Figure 3.

Immunolabeling of normal and XLPRA2 mutant 16- and 7-week retinas with the same four antibodies (NDUFS4, SAG, GFAP, and OPN1SW) as were used in Western analysis. Except for NDUFS4 (A), images were merged with DIC-transmitted light. (A) NDUFS4 was expressed in the mitochondrion inner membrane. Staining was observed in the retinal pigment epithelium (RPE), photoreceptor inner segment (IS), inner plexiform (IPL), and ganglion cell (GCL) layers. Lower NDUFS4 labeling was seen in the mutant retina at 16 weeks, particularly in the IS, owing to the loss of photoreceptors. Intense staining was found in the inner nuclear layer (INL) in the normal retinas at 16 weeks. (B) SAG was highly expressed in the photoreceptor outer segments (OS) and in the outer plexiform layer (OPL) in normal retinas. In the mutant, it mislocalized to the outer nuclear layer (ONL). (C) GFAP staining was weak and limited to astrocytes and Müller cell end feet in normal retinas at 7 weeks and was minimal at 16 weeks. In the mutant retinas, GFAP immunoreactivity was evidenced by intense GFAP labeling in Müller cells at both 7 and 16 weeks, and labeled radial processes extended from the inner retina into the ONL. (D) OPN1SW is exclusively expressed in the OS of S-cones, in the 16-week mutant retina OPN1SW were minimal to absent. Scale bar: 2.5 μm.