Fig. 10

Surface-rendered three-dimensional representation of cell shapes and localization of CBs observed before, during and after embryonic inversion of P. californica. All cell shapes are radially symmetrical around their apical–basal axis. a1, b1, c1, d1, e1 Wireframe models; cell sizes are indicated; fla: flagellar/apical cell end; chl: chloroplast/basal cell end. a2, a3, a4, b2, b3, b4, c2, c3, c4, d2, d3, d4, e2 Textured models; groups of cells captured from different angles. Green: cell surfaces; red: CBs. Arrows indicate the angle of view in other images of the same cell shape. a2-e2 Frontal side view. a3-d3 View from below. a4-d4 Slanted side view. a1-a4 Teardrop-shaped cells: conical apical cell ends; hemispherical basal cell ends; transversal cross-sections at the basal cell ends have hexagonal outlines; CBs are located at the basal halves of the cells. b1-b4 Spindle-shaped cells: conical apical and basal cell ends; transversal cross-sections at the cell equators have hexagonal outlines; CBs are located near the cell equators. c1-c4 Elongated teardrop-shaped cells: cells are elongated compared to the teardrop and spindle-shaped cells and have thinned basal cell ends; transversal cross-sections along their entire length have hexagonal outlines; CBs are located close to the basal cell ends. d1-d4 Truncated pyramid-shaped cells: cells have expanded apical cell ends and thinned basal cell ends; both cell ends are flattened; longitudinal cross-sections have trapezoid outlines; transversal cross-sections along their entire length have hexagonal outlines; CBs are located near the basal cell ends. e1-e2 Spherical cells. The cells no longer have CBs and the distance between the cells increased due to ECM secretion