Figure 1. Generation of IR^Δper mice.

(A) General scheme of the inducible peripheral IR knockout mouse strain. Mice expressing a CreER^T2 fusion protein under the control of the Rosa26 promoter were crossed with mice homozygous for the floxed IR allele. Binding of tamoxifen (T) to the mutated ligand binding domain of the ER (ER_LBD) promotes a nuclear import of the fusion protein and results in the excision of exon 4 by the Cre recombinase. (B) Genomic map of the mouse IR locus surrounding exon 4. Location of the probe used for Southern blot analysis is indicated by black bars. NcoI, restriction enzyme sites; 4, exon 4 of the IR gene; 2.5 kb, size of floxed allele band; 5 kb, size of deleted allele band. (C) Southern blot analysis of IR deletion in whole brain, heart, skeletal muscle, liver, pancreas, and WAT of 12-week-old IR^Δper mice over a period of 12 days. Day 1, beginning of tamoxifen treatment; Δ, 5-kb band of the deleted allele; flox, 2.5-kb band of the floxed allele. (D) Western blot analysis of IR and AKT (loading control) in whole brain, heart, skeletal muscle, liver, pancreas, and WAT of tamoxifen-treated 13-week-old IR^Δper mice and control mice over a period of 24 days. Day 1, beginning of tamoxifen feeding.