Fig. 4: Degenerative features of rod and cone photoreceptors in Gm20541SKO retina.
A Retinal cryosections from 12-month-old mice were labeled with rod-specific markers rhodopsin (outer segment) and Na-K ATPase (inner segment). DAPI was used to counterstain the nuclei. Scale bars, 25 μm. The panels on the right show high-magnification images of the boxed areas. Scale bars: 10 μm. B Representative transmission electron microscope (TEM) images of photoreceptor outer segments in 12-month-old Gm20541f/f and Gm20541SKO mice. Scale bar: 1 µm. Higher-magnification images of representative ciliary region are shown in the lower of each genotype. Scale bars: 500 nm. C Quantitative analyses of the length of BB and CC between Gm20541f/f and Gm20541SKO photoreceptors (n = 10 from 3 mice). D Western blot analysis of typical OS proteins in 12-month-old Gm20541f/f and Gm20541SKO mouse retinas. GAPDH was used as a loading control. E Quantification analysis of the protein expression levels (n = 4 for each genotype). The expression of each protein was normalized to that of GAPDH. F Retinal cryosections from 12-month-old mice were labeled with cone markers PNA and M-opsin. DAPI was used to counterstain the nuclei; scale bars, 25 μm. G Quantification analysis of the M-opsin marked cone OS length (n = 12 from 3 mice). H Immunostaining of flatmount retinas from 12-month-old mice for M-opsin and PNA markers. Scale bars, 50 μm. Representitive image from dorsal retinal quadrant were shown in the lower panel. Scale bars, 25 µm. I Quantification of M-opsin positive cone number per 1 mm2 field in Gm20541f/f and Gm20541SKO retinas (n = 8 from 3 mice). schematic of retinal flat mount indicating the two sectors (radii: 1 and 2 mm) that were used to count cones. OS, outer segment; IS, inner segment; ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer. *P < 0.05; **P < 0.01; ***P < 0.001. ns, no significance. The data are represented as means ± SEM.
