DP cell segmentation and area threshold color-map. Combined movie from a time-lapse using βactin:LifeAct-RFPe2212Tg;epi:GFP embryos from 48 hpf onwards and color coded segmentation of 47 cell shapes from time series above. White spots indicate reference location on the midline. Color-code: red, 0–50 μm2; green, 50–150 μm2; blue, >250 μm2. Scale bar: 50 μm. Shown is a representative movie from ≥ 3 biological and ≥ 2 technical replicates.