Figure 14. Ultrastructure of the OLL/OLQ and CEP neuron cilia.
(A) 3D reconstruction model of OLL cilium indicating TZ (purple) and a non-ciliary type III dendritic branch (arrow). Approximate locations of cross sections in B–E are shown. Scale bar: 500 nm. (B) Far distal segment of OLL containing electron-dense material (arrow) and MTs (arrowhead). (C–E) Distal (C) and middle segments (D) of OLL have few disorganized MTs whereas the OLL TZ (E) has nine dMTs. Scale bars: 100 nm. (F) 3D recconstruction model of CEP (lavender) and OLQ (blue) cilia indicating TZs (purple). Approximate locations of cross sections in G–N are shown. Scale bar: 500 nm. (G) Cross section of OLQ far distal segment containing electron-dense material. (H) Cross-sectional ET slice shows distal segment of OLQ containing four dMTs linked by thin fibers to each other and to a central filament (arrowhead); note the electron-dense MIPs in both the A- and B-tubules of all dMTs (seen as black dots in the tubule-lumen). (I–J) Cross-sectional TEM (I) and ET (J) images of the disorganized middle segment (I) and at the OLQ TZ (J). (K) OLQ has electron-dense material (arrow) corresponding to a striated rootlet that is directed from the OLQ TZ into the dendrite. (L) Cross-sectional ET slices at the distal end of the CEP sensory ending shows a large tubular body containing many MTs (arrowhead) together with amorphous, electron-dense material (arrow). (M) dMTs and sMTs present within the middle segment of a CEP cilium. (N) Cross-section TEM image shows nine dMTs with isMTs in the CEP cilia TZ. Scale bar: 200 nm. See Figure 14—figure supplement 1 for views of the spurs and cuticular strings associated with OLL/OLQ and CEP cilia.