TY - JOUR TI - 3D cell neighbour dynamics in growing pseudostratified epithelia AU - Gómez, Harold Fernando AU - Dumond, Mathilde Sabine AU - Hodel, Leonie AU - Vetter, Roman AU - Iber, Dagmar A2 - Akhmanova, Anna A2 - Merkel, Matthias VL - 10 PY - 2021 DA - 2021/10/05 SP - e68135 C1 - eLife 2021;10:e68135 DO - 10.7554/eLife.68135 UR - https://doi.org/10.7554/eLife.68135 AB - During morphogenesis, epithelial sheets remodel into complex geometries. How cells dynamically organise their contact with neighbouring cells in these tightly packed tissues is poorly understood. We have used light-sheet microscopy of growing mouse embryonic lung explants, three-dimensional cell segmentation, and physical theory to unravel the principles behind 3D cell organisation in growing pseudostratified epithelia. We find that cells have highly irregular 3D shapes and exhibit numerous neighbour intercalations along the apical-basal axis as well as over time. Despite the fluidic nature, the cell packing configurations follow fundamental relationships previously described for apical epithelial layers, that is, Euler's polyhedron formula, Lewis’ law, and Aboav-Weaire's law, at all times and across the entire tissue thickness. This arrangement minimises the lateral cell-cell surface energy for a given cross-sectional area variability, generated primarily by the distribution and movement of nuclei. We conclude that the complex 3D cell organisation in growing epithelia emerges from simple physical principles. KW - epithelial organisation KW - Euler's formula KW - Lewis' law KW - Aboav-Weaire's law KW - physical principles KW - lightsheet microscopy JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -