Video 3. Extraembryonic rupture filmed at high temporal resolution.
Embryos are shown in anterior-ventral aspect with anterior left, and labeled with EGFP from a heterozygote cross of enhancer trap lines labeling the amnion (line HC079) or serosa (line G12424) with selected embryonic domains in the head, segments, and legs (line G04609, 'heart'). During the movie, the EE tissues rupture and withdraw to the extent that the head and first leg pair are exposed. Selected EE nuclei were tracked, where track color segments correspond to fixed units of time (red, orange, yellow, and green: 8.3 min; blue: final 3.3 min). Elapsed time is shown. Images are maximum intensity projections from a z-stack (2.58 µm step size for a 175 or 200 µm stack) recorded every 20 s at 19.5 ± 1°C and shown for a 36.7-minute period (see Supplementary file 1 for further acquisition details). Single-sided light sheet illumination is from the top, resulting in deterioration of the signal in the lower part of the image due to scattering. The final frame shows time point 36:40 with the approximate position of mouthparts labeled for orientation: An, antennae; Lr, labrum; Mx, maxillae; Lb, labium; T1, first thoracic segment. Scale bar is 50 µm. See also Figure 4—figure supplement 1 for a visual summary.