FIG. 2.

Southern blot analysis of genomic DNA. (A) Physical maps and predicted structural changes in pCALNdLG after the introduction of Cre recombinase. In the case of pCALNLG, the predicted NcoI fragment is 1.2 kb in size because of the lack of the mRNA-destabilizing signal. The 0.7-kb VSV-G probe was isolated from pCALNdLG by MluI and NcoI digestion. N, NcoI sites. (B) Autoradiogram of Southern blotting of NcoI digests of genomic DNA (15 μg per lane) from PtG-L1 and PtG-S2 before (−) and 4 days after (+) the introduction of Cre recombinase (right) and of plasmid pCALNdLG DNA for quantitation (left).