Movie 1.

Live imaging of ta4/ta5 fold formation. Live imaging of prepupal leg imaginal disc to visualize the formation of the ta4/ta5 leg epithelial fold from 0 to 5 hrs APF. Cell membranes are marked with Atpα-GFP. Apical and sagittal views are shown for the whole leg. A close-up sagittal view of the ta4/ta5 fold is shown where the relative height of the interjoint and joint domain are marked with colored lines.