FIG. 7.

Subgenomic RNA transcription does not inhibit negative-strand RNA3 accumulation. (A) Schematic diagram of expression cassettes for B3CPfs and RNA3 derivatives in which the viral 5′-UTR was replaced with the GAL1 mRNA 5′-UTR. (B) Northern blot analysis of BMV-specific RNA products. Total RNA was extracted from yeast expressing RNA3 alone or in combination with 1a or both 1a and 2a (indicated at the top). Ethidium bromide-stained rRNA is shown below the Northern blots as a loading control. (C) GAL1 5′-UTR replacement strongly stimulates sgRNA transcription efficiency. The histogram compares negative-strand RNA3 synthesis efficiency (measured as the ratio of negative-strand RNA3 to positive-strand RNA3) and sgRNA transcription efficiency (measured as the ratio of sgRNA to negative-strand RNA3) for B3CPfs (gray boxes) and B3GAL1-CPfs (black boxes).