【摘要】 提取2株A型口蹄疫病毒FMDV L1和FMDV L2的RNA,用1对通用引物经RT PCR扩增出2株病毒VP1基因的DNA片段,将扩增的VP1编码序列克隆到质粒载体pGEM TEasy中,转入大肠埃希氏菌JM109,得到大量携带目的基因的质粒;经过重组质粒的鉴定、测序获得其核苷酸序列;利用序列分析软件及系统发生树绘制软件对FMDV L1和FMDV L2以及作为参考毒株的A22/India/17/77进行序列分析。结果表明,核酸序列中的变异多发区要多于氨基酸序列,氨基酸序列最明显的变异发生在构成FMDV抗原位点1的βG βH环内,其中毒株FMDV L1和FMDV L2RGD序列中的精氨酸(R)发生了变异,分别变成了亮氨酸(L)和谷氨酰胺(Q)。更多还原

【Abstract】 Viral RNAs of FMDV-L1 strain and FMDV-L2 strain were extracted from bovine tongue epithelium infected with foot-and-mouth disease virus （FMDV） type A, and the fragment of VP1 was amplified with a pair of primers by RT-PCR.The fragment was inserted into pGEM-T Easy vectors to construct recombinant vectors. The recombinant vectors were transferred into Escherichia coli JM109 competent cells,which were incubated on ampicillin⁺ plates with X-gal and IPTG at 37 ℃ overnight. White clones were selected and incubated.After being identified, nucleotide sequence of the expected VP1 gene was determined by Sanger’s DNA sequencing method and then the amino acid sequence was deduced. By DNAstar software, both the nucleotide sequence and the amino acid sequence were respectively compared with the published sequence of VP1 gene of A22/India/17/77 strain and the deduced amino acid sequence（ ） from the sequence of VP1 gene of A22/India/17/77 strain. Results showed that variant regions of the nucleotide sequence were more than those of the amino acid sequence, that the most remarkable variant of the amino acid sequence located in the βG-βH ring of antigen site 1 of FMDV, and that the central tripeptide of binding cell receptor in FMDV L （1） and L （2） is Leu-Gly-Asp and Gln-Gly-Asp respectively instead of Arg-Gly-Asp motif.更多还原