Sirt1^tm1.1Ygu

A floxed neomycin cassette was inserted just upstream of exon 4 and a third loxP site was inserted just downstream. The floxed mutation does not affect the protein expression of the targeted gene in MEF's or mammary tissue from homozygotes. Exon 4 (encoding a conserved Sir2 motif) was then removed by cre-mediated recombination to create a null allele. Absence of protein product was confirmed by western blot analysis. (J:121948)