Cytoplasmic microtubules form an organized network in multiciliated cells that becomes polarized during cilia refinement. (A) A late embryo injected with the microtubule marker EMTB-3XGFP and centrin-RFP. (B) A late embryo with EMTB-3XGFP and mCherry-CLAMP. (A and B) The boxed areas are enlarged on the right. (C and D) Triple labeling with centrin–tag BFP, RFP-CLAMP, and EMTB-3XGFP in early (C) and late (D) embryos, with circular graphs of the mean position of microtubule foci relative to the nearest basal body (n > 15, five cells from three embryos) and a diagram of microtubule basal body interactions.