Figure 2.

Cre-mediated recombination specifically in the brain of ObR^SynIKO mice. (a) The breeding strategy that was used to generate ObR^SynIKO mice and littermate controls. ObR^AlbKO mice (described below) were generated using the same strategy. (b) Genomic DNA was prepared from several tissues from ObR^flox/+, SynI-Cre(+) mice and were PCR-amplified using primers flanking the first coding exon of ObR. The locations of the primers are shown on the schematic below the gel. In tissues expressing the Cre recombinase, exon 1 is excised and a single loxP site remains, generating an ObR^Δ allele. While primers 1 and 3 can amplify a product from the ObR^Δ allele, in the ObR^flox or ObR⁺ (wild-type) DNA, the primers are separated by a distance too great for amplification to occur. As a control, primers 1 and 2 were used to amplify both the ObR^flox allele and the ObR⁺ alleles from all tissues. The ObR⁺ allele produces a slightly smaller product due to the absence of loxP sequences.