Fig. 1.

Localization and DNA sequences of the PFV purine-rich sequences used in this study. (A) Gene map of the PFV provirus (LTR, long terminal repeat; the open reading frames of the viral genes are shown by open boxes). The localization of cis-acting sequences CasI and CasII is indicated. CasI is localized in the 5′ and gag regions of the viral RNA (nt 1 to 645), and CasII is located in the 3′ region of the pol gene. The various RNAs used are displayed below the map. The relative positions of the purine-rich elements A to D and the lengths of the different RNAs used are indicated. (B) DNA sequences of the PFV purine-rich elements A, B, C, and D. WT, wild type.