C. reinhardtii CEP290 is located in the transition zone. (A) Wild-type and cep290 mutant cells were fixed and processed for immunofluorescence using the indicated antibodies. (B and C) Wild-type cells were detergent-extracted, and the resulting cytoskeletons were processed for immunofluorescence using the indicated antibodies. Co-labeling with antibodies to CEP290 and acetylated tubulin revealed CEP290 localization at the base of each flagellum (A and B). (C) Co-labeling with polyglutamylated tubulin indicated that CEP290 is located within the transition zone (arrowheads; Lechtreck and Geimer, 2000). Also see Fig. S1. Bars, 1 µm.