FIGURE 3:

Deletion of CEN2 leads to basal body orientation and separation defects. (A) Left panels show the basal body angle distribution for wild type and the cen2Δ. Green, Cen1; red, KD fibers. Scale bar: 5 μm. x, average angle; σ, SD. In the circular plots, each point corresponds to five measurements in wild type and two measurements in the cen2Δ. n = 200 measurements. Right panels show electron micrographs of the basal body orientation defect. Basal bodies (white arrow) and their accessory structures (KD fiber, white arrowhead; postciliary microtubules, blue arrow) are rotated in cen2Δ cells. Scale bar: 500 or 100 nm (cen2Δ). (B) Close proximity of mature basal bodies suggests that there is a basal body separation defect in the cen2Δ (blue arrows). The average distance between a pair of old basal bodies is 1.5 ± 0.3 μm in wild type and 1.2 ± 0.4 μm in the cen2Δ, a significant difference (n = 150 basal body pairs). Green, Cen1; red, K-like antigen (mature basal body marker); white arrowhead, immature basal body; white arrow, mature basal body. Scale bar: 1 μm. (C) Electron micrographs showing that cilia in the cen2Δ share a ciliary pocket (arrow), whereas cilia in wild type do not. Scale bar: 500 nm.