Movie 3.

Dinaciclib treatment inhibits ectoderm divisions and prevents ME boundary refinement. Mesectoderm (centre) and ectoderm (top and bottom) cells in embryos expressing Ecadherin: GFP, and injected, 1 hour after the onset of mesectoderm divisions, with 50% DMSO (left) or 500 μM dinaciclib (right). Anterior, left. Images were acquired every 30 seconds.