摘要：通过差速离心从感染的马尾松毛虫幼虫虫体中提取质型多角体病毒。碱解法提纯病毒粒子，1％琼脂糖凝胶 分离基因组dsRNA，回收纯化第五片段(S5)。根据同源性设计五对引物，经RT．PCR，最终获得五个亚克隆片断， 测序拼接后，得到S5全长。片断全长2851个核苷酸，包括一个2643个核苷酸的开放阅读框。推测DpCPV S5 基因编码了881个氨基酸长的多肽，分子量为100．3kDa，与舞毒蛾质型多角体病毒(LdCPV一1)和家蚕质型多角 体病毒(BmCPV)比较，核苷酸和氨基酸的同源性都很高。进一步分析，利用几种CPV序列绘制了系统进化树， 对病毒的分类和进化做了探讨研究

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．