Cadm1^tm1.2Brd

ES cells targeted with a vector designed to flank exon 9 with loxP sites and insert an FRT-flanked neo were transfected with Cre recombinase. The floxed region including exon 9 and the neo were removed. Exon 9 encodes the transmembrane domain. The skipping of exon 9 resulted in a reading frame shift, which was predicted to result in a nonsense transcript. RT-PCR confirmed that the mutant allele was null. Immunohistochemistry demonstrated the absence of protein in mutant testis. (J:108386)