Fig. 3: In situ structure of the human centriole.

a, Cross-sectional view of human centriole slices in different local regions, which are reconstructed by STA. MTTs with a complete C-tubule and an incomplete C-tubule are colored sandy brown and Navajo white, respectively. The A–C linker, pinhead, RD1, RD2, RD3 and DA are colored light blue, light green, medium violet red, pale violet red, pink and medium slate blue, respectively. b, RD1 and MTTs with a complete C-tubule indicated by the arrows in the tomogram (left) and a cross-sectional view of the RD1 map (ninefold symmetry applied) obtained by STA (right). The RD1 peak is indicated by the arrow. The CH is observed inside. The tomogram slice shows one representative RD1 structure selected from three observed ones. c, RD2, A–C linker and pinhead indicated by the arrows in the tomogram (left) and cross-sectional view of the RD2 map (ninefold symmetry applied) obtained by STA (right). The RD2 peak is indicated by the arrow. Only one representative RD2 structure was observed in the dataset. d, RD3, MTTs with an incomplete C-tubule, A–C linker and DA indicated by arrows and boxes in the tomogram (left) and cross-sectional view of the RD3 map (ninefold symmetry applied) obtained by STA (right). The 27 rod-like density peaks of RD3 are indicated by the arrow. The tomogram slice shows one representative RD3 structure selected from three observed ones. e, SDA and DA indicated by boxes in the tomogram (left) and cross-sectional view of the DA map (ninefold symmetry applied) obtained by STA (right). The tomogram slice shows one centriole with representative SDA and DA structures selected from two observed ones. The baseball bat-shaped density of the DA is indicated by the arrow. The color schemes in b–e are the same as that in a.