FIGURE 6.

Basal body organization in Paramecium tetraurelia. (A) left: Paramecium stained Basal bodies (BB) are decorated by polyclonal anti-glutamylated tubulin (green) and anti-epiplasmin antibodies (red). Right: purified Paramecium cortex stained with anti-glutamylated tubulin (green) and anti-epiplasmin antibodies (red). Scale bar: 10 µm. (B) Purified basal body units obtained by 5 s of sonication. Scale bar: 2 µm. (C) Cryo-electron tomography of two Paramecium basal bodies. Z slice from a tomographic three-dimensional reconstruction showing a longitudinal section of a two basal body-cortical unit with the transition zone (green square), the central region (red square) and the proximal region (blue square). 1, 2, 3: Transverse projection of the cryo-tomogram at the respective three levels; 1′, 2′, 3’: 9-fold circularizations have been applied to the transverse projection. 1-1′, show the transition zone, 2-2′ show the central region of the basal body and 3-3′ show the basal body proximal region with the cartwheel structure inside. (D) The inner scaffold forms a dense helical lattice. Three-dimensional (3D) view of the ninefold symmetric central regions from Paramecium BB. Unrolled inner scaffold structures. In Paramecium a 2-start helix is observed (the pink color indicates one helix while the orange one indicated the second helix). Adapted from Le Guennec et al., 2020. (E) Cartoon of a longitudinal section of a Basal body. The microtubules are in grey, the cartwheel is in blue, CID in red, pinheads in violet, (A–C) linker in turquoise, triplet base in green and the inner scaffold in orange [Reprinted from (Klena et al., 2020; Le Guennec et al., 2020)]. The Authors, some rights reserved; exclusive licensee AAAS. Distributed under a CC BY-NC 4.0 License (http://creativecommons.org/licenses/by-nc/4.0/).