Centrioles initiate cilia assembly but are dispensable for maturation and maintenance in C. elegans

Centrioles are known to be essential for cilia assembly. However, their contribution has not been clearly defined. Serwas et al. show that centrioles degenerate early in C. elegans ciliogenesis. Ciliary structures are not completely formed at this time, indicating that cilia maturation does not depend on intact centrioles.

Video 1. Electron tomogram and 3D model of the ciliary base in L1-stage larva. Z scan through 130 nm of the ciliary base beginning in the transition zone and 3D reconstruction model highlighting ciliary membrane (gray) and doublet microtubules (green). Dual-axis tilt series was acquired on a Tecnai G2 20 microscope (FEI). Tomogram reconstruction was performed using IMOD.
Video 2. Electron tomogram and 3D model of ciliary base in chemically fixed L4-stage larva. Z scan through 90 nm of the ciliary base beginning in the transition zone and 3D reconstruction model highlighting ciliary membrane (gray) and doublet microtubules (green). Dual-axis tilt series was acquired on a Tecnai G2 20 microscope (FEI). Tomogram reconstruction was performed using IMOD.
Video 3. Neuronal development in late-stage C. elegans embryo. Time-lapse sequence of an embryo expressing myristoylated GFP in amphid neurons beginning at the comma stage and continuing until the threefold stage. Single-plane GFP and transmitted light images were acquired every 5 min on a wide-field deconvolution microscope (DeltaVision; Applied Precision). The video playback is eight frames per second. Retrograde extension of dendrites begins at ∼30 min, with cell bodies moving posterior, whereas dendritic tips remain fixed in position. At ∼1 h 40 min, the worm begins to move inside the egg because of muscle contraction.
Video 4. Electron tomogram and 3D model of the centriole in a comma-stage embryo. Z scan through 85 nm of a centriole and 3D reconstruction model highlighting doublet microtubules (green). Dual-axis tilt series acquired on a Tecnai G2 20 microscope (FEI). Tomogram reconstruction was performed using IMOD.
Video 5. Electron tomogram and 3D model of docked centriole in a twofold-stage embryo. Z scan through 150 nm of the amphid channel, zooming in on a docked centriole with a 3D reconstruction model highlighting ciliary membrane (gray), doublet microtubules (green), transition zone Y-links (red), and the central cylinder (brown). Parts of a second centriole, also composed of doublet microtubules and oriented orthogonally, are also captured in the section. Single-axis tilt series was acquired on a Tecnai G2 20 microscope (FEI). Tomogram reconstruction was performed using IMOD. Video 6. Electron tomogram and 3D model of cilium in L1-stage larva. Z scan through 110 nm of the base of the amphid channel, zooming in on cilium with a 3D reconstruction model highlighting the ciliary membrane (gray) and doublet microtubules (green). Dual-axis tilt series was acquired on a Tecnai G2 20 microscope (FEI). Tomogram reconstruction was performed using IMOD.