Long-term live imaging of the Drosophila adult midgut reveals real-time dynamics of cell division, differentiation, and loss

Organ renewal is governed by the dynamics of cell division, differentiation, and loss. To study these dynamics in real time, here we present a platform for extended live imaging of the adult Drosophila midgut, a premier genetic model for stem cell-based organs. A window cut into a living animal allows the midgut to be imaged while intact and physiologically functioning. This approach prolongs imaging sessions to 12-16 hours and yields movies that document cell and tissue dynamics at vivid spatiotemporal resolution. Applying a pipeline for movie processing and analysis, we uncover new, intriguing cell behaviors: that mitotic stem cells dynamically re-orient, that daughter cells delay fate-determining Notch activation for many hours after birth, and that enterocytes extrude via constriction of a pulsatile cadherin ring. By enabling real-time study of cellular phenomena that were previously inaccessible, our platform opens a new realm for dynamic understanding of midgut organ renewal.