M olecular Cloning and Sequence Analysis of Dendrolimus punctatus cytoplasmic polyhedrosis virus Segment 5

Abstract：DendrolimUS punctatus polyhedra were purified from infected Dendrolimus punctatus Larvae using density centrifugation．Dendrolimus punctatus cytoplasmic polyhedrosis viruses(DpCPV)were subsequently extracted from polyhedra by SDS treatment，followed by l％ agrose gel electrophoresis， and the segement dsRNA 5 was purified after being excised from the ge1．On the basis of nucleotides homology，five pairs of primers were designed．After the RT—PCR，five sub—clone segments were obtained，following sequencing and splicing，the complete nucleotide seq uence of the genome segment 5(S5)of DpCPV was determined．The 285 1-nucleotide sequence contains a single long open reading frame which span s nucleotides 7 1 to 27 1 4 an d was predicted to encode a protein with a molecular mass of about 100．3kDa．Sequence an alysis an d deduced amino acid seq uence of DpCPV S5 revealed high homology with proteins from LdCPV一1 an d BmCPV．From the phylogenetic tree，we can an alyse the classification an d evolutionary relationship in viruses．