肾型IBV陕西分离株CK/CH/Shaanxi/2009/H09全基因的克隆与序列分析

Cloning and Analysis of the Complete Genome of IBV Isolate CK/CH/Shaanxi/2009/H09from Shaanxi Province

为了解鸡肾型传染性支气管炎病毒陕西流行株的分子生物学特征，参考DY07株全基因核苷酸序列设计22对引物，采用RT PCR方法对西北农林科技大学动物医学院禽病研究室分离的1株肾型IBV陕西分离株CK/CH/Shaanxi/2009/H09的全基因进行分段扩增并测序，将测序成功的各序列依次拼接，得到全基因序列后进行序列比对分析。研究结果表明，该分离株基因组全长27 675 bp，共有10个开放阅读框，其基因排序为5′cap Replicase S 3a 3b 3c M 5a 5b N poly（A）3′，纤突蛋白裂解位点为到536RRFRR540， 3a、5a和N基因的大小与参考毒株相比是保守的，但编码其他蛋白的基因长度存在差异；同源性分析结果显示，该毒株与48个参考毒株的同源性为85.2%~93.5%；系统进化树分析结果显示，该毒株与中国分离株ck/CH/LDL/091022、YX10株和DY07 株的亲缘关系较近，同属于中国近年来主要流行的血清型毒株，但在基因水平上已经产生一定程度的变异。

In order to understand the molecular characteristics of avian nephropathogenic infectious bronchitis virus（NIBV） in Shaanxi province, based on the genome sequence of IBV strain DY07, twenty two pairs of primers were designed, and genome of IBV strain CK/CH/Shaanxi/2009/H09 was amplified, sequenced and aligned with other IBV strains. The sequences analysis showed that the 27 675 bp of CK/CH/Shaanxi/2009/H09 had the 5′cap Replicase S 3a 3b 3c M 5a 5b N poly（A）3′ gene order, and the typical avian coronavirus cleavage site of 536RRFRR540 in spike protein, and the length of the 3a, 5a and N genes were conserved while the length of other genes were varied. The sequence analysis results indicated that homology of the strain with reference strains was 85.2%-93.5%, genetically close to ck/CH/LDL/091022, YX10 and DY07. Although the strain CK/CH/Shaanxi/2009/H09 belonged to epidemic serotype of IBV, it has been mutated at gene level.