This allele was created by crossing mice carying the Usp29tm1Jkim allele with cre-expressing mice (Tg(Zp3-cre)93Knw). Usp29tm1Jkim was created as follows: a loxP site was inserted into intron 1 of Peg3 upstream of the Peg3-DMR (differentially methylated region). A neomycin resistance gene cassette (in the same transcriptional direction as the targeted gene) and a second loxP site were inserted into intron 1 of downstream neigbor Usp29, with which Peg3 shares a bidirectional promoter. Cre-mediated recombination deletes the ~4 kb Peg3-DMR region including the first exons of Peg3 and Usp29. (J:259918)