Rosette formation during endoderm internalization. (A) Dynamics during Ea/Ep internalization. Three-dimensional (3D) projection still images, orientation, and aspect (on the left) and fluorescent markers (in the top right corner) are indicated similarly for each panel throughout the paper. Lower panels depict orthogonal projections along the black dashed line. The final rosette (10 minutes) is highlighted by white dashed lines (see also Additional file 1). (B) Correlation between membrane and non-muscle myosin (NMY)-2 dynamics in three representative wild-type embryos. Fluorescence intensities (mean ± SD) were measured on the ventral surface of Ea/Ep along a line similar to the white dashed line in (A). Areas shaded in gray indicate uncovered endodermal cell surfaces. (C) 3D reconstructions of cells during endoderm internalization. (see also Additional file 2).