中文摘要：

为分析近交系连续3代次五指山小型猪内源性反转录病毒囊膜基因（PERV．env）变异特征，本研究采用PCR方法对该基因进行扩增、克隆和序列测定，将其与参考序列比对和遗传进化分析。序列分析显示：PERV-env核苷酸序列与参考序列之间的同源性为98．3％～99．3％，具有明显G→A突变，并且偏好发生于GA、GG。进一步分析表明，在PERV．env序列190bp和1875bp位置均有G→A突变发生。PERV-env基因遗传进化树分析表明，五指山来源的PERV与国外小型猪PERV-A亲缘关系较近，但仍存在差异。本实验将有助于PERV分子特性的研究，为进一步开展异种移植中PERV的安全性评价奠定基础。

英文摘要：

To analyze the variation in env gene of porcine endogenous retrovirus （PERV）, PERV-env gene were cloned and sequenced from different generations of Wuzhishan miniature pigs （WZSPs） inbred. Compared with PERV reference sequence, the G to A mutation occurred in all the tested sequences, whose site preferences took place in 5＇-TC, CC （on the negative strand）. Two occurrence of stable G to A mutation sites in PERV-env sequences were found. Sequence analysis revealed that env gene shared 98.3% to 99.3% nucleotide identities with that of PERV reference strains. Phylogenetic analysis revealed that these tested sequences had high homology and close relationship with the PERV-A, but some differences still existed. This study will be helpful to investigations on the biological characteristics of PERV, and will contribute to the evaluation of viral safety in xenotransplantation.