FIG 6.
The critical region of the S protein subdomains for PEDV trypsin dependency. (A) Schematic map of the chimeric S proteins of the recombinant viruses. Orange and red regions represent YN200 S and DR13 S, respectively. (B) Vero cells were infected with rYN200-S1DR13 or rYN200-S2DR13 with or without trypsin at an MOI of 0.01 for 24 h, while rYN200-NS2′DR13-infected cells were incubated for another 48 h before monitoring. (C) Trypsin sensitivities of chimeric S proteins, determined as described in the legend to Fig. 2C. S0, full-length S protein; S2*, a cleavage product.