Figure legend
Figure 1. Replicative capacity of variant viruses with indicated PA/I38 substitutions in MDCK cells. MDCK cells were infected with wild-type (WT) or indicated mutant viruses based on rgA/WSN/33(H1N1) (A, C) and rgA/Victoria/3/75(H3N2) (B, D). The culture supernatants were collected at the indicated time points and viral titers (TCID50/mL) were determined in MDCK cells. Each plot represents the mean and standard deviation of triplicate experiments. The lower limit of quantification of the virus titers was indicated by a dashed line. *P < 0.05 to WT by Welch’s t -test at the indicated time point.