Figure 3. Fit of MT subtomogram averages into raw tomogram and range of MT twist angles in the cross-sectional plane.

(A) Averaged subvolumes of triplets (cyan; the same subvolumes used for Fig 2) and doublets (magenta) were fitted back into the raw tomogram of an entire mother centriole–CC to generate a whole-cilium map. (A, B) Cross sections (top panel, model; bottom panel, raw tomogram) corresponding to the positions indicated by dashed white lines in (A) and denoted by A1–A5 in panel (B). (C, D, E) Twist angles β (defined in panel (C)) were measured and averaged for each cross section, and are plotted in (D) for the cilium map and (E) for the centriole map as a function of longitudinal position. (E) This procedure was repeated using a ninefold rotationally averaged centriole map (Fig S1) and are plotted as boxes in (E). Points and error bars represent means ± SD.