Expanded myosin contractility analyses. (A) Number of initially vertical interfaces (within ± 15° of vertical) remaining over time in germband extension (n = 129 interfaces, k = 6 embryos). (B) Box plot of the relative myosin intensity for three different time periods denoted in Fig. 5 D. (C) Time evolution of the interface myosin intensity and interface angle in a sample interface. The color of the markers indicates time (going from blue to red). (C′) Interface myosin intensity and angle as a function of time for the same sample interface. (D) Raw microscope images of the same sample interface at 4, 10 and 16 min into germband extension in E-cadherin and Myosin channels. (Scale bars = 5 μm). (E) Heat map of the rate of change in interface length (red: contraction; blue: elongation) interpolated as a function of interface orientation angle and relative myosin intensity. (n = 2,296 interfaces, k = 6 embryos).