FIG. 6.

Southern blot analysis of LTR circles. Purified DNA from FV vector and wild-type FV stocks was digested with StuI, SwaI, EagI, PacI, and/or NheI as indicated and analyzed by Southern blotting. The vector preparation DNA was also digested with DpnI to remove transfected plasmid DNA. Diagrams of the predicted LTR-containing fragments (not to scale) are shown below the corresponding Southern blots with the predicted sizes of linear, one-LTR circle (1-LTRc), and two-LTR circle (2-LTRc) DNA fragments. The position of the FV probe used is shown with a black bar.