DEV01668 Supplementary Material

Files in this Data Supplement:

• Movie 1 -

  Movie 1. Radial intercalation in ZMD heterozygote. Time lapse recording of a region of the lateral epiblast over 20 minutes from ~70-75% epiboly showing the intercalation of an interior layer cell (blue) into a cohort of exterior layer cells (turquoise) (see Fig. 7A). As the interior layer cell enters the exterior layer the cohort spreads apart, causing a net gain of surface area. One of the exterior layer cells also undergoes a division, and then one of the daughters skips in and out of the interior layer (under an exterior layer cell) and then rejoins the exterior layer.

• Movie 2 -

  Movie 2. Radial intercalation in homozygous hab mutant. Time lapse recording of a region of the lateral epiblast over 20 minutes from ~70-75% epiboly showing the intercalation of an interior layer cell (blue) into a cohort of exterior layer cells (turquoise) (see Fig. 7B). As the interior layer cell enters the exterior layer the cohort spreads apart, causing a net gain of surface area. From this surface view, cells in the exterior layer of the epiblast of the mutant appear smaller and more rounded than the cells in the exterior layer of the heterozygote in Movie 1.

• Movie 3 -

  Movie 3. Radial de-intercalation in homozygous hab mutant. Time lapse recording of a portion of the lateral epiblast over 20 minutes from ~70-75% epiboly showing the loss of three cells from a cohort of cells in the exterior layer (turquoise). The cells move into the interior layer (blue) (see Fig. 7C). As the cells descend, neighboring cells of the cohort close over the gap, covering the descending cells and causing a net loss of surface area.