Cell migration driven by substrate deformation gradients.

Identifying the cues followed by cells is key to understand processes as embryonic development, tissue homeostasis, or several pathological conditions. Based on a durotaxis model, it is shown that cells moving on predeformed thin elastic membrane follow the direction of increasing strain of the substrate. This mechanism, straintaxis, does not distinguish the origin of the strain, but the active stresses produce large strains on cells or tissues being used as substrates. Hence, straintaxis is the natural realization of duratoaxis in vivo. Considering a circular geometry for the substrate cells, it is shown that if the annular component of the active stress component increases with the radial distance, cells migrate toward the substrate cell borders. With appropriate estimation for the different parameters, the migration speeds are similar to those obtained in recent experiments (Reig et al 2017 Nat. Commun. 8 15431). In these, during the annual killifish epiboly, deep cells that move in contact with the epithelial enveloping cell layer (EVL), migrate toward the EVL cell borders with speeds of microns per minute.