Figure 3. Synaptic ribbon proteins co-distribute with RIBEYE. A, B: Representative images of the outer plexiform layer (OPL) with the photoreceptor ribbon synapses triple labeled for RIBEYE (green), Piccolo (red), and Bassoon (blue) from untreated (A) and EGTA-treated (B) retinae. Under EGTA treatment, both RIBEYE and Piccolo change from a horseshoe-shaped to a punctate appearance, even when a Bassoon horseshoe shape is still visible (B). C-H: Representative images of the OPL with the photoreceptor ribbon synapses double labeled for RIBEYE (green) and ribbon associated proteins (red) from untreated (C, E, G) and EGTA-treated (D, F, H) retinae. Like RIBEYE and Piccolo, RIM1, CtBP1, and KIF3A also change from a horseshoe-shaped to a punctate appearance under EGTA treatment and co-localize with the RIBEYE aggregates. Scale bar: 5 µm.