Fig. 1
Prpf31A216P/+ mice exhibit degenerative phenotype of the RPE with drusen-like deposits. Funduscopy of WT (a-d) and Prpf31A216P/+ mice (e-j) are shown. Numerous white-yellowish round lesions were observed in the retina of Prpf31A216P/+ mice (e-h). These lesions were distributed in the central (g) and peripheral retina (h) and most of them showed autofluorescence (i, j; white arrows). The optic nerve head (g) and retinal vessels (h; white arrowhead) did not show differences when compared to WT mice (c, d; white arrowhead). TEM images of RPE of 8-month-old WT (k, l) and Prpf31A216P/+ mice (m-o) and the amplified images of Bruch’s membrane (BM) are displayed (l, n, o). Photoreceptor outer segments (OS) were observed in contact with the RPE microvilli in WT mice (k). Accumulation of lipofuscin granules (Lf), large vacuoles (Va) and atrophy of basal infoldings (BI) were observed in the RPE of Prpf31A216P/+ mice (m). The distance between both basal laminae (BL) was measured (l, n; arrowheads), and thickening of the BM was detected in Prpf31A216P/+ mice (n). In addition, the homogeneity of the fundamental substance (fs) was lost and amorphous electrodense material was accumulated within the BM of these mice (o; black arrow). The morphology of melanin granules (Me), nuclei (Nu) and choroid (Co) was normal. Lipofuscin staining in dark magenta (p, r) showed large accumulation of lipofuscin granules in the RPE of Prpf31A216P/+ mice (r). Filipin blue dye was used to stain free cholesterol (q, s, t; blue). Prpf31A216P/+ mice showed free cholesterol accumulation (s, t; blue) between the RPE and BM (s) or within the BM (t). Anti-Laminin antibodies were used to stain the BL (q, s, t; red) and the RPE was visualized by anti-Rpe65 antibody (q,s, t; green). Scale bars represent 2 μm (k-o) or 12.5 μm (p-t)