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