广东省鸡传染性贫血病毒编码区基因的克隆与分子进化分析

Gene cloning and molecular evolution analysis of chicken anemia virus in Guangdong

为了解鸡传染性贫血病毒（chickenanemiavirus，CAV）广东分离株变异情况，通过PCR方-法克隆了于2012年分离到的10株cAV的编码区序列，并对其进行了测序及分子进化分析。结果显示，广东CAV分离株编码区全长1823bp，含有3个互相重叠的开放阅读框（ORF）。序列分析表明，广东省CAV分离株与GenBank上已发表的其他36株cAV比较，VP1核苷酸的同源性在94．1％～99．2％之间，推导出的氨基酸的同源性在95．3％～99．3％之间；VP2的核苷酸同源性在98．2％～100％之间，推导出的氨基酸的同源性在95．9％～99．5％之间；VP3的核苷酸同源性在97．8％～100％之间，推导出的氨基酸的同源性在95．1％～99．2％之间；VPl蛋白共有17个位点发生了变异，VP2蛋白共有11个位点发生了变异，VP3蛋白共有6个位点发生了变异。分子进化分析显示，10株CAV广东分离株主要位于两个分支，其中9株CAV分离株与GenBank上已发表的35株CAV处于一个大分支，而GI）IN一12与分离株KC414026处于另外一个小分支，由此得出其中9株广东CAV分离株是目前主要的流行毒株。

In order to understand the variation of chicken anemia virus （CAV） strains isolated from Guangdong,the coding sequences of the Guangdong strains isolated in 2012 were cloned through polymerase chain reaction （PCR） and molecular evolution of the coding region were analyzed. The coding sequences are made of 1 823 bp including three overlapping open reading frames （ORF）. The results of coding sequences analyses indicated that compared to 36 other published CAV se- quences in GenBank,the homologies of the VP1 nucleotide sequences and the deduced amino acid sequences are 94.1 0//00-99.2o//00 and 95.30//oo-99.3 % ,respectively; the homologies of the VP2 nucleo- tide sequences and the deduced amino acid sequences are 98. 2%-100~ and 95. 9%-99. 5%,re- spectively; the homologies of the VP3 nucleotide sequences and the deduced amino acid sequences are 97.8 %-100 % and 95.1%-99.2 %, respectively; the VP1 protein has 17 variations ,the VP2 protein has 11 variations,the VP3 protein has 6 variations. Molecular evolution analysis of the complete coding sequences indicated that the isolates of Guangdong were located in two clusters, nine CAV isolates are lo- cated in the bigger group with 35 other published CAV isolates in GenBank, and one CAV isolate is loca- ted in other small group with KCA14026 isolate.