Live imaging of the initiation of MES breakdown during secondary palate fusion. Confocal live imaging of GFP expression in E14.75 CrectTg/0; R26mTmG/+ secondary palate sagittal section shows MES breakage at an early stage of MES removal. Red arrowheads indicate membrane blebbing. Images were captured every 15 minutes for 20 hours. Scale bar, 15μm.