6株O型口蹄疫病毒结构蛋白vp1基因的克隆与序列分析

Cloning and Sequence Analysis of the vp1 Gene of Six Strains of Foot-and-mouth Disease Virus Type O

提取6株O型口蹄疫病毒(FMDV)(T1-T6)的RNA,用一对通用引物经RT-PCR方法将6株FMDVVP1基因片段扩增出来。克隆测序,核苷酸序列分析表明,T1-T6六株vp1基因的核苷酸序列同源性在95%～99.8%之间,氨基酸序列同源性在94.8%～100%之间。T1-T6六株病毒vp1基因的核苷酸序列与已经发表的O/HKN/14/82、O/TAW/81/97、O/PHI/7/96、O/HKN/1/99和O/HKN/16/96的同源性较高,核苷酸序列同源性在86.1%～95.8%之间;发现6株毒株的主要中和抗原表位140-160、200-213位的氨基酸序列完全相同,推测它们有相近的中和抗体表位和抗原性。故推断本试验中的6株FMDV株属于同一基因型,即FMDVO型中国拓朴型(Cathaytopotype)。

The nucleotide sequences of six strains named T1, T2, T3, T4, T5 and T6 of FMDV type O were determined. RNA of the six cell-adapted virus strains were extracted by single-step method of RNA isolation, reverse-transcripted and amplified by PCR, respectively. PCR products were cloned and sequenced. The homology among these T1-T6 strains is 95%～99.8% for nucleotide sequence and 94.8～100% for amino acid sequences. Homology among the T1,T2,T3,T4,T5,T6, O/HKN/14/82、 O/TAW/81/97、O/PHI/7/96、O/HKN/1/99 and O/HKN/16/96 strains are 86.1%～95.8%.The relative degree of variation of VP1 140-160 and 200～213 amino acids, the major neutralizing site determined, were same within the T1, T2, T3, T4, T5 and T6 strains, indicating the similarity in epitopes and antigenicity. The nuleotide sequences of six virus strains belong to the same genetype-Cathay topotype.