Identification of retroviral integration sites. (Top) A scheme of an integration site of the provirus into D3 locus determined on the basis of the results of LAM-PCR analysis. BamHI sites and probes used in Southern blotting are also shown. (Bottom) Southern blotting of BamHI-digested genomic DNA obtained from F1 (lanes 1 and 3) and F2 (lanes 2 and 4) of transgenic mice using an EGFP (lanes 1-2) or D3 (lanes 3-4) probe.