Fig. 4.

Analysis of clones from of a TARGET × DELETER cross. The RBC stages of mouse B after the TARGET × DELETER cross were cloned by limiting dilution, and their CS and TRAP loci were analyzed by Southern hybridization after HindIII (H3) digestion by using a mix of Flp and GFP internal probes. The predicted sizes (in kilobases) of restriction fragments generated by digestion with HindIII at the TARGET, TARGET/Exc, and DELETER loci are shown on the right. A clone carrying a TARGET/Exc locus without the Flp gene at the TRAP locus is shown in lane 1. Clones carrying a TARGET locus and a WT TRAP, a WT CS and DELETER locus, and a WT CS and a WT TRAP are shown in lanes 2, 3, and 4, respectively.