Figure 6. CERKL expression pattern in the mouse retina. Serial sagittal sections of adult mouse retina were immunostained with the RA anti-CERKL antibody. A-C: CERKL staining (green) shows expression in the photoreceptor cell layer (PRL), the inner nuclear layer (INL), and the ganglion cell layer (GCL). D-F: Double staining for CERKL (green) and PAX6 (red), a marker for amacrine cells, in the INL and GCL. G-I: Double staining for CERKL (green) and OPN1 (red), a marker for cone photoreceptor cells. The insert in panel I shows a higher magnification of a double-stained cone photoreceptor. J-L: Double staining for CERKL (green) and RHO (rhodopsin; red), a marker for rod photoreceptor cells. Nuclei are stained with TO-PRO-3 (blue). Note that CERKL is highly expressed in cone photoreceptors, while its expression level in rod photoreceptors is very low. No staining was observed when sections were stained with serum from pre-immune rabbits or with secondary antibody only (data not shown). PRL, photoreceptor layer; ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer. Scale bars, 20 µm.