Fig. 1.

Cell fusion induced by recombinant S proteins of PEDV MK and MK-p10. (a) A schematic presentation of amino acid substitutions in the S protein of MK-p10 compared with the parental MK S protein and of constructed plasmids. (b) Cell fusion induced by recombinant PEDV S proteins. The S protein expression plasmids were transfected into Vero cells using the DMRIE-C reagent. After 3 days of incubation, cells were washed with PBS, added to DMEM containing 10% TPB and 1.25 μg/mL of trypsin, and incubated for 15 h. These cells were fixed and stained with PBS containing 20% formalin and 0.1% crystal violet and observed by microscopy. Fused cells are indicated by white arrows.