Targeted disruption of the mAF4 gene.

Homologous recombination at the mAF4 locus in ES cells. (A) Structure of the targeting vector and partial restriction map of the mAF4 locus before and after targeted integration. The targeting vector contains the neomycin-resistance (neo) gene flanked by genomic mAF4 sequences. After the recombination event, the neo gene replaces a BamHI-HindIII fragment interrupting exon 11 of the mAF4 gene. E indicates EcoRI; H, HindIII. (B) Southern blot analysis of a representative litter showing alleles from a wild-type (+/+), a heterozygous (+/−), and a homozygous (−/−) animal. Hybridization of genomic DNA with an external probe (5′ probe) reveals a 20-kb EcoRI fragment for the mAF4 wild-type allele and a 8-kb EcoRI fragment corresponding to the inactivated allele. (C) Northern blot analysis of a representative litter showing the mAF4 transcript of RNA (10 μg) extracted from the kidney of a heterozygous mouse (+/−) and from 2 homozygous mice (−/−).