Fig. 1.

(A) FRAP of proteins in the whole cilium 24 hours after serum starvation. IMCD3 cells stably (a) or transiently (b) expressing Htr6^SEP or IFT88^YFP (d), and Smo^YFP stably expressed in MEFs treated with 100 nM SAG for 24 hours (c); arrowheads mark one end of the cilium. Scale bars, 5 μm. (B) Kinetics of average (±SEM) fluorescence recovery of proteins photobleached in the whole cilium (a, b; n = 8 to 12). Summary of fluorescence recovery of ciliary membrane proteins as a percentage of the initial unbleached fluorescence level compared with IFT88^YFP distribution (c; ***P < 0.0001). (C) FRAP of Htr6^SEP (a), Smo^YFP (b), and IFT88^YFP (c) represented as heat-map images after photobleaching part of the cilium in IMCD3 cells; dotted lines mark the photobleached/unbleached boundary. Scale bars, 5 µm. (D) Representative example of kinetics of fluorescence recovery of photobleached region (orange curve), unbleached region (blue curve), and the two regions combined (red curve) of a primary cilium (n = 12 to 13).