FIGURE 3.

Generation of rod-specific PTP1B conditional knock-out mouse model. Rod photoreceptor-specific deletion of PTP1B was done by cross-breeding floxed PTP1B mice to mice that express Cre recombinase under the control of the mouse rod opsin promoter. A, immunohistochemical analysis of Cre recombinase expression in knock-out and wild-type control retinas harvested from litter mates. Immunoblot analysis of duplicate knock-out and wild-type control retinal extracts was used to determine the expression of Cre recombinase (B), and actin levels were used as a loading control (C). IR kinase activity was measured from retinas harvested from dark- and light-adapted wild-type and PTP1B^−/− mice (D). The IR immunoprecipitates (E) were subjected to IR kinase activity employing poly-Glu:Tyr peptide as substrate. Actin levels were used as loading control (F).