[Construction and identification of infectious molecular clone of foot-and-mouth disease virus strain O/CHINA/99].
Nine primers were designed for the full-length genome of O/CHINA/99 and each sequence fragment was obtained by RT-PCR, and cloned into pOK12 vecter, the full-length genome cDNA clone of O/CHINA/99 was identified by restriction enzymes digestion, PCR, and the whole genome sequencing. The results showed that the O/CHINA/99 whole genome was formed with the length of 8200 nt. The nucleotide sequence of the full-length cDNA shared 99.1% homology with its prototype. RNA synthesized in vitro by means of a bacteriophage T7 promter inserted in front of the cDNA led to the production of infectious particle upon transfection of BHK-21 cell using lipofectamine reagent, as shown by cytopathic effects. The rescued virus had high pathogenicity in mice by endermic infection too. All the results showed that an infectious molecular clone was successfully constructed and rescued virus could be obtained.