Fig. 1.

Recovery of the recombinant IBVs from cells.

(a) Diagram showing the organization of the genomes in the recombinant IBVs. The genome structure of the IBV Beaudette strain is shown in the white rectangle. Regions coding for the hypervariable regions (HVRs) in the IBV strain ck/CH/LDL/091022 are shown in the black rectangle. (b) Immunofluorescent staining of Vero cells infected with the recombinant IBVs. The cells were infected with the recombinant IBVs and the two parental strains. At 24 h post-infection, the cells were fixed and stained with the monoclonal antibody against IBV N protein. (c) Detection of the viral RNA in Vero cells by RT-PCR. Total RNA was extracted from Vero cells electroporated with full-length transcripts at 48 h post-electroporation. RT-PCR was used to amplify the regions corresponding to the 5′-terminal 415 bp and 1010 bp of subgenomic mRNA 4 and 3, respectively.