Fig. 7. Comparison of the replication silencers in TBSV genomic and DI RNAs. (A) The sequences of the genomic (g)RNA and the DI RNA differ at one position within the replication silencer region, which is the presence of an extra guanylate within the internal loop in DI-72 as shown (two versus three Gs, boxed). Note that a letter in a black box represents a single mutation (see Figure 6). (B) Representative denaturing gel analyses of radiolabeled RNA products synthesized by in vitro transcription with CNV RdRp. Arrows point to the RdRp products generated by initiation from the 3′-terminus. Further details are as described in the legend to Figures 1 and 3.