Myosin II partial RNAi rescued gastrulation defects caused by WAVE depletion. (A) Micrographs from time-lapse DIC movies in three backgrounds with time on the left from MSa/p cell division. E lineage cells are outlined and pseudocolored in green. Gastrulation defects (Ea or Ep cell dividing before being fully covered by neighboring cells) are indicated with white arrowheads. An enclosed outline and absence of the arrowhead indicate that endodermal precursors became internalized at the 2E stage, as in wild-type embryos. Scale bar: 5 µm. (B) The bar graph summarizes the percentage of embryos that have gastrulation defects. Fisher’s exact test was used for categorical data in B. ****P < 0.0001.