Fig 2: Retinal pigment epithelium (RPE) remodeling in Pde6g−/− mice. RPE-choroid-sclera preparations from Pde6g+/− mice at postnatal day (P) 44 and Pde6g−/− mice at P16, P30, and P44 were flat-mounted, immunostained for β-catenin, images were taken in center and periphery, and Z-Stacks merged. A, Representative immunofluorescence images. Scale bar, 50 μm. B–F, Quantification of RPE cell parameters from P44 mice. Circles and squares, individual mice. N values for Pde6g+/− and Pde6g−/− mice, respectively: (B, D–F) 4–5 and 4; (C) 5 and 2–4. Data presented as mean ± standard error of the mean. Pde6g−/− vs. Pde6g+/− age-matched group means were compared by unpaired t tests. ∗P < 0.03; ∗∗P 0.01; ∗∗∗P < 0.001.

Fig 3: Loss of phosphodiesterase 6 (PDE6G) results in rapid photoreceptor degeneration and retinal remodeling. A, Representative images of retinal sections immunolabeled for PDE6G (rod outer segment [OS]), cone arrestin (cones), PDE6B (rod OS), protein kinase C alpha (PKCα) (rod bipolar cells), calbindin (horizontal cells), and secretagonin (SCGN) (cone bipolar cells) and counterstained with Hoechst. B, Outer nuclear layer (ONL) thickness of mice at postnatal day (P) 16 (n = 2–3), P30 (n = 3), P44 (n = 3), and P56 (n = 3–4). Circles and squares, individual mice. Data, presented as the mean ± standard error of the mean (SEM), were compared by unpaired t test. ∗∗∗P < 0.001. C–E, Quantification of dendrite area from rod bipolar cells (C), horizontal cells (D), and cone bipolar cells (E) at P16 (n = 2–3), P30 (n = 3), and P44 (n = 4), respectively. Circles and squares, individual mice. Data, presented as the mean ± SEM, were compared by unpaired t test. ∗P < 0.03; ∗∗P < 0.002; ∗∗∗P < 0.001. F, Representative immunoblot of P30 retinal lysates. β-actin, loading control. G, Representative images of microglia/macrophages in the center of P44 flat-mounted retinas immunostained for ionized calcium-binding adapter molecule 1 (Iba1). Scale bars, 10 μm. GARP = glutamic-acid-rich protein; GFAP = glial fibrillary acidic protein; INL = inner nuclear layer; IPL = inner plexiform layer; kDa = kilodalton; OPL = outer plexiform layer.

Fig 4: Morphological development of photoreceptors before postnatal day (P) 7 is not affected by phosphodiesterase 6 (PDE6G) depletion. Retinas were dissected from P7 Pde6g+/− (control) and Pde6g−/− (mutant) mice, sectioned, and immunolabeled. A, Representative images of sections stained for PDE6G and cone arrestin, PDE6B, or glutamic-acid-rich protein (GARP), and counterstained with Hoechst. B, Outer nuclear layer (ONL) thickness. Circles and squares, individual mice. Pde6g+/− (n = 3); Pde6g−/− (n = 5). Data are presented as the mean ± standard error of the mean and group means compared by an unpaired t test. Scale bar, 20 μm. INL = inner nuclear layer; ns = not significant; OS = outer segment.