广西猪瘟流行毒与C-株疫苗毒gp55(E_2)主要抗原区DNA序列差异的比较

Amino-acid difference in the main antigen domain GP55(E_2) of the C-strain and the Guangxi prevalent strains hog cholera virus(HCV)

采用反转录 PCR(RT- PCR)和套式 PCR(nest Polym erase Chain Reaction,n PCR)扩增出 3株广西省近期 (1999～ 2 0 0 0年 )猪瘟流行野毒的 E2 基因 ,将其分别克隆于 PMD- 18T载体上并进行了核苷酸序列测定 ,根据 C株及 Brescia和 Alfort株确定起始氨基酸三联体的正确位置后进行氨基酸序列推导 ,同时进行了同源性比较及 E2 糖蛋白结构的分析。结果表明 ,所测 3株 HCV E2 基因的长度均为 1170 bp,编码的氨基酸序列均包括完整信号肽序列和部分跨膜序列 ,共由 384个氨基酸组成。3株流行毒的 E2 基因核苷酸序列同源性为 90 .10 %～ 98.5 4%,相应的氨基酸序列同源性为 89.5 9%～ 97.92 %。这 3株流行毒与 C-株兔脾组织毒 (疫苗种毒 ) E2 基因的核苷酸序列同源性为 82 .87%～ 83.99%,相应的氨基酸序列同源性为 86 .98%～ 90 .10 %,表明近期猪瘟流行毒与 C-株疫苗毒的 gp5 5蛋白之间存在一定的差异。

The E 2 gene of three prevalent virulent strains of Hog Cholera Virus (HCV) from Guangxi China were amplified by reverse transcription (RT) and the nested Polymerase Chain Reaction (nPCR).The amplifed E 2 fragments of three HCV strains were all 1 170 bp in length by agarose gel electrophoresis.Three E 2 fragments were cloned respectively into PMD-18T vector.1 170 bp cDNA fragments of three prevalent virulent E 2 gene were sequenced,and based on the amino acid sequences of C-strain,Brescia and Alfort strain 384 residues,amino acid sequences of E 2 were deduced.The nucleotide homology among three prevalents virulents were 90.10% to 98.54%;and that of amino acid were 89.59% to 97.92%.The nucleotide identity of C-strain from spleen tissue of rabbit with that of three Chinese prevalent virulent strains were 82.87% to 83.99%,and that of amino acid were 86.98% to 90.10%.This showed that there was some differences between gp55 of C-strain and the 3 prevalent virulent strains.