The pseudoknot region and poly-(C) tract comprise an essential RNA packaging signal for assembly of foot-and-mouth disease virus
Fig 5
Transcripts with shorter poly-(C) tracts are less competitive during encapsidation.
Replicons with differing length poly-(C) tracts were compared in the trans-encapsidation assay and were assessed according to the (A) first round GFP object count, (B) first round green MFI and (C) second round GFP object count. (D) RNA transcripts containing the equivalent poly-(C) tracts were compared in terms of speed of CPE development and (E) their ability to compete with a standard replicon for packaging resources, when used as the capsid-donor in the trans-encapsidation assay; high replicon trans-encapsidation efficiency equates to the capsid-donor being poorer at competing with the replicon. Data shown represent the mean from triplicate wells at either the point of harvest (A-B) or the time point with peak GFP expression (C and E), and error bars represent the SEM calculated from 5 (A-B), 12 (C and E), and 15 (D) images. Significance is shown for A-C and E comparing the samples to each other and between the wt replicon and the cell only/transfected replicon only controls using a one-way ANOVA (**** p < 0.0001). Significance in D was calculated using Wilcoxon tests between each sample, but none were significant (p < 0.001).