Cilium deconstruction and docking intermediates. (A and B) Representative images of short cilia with electron-lucent (A) or electron-rich (B) cilioplasm. Microtubules are highlighted with orange arrowheads and distal appendages with blue arrowheads. The scale bar is 200 nm. (C and D) A single cilium was observed with a constriction that could be indicative of cilium severing. Serial EM sections are shown in C. Microtubule singlets are visible in the insets on the top row and the cilium (and potential cilium fragment) are shaded cyan in the lower panel. A view of the 3D segmented image is presented in D.