2026-04-17T13:59:06Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1422452025-12-04T20:45:03Zcom_2072_1057col_2072_478822col_2072_478917

00925njm 22002777a 4500 dc Alert Zenón, Ricard author Blanch Mercader, Carles author Casademunt i Viader, Jaume author 2019-10-14T13:54:10Z 2019-10-14T13:54:10Z 2019-03-01 2019-10-14T13:54:10Z During the spreading of epithelial tissues, the advancing tissue front often develops fingerlike protrusions. Their resemblance to traditional viscous fingering patterns in driven fluids suggests that epithelial fingers could arise from an interfacial instability. However, the existence and physical mechanism of such a putative instability remain unclear. Here, based on an active polar fluid model for epithelial spreading, we analytically predict a generic instability of the tissue front. On the one hand, active cellular traction forces impose a velocity gradient that leads to an accelerated front, which is, thus, unstable to long-wavelength perturbations. On the other hand, contractile intercellular stresses typically dominate over surface tension in stabilizing short-wavelength perturbations. Finally, the finite range of hydrodynamic interactions in the tissue selects a wavelength for the fingering pattern, which is, thus, given by the smallest between the tissue size and the hydrodynamic screening length. Overall, we show that spreading epithelia experience an active fingering instability based on a simple kinematic mechanism. Moreover, our results underscore the crucial role of long-range hydrodynamic interactions in the dynamics of tissue morphology. Cèl·lules epitelials Teixits (Histologia) Pel·lícules fines Epithelial cells Tissues Thin films Active fingering instability in tissue spreading