limited.…”

Possible functional co-operation of palindromes hr3 and hr4 in the genome of Cydia pomonella granulovirus affects viral replication capacity

“…Later, multiple infections were blocked (Beperet et al, 2014). Thus, co-infection of the same cell and consequently coreplication in the same nucleus may result in genetic recombination of baculoviruses and baculovirus genotypes, as was proposed by DNA restriction analysis and Southern hybridization (Croizier & Quiot, 1981;Smith & Crook, 1993), phylogenetic analysis (Jehle, 2004) and direct co-infection experiments (Kondo & Maeda, 1991;Merryweather-Clarke et al, 1994;Jehle et al, 2003;Kamita et al, 2003). In addition, the combination of a defective genotype and a complete genotype of Spodoptera frugiperda multiple nucleopolyhedrovirus resulted in an increased pathogenicity compared with that of the complete genotype alone (Ló pez-Ferber et al, 2003).…”