猪伪狂犬病毒gB基因序列分析

Sequence Analysis on gB Gene from Pseudorabies Virus

2011年以来我国多省免疫猪伪狂犬病毒gE基因缺失苗猪场出现变异型猪伪狂犬病毒（PRV）感染,经典猪伪狂犬病毒疫苗（Bartha-k61）对该病无法提供100%有效保护,已有研究发现变异型PRV和经典PRV gE基因存在特征性变异。为明确变异型PRVgB基因特征,本研究对GenBank中登录的部分PRV代表株gB基因进行分析比较。结果表明,我国经典型和变异型PRV在gB蛋白氨基酸编码区第395位、453位、562位和739位存在特征性差异,但不同来源PRVgB基因的核苷酸和氨基酸同源性分别在98.1%-100%和96.1%-100%。从相互之间的遗传进化关系可以看出,PRV遗传进化出现两个大的遗传分支,呈现明显的地域性。新发变异型和经典型PRV在中国PRV遗传进化分支上呈现各自独立进化小分支;我国近年分离的貉源和约克夏梗犬源与新发变异型PRV则处于同一进化小分支。

Since 2011,variant pseudorabies（PR）had occurred to the Bartha-k61 vaccinated pigs on farms in most provinces in China.The traditional Bartha-k61 vaccine could not prevent those pigs from contracting the viral disease.As a result,substantial financial losses had incurred to the porcine industry.A previous study indicated that there existed distinctive variations between the gE gene of the typical PR virus（PRV）and that of the variant PRV.For comparison,the sequence of the gB gene of the typical PRV was downloaded from GenBank.It was found that at Positions 395,453,562,and 739 they showed different characteristics,and their nucleotide homology was 98.1%-100% and amino acids 96.1%-100%.A phylogenetic analysis suggested that the viruses were from two different branches and differed significantly depending upon their geographic origins.In China,these viruses had different sub-branches.And,the variant PRV shared a same sub-branch in origin with the newly identified Nyctereutes procyonoides and Yorkshire Terrier PR.The information obtained would be valuable for studying biological functions of gB as well as origin-tracing on variant PRV.