In vitro transcription of v84 mutant templates. The model RNA templates, v84wt (A), v84+A (B), v84+G (C), v84+U (D), v84+ C (E), and v53 (F), were transcribed in vitro. The sequences of the templates (boldface type) and primers are shown above the PAGE. The sizes of the RNA products are shown on the left and on the right of the PAGE. The 85- and 87-nt products are indicated by arrowheads (A).