Fig. 7

The effect of 1/244 DI RNA on its own levels of transcribed RNA in the presence or absence of seg 1-GFP. Human 293T cells were transfected with pPolI-244 and expression plasmids as described in Fig. 3. Primer extension analysis of levels of RNA transcribed from 1/244 DI RNA in the presence (a) or absence (c) of 1.0 μg segment 1-GFP. The faint band indicated by (*) is the extension product from the pcDNA PB2 expression plasmid used in the transfection. b shows the quantitation of viral RNA levels from four independent experiments with the standard error of the mean, and (d) shows the range for two replicates. vRNA (■), positive-sense RNA (cRNA + mRNA) (▲). The effect of omitting the plasmid expressing the influenza PB2 protein on virus RNA synthesis is shown in panel (e)