Fig. 1: Flipper-TR reports membrane tension gradients in reconstituted membranes.
From: Adherent cells sustain membrane tension gradients independently of migration
a Schematics of supported lipid bilayer experiments. The bilayer wets the glass and expands from the lipid source due to tension-induced flows. The spreading velocity is proportional to the tension gradient. b Examples of expanding supported lipid bilayers with different compositions. Color indicates average Flipper-TR fluorescence lifetime (ns); black mask shows the average photon count. Scale bar, 10 µm. c Bilayer spreading speed (µm/min) over time in log-log plot. Red line for visual reference. d Average Flipper-TR lifetime (ns) as a function of the distance from the leading edge, for two representative examples of two compositions. e Front (expanding edge) and rear (closest to lipid source) average Flipper-TR fluorescence lifetime in supported lipid bilayers with different compositions. Lines represent data pairing. Right, front-rear differences for different lipid compositions. f Top left, diagram of the quantification. Bilayer spreading speed (µm/min) as a function of linear fits of spatial Flipper-TR gradients (ns/µm) for different lipid compositions. Histograms of binned data overlaid in black. N = 5, n = 277. Boxplots show the median (center line), 25th and 75th percentiles (bounds of the box), and whiskers extending to the most extreme data points within 1.5 × the interquartile range from the box.
