CME dynamics in Drosophila amnioserosa. (A) Amnioserosa tissue of a late Drosophila embryo is imaged for 4 min using confocal z-stacks acquired every 3 s. Representative frame is an image section at the middle of a stack. Red lines represent the boundaries between amnioserosa cell centers, which are marked by numbers. Cell boundaries determined in each frame of a 3D time-lapse acquisition are shown in Video 4. Bar, 10 µm. (B) Histograms show evolution of the growth rates corresponding to different cells selected from the amnioserosa tissue in A. Frequencies of the five phases are plotted as a function of time for the apical and basal surfaces. (C) Thumbnails represent 30-s-long 3D time-lapse acquisitions separated by intermissions. (D) Transformation of CCS growth rates at the basal and apical surfaces of the amnioserosa during dorsal closure of a Drosophila embryo. Each bar in the histograms represents the frequency of growth rates obtained from CCS traces detected in individual 30-s-long acquisitions. A significant change in the growth rates is observed at the apical surface. (E) CCS intensity profiles predicted using the growth rates in (D). The change in the apical CCS dynamics is observed as gradually elongated lifetime (right). No major change is observed in the basal surface dynamics (left). (F) Histograms show the CCS growth rates at the apical amnioserosa of three embryos. Increasing frequency of the plateau phase is a hallmark of reduced CCS dynamics. FD, fast dissolution; FF, fast formation; P, plateau; SD, slow dissolution; SF, slow formation.