根据GenBank的核酸序列,设计6对引物自TGEV SCY株中分别扩增了长为1.5kb、2.0kb、1.1kb、1.4kb、1.4kb、1.3kb的6个片段,经克隆测序拼接后获得8495bp的TGEV部分序列。根据与其他TGEV和冠状病毒的序列和结构特征比较表明,该段序列克隆了除TGEV聚合酶基因以外的S、M、N、E、NSP3a、NSP3b、ORF7共7个基因的核酸序列;根据S、M、N基因的序列构建了系统进化树,分析表明TGEV-SCY株与TS、HN2002、TO14、pudue等毒株亲缘关系较近;密码子偏爱性分析结果认为TGEV在对密码子的使用上存在轻微的偏向性,个别氨基酸偏向于选择以A和T结尾的密码子。
Six fragments about 1.5 kb,2.0 kb,1.1 kb,1.4 kb,1.4 kb,1.3 kb of transmissible gastroenteritis virus strain SCY were amplified by PCR , then were cloned into the pGM-T vector and sequences were determined in Takara . 8 495 bp sequence was obtained after assembling by CAP program. Bioinformatics analysis showed that the 8 495 bp sequence included S, M, N, E, NSP3a,NSP3b,ORF7 genes. Phylogenetic trees based on S,M,N genes showed that TGEV SCY strain was closed to the TS, HN2002 ,TO14 ,pudue strains. TGEV SCY didn't bias remarkably on any codons,but some of the amino acids biased slightly on the codons which ended by A or T.