Figure 2. Cone but not rod photoreceptor dysfunction in RPE-specific Vegfa mutants.

(A) Immunohistochemistry for rhodopsin (rods) and cone opsin (cones) 45 days after induction. Note that rhodopsin expression in Vegfa mutants is comparable to that observed in controls. (B) Optical coherence tomographic analysis indicates that retinal thicknesses remain relatively unchanged at all stages through 7 months. (C) Scotopic dark-adapted ERG captured in Vegfa mutants 3 or 7 days after induction. Note that no significant reduction in the a- and b-wave amplitudes is observed (n = 4). (D) Indocyanine green angiography for Vegfa mutants 45 days after induction. Note that choroidal circulation is significantly diminished in the mutants, while the retinal circulation is normal. (E) Electron micrograph of a cross-sectioned Vegfa mutant retina 14 days, 2 months, and 7 months after induction. Note that a few deep choroidal vessels are observed (asterisk). (F) mRNA array for angiogenic genes in Vegfa mutant RPE/choroids compared with controls 3 days after injection (n = 3). Fold-change (x axis) and P value (y axis) of gene expression compared with controls are shown. Note that 32 of 84 genes are significantly downregulated. Error bars indicate mean ± SD. Scale bars: 2,000 μm (D); 200 μm (B); 20 μm (A); 10 μm (E).