Examples of plugs, MIPs, and IFT-train-like particles. (A and B) Examples of filamentous plugs in A-tubules (A) and CP microtubules (B). Arrowheads point to the extremities of the filamentous plugs. (C–E) Examples of MIPs found in A-tubules (C) and CP microtubules (D). (E) Examples of IFT train-like particles. Longitudinal slices along tomograms. Dotted lines indicate cross-sections. (F) Fourier shell correlation (FSC) curves of the cap complex and the singlet A-tubules.