4株鸡马立克氏病病毒国内分离株Meq基因的克隆与序列分析  

Cloning and Sequence Analysis of the Meq Gene of 4 Marek's Disease Virus Isolates from China

作　　者：施维松[1] 刘长军[1] 张艳萍[1] 秦运安[1] 张晓巍[1] 李晶梅[1] 陈洪岩[1] 

机构地区：[1]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室禽传染病研究室

出　　处：《病毒学报》2008年第2期117-125,共9页Chinese Journal of Virology

基　　金：中国农业科学院哈尔滨兽医研究所所长基金(2007-A-05)

摘　　要：根据鸡马立克氏病病毒（MDV）GA株Meq基因序列，设计并合成一对用于扩增Meq基因的引物，利用这对引物通过PCR方法分别扩增4株东北地区分离的强毒株、国内标准强毒株J-1株、国内疫苗株814株的Meq基因片段，进行克隆测序，对4株MDV分离毒株Meq基因与国内传统毒株Meq基因及GenBank上收录的国内外9株毒株Meq基因序列进行比较分析。序列比较显示，不同的MDV株的Meq基因序列相对比较保守，它们相互间氨基酸序列的同源性在96．5％～99．7％之间。4株MDV分离毒株Meq基因在相关报道中提到的与毒力相关的脯氨酸重复区存在点突变；3株分离毒株Meq基因上相同位置均存在两个定点突变，这两处点突变是国内近几年分离株所特有的，国外已发表的MDV毒株Meq序列中不存在这种变化。分离株Meq基因的这些突变和毒株毒力的关系具有一定的规律性，但是这些规律性还有待进一步研究。Earlier studies have determined that the repeat regions of oncogenic serotype 1 MDV （Marek＇ s disease virus） encode a basic leucine zipper protein ,Meq, which structurally resembles the Jun/Fos family of transcriptional activators. Meq has been suggested as the MDV-associated oncogene. In this paper, based on the published sequence of Meq gene of GA strain of MDV, a pair of primers were designed and synthesized. Meq gene ORF （Open reading frame） of the four Chinese local MDV isolates, the reference strain J-1 and the vaccine strain 814 were amplified by using polymerase chain reaction（PCR）. Then the PCR products were cloned and sequenced respectively. The results of sequence comparison indicated that the sequences of Meq gene in different strains are relatively conserved and homology of the amino acid sequences is 96.5%-99. 7%. The proline-rich repeats of Meq gene of four MDV isolates have site mutations,and it is related to MDV＇s virulence. Two unique site mutations appear in Meq gene of Chinese local MDV isolates,but they aren＇t present in Meq gene of the published MDV strains from abroad and the early domestic strains. It seems that some regularities exist between such mutations in four Chinese local MDV isolates and the virulence of MDV, but the regularities need further research.

关 键 词：马立克氏病病毒 MEQ基因 序列比较 定点突变 

分 类 号：S858.31[农业科学—临床兽医学]