Schematic diagram of the RNA primers used in this study. The gray rectangle represents nt 8994–9138 from the 3′-end of the HIV-1 NL4-3 RNA genome (numbering according to GenBank accession number: AF324493) (70). The RNA primers (each 20 nt) are shown beneath the gray rectangle and the tick marks are placed according to the position of the first base in the primer sequence in the viral RNA genome. Note that in the case of the PPT, we used a primer containing the PPT plus the five downstream bases, so that all primers would be the same size. The five additional bases are removed by RNase H to generate the actual PPT primer (9). Symbols: 589R, stippled; 194R (PPT+5), open; 587R, solid; and 591R, hatched. The table below the diagram indicates the nt positions and the sequence (5′ to 3′ direction) of each primer.