Figure 1

Targeting strategy for disruption of the murine Capn2 gene. The murine Capn2 gene, encoding the m-80 k subunit, was disrupted in ES cells by homologous recombination. The structures of the wild-type allele (top), the targeting vector (middle), and the mutant allele (bottom) are depicted. In the mutant allele, a PGK-Neo cassette replaces a 0.8-kb genomic fragment containing exon 7 (grey rectangle) which encodes the active site asparagine residue (Asn286) In the targeting vector, the PGK-Neo cassette is flanked by 2.7-kb of Capn2 homologous sequence in the upstream (short) arm and 7.9-kb of homology in the downstream (long) arm. A probe located immediately outside of the short arm detects a 3.5-kb BamHI fragment from the wild-type allele and a 5.3-kb BamHI fragment from the mutant allele. Exons are depicted as open vertical rectangles except for exon 7 which is represented by a solid vertical rectangle. The probe used in most Southern blot analyses is shown as a solid, horizontal rectangle, while triangles mark the positions of PCR primers also used for genotyping purposes.