Dynamic changes in epithelial cell packing during tissue morphogenesis. Author Sandra Lemke, Celeste Nelson Publication Year 2021 Type Journal Article Abstract Cell packing - the spatial arrangement of cells - determines the shapes of organs. Recently, investigations of organ development in a variety of model organisms have uncovered cellular mechanisms that are used by epithelial tissues to change cell packing, and thereby their shapes, to generate functional architectures. Here, we review these cellular mechanisms across a wide variety of developmental processes in vertebrates and invertebrates and identify a set of common motifs in the morphogenesis toolbox that, in combination, appear to allow any change in tissue shape. We focus on tissue elongation, folding and invagination, and branching. We also highlight how these morphogenetic processes are achieved by cell-shape changes, cell rearrangements, and oriented cell division. Finally, we describe approaches that have the potential to engineer three-dimensional tissues for both basic science and translational purposes. This review provides a framework for future analyses of how tissues are shaped by the dynamics of epithelial cell packing. Keywords Animals, Morphogenesis, Models, Biological, Cell Shape, Epithelium, Epithelial Cells Journal Curr Biol Volume 31 Issue 18 Pages R1098-R1110 Date Published 2021 Sep 27 ISSN Number 1879-0445 DOI 10.1016/j.cub.2021.07.078 Alternate Journal Curr Biol PMCID PMC8496771 PMID 34582821 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML