Fig. 7

Immunohistochemical analysis for rhodopsin and cone opsin in retinas ofRbpr2^−/−mice. Levels and localization of rhodopsin (Rho) in wild-type (WT) and Rbpr2^−/− mice on either vitamin A-sufficient diets (A) or vitamin A-deficient diets (C). Red/green medium wavelength cone opsin (M-opsin) staining in WT and Rbpr2^−/− mice on either vitamin A-sufficient diets (B) or vitamin A-deficient diets (D). Loss of cone opsin staining was observed in Rbpr2^−/− mice under both dietary conditions (** p < 0.005). Rbpr2^−/− mice on either vitamin A diet showed a significant loss of rhodopsin staining (* p < 0.05; ** p < 0.005) and mislocalization to the inner segments (arrows in panels A and C). Images in panels (A–D) are representative of immunostained retinal sections (n = 5–7 sections per eye) imaged from n = 8 animals per genotype and age group (50:50 male to female ratio). (E,F) Quantification of rhodopsin and cone-opsin in OS among various genotypes and dietary conditions (* p < 0.05; ** p < 0.005). Scale bars = 75 µm (A,B). Scale bars = 25 µm (C,D). OS, outer segments; IS, inner segments; ONL, outer nuclear layer; INL, inner nuclear layer. (G) Protein expression analysis of components of the photoreceptors. Western blot analysis for PKC, GNAT1, and CRALBP1 in total protein preparations of the retina in vitamin A-deficient Rbpr2^−/− mice and WT mice (pooled n = 6 retinas per genotype and age). β-actin gene expression was used as the internal control. (H) Protein densitometry analysis and quantification. The statistical analysis was performed using an unpaired two-tail Student t-test by comparing values from age-matched Rbpr2^−/− and WT mice. * p < 0.05.