鸡肾型IBV地方分离株N基因的克隆及分子遗传变异分析

用RT-PCR方法对分离于陕西省不同地区的8个鸡肾型IBV毒株的Ⅳ基因分别进行了扩增,将各扩增产物与T载体连接后,转化感受态细胞筛选阳性克隆质粒并进行基因测序,用DNAstar软件将这8个毒株与GenBank收录的7个IBV代表毒株的Ⅳ基因进行了比较分析,研究了其变异情况。结果表明,B01,YL,WH和 YX株与7株代表毒株的同源性较高,而G,BJ,WG,FF株与7个代表毒株的同源性相对较低。氨基酸推导序列比对结果表明,N蛋白突变以散在的点突变形式为主,其中46,48,50,75,78,189,232,236,237,299,301,350,366等位点容易发生突变,突变位点无明显规律性。

Clone and genetic variation analysis of N gene of nephropathogenic avian infectious bronchitis virus isolates

The complete N genes of eight avian infectious bronchitis viruses (IBV) isolated from different places of Shaanxi province were amplified by using RT-PCR method. The products were ligated with Tvector separately and the transfered plasmids were obtained respectively. The N genes were sequenced in invitorgen cooperation. Sequences were analyzed among the eight isolates in China and the reference strains in GenBank by using DNAstar software. According to the analyzed results of N genes nucleotide, BO1 strain, YL strain,WH strain and YX strain share high identities,while the identities of G strain,BJ strain, WG strain and FF strain are low. The results of deduced amino acid sequences show that the mutation of N protein mainly display sporadic point mutation as 46,48,50,75,78,189,223,236,237,298,301,350,366 et al. Mutational site did not show obvious regularity.