Journal of General Virology (2007) 88, 3307-3316

Xiaoyu Pan, Gang Long, RanRan Wang, Songwang Hou, Huiyuan Wang, Yueting Zheng, Xiulian Sun, Marcel Westenberg, Fei Deng, Hualin Wang, Just M. Vlak and Zhihong Hu (2007)
Deletion of a Helicoverpa armigera nucleopolyhedrovirus gene encoding a virion structural protein (ORF107) increases the budded virion titre and reduces in vivo infectivity
Journal of General Virology 88 (12), 3307-3316
Abstract: The open reading frame Ha107 of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV) encodes a putative protein of 51 kDa with homologues in a few group II NPVs and a granulovirus. Ha107 was transcribed as polyadenylated transcripts in infected HzAM1 insect cells. The transcripts were initiated at two distinct locations, one upstream of Ha106 (superoxide dismutase gene, sod) and the second upstream of Ha107. By Western blot analysis, two forms of the HA107 protein were detected in infected cells, a major polypeptide of 48 kDa and a minor one of 51 kDa. Western blot and immunoelectron microscopy analyses further showed that the HA107 protein was associated with the nucleocapsids of both budded virions (BVs) and occlusion-derived virions. A Ha107 knockout virus expressing enhanced green fluorescent protein and polyhedrin was constructed using bacmid technology. A one-step virus growth curve indicated that the BV titre of the knockout virus was significantly higher than that of the parental virus and a Ha107 repair virus. Bioassays indicated that the knockout virus was able to infect third-instar H. armigera larvae; however, its median lethal dose (LD₅₀) was significantly higher than those of the parental virus and Ha107 repair virus. These data indicate that Ha107 encodes a non-essential structural protein of HearNPV virions and that deletion of this gene increases the BV titre and LD₅₀ of the occluded virus.
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Database assignments for author(s): Zhihong Hu, Just M. Vlak

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera
Alphabaculovirus helarmigerae (entomopathogen)	Helicoverpa armigera