猪伪狂犬病病毒GD株的生物学特性和gB基因进化分析

Biological Characteristics and Phylogenetic Analysis of gBGene of Porcine Pseudorabies Virus GDStrain

为了解猪伪狂犬病病毒(Pseudorabies virus,PRV)变异毒株的生物学特性和gB基因遗传变异特性,本研究对本实验室分离鉴定的变异株PRV GD的一步生长曲线和病毒对小鼠的毒力进行了研究,结果显示PRVGD毒株对KM小鼠的LD50为102.32TCID50。此外,对PRVGD株的gB基因进行了全长扩增,并对gB基因进行了测序和序列分析。研究结果显示,PRVGD株的gB基因与国内外PRV参考株的核苷酸同源性为98.3%~100%,氨基酸同源性为96.8%~99.9%。与经典毒株相比,PRV GD株的gB基因有位点插入、突变和缺失。基于gB基因的系统进化树分析发现,PRV GD株与国内近几年分离鉴定的PRV流行变异毒株如ZJ01、TJ、HeN1和JS-2012株位于同一分支上,同源性较高,亲缘关系较近。与国内外经典毒株均处于不同进化树分支,亲缘关系较远。本研究为PRV流行变异毒株的分子流行病学研究以及针对变异毒株的控制和新型疫苗的研发提供一定的参考价值。

In order to understand the biological characteristics and the genetic variation characteristics of gB gene of PRV variant strain in this study, we studied the one-step growth curve of PRV GD strain which isolated and identified by our laboratory and the virulence of the virus to mice. The results of virulence test in KM mice showedas 102.32 TCID50. Furthermore, full length of gB gene of PRV GD strain was amplified, sequenced and analyzed. The sequence analysis results showed that the nucleotide identities of gBgene of PRV GD strain with other PRV strains domestic and overseas was 98.3% to 100%, the amino acid homology was 96.8% to 99.9%. Compared with the classical strains, the gB of PRV GD strain had site insertions, mutations and deletions. Phylogenetic tree analysis based on gB gene showed that PRV GD strain with PRV prevalent variant strains isolated and identified in China in recent years, such as ZJ01, TJ, HeN1 and JS-2012 strains had higher homology and closer relationship because of their location in the same branch,while that with the classical strains at home and abroad had a distant relationship for the different branches on the tree among them. This study provided certain reference for the molecular epidemiological study of PRV prevalent variant strains, as well as for the control and the development of new vaccines against variant strains.