Sequence Determination And Analyses Of Complete Genome Segments Of Dendrolimus Punctatus Cytoplasmic Polyhedrosis Virus

There are two chapters in this thesis.Chapter one is a general introduction of cytoplasmic polyhedrosis virus (CPV), including the classification about CPV, the polyhedrin and virus particle of CPV and gene structures and functions of CPV. The research on Dendrolimus punctatus CPV (DpCPV) also has been introduced in this chapter.Chapter two is about the sequence determination and analyse of complete genome segments of Dendrolimus punctatus cytoplasmic polyhedrosis virus (DpCPV). DpCPV belongs to genus Cypovirus in the family Reoviridae. Its genome consist ten dsRNA segments. Each segment posses a single open reading frame. Conserved motifs 5'(AGUAA) and 3'(GUUAGCC) were found at the ends of each segment. Comparison of proteins of DpCPV-Hn with those of other members in the family Reoviridae lead us suggest that S1, S3, S4, S6 and S7 encode viral structural protein VP1, VP2, VP3, VP4 and VP5, respectively. S5, S8 and S9 encode viral non-stuctural proteins. S2 encodes an RNA-dependent-RNA polymerase (RdRp). S10 encodes polyhedrin. Motif analysis shows that VP3 is similar to the methyltransferase of Methanosarcina mazei Goel, VP4 has motifs for leucine zipper and ATP/GTP-binding sites, and the protein encoded by DpCPV S5 is remarkably similar to foot-and-mouth disease virus 2A protease (FMDV 2Apro). Phylogenetic analysis of RdRps from nine viruses of the family Reoviridae and polyhedrin from several characterized cypoviruses indicate that DpCPV-Hn is a type 1 cypovirus, more related to Bombyx mori cypovirus (BmCPV) than to other cypovirus species...