SpltMNPV日本分离株gp41的克隆表达及gp41和ph的进化分析

从斜纹夜蛾核型多角体病毒(Spodopteralituramulticapsidnucleopolyhedrovirus,SpltMNPV)日本分离株(C3)基因组中克隆了gp41基因。该基因编码区含993bp核苷酸,编码分子量为36.9kDa的多肽。将该基因克隆至原核表达载体pET28a,经IPTG诱导后在大肠杆菌BL21(DE3)中获得了表达。应用CLUSTAL程序分析表明,SpltMNPV日本株(C3)gp41的核苷酸序列和氨基酸序列与SpltMNPV中国G2株相似性最高,均达99.9%。用MEGA分别构建了基于gp41和ph的聚类分析图和分子进化树,发现它们具有相似的拓扑结构。将这两个基因序列结合在一起构建进化树,该树的结构与基于gp41的进化树相似。突变率分析显示gp41的突变率高于ph,这意味着在杆状病毒进化过程中,gp41和ph面临不同的选择压力。

Cloning and Expression of the gp41 Gene from SpltMNPV Japan Strain and Analysis of Phylogeny Based on gp41 and ph gene

The gp41 gene was cloned from Spodoptera litura multicapsid nucleopolyhedrovirus(SpltMNPV)Japan-C3 strain.This gene is 993bp long and encodes a polypeptide with a predicted molecular mass of 36.9 kDa.Analysis showed the gp41of SpltMNPV Japan-C3 strain was most closely related to that of SpltMNPV Chinese-G2 strain with 99.9% identity in nucleotide sequence and 99.9% in amino acid sequence.The phylogenetic trees based on gp4l and polyhedrin had the similar topologies.The combined tree of gp41 and polyhedrin had an identical topology as the gp41 gene.Mutation rate analysis showed the gp41 gene had a higher nucleotide substitution rate than that of the polyhedrin gene,implying that the polyhedrin gene may have a different selection constraint than the gp41 gene.