Figure S1.

Microtubule angle quantification in the centriole and axoneme. (A and B) Cross sections were taken through a CHO centriole, ∼50 and ∼400 nm from the proximal end. (C) A cross section was also taken through an axoneme from bovine tracheae. A nonagon was then fitted to the ninefold geometry of these cross sections. The sides of the nonagon were determined by drawing lines between the centers of adjacent DMTs (blue lines). The vector of the DMTs was defined by a line from the A-tubule center through protofilament B06 of the B-tubule (green lines). (D–F) The angles between a nonagon side and the microtubule were then measured and averaged for a given geometry. Scale bars are 50 nm.