狐貉源犬瘟热病毒核蛋白基因的克隆及序列比较分析

参照已发表的犬瘟热病毒(CDV)核蛋白基因(N)序列设计合成了1对引物,用RT-PCR方法对从发病狐、貉中分离的MS01、SC01、ZD01三株CDV的N基因进行扩增,并分别将其PCR产物进行克隆和测序。测序结果表明:3病毒分离株N基因阅读框架全长均为1572bp,编码523个氨基酸。利用DNAstar的MegAlign生物软件,将3病毒分离株与Genbank数据库中现有的CDV毒株的N基因序列及推导出的氨基酸序列进行了同源性比较和系统进化树分析,结果发现:3病毒分离株与强毒参考株A75/17等野毒株高度同源,核苷酸同源为96.2%～99.1%,氨基酸同源为96.0%～99.8%,而与疫苗株Onderstepoor相对较远,核苷酸同源为93.6%～94.0%。N基因的系统进化关系分析显示:3病毒分离株均归为强毒株,并且与中国新疆的TN株、中国台湾的Kaohsiung株基因型最近,表现出一定的地理位置相关性。

Cloning and Sequence Analysis of Nucleocapsid Protein Gene of Canine Distemper Virus Isolated from Fox and Raccoon Dog

A pair of primers was designed in accordance with N gene of Canine Distemper Virus(CDV)published,and a fragment of N gene was amplified by RT-PCR from three CDV strains(MS01,SC01,ZD01)isolated from fox and raccoon dog.The PCR product was cloned and then sequenced.Result indicated that the open reading frame lengths of N genes of three strains were all 1 572 bp,encoding 523 acids.The homology between the three strains and 11 CDV strains in GenBank database was analysed and a phylogenetic tree was built by DNAstar.Results show that the three strains have higher homology with wild-type strain of A75/17,and the homologies of nucleic acid and amino acid range from 96.2% to 99.1% and 96.0% to 99.8%,respectively;while they have lower homology with vaccine strain of Onderstepoor,and the homology of nucleic acid ranges from 93.6% to 94.0%.The analysis of phylogenetic tree of N gene indicates that the three strains are all virulent,and they have the highest homology with TN strain isolate from Xinjiang Uyaur Autonomous Region of China and Kaohsiung strain isolate from Taiwan Province of China,exhibiting geographical correlation to a certain extent.