(a) D. melanogaster embryo shape characterized in terms of AP length, DV diameter, and eccentricity. (b) Ensemble quantification for AP length, DV diameter, and eccentricity. Error-bars indicate standard deviation. (c) DV cross section of sqh-GFP labeled embryo showing apical surface in cyan, midplane in yellow and basal surface in magenta. Arrowheads indicate normal evolution is used to relate apical and basal surfaces with the lateral surface. (d,f,h) Myosin signal on apical, basal, and midplane surface respectively as indicated by bold dashed frame. Time is indicated in each dataset with respect to cephalic furrow formation. Small insets refer to zoom on dorsal (indicated by white dashed box), and ventro-lateral region (indicated by solid red box) respectively. (e,g) Myosin signal shown in (d,f) respectively, plotted on actual apical (e) or basal (g) surface, respectively. Shown are a dorsal view on top and lateral view on the bottom. (i) The flow field used for quantitative analysis is evaluated on the midplane surface.