LASSP & AEP Seminar by Noah Mitchell (University of California, Santa Barbara)

Noah Mitchell

From genes to organ geometry: morphogenesis via calcium-patterned muscle constrictions

During embryonic development, organs fold into complex shapes that are vital for function. Specific genes are known to regulate organ form, but the mechanical programs by which organ tissues sculpt themselves into shape remain mysterious. Here, we trace the dynamics and mechanical interactions driving inner organ shape change using the embryonic midgut of the fly Drosophila melanogaster. By leveraging deep-tissue light-sheet microscopy for whole-organ live imaging and building a computational framework for extracting tissue deformations in dynamic 3D geometries, we find a mechanical program folding the gut. Hox genes control the emergence of high-frequency calcium pulses, which trigger muscle contractions. These contractions, in turn, induce cell shape change in the adjacent tissue layer, collectively driving a pattern of in-plane tissue deformations. As seen in a simple model, this in-plane pattern is linked to out-of-plane organ folding. These findings offer a mechanical route for gene expression to induce organ shape change: genetic patterning in one layer triggers a physical process to fold the organ into chambers.

Speaker Biography: Noah Mitchell is a Helen Hay Whitney Foundation fellow at the University of California, Santa Barbara. He is interested in the interplay between mechanics and geometry during morphogenesis. To gain insight into the physics at play, he blends experimental biological techniques with computational and analytic approaches. His PhD in Physics at the University of Chicago focused on the mechanical behavior of thin elastic sheets and metamaterials using experiments, simulations, and theory. In the course of his studies, he became interested in how mechanical forces are patterned to drive tissue shape change in living systems. 

Hosted by Itai Cohen

Pizza served starting at 12:10 p.m.

Please bring your own beverage.