猪繁殖与呼吸综合征病毒SDZP株与其Marc-145细胞传代株的基因变异分析

Gene Mutation Analysis of Porcine Reproductive and Respiratory Syndrome Virus SDZP Strain and Its Marc-145 Cell Passaged Strain

为了研究PRRSV病毒在Marc-145细胞中长期传代后的基因变异特点,将高致病性PRRSV野毒株SDZP株感染Marc-145细胞,经连续传代120代获得了较为稳定的SDZP-p120传代毒株。通过RT-PCR分段扩增出SDZP亲本株与SDZP-p120株的全长基因,测序分析病毒传代过程中各基因的特征性变化。在传代过程中,病毒增殖速度出现了从慢到快的过程。连续传代后,SDZP-p120株出现了76个碱基的突变,涵盖了绝大部分功能基因,其中出现42个非同义突变,25个位于非结构蛋白,17个位于结构蛋白。囊膜相关结构蛋白的氨基酸突变率明显高于非结构蛋白,且多个囊膜相关结构蛋白的氨基酸突变规律与HuN4、JXA1等其他在Marc-145细胞上传代致弱的毒株具有相似性。研究结果为深入了解病毒与宿主细胞间的相互作用提供了参考数据。

In order to study the gene variation of PRRSV after long-term passages in Marc-145 cells,the highly pathogenic PRRSV isolate SDZP was passaged in Marc-145 cells and a stable strain of SDZP-p120 was obtained after 120 passages.The full-length genome of SDZP parental strain and SDZP-p120 strain were amplified by RT-PCR,and the characteristic changes of each gene during virus passage were analyzed by sequencing.During the passage,virus proliferation rate showed a marked increase.After continuous passage,76 mutations occurred in SDZP-p120 strains,covering most of the functional genes,including 42 non-synonymous mutations,25 of which located in non-structural proteins and 17 sites in structural proteins.The amino acid mutation rate of the envelope-associated structural proteins was significantly higher than that of the non-structural proteins,and the mutation pattern of several envelope-related structural proteins was similar to that of other viruses such as HuN4,JXA1,which were weakened in Marc-145 cells.This study provided a reference for further study of the interaction between PRRSV and host cells.