Signature of mechanically induced cell extrusions in cell size distribution

Our new preprint with Ali Tahaei, Signature of mechanically induced cell extrusions in cell size distribution, is now available on arXiv:2609.21702.

In this work, we describe a growing epithelial tissue as an active amorphous solid. Cell growth builds up in-plane pressure, while mechanically induced cell extrusions release it. Their balance drives the tissue towards a homeostatic pressure analogous to the yield stress of an amorphous material. Simulations and analytical theory show that this homeostatic state is marginally stable, with a pseudogap in the distribution of local distances to the extrusion threshold.

Because these extrusions arise through a mechanical instability of individual cells, the pseudogap leaves a measurable signature in the distribution of cell areas. We identify this signature in the developing wing epithelium of Drosophila melanogaster, providing an image-based way to test for mechanically induced extrusions in living tissues.