Isolation of an Adoxophyes orana granulovirus (AdorGV) occlusion body morphology mutant: biological activity, genome sequence and relationship to other isolates of AdorGV

Abstract

A granulovirus (GV) producing occlusion bodies (OBs) with an unusual appearance was isolated from Adoxophyes spp. larvae in the field. Ultrastructural observations revealed that its OBs were significantly larger and cuboidal in shape, rather than the standard ovo-cylindrical shape typical of GVs. N-terminal amino acid sequence analysis of the OB matrix protein from this virus suggested that this new isolate was a variant of Adoxophyes orana granulovirus (AdorGV). Bioassays of this GV (termed AdorGV-M) and an English isolate of AdorGV (termed AdorGV-E) indicated that the two isolates were equally pathogenic against larvae of Adoxophyes honmai. However, AdorGV-M retained more infectivity towards larvae after irradiation with UV light than did AdorGV-E. Sequencing and analysis of the AdorGV-M genome revealed little sequence divergence between this isolate and AdorGV-E. Comparison of selected genes among the two AdorGV isolates and other Japanese AdorGV isolates revealed differences that may account for the unusual OB morphology of AdorGV-M.

Selection for and Analysis of UV-Resistant Cryptophlebia Leucotreta Granulovirus-SA as a Biopesticide for Thaumatotibia leucotreta

“…Such a process would enable development of a biopesticide that persists longer in the field. Repeated exposure to UV, followed by selection of active virus, has been successfully undertaken with other baculoviruses to increase UV resistance [33][34][35][36][37].…”

“…A new variant of Adoxophyes orana granulovirus (AdorGV), designated AdorGV-M, isolated from Adoxophyes spp. larvae in the field, was shown to be as pathogenic as an English isolate AdorGV-E, and to have a five-fold longer half-life than AdorGV-E after UV irradiation [37]. The AdorGV-M isolate had significantly larger cuboidal OBs, as opposed to the usual ovo-cylindrical shape associated with most granuloviruses.…”

“…The AdorGV-M isolate had significantly larger cuboidal OBs, as opposed to the usual ovo-cylindrical shape associated with most granuloviruses. The larger OBs were thought to contribute to this difference in UV tolerance, as the larger OBs provided a thicker layer of crystalline protein matrix than those of AdorGV-E [37].…”

Comparison of tolerance to sunlight between spatially distant and genetically different strains of Lymantria dispar nucleopolyhedrovirus

“…Recent work conducted on a mutant strain of Adoxophyes orana granulovirus showed that the size and shape of granules (occlusion bodies) are responsible for virus tolerance against UV [ 52 ]. To assess the possible impact of polyhedral morphology on the susceptibility to sunlight exposure observed in our study, we compared the shapes and sizes of OBs in the studied strains.…”

New Method for Differentiation of Granuloviruses (Betabaculoviruses) Based on Multitemperature Single Stranded Conformational Polymorphism

“…The Betabaculovirus genus is represented by lepidopteran-specific granuloviruses (GVs) [ 7 , 8 ]. They can be distinguished from nucleopolyhedroviruses (NPVs) from the other three genera ( Alphabaculovirus , Gammabaculovirus , and Deltabaculovirus ) because they are built of smaller, ovo-cylindrical occlusion bodies (OBs) made of granulin (highly conserved structural protein homolog of polyhedrin), that ranges in size from 0.12–0.35 µm in width by 0.3–0.5 µm in length [ 9 ].…”