猪流行性腹泻病毒YL112株的M基因序列分析及其在Vero细胞的传代适应性研究

Sequence Analysis of the M gene of Porcine Epidemic Diarrhea Virus YL112 Strain and Its Adaptation to Vero Cells

为了解PEDV YL112株与其他不同来源PEDV毒株之间在分子生物学上的差异,对PEDV YL112株的M基因进行了扩增和序列分析。结果表明:PEDV YL112株与参考株的M基因核苷酸同源性在97.9%~99.8%之间,显示出高度保守性。系统进化树分析表明,PEDV YL112株与经典株CV777的亲缘关系较远,而与我国地方流行毒株HLJBY分离株以及HN-XYYYP-2007的亲缘关系较近。为进一步了解该毒株的复制特征,采用Vero细胞对PEDV YL112株进行体外细胞传代适应性研究。结果表明:经过连续传代培养后,PEDV YL112株对Vero细胞的适应性显著增强,其滴度从第5代的104.8 TCID50/0.1m L提高至第40代的10^(7.6) TCID_(50)/0.1m L。本研究对于分析PEDV的遗传变异规律、了解病毒的致病特征及开发新型疫苗等均具有重要理论和现实意义。

To analyze the genetic variation between PEDV YL112 strain and other isolates, the M gene of PEDV YL112 strain was amplified and sequenced. The M gene of PEDV YL 112 strain shared 97.9%-99.8% homology with PEDV reference strains. Phylogenetic analysis indicated that PEDV YL112 strain was genetically close to isolates HLJBY and HN-XYYYP-2007 rather than the classic strain CV777. Furthermore, adaptation of PEDV YL112 to Vero cells was conducted and its titer significantly increased from 10^4.8TCID50/0.1mL to 10^7.6TCID50/0.1mL by cellular adaptation. These results may contribute to further study on the genetic evolution, viral virulence and new vaccines of PEDV.