鸡马立克氏病病毒广西株Meq基因的克隆与序列分析

为研究鸡马立克氏病病毒(MDV)广西流行株的遗传变异情况,本研究从广西发病鸡中分离鉴定了3株MDV。参照GenBank中MDV的核苷酸序列设计1对引物,利用PCR技术对分离毒株的Meq基因进行了克隆、序列测定,并与GenBank中发表的国内外参考毒株进行比对分析。结果显示, Meq基因序列全长为1020 bp,编码一条由339个氨基酸组成的多肽,分离株与国内外MDV参考毒株相比,不同MDV株的Meq基因序列相对较保守,它们之间核苷酸同源性为83.8%~99.9%,氨基酸同源性为88.4%~99.6%。3株MDV分离株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株分离株与国内参考株YL、GXY2关系较近,与参考株RB1B、GA、Md5、648A及疫苗株亲缘关系较远。该研究为中国MDV的流行、遗传变异及防控研究提供了材料。

Cloning and Sequence Analysis of Meq Gene of Marek's Disease Virus Guangxi Strain

To investigate genetic variation of Marek's disease virus(MDV) in Guangxi province, three isolates of MDV were isolated from infected chicken.One pair of primers for amplifying Meq gene of MDV was designed according to nucleotide sequence in GenBank, Meq gene of the isolates were amplified by PCR, and then cloned, sequenced and compared with reference MDV strains published in GenBank.The results showed that Meq gene from all of the MDV isolates consisted of 1020 bp, coding for 339 amino acids.Compared with reference strains published in GenBank, the sequences of Meq gene in different isolates were relatively conserved and the homologies of nucleotide and amino acid sequence of the isolates were 83.8% to 99.9% and 88.4% to 99.6%, respectively.The proline-rich repeats of Meq gene of the MDV isolates had site mutations, and it was related to MDV's virulence.The isolate were nearly related to YL and GXY2, and far away from RB1B, GA, Md5, 648A and the immune strain phylogenetically.The study would provide research materials for the prevalence, genetic variation, protection and control of MDV in China.