[Rescue of bovine Asia 1 serotype foot-and-mouth disease virus from a full-length cDNA clone]

Abstract

After sequencing the Asia 1 foot-and-mouth disease virus (FMDV) (As01 strain), we amplified the two fragments covering the whole genome by overlapping PCR and long PCR. The 5' fragment was 1.8 kb in length including 15Cs, and the 3' fragment was 6.7 kb in length. The two fragments were cloned into the pBluescript SK vector to construct recombinant plasmid pBSAs carrying the full-length cDNA of FMDV As01 strain. The RNA transcript was synthesized in vitro using T7 polymerase and transfected into BHK-21 cells. We observed the typical CPE caused by rescued FMDV. The harvested virus was confirmed to be Asia 1 FMDV by RT-PCR, indirect immunofluorescence assay (IFA) and electron microscope observation. The rescued virus showed a similar pathogenicity in suckling mouse (LD50) compared to its wild-type virus. The infectious cDNA clone of the FMDV As01 strain laid a new ground for further investigation of FMDV virulence determinants and development of novel vaccines against FMD.