CPEs of BHK-21 cells infected with FMDV at different times. A. CPEs of BHK-21 cells transfected with FMDV-specific siRNA-expressing plasmid;. B. CPEs of BHK-21 cells transfected with control plasmid;. C. CPEs of Control BHK-21 cells. As showed in Fig. 1, CPEs appeared in the BHK-21 cells infected with FMDV serotype A at 12 h postinfection and were particularly severe among the 4 groups between 24 h to 36 h. Cellular detachment, rounding, and destruction of the control group were more severe than the experimental group. At 48 h postinfection, the cells of the control group were dead and almost detached.