Identification of a Novel Splice Variant Form of the Influenza A Virus M2 Ion Channel with an Antigenically Distinct Ectodomain (original) (raw)
Figure 4
Genetic and biochemical evidence for pseudoreversion through upregulation of mRNA4.
(A) Endpoint titres after multicycle replication in MDCK cells of viruses with the indicated mutations to segment 7. Values are plotted are the mean + SEM of between 2 and 18 independent rescues. NR; not rescuable in 2 or more attempts. Viruses were also visually classified into normal (black bar) and small (white bar) plaque phenotypes. (B, C) Segment 7 mRNA accumulation. Total RNA isolated from cells infected with the indicated viruses at 6 h p.i. was analysed by RT-primer extension and urea-PAGE using primers specific for segment 7 mRNAs, vRNA or (as a loading control), cellular 5S rRNA. (C) The amounts of mRNAs 1–4 were quantified by phosphorimager and plotted as the mean ± SD of 3 experiments (D) Segment 7 polypeptide accumulation was monitored by western blot analysis of lysates from 293T cells transfected with reverse genetics plasmids for the indicated viruses at 72 h post transfection with the indicated antisera.