|Nakai, Madoka - Tokyo University Of Agriculture & Technology|
|Harrison, Robert - Bob|
|Uchida, Haruaki - Tokyo University Of Agriculture & Technology|
|Ukuda, Rie - Tokyo University Of Agriculture & Technology|
|Hikihara, Shohei - Tokyo University Of Agriculture & Technology|
|Ishii, Kazuo - Tokyo University Of Agriculture & Technology|
|Kunimi, Yasuhisa - Tokyo University Of Agriculture & Technology|
Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2014
Publication Date: 4/1/2015
Citation: Nakai, M., Harrison, R.L., Uchida, H., Ukuda, R., Hikihara, S., Ishii, K., Kunimi, Y. 2015. Isolation of an adoxophyes orana granulovirus (AdorGV) occlusion body morphology mutant: Biological activity, genome sequence, and relationship to other isolates of AdorGV. Journal of General Virology. 96(4):904-914.
Interpretive Summary: The summer fruit tortrix moth is a foreign pest species that could cause tremendous damage to fruit production if it should enter and become established in the United States. An environmentally safe insecticide based on an insect virus has been developed for suppressing outbreaks of this moth in Japan. In this study, a strain of this virus was identified that produced infectious virus particles with an unusual shape. Experiments with this virus strain revealed that it was unusually resistant to inactivation by ultraviolet rays in sunlight. Genetic sequences were determined for this strain and other strains of the virus, and genes were identified that may contribute to the strain’s unusual shape and resistance to inactivation by sunlight. The information in this study contributes to progress towards a virus-based insecticide that could be used against invading populations of the summer fruit tortrix moth, and will be of interest to those in academia, government, and industry who work with the same group of insect viruses.
Technical Abstract: A granulovirus (GV) producing occlusion bodies (OBs) with an unusual appearance was isolated from Adoxophyes spp. larvae in a 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 it 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 A. honmai. However, AdorGV-M retained more infectivity towards larvae after irradiation with UV light than 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 AdorGVs isolates and other Japanese AdorGV isolates revealed differences that may account for the unusual OB morphology of the AdorGV-M.