FIG. 2.

Recombinant TGEV virus expressing GFP. (a) Cultures of ST cells were infected with either recombinant TGEV-GFP2 virus or the TGEV infectious construct (icTGEV) (80) at an MOI of 5 for 1 h at room temperature. The inocula were removed, and the cultures were incubated in complete medium at 37°C. Samples were harvested at the indicated times and assayed by plaque assay in ST cells. (b) Cultures of ST cells were infected as described for panel a. At ∼12 h postinfection, GFP expression was observed by fluorescent microscopy in TGEV-GFP2-infected cultures (B) but not in icTGEV-infected cultures (A).