Rok colocalizes with Myo-II pulses. (A) Schematic of apical constriction of prospective mesodermal cells (shaded in blue) during Drosophila ventral furrow formation. (bottom) An individual cell undergoes pulsatile apical constriction. Myo-II undergoes cycles of assembly and coalescence (indicated by arrows) followed by remodeling. (B) Rok localizes with Myo-II at furrow canals during cellularization and apically (apical is up in YZ cross sections) during ventral furrow formation. Bar, 10 µm. (C) Time-lapse images of Rok and Myo-II intensity during a pulse from rok2; Venus::Rok (WT); sqh::mCherry embryo. Bar, 5 µm. (D) Myo-II and Rok appear simultaneously during pulse. Graph represents signal intensity of Rok and Myo-II within a single pulse event. (E) Rok signal is correlated with Myo-II signal with no temporal lag. Mean cross-correlation for different time offsets between Rok and Myo-II signals from pulses (n = 30 pulses; shaded area is ±SD).
