目的分析3株经野狼-家犬-牦牛传播的狂犬病病毒N基因部分核酸序列,以确定其传染源和传染途径。方法分离发病动物的RNA进行DFA检测和RT-PCR检测,阳性者进行N基因部分编码区核苷酸测序检测,采用ATCG ver4软件进行序列拼接,用DNAMAN将所测序列N基因进行核苷酸序列同源性比对,用ClustalX软件Bootstrap N-J Tree法构建系统发生树。结果发病宿主动物脑组织标本和脊髓经DFA检测到内基氏小体和病毒颗粒,RT-PCR扩增狂犬病毒核酸阳性,扩增产物大小为256bp,与目标片段大小一致。RT-PCR扩增产物经纯化后测序,N基因核苷酸序列3毒株间的同源性为99.28%~99.73%,推导的氨基酸序列同源性为99.46%~100.00%,牦牛狂犬病毒核苷酸序列与咬伤犬同源性99.28%,在自毙狼和病犬同源性为100%,牦牛狂犬病毒核苷酸序列与本室2012年测序的玛多犬N基因核苷酸同源性99.7%,与2012年内蒙古野生狸neimeng102B(EU652445.1)的同源性为95.28%,与2008年USA994-dog(EF611868.1)的同源性为95.94%,与2009BeijingHu1(EU700031.1)的同源性为85.9%。3株狂犬病毒株间N基因变异较小,稳定性较高,病毒核苷酸序列均为基因China IV,具有一定的地域性,进化分析显示均属于与野生动物最为相关的北极群。结论狂犬病可经野狼-家犬-家养牦牛传播,本起疫情中野狼为第一传染源。 Objective To analyze the nucleic acid sequences of three parts of N gene of rabies virus transmitted by wolf - dog - yak in order to determine the source of infection and the route of infection. Methods RNA was isolated from diseased animals for DFA detection and RT-PCR detection. The positive individuals were sequenced for the nucleotide sequence of part of coding region of N gene. The nucleotide sequences of the N gene in the tested sequences were sequenced by DNAMAN using ATCMAN4 software. Homology comparison, ClustalX software Bootstrap NJ Tree method to construct phylogenetic tree. Results The Neisseria gonorrhoeae and virus particles were detected by DFA in the brain tissues and spinal cord of the host animals. The results of RT-PCR showed that the size of the amplified product was 256bp, which was consistent with the size of the target fragment. The products of RT-PCR were purified and sequenced. The homology of the N gene nucleotide sequence 3 strains was 99.28% -99.73%, the deduced amino acid sequence homology was 99.46% -100.00%, the yak rabies virus nucleus 99.28% homology of the nucleotide sequence with bite dogs, dogs and dogs in the self-defeating wolf homology was 100%, yak rabies virus nucleotide sequence and the room in 2012 sequencing Maduo N nucleotide nucleotide homology The homology was 99.7% with that of neimeng102B (EU652445.1) in Inner Mongolia in 2012 and 95.28% with that of USA994-dog (EF611868.1) in 2008, which was similar to 2009BeijingHu1 (EU700031.1) The homology was 85.9%. Three strains of rabies virus N gene variation is small, high stability, the virus nucleotide sequence is gene China IV, has a certain geographical, evolutionary analysis showed that most are associated with the wildlife of the Arctic group. Conclusion Rabies can be transmitted by wolf - domestic dogs - domestic yaks, wolves were the first source of infection in this epidemic.