Fig. 3

Rotation of the newly mature basal body around the old flagellum in T. brucei. a–c Representative tomograms showing different stages of basal body and flagellar pocket morphogenesis; a1,b1,c1 slices through the flagellar pockets from the original tomograms; Tomogram models (a2–c3) contain Cartesian axes previously described that are used to map and describe the rotation [7]; a2,a3 Two views of the model of a tomogram illustrating a cell in which the pro-basal body (PBB; BB2) is located on the bulge side of the flagellar pocket in quadrant 2 prior to the start of the cell cycle; b2–b3: In this cell, the pro-basal body (BB2) has matured and has subtended a new flagellum (NF) that has invaded the existing flagellar pocket and connected to the old flagellum (OF). The new flagellum is still positioned essentially as in a2–a3: quadrant 2; c2,c3 A later stage in the cell cycle just before flagellar pocket division. The new flagellum (NF) is now in a more posterior location and lies in quadrant 4. Thus, a rotation of the newly mature basal body (BB2) has occurred around the old flagellum within the confines of the existing flagellar pocket. Please see text for explanation of the rotation. Mature basal body (MBB); pro-basal body (PBB); Two new pro-basal bodies (BB3 and BB4) in yellow. Microtubule Quartet (MtQ). Scale bars: 200 nm. Reprinted from [25]