Fig. 3
METTL14 depletion in cone cells leads to cone photoreceptor defects. A Representative immunofluorescence images of cone arrestin (green) and PNA (red) in retinas from 6-month-old Ctrl and HKO mice. Nuclei were counterstained with DAPI (blue). Scale bars, 25 μm. B Number of cone arrestin-marked cones per 500 μm field in Ctrl and HKO retinas (n = 6, two-way ANOVA followed by Tukey’s post hoc test). Each cone population was counted in the inferior and superior retinal quadrant starting -2500 μm from the ora serrata and moving toward the optic disc every 500 μm. C Immunostaining of flat-mount retinas from 5-month-old control and HKO mice for M-opsin and PNA markers revealed cone cell disorganization in HKO retinas. Scale bars, 50 μm. Representative images from the dorsal retinal quadrant are shown in the lower panel. Yellow arrowheads indicate mislocalized M-opsin in the IS. Inset images show a cropped and zoomed image. Scale bars, 1 μm. Schematic of a retinal flat mount indicating the two sectors (radii: 1 and 2 mm) that were used to count cones. D Number of M-opsin-marked cones per 1 mm2 field in the two sectors of Ctrl and HKO retinas (n = 6). E Distribution of the fluorescence intensity of M-opsin (green) and PNA (red) in retinal flat mounts from control and HKO mice. F Retinal cryosections from 5-month-old mice were labeled with the cone markers PNA and M-opsin. DAPI was used to counterstain the nuclei. scale bars, 25 μm. Yellow arrowheads indicate mislocalized M-opsin in the IS. The right panels show high-magnification images of the outline areas. Scale bars: 1 μm. OS, outer segment; IS, inner segment; ONL, outer nuclear layer; *p < 0.05; **p < 0.01; ***p < 0.001. #, no significant difference. Data are presented as the mean ± SEM