我国西藏小反刍兽疫病毒China／Tib／Gej／07—30核衣壳蛋白基因和基因组启动子区的分子特征分析

首次对我国西藏小反刍兽疫病毒China/Tib/Gej/07-30的核衣壳蛋白(N)基因和基因组启动子(GP)区进行序列测定和分子生物学特征分析。首先应用逆转录聚合酶链式反应从发病山羊病料中扩增出小反刍兽疫病毒N基因片段,用cDNA3′末端快速扩增方法获得基因组启动子区片段,对聚合酶链式反应产物进行直接测序,然后对测定的核苷酸和推测的氨基酸序列进行比较分析,绘制系统发生树。我国西藏小反刍兽疫病毒China/Tib/Gej/07-30的N基因由1689个核苷酸组成,编码525个氨基酸,与India/Jhansi/03等6个已知N基因全序列的PPRV毒株核苷酸和氨基酸序列同源性分别为91.7～97.6和94.9～98.5。小反刍兽疫病毒China/Tib/Gej/07-30N蛋白与磷蛋白作用的结构序列之一为495LFRLQAM501保守序列,N蛋白281-289位氨基酸含有一个T细胞表位,为281YPALGLHEF289保守序列。小反刍兽疫病毒China/Tib/Gej/07-30的GP区由107个核苷酸组成,与Tur-key2000等5株其他PPRV毒株同源性为91.8～98.2。N基因核苷酸序列和相应的氨基酸序列系统进化分析表明小反刍兽疫病毒China/Tib/Gej/07-30与亚洲国家分离株关系最近。

Sequence Analysis of the Nucleocapsid Gene and Genome Promoter Region of Peste Des Petits Ruminants Virus of Chinese Origin

The N gene and genome promoter nucleotide sequence of a Chinese Peste des petits rumiants virus(PPRV)("China/Tib/Gej/07-30") was firstly determined.The length of N gene was 1689 nucleotides with a single open reading frame(ORF).The nucleotide and deduced amino acid sequence was compared with the homologous region of other PPRV isolates.The nucleotide sequence of the "China/Tib/Gej/07-30" was 91.7%-97.6% identical to other PPRV isolates,while a homology of 94.9%-98.5% could be observed at the amino acids level.The N gene encoded a protein of 525 amino acids.Several sequence motifs were identified on the basis of conservation in the PPRVs and the morbilliviruses.The genome length of promoter region was 107 nucleotides with 91.8%-98.2% identity to other PPRV isolates.Phylogenetic analysis showed that the "China/Tib/Gej/07-30" belonged to the Asian lineage.