Figure 1.

Targeted disruption of the calbindin gene. (A) The targeting vector replaces part of the promoter and first exon with a neo cassette. H, HindIII. (B) Southern blot analysis of progeny from a heterozygote intercross. The 7.8- and 5.5-kb fragments indicate the wild-type and mutated alleles, respectively. (C) Calbindin protein is absent in homozygous and reduced in heterozygous mutant mice. (D) Western blot analysis of brain without cerebellum, cerebellum, and kidney of adult wild-type and mutant mice using a polyclonal calbindin antiserum. (E) Western blot analysis (Upper) and calcium-overlay assay (Lower) of adult cerebellum, brain without cerebellum, and kidney. Note the disappearance of the 28-kDa calbindin band (arrow) also in the Coomassie stained gel (Upper). Protein standards: Cb, calbindin; Pv, parvalbumin. +/+, Wild type; +/−, heterozygous; −/−, homozygous mutant.