Molecular Characterization of Major Structural Protein Genes of Avian Coronavirus Infectious Bronchitis Virus Isolates in Southern China
Molecular Characterization of Major Structural Protein Genes of Avian Coronavirus Infectious Bronchitis Virus Isolates in Southern China
复制标题
中国南方禽冠状病毒传染性支气管炎病毒分离株主要结构蛋白基因的分子特征
DOI：
10.3390/v5123007
复制
发表时间：
2013-12-01
期刊：
影响因子：
4.7
通讯作者：
Lang, Ya-Hui
中科院分区：
文献类型：
--
作者：
Mo, Mei-Lan;Li, Meng;Lang, Ya-Hui
为全面了解我国禽冠状病毒传染性支气管炎病毒（IBV）流行株的遗传信息，对23个IBV流行株的S1、M和N基因进行了系统发育树分析、氨基酸序列熵分析、正选择分析和计算重组分析。基于S1、M和N基因构建的系统发育树显示出明显的拓扑结构差异，其中CK/CH/LSC/99 I型是IBV的优势分离株。氨基酸序列熵分析结果显示，S1基因的变异最大，M基因的变异小于N基因。不仅在S1基因蛋白中，而且在M和N基因蛋白中也检测到阳性选择。此外，还确认了疫苗株4/91与CK/CH/LSC/99 I型野毒株之间的5个S1基因重组体。结果表明，我国IBV存在多基因型共存，S1、M和N基因存在遗传多样性和正选择，国内出现4/91株重组疫苗株。我们的研究结果表明，在中国的野外IBV正在继续进化，疫苗株可能通过重组在新的IBV毒株的出现中起重要作用。此外，本研究表明，IBV的进化是由两代的遗传多样性和选择驱动的。
To gain comprehensive genetic information of circulating avian coronavirus infectious bronchitis virus (IBV) isolates in China, analysis of the phylogenetic tree, entropy of the amino acid sequences, and the positive selection as well as computational recombinations of S1, M and N genes of 23 IBV isolates was conducted in the present study. The phylogenetic trees based on the S1, M and N genes exhibited considerably different topology and the CK/CH/LSC/99I-type isolates were the predominant IBVs based on the phylogenetic analysis of S1 gene. Results of entropy of amino acid sequences revealed that the S1 gene had the largest variation; the M gene had less variation than the N gene. Positive selections were detected in not only S1 but also M and N gene proteins. In addition, five S1 gene recombinants between vaccine strain 4/91 and CK/CH/LSC/99I-type field isolate were confirmed. In conclusion, multiple IBV genotypes co-circulated; genetic diversity and positive selections existed in S1, M and N genes; 4/91 vaccine recombinants emerged in China. Our results show that field IBVs in China are continuing to evolve and vaccine strains may have an important role in the appearance of new IBV strains via recombination. In addition, the present study indicates that IBV evolution is driven by both generations of genetic diversity and selection.