Dnmt3b^tm5.1Enl

A loxP-flanked PGK-neo cassette was inserted in the intron upstream of exon 19 and a third loxP site in the intron between exons 19 and 20. Cre-mediated recombination deleted the selection cassette in the germline, leaving loxP sites upstream and downstream of exon 19. When mice bearing the present mutation are crossed to Cre recombinase expressing mice, deletion of the floxed DNA segment leads to out-of-frame splicing of the mRNAs encoding all active isoforms of the protein in the tissues where Cre is expressed. (J:91108)