Figure 1. Phenotyping Nphp5 and Nphp5; Nrl double-knockout mice. A: Genotyping of Nphp5 and Nrl alleles. B–E: Expression of ML-opsin (red) in Nphp5^+/+ (left panels) and Nphp5^-/- cones (right panels) at P10 (B), P15 (C), 1 month (D), and 2 months (E) in the presence of Egfp-Cetn2⁺ (C, D). F: Absence of rhodopsin in the Nphp5^+/−; Nrl^-/- retina. G–M: Expression of ML-opsin in Nphp5^+/+; Nrl^-/- (left panels) and Nphp5^-/-; Nrl^-/- cones (right panels) at P10 (G), P15 (H), 1 month (I), 2 months (J), 3 months (L), and 6 months (M). Egfp-Cetn2⁺ (eCetn2⁺, green) identifies the centrioles and transition zones. Nuclei are contrasted using 4′,6-diamidino-2-phenylindole (DAPI, blue). Scale bar, 20 µm. N: ONL thickness of Nrl^-/-, Nphp5^−/−, and Nphp5^-/-; Nrl^-/- retinas (n=3) as a function of time. The deterioration of the double-knockout ONL relative to the Nrl^−/− control is not statistically significant. OS, outer segment; IS, inner segment; ONL, outer nuclear layer; P, postnatal day; M, month.