Active folding and coiling in vivo

A common theme in biology is the assembly of cells into tubes, which in turn develop into specific shapes for specific functions. In a large class of organs including the gut, a simple tube transforms into a coil of compartments. This process is particularly striking in the Drosophila melanogaster midgut -- a tube that folds and then coils into a helical configuration in only two hours. Using a combination of light-sheet microscopy, genetics, and computer vision techniques, we extract the full 3D dynamics of this organ with sub-cellular resolution. We present a quantitative account of the dynamics of folding and coiling of the midgut that links cellular motion and deformation to the macroscopic shape change of the organ.