FIG 4.

The 3′-end H1-ssNCR-truncated mutant viruses show decreased HA vRNA levels in virions and in cells. (A, B) Wild-type or mutant viruses were rescued in HEK-293T cells and then passaged in MDCK cells once. The vRNA levels of P0(A) and P1(B) virus in virions and in cells were analyzed by RT-qPCR. The graphs show the mean values of HA vRNA relative to those of NA vRNA. The data represent the means ± SEM of three independent experiments. Two-way analysis of variance (ANOVA) with Dunnett correction for multiple testing; asterisks represent a significant difference from wild-type virus as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.