(A) A 450 bp and a 3.1 kb Pax6 genomic sequence were deleted by gene targeting in Pax6ΔPE and Pax6ΔDP, respectively. Frt and LoxP sites are represented by open arrows and solid triangles. PE, the Pax6 promoter-proximal enhancer; EE, the ectodermal enhancer; DE, the promoter-distal enhancer; Sh, Sph I; Sp, Spe I. (B) Southern Blots using the 5′ Sph I or the 3′ Spe I probes confirmed the Pax6Neo allele in the ES cell lysates and the Pax6ΔPE and Pax6ΔDP alleles in mouse tail extracts. (C) Genotyping confirmation of the Pax6ΔPE and Pax6ΔDP mice.