Molecular characterization of segments 7-10 of Dendrolimus punctatus cytoplasmic polyhedrosis virus provides the complete genome.

The nucleotide sequences of genomic segments S7-S10 from Dendrolimus punctatus cypovirus strain Hunan (DpCPV-Hn) have been determined. This provides the complete genome sequences of DpCPV-Hn. Each segment of S7-S10 possess a single segment each. Homology searches showed that the nucleotide sequences and the deduced amino acid sequences of DpCPV S7-10 had high level of identities with those of Bombyx mori cypovirus (BmCPV) S7-10, respectively. While the amino acid sequences of the proteins encoded by DpCPV S7 and S8 have low identities with those of the proteins encoded by type 14 Lymantria dispar cypovirus S7 and S8, respectively. DpCPV S7 encodes viral structural protein VP5, S8 and S9 encode viral non-structural proteins, and S10 encodes polyhedrin gene, according to the function of the genome segments of BmCPV. There are glutamic-acid-rich and proline-rich domains in the central region of DpCPV S8 encoded protein. A nuclear localization signal was found in the protein encoded by DpCPV S9. Phylogenetic analysis of RNA-dependent RNA polymerases from nine viruses of the family Reoviridae and polyhedrin from eight viruses of the genus Cypovirus indicate that DpCPV is a type 1 cypovirus, more closely related to BmCPV than to other cypovirus species. These results also support the classification of CPV groups based on the electrophoretic migration of genomic dsRNA.