Epithelial island cells collectively migrate in MES removal. Confocal live imaging of GFP expression in E15.5 CrectTg/0; R26nTnG/+ secondary palate sagittal section shows an island at the anterior palate being incorporated into the oral epithelium (bottom of image). Animation on the right shows cell-tracks overlaid on the confocal imaging. Each tracked cell is represented by a colored sphere and respective time-coded tail. Images were captured every 15 minutes for 10 hours. Scale bar, 15μm.