Monitoring cilia formation and Sonic hedgehog signaling in dividing cells of the developing neural tube. (A-E) Single dsRed positive cell undergoing division shows that a cilium forms in one daughter cell prior to the other cell (E, white arrow). The movie was imaged at a rate of one frame every 10 minutes. (F-H) Immunofluorescence using antibodies against red fluorescent protein in red (for dsRed lineage tracing) and Arl13b in green (for cilia) demonstrate that a cilium forms in one daughter cell prior to the other daughter cell (white arrow). Enlargement of boxed area in (F), without or with Hoechst staining (G, H). (I-R) The dsRed positive cell undergoes division (I-M). The Olig2-GFP is expressed only in one daughter (N-R). The recording was imaged at a rate of one frame every 10 minutes. Bar is 10 μm (A-E), 100 μm (F), 25 μm (G, H) and 5 μm (I-R).