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.