Figure EV1. Activation status of microglia infiltrating the outer nuclear layer (ONL) and the exposure of phosphatidylserine (PS) on ONL photoreceptors.

1. Microglia infiltrating the outer nuclear layer (ONL) of the rd10 retina during rod photoreceptor degeneration demonstrate markers of activation. At P18, Iba1⁺ microglia (green, arrow) in the outer plexiform layer were negative for TSPO (red), an activation marker. At P22, Iba1⁺ microglia (arrow) infiltrated the ONL and acquired TSPO immunopositivity, indicating their activated status. Scale bars, 25 μm.
2. Phosphatidylserine (PS) exposure in ONL nuclei of unfixed cryosections of rd10 retina during rod degeneration. PS exposure in the ONL was monitored in unfixed frozen sections using fluorescently conjugated annexin V which binds cell-surface PS. While minimal annexin V staining was evident in the ONL in P18 wild-type (top row) and P18 rd10 (middle row) retinas in which rod degeneration is absent, staining was prominent in P21 rd10 retina during rod degeneration (bottom row). Scale bar, 40 μm.