Live imaging of mKif6 (1-493)-mNG at a developing ependymal cilium, shown in Fig. 1G. mKif6 (1-493)-mNG was transfected in D5 ependymal cell, and mKif6 (1-493)-mNG at short developing cilia was imaged at D7. Time-lapse imaging was acquired at 1 frame every 5s for 60 frames. The display rate of the movie is 3 fps.