TY - JOUR TI - Size-dependent patterns of cell proliferation and migration in freely-expanding epithelia AU - Heinrich, Matthew A AU - Alert, Ricard AU - LaChance, Julienne M AU - Zajdel, Tom J AU - KoĊĦmrlj, Andrej AU - Cohen, Daniel J A2 - Rosenblatt, Jody A2 - Stainier, Didier YR A2 - Kabla, Alexandre VL - 9 PY - 2020 DA - 2020/08/19 SP - e58945 C1 - eLife 2020;9:e58945 DO - 10.7554/eLife.58945 UR - https://doi.org/10.7554/eLife.58945 AB - The coordination of cell proliferation and migration in growing tissues is crucial in development and regeneration but remains poorly understood. Here, we find that, while expanding with an edge speed independent of initial conditions, millimeter-scale epithelial monolayers exhibit internal patterns of proliferation and migration that depend not on the current but on the initial tissue size, indicating memory effects. Specifically, the core of large tissues becomes very dense, almost quiescent, and ceases cell-cycle progression. In contrast, initially-smaller tissues develop a local minimum of cell density and a tissue-spanning vortex. To explain vortex formation, we propose an active polar fluid model with a feedback between cell polarization and tissue flow. Taken together, our findings suggest that expanding epithelia decouple their internal and edge regions, which enables robust expansion dynamics despite the presence of size- and history-dependent patterns in the tissue interior. KW - collective migration KW - epithelia KW - MDCK cells KW - cell cycle JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -