Figure 5. Ultrastructure of mature disc incisures.
(A) Representative z-section from a reconstructed electron tomogram of a 750-nm-thick WT mouse retinal section. Full tomogram of the boxed area is shown in Figure 5—video 1. (B) Representative maximum intensity projections of 3 (left) or 4 (right) z-sections highlighting various structures observed in a mature incisure. Green arrows point to structures spanning between microtubules and the disc rim; purple arrows point to connectors between apposing sides of the incisure; blue arrow points to the electron-dense structure at the incisure end. Yellow asterisk indicates the microtubule adjacent to the incisure. (C) Representative z-sections at the depths of 0 (Disc 1),+31.5 (Disc 2) and +63 nm (Disc 3) illustrating an imperfect alignment of incisures in three adjacent discs. Yellow arrowheads point to the incisure end in Disc 1 and the same x,y-coordinates in subsequent discs. Tomogram pixel size is 2.1 nm; scale bars: 0.25 µm (A, C) or 25 nm (B).
