Fig. 1.
Construction of recombinant IBV viruses with insertion of EGEP at different positions of the IBV genome, and analysis of EGFP expression and recovery of the infectious viruses. (a) Diagram outlining the genome organization of IBV and the positions of the inserted EGFP in each construct. Green and red boxes indicate EGFP gene and TRS sites, respectively. The EGFP gene expression (GE) in cells electroporated with different constructs and the recovery of infectious virus (VR) from each construct were listed. (b) EGFP expression observed by fluorescence microscopy in Vero cells electroporated with IBV-EGFP25180, IBV-EGFP27105, IBV-S-EGFP, IBV-EGFP-M and IBV-N-EGFP, respectively, at 3 days post-electroporation. Typical CPE and expression of EGFP were observed in cells electroporated with IBV-EGFP25180, IBV-EGFP27105, IBV-S-EGFP and IBV-N-EGFP transcripts. Less CPE was observed. The corresponding EGFP expression was also found in cells electroporated with IBV-M-EGFP transcripts. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of the article.)