Table 2 Summary of the live-cell imaging analysis.

Live-cell imaging in three independent experiments was analyzed under Icy software, sequentially using Spot Detector, Spot Tracking, and Motion Profiler plugins. Tracks over 10 s of duration were quantified; immobile vesicles were defined as having a net displacement under 1 μm. Because the speed is not constant over the whole tracking of a given vesicle, we monitored the average speed and the maximal speed of the vesicles. Speeds are expressed as means from the total mobile vesicles. Note that because the movies are acquired using a fixed z-stack, vesicle movements can be underestimated when they become out of focus. The number of analyzed cells for each condition is indicated in the table. Dll-Fc stimulation is with clustered Dll-Fc. n.a., not applicable.