Diminished recruitment of vesicles to the distal appendages in CbyKO ciliated cells. (A) Immuno-EM localization of Cby in early ciliated cell differentiation in MTEC cultures. Cby protein (arrowheads) localizes to the distal appendages of migrating basal bodies in the cytoplasm. See also Video 2. (B) Tracheal explants from P6 WT and CbyKO mice were cultured in the presence of taxol for 16 h to enrich vesicle-bound centrioles and processed for EM. Representative EM images are shown. Centrioles attached to vesicles (arrowheads) were more abundant in WT than CbyKO ciliated cells. (C) EM images of ciliated cells from taxol-treated P6 tracheas. The squared areas are shown in higher magnification at the top corners. In WT, cilium growth was occasionally observed in the cytoplasm, with ciliary membrane originating from the distal appendages (arrowheads). Although extended axonemal microtubules were present in CbyKO (yellow arrowheads), elongated ciliary membrane was not noticeable, but instead, centrioles were associated with small vesicles (white arrowheads). N, nucleus. Bars: (A and C, insets) 0.2 µm; (B and C, main images) 0.5 µm.