Figure 1.

The machinery of microtubule-severing isolates with the FBBC. Representative phase-contrast micrographs of purified FBBCs immediately after purification (A) and after calcium treatment (B). Each flagella is connected to a basal body and the two basal bodies are linked by connecting fibers. FBBCs were purified on a Percoll gradient after detergent lysis of GLE-treated wild-type cells and resuspended in calcium-free DB (see MATERIALS AND METHODS). Deflagellation of the FBBCs was induced by addition of CaCl₂ to a final free Ca²⁺ concentration of 1 μM. As shown in panel B, the addition of micromolar free Ca²⁺ resulted in the complete severing of the axonemes from the basal bodies. The flagella and basal bodies are labeled F and B, respectively.