Test of purine-rich sequences in the vicinity of DIS during FIV gRNA packaging and propagation. (A) Schematic drawing of the previously published secondary structure of FIV packaging signal RNA (Kenyon et al. 2011). For clarity, the purine-rich region targeted for introducing substitution mutations is enlarged and shown as an inset. (B) Description of mutations introduced in the selected purine-rich sequences. Red and underlined nucleotides represent the substitutions introduced. The nucleotide positions are shown as superscripts. The relative RNA propagation efficiency of each mutant RNA is shown in the far-right column as hygromycin-resistant (HygR) colony-forming units per mL (CFU/mL) normalized to the transfection efficiency. The data shown here are from a minimum of three independent experiments performed in triplicate (± standard deviation [SD]).
