Ultrastructural changes in the retinal pigment epithelium induced by the loss of DJ-1 are inhibited by introducing DJ-1 in Müller cells. Electron micrographs of photoreceptors (pr) and retinal pigment epithelium (RPE) of wild-type (A), DJ-1 knockout (B), Müller-expressed DJ-1 (C) and Müller-expressed DJ-1c106a mutant (D) retinas from 4-month-old adult zebrafish. DJ-1-deficient retinas displayed a high degree of vacuolization (v), in addition to large electron-dense structures (*) in the RPE. The large electron-dense structures contained remnants of membranous/filamentous structures. Transgenic retinas expressing Müller-selective DJ-1c106a mutant displayed similar morphology as DJ-1 knockouts. The ultrastructural changes induced by DJ-1 loss were prevented by Müller cell selective expression of wild type DJ-1. Different stages of phagosomes containing segment filaments can be seen in wild-type and Müller_DJ-1 retinas (marked with arrowhead and p). Bar, 1 µm.
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