我国部分地区蛋鸡ALV-J分离株gp85基因遗传进化分析

Analysis of gp85 gene of subgroup J avian leukosis viruses from layer chickens in China

为了解我国蛋鸡J亚型白血病病毒(ALV-J)株来源及其遗传进化关系,本研究对2009年从我国6个省区蛋鸡场分离到的19株ALV-J的gp85基因进行克隆和测序,并与11个ALV-J参考株gp85基因作了比较分析。结果表明:19个ALV-J分离株的gp85基因长度为894bp～924bp不等,分别编码298～308个氨基酸;各病毒株间gp85推导氨基酸的同源性为71.3%～100%。遗传进化分析表明,目前我国蛋鸡ALV-J分离株来源复杂,其中13个分离株与英国原型株HPRS-103、国内麻黄肉鸡株SCAU-0901亲缘关系较近;3个分离株与美国株ADOL-7501及国内白羽肉鸡株HN0001处在同一大的分支;而另外3个分离株则各自形成独立的分支,表明其gp85基因发生了较大变异。本研究表明,19个分离株与国内早期肉鸡分离株亲缘关系较远,提示我国当前蛋鸡ALV-J株可能并非源自国内早期肉鸡ALV-J株,其来源有待进一步研究。

To investigate the variation of subgroup J avian leukosis viruses （ALV-J） isolated from layer flocks in China, the gp85 gene of the ALV-J isolated from different areas of China during 2009 to 2010 were cloned and sequenced. Comparing with the reference strain in GenBank, the results showed that the length of gp85 genes of those isolates ranged from 894 bp to 924 bp, encoding 298 to 308 amino acids, sharing identity from 71.3% to 100%. Phylogenetic analysis indicated that all 19 isolates classified into 3 branches. Among those isolates, 13 iolates were close relationships with the prototype ALV-J strain HPRS-103 and boiler chicken strain SCAU-0901, 3 isolates were highly related with the US strain ADOL-7501 and Chinese isolate HN0001,while 3 isolates with a big variation in gp85 gene formed an independent branch. To the conclusion, the 19 isolates from layer flocks had an less related with other Chinese ALV-J isolated from boiler chickens except the HN0001 isolate, indicating that the origination of ALV-J isolates need to further investigations.