犬瘟热病毒临床流行野毒株F蛋白信号肽区分析

Analysis of Signal Peptide Fragment of Canine Distemper Virus Wild-type Strain Fusion Protein

根据GenBank上发表的犬瘟热病毒（CDV）融合蛋白基因（F）序列，设计引物扩增F蛋白部分信号肽区，片段长369bp。对2005年～2007年收集的犬瘟热阳性的水貂、狐、貉实质脏器、血液、尿液等样品进行扩增，获得了13个CDVF蛋白部分信号肽区基因片段。序列分析发现，CDV野毒F蛋白该区段核苷酸与氨基酸序列与目前我国使用疫苗株CDV，及其他国内外疫苗株比较存在较大差异，与CDV3对应区段的核苷酸同源性在80．7％～83．2％之间，而推导的对应氨基酸序列同源性只有64．8％～71．3％。部分信号肽区的氨基酸疏水性分析，推测其调控功能也发生变化，本研究为CDV遗传变异和分子流行病学提供理论数据。

A pairs of primers were designed according to the fusion protein （F） gene sequences of canine distemper virus （CDV） in GenBank. A 369 bp fragment aimed signal peptide fragment of F gene was amplified. The PCR products from viscera samples, blood, urine of fur animals including foxes, minks and raccoon dogs, which collected in the years 2005-2007, were cloned to pMD18-T Vector and sequenced. We obtained 13 positive signal peptide fragments from wild-type strains. The results indicated there was obviously genetic diversity between the wild-type strains and CDV3 and other vaccine strains. The homology with CDV3 is 80.7% - 83.2% in nucleotide, and 64.8% -71.3% in amino acid. The analysis for the hydrophobic regions indicated the function of signal peptide fragment may be changed. This study can offer academic data to research of CDV genetic variation and epidemiology.