Figure 1.

Targeted disruption of the Ca²⁺ channel β₃ (ccβ₃) gene by homologous recombination. (A) Restriction maps of the murine ccβ₃ locus, the targeting vector, and the targeted ccβ₃ locus. Hatched boxes represent partially identified exons by DNA sequencing and Southern blot analysis. Solid box underneath the wt locus indicates the probe used for Southern blot analysis; B, BamHI; E, EcoRI; H, HindIII. (B) Southern blotting for genotyping. Ten micrograms of DNA from each tail tip was digested with BamHI and HindIII and hybridized with the probe. The 10.1-kb fragment is the wt allele, and the 7.2-kb fragment is the targeted allele. (C) Northern blot analysis. Total brain RNAs (30 μg each) from ccβ₃ (+/+), (+/−), and (−/−) mice were hybridized with BglII–SacI (0.8 kb) fragment of murine ccβ₃ cDNA.