安徽省五华鸡J亚群禽白血病病毒gp85基因分子序列特征分析

为进一步了解J亚群禽白血病病毒(avian leukosis virus subgroup J,ALV-J)gp85基因的结构、功能及其遗传变异趋势,采用PCR方法克隆了安徽省地方品种五华鸡ALV-J gp85基因序列ALV-J-WH,并将该序列与GenBank数据库中登录的15个gp85基因序列进行了比对分析。结果显示,ALV-J-WH与所比对的氨基酸序列同源性介于85.9%~96.2%之间,与其同源性最高的是来自于国内ALV-J毒株的JN378888基因序列,进化树也证实两者亲缘关系较近;此外,相对其他ALV-J gp85氨基酸序列,ALV-J-WH在223位氨基酸后有10个氨基酸的缺失;对所有全长序列分析结果表明,共有71个可变氨基酸位点,10个高度变异位点,尤其是hr1和hr2区域分布较多。结果表明,ALV-J-WH与国内部分ALV-J毒株分离gp85基因来自共同的原始病毒,但其具有独特的序列特征;ALV-J gp85基因高度易变,部分高频率突变的氨基酸位点可能是ALV-J在抗体免疫选择压下的作用位点。

Sequence Feature Analysis of gp85 Gene of Avian Leukosis Virus Subgroup J in Wuhua Chickens in Anhui Province

In order to further understand the structure,function and genetic variation of ALV-J gp85 gene,the gene was cloned by PCR in Anhui province,which named as ALV-J-WH. We compared ALV-J-WH with fifteen amino acid sequence of ALV-J gp85 genes in GenBank database. The results showed that the homology between ALV-J-WH and the other sequences ranged from 85.9% to 96.2%, the highest homology with ALV-J-WH were JN378888 sequences isolated from China. Evolution analysis further revealed that they had a close genetic relationship. Moreover,the deletion of a 10 amino acid was observed in the ALV-J-WH between position 223 and 224 of amino acid sequence. Alignment of the full-length sequences revealed 71 variable amino acid sites,10 sites had high mutation frequency,expecially sites in hr1 and hr2 domains. The results confirmed that ALV-J-WH and partial genes of strains isolated from China evolved from common strains,but the sequence was unique. ALV-J gp85 gene was highly variable,and some amino acids with high degree of mutation frequency might be action sites of ALV-J antibody under immune selective pressure.