导　　师： 罗廷荣

学科专业： 090602

授予学位： 硕士

作　　者： ;

机构地区： 广西大学

摘　　要： 本研究采用RT—PCR技术对来自广西不同地区共15株猪瘟病毒进行E2基因的扩增、克隆和测序，得到长度为1092 bp编码364个氨基酸残基的目的基因片段。 应用DNAStar序列分析软件对所测定的广西15株与已知序列的HCLV、Shimen毒株的相应片段进行同源性分析比较。结果显示，广西株与HCLV、Shimen株的核苷酸同源性分别为81.5％～2.8％和82.8％～84.3％，推定的氨基酸同源性分别为87.1％～88.8％和88.5％～89.9％。广西毒株之间核苷酸和推定的氨基酸同源性分别为92.3％～99.9％和94.8％～100％。HCLV与Shimen核苷酸和推定的氨基酸的同源性分别为95.9％和95.3％。说明广西毒株之间的同源性很高，而广西毒株与HCLV、Shimen之间同源性都比较低。广西的15株病毒的E2蛋白的Cys位点没变，可推测CSFV E2蛋白在抗原结构方面依然保持很高的稳定性。在具有中和特性的B、C区域内724、725、729、734和738氨基酸位点发生了变异，这些变异可能导致E2蛋白的抗原性发生改变。 把15株广西流行毒株与国内外已发表的19株CSFV相应序列进行比较，并建立了遗传进化树。该遗传树主要分为两大群和一个另类，广西株皆属于基因群Ⅱ，但我国的主要参考毒株HCLV、Shimen则属于基因群Ⅰ，说明广西流行CSFV株与HCLV、Shimen有很大差异。 In this study the E2 genes of 15 Classical Swine Fever Virus /(CSFV/) strains isolated from Guangxi /(GX/) were amplified by reverse transcription polymerase chain reaction /(RT-PCR/). These E2 gene fragments which contain 1092 base pair in length and encode 364 amino acid residues were cloned and sequenced . Comparison of E2 seqences between 15 GX strains and Hog Cholera Lapinised Virus /(HCLV/), Shimen strains using DNAStar software was carried out, the result showed that the homology between GX strains and HCLV were 81.5/%~82.8/% for nucleotide sequence and 82.8/%~84.3/% for deduced amino acid sequence. The homology between GX strains and Shimen were 87.1/%~88.8/% for nucleotide sequence and 88.5/%~89.9/% for deduced amino acid sequence. The nucleotide homology among GX strains were 92.3/%~99.9/% , and the deduced amino acid homology were 94.8/%~100/% . Howerer, the homology of nucleotide and deduced amino acid sequence between HCLV and Shimen were 95.9/% , 95.3/%, respectively. These results demonstrated that the homology among GX strains is high, but between GX strains and reference strains is low. No Cystein residues change on E2 glycoprotein of GX strains had been shown, indicating that E2 glycoprotein of GX strains still remain highly stability. The antigenic domain B and C which related with neutralizing activity , were variable on the position 724, 725, 729, 734 and 738 of residues. These varieties likely led to antigenic difference among CFSV . Phylogenetic tree among 15 strains of GX and other 19 CSFV strains published were obtained by analyzing nucleotide sequences of E2 gene. These 34 strains are classified into two major Genogroups and a special individual /(which agreed with domestic and foreign scholors' conclusions/) .Fifteen GX Strains belonged to Genogroup II , but HCLV and Shimen strains belonged to Genogroup I . The Phylogenetic tree revealed that CSFV epidemic strains from GuangXi were significantly genetic divergent from strains Shimen and HCLV in recent years.

关 键 词： 猪瘟病毒 基因 同源性 变异

分 类 号： [S852.65]

领　　域： [农业科学] [农业科学] [农业科学]