Figure 5.

Reduction of CCT in E2(−) media reduces the coordination of neighboring cells at the blastoderm margin. (A and B) View of the blastoderm margin in TMR-phalloidin-stained embryos fixed at 60% epiboly after developing in E2(+) (A) or E2(−) (B). Cell-to-cell coordination is markedly reduced in low Ca²⁺ media. The apparent striations in (A) and (B) result from finite slice spacing in the confocal images (see also Fig. S2 and Movie S6). (C) The distribution of cell-cell correlation vectors shows a statistically significant increase in margin roughness for embryos grown in E2(−). Red line, mean; box, first and third quartiles; whiskers, 2.7 standard deviations. (D) Schematic of tension along the blastoderm margin. Tension (blue arrows) generates a net restorative force (green arrow) against local perturbations. Scale bars, 40 μm.