Genomic analyses of Biston suppressaria nucleopolyhedrovirus: a viral isolate obtained from the tea looper caterpillar, Biston suppressaria (Guenée, 1857).

We described the complete genome sequence of a novel baculovirus isolate of species Buzura suppressaria nucleopolyhedrovirus, called by isolate CNPSo-25. The occlusion bodies were found to be polyhedral in shape and to contain virions with singly embedded nucleocapsids. The size of the genome is 121,377 bp with a G+C content of 36.7%. We annotated 131 ORFs that cover 90.42% of the genome. Moreover, phylogenetic inference indicated that CNPSo-25 is a member of genus Alphabaculovirus that clustered together with two other Chinese isolates of the same species. We called the virus by Biston suppressaria nucleopolyhedrovirus isolate CNPSo-25 (BisuNPV-CNPSo-25), as Buzura was placed inside the lepidopteran genus Biston. As expected, we detected intra-population variability in the virus sample when the novel isolate was compared to the Chinese isolates: 292 single nucleotide variants were found in the genome, with 181 affecting the protein product. The closest representatives of other species to BisuNPV-CNPSo-25 was found to be Sucra jujuba nucleopolyhedrovirus and Hyposidra talaca nucleopolyhedrovirus, two other virus isolates of geometrid caterpillars. The study of baculovirus genomes is of importance for the development of tools for insect pest biological control and biotechnology.