Reduced force generation leads to changes in angle rotation rate. (A) Heatmaps of the rate of change in interface length (red: contraction, blue: elongation) as a function of time and interface orientation angle for movies of control and small-molecule-treated embryos, specifically H2O-injected Control (n = 2,534 interfaces, k = 3 embryos), CK-666 (Arp-Inhibition) (n = 2,321 interfaces, k = 4 embryos), SMIFH2 (Diaphanous-Formin Inhibition) (n = 2,306, k = 4 embryos), and 100 mM Y27632 (Rho kinase inhibition) (n = 1,240 interfaces, k = 3 embryos). Associated examples of real-cell images taken at ∼5 min after the onset of germband extension, with interfaces false-colored based on instantaneous contraction/elongation rate. Scale bars = 10 μm. (B) Heat map of the rotation rate (orange: clockwise, purple: counterclockwise) as a function of time and interface angle for the same data sets as in A. The same real-cell images are false-colored based on instantaneous rotation rate. Scale bars = 10 μm. (C and C′) Probability distributions of contraction/elongation rates of the same treatments; (C′) corresponding box and whisker plots (C′). (D and D′) Probability distribution of rotation rates of the same treatments; (D′) associated box and whisker plots. Statistical significance was determined with two-sample Kolmogorov–Smirnov test (****P < 0.0001).
