FIGURE 1.

Plasmid DNA used for transfection. The structures of pSFVdhfr, pSFV-V, and pΔBM-d2EGFP are depicted. The plasmids were linearized at the indicated restriction enzyme sites and ligated to synthetic oligonucleotides to generate hairpin-capped ends, as described under “Experimental Procedures.” For pSFVdhfr and pSFV-V, the linear dimer DNA with hairpin ends at both sides was digested with MluI to produce the monomer DNA with hairpin end at one side (A). In C and D, the images of analytical gel for the transfected DNA preparation that appear in A and B are shown. The sizes of all bands were as anticipated from the diagrams in A and B. MW, molecular weight.