Figure 1.

Targeting of the GPI-DAF locus. (A) Partial restriction maps of the GPI-DAF gene fragment and the targeting vector. N, NotI; X, XbaI; E, EcoRI; B, BamHI; Xh, XhoI. After correct targeting, the first three exons (represented by thick vertical bars) would be deleted and replaced with the NEO gene. Targeted ES-cell clones were identified by the presence of an extra 5-kb band, in addition to the 8-kb wild-type band, on Southern blot analysis of XbaI-digested genomic DNAs. The probe used for Southern blot screening was a 300-bp XbaI-BamHI fragment immediately 5′ to the 5-kb BamHI fragment. (B) Representative Southern blot result of tail DNA showing the three genotypes of progeny between heterozygous mouse matings. +/+, wild-type; −/− homozygous; +/−, heterozygous.