FIG. 4.

Photoreceptor cell preservation after gene editing with tru-sgRNA2 and SpCas9-VRQR in P23H heterozygous mice. (A) Retinal images from the treated region (enhanced green fluorescent protein [EGFP] positive) and adjacent untreated region (EGFP negative) in the P23H het mice at 5 weeks post injection. Wild-type uninjected retina was used as control (bottom). Rhodopsin expression was detected by a rhodopsin antibody (red), the EGFP signal indicates transfection (green), and nuclei were counterstained with Hoechst (blue). OS, outer segment; ONL, outer nuclear layer; INL, inner nuclear layer. Insets at the bottom left corner of each rhodopsin panel were high magnification images of the regions outlined in white. (B) Comparison of ONL thickness of the treated (EGFP positive) area to its adjacent untreated (EGFP negative) central area and to uninjected wild-type retinas (n = 3). *p < 0.05; **p < 0.01; ***p < 0.001 (n = 3).