Geometric factors for cell arrangement: How do cells determine their position in vivo?

The spatial arrangement of cells plays a crucial role in ensuring robust development of organisms, directing cells to their specific fates in the right place and at the right time. In early embryogenesis, the cell arrangement is determined by several factors such as the cell division axis, cell-cell interactions, and surrounding geometric constraints. While many species utilize similar principles to determine the cell arrangement, the precise dynamics of cell arrangement differ among species, even at early stages. In particular, geometric constraints significantly impact cell arrangement. Nematode species exhibit diverse cell arrangement dynamics due to their rigid eggshells, which intensively confine the internal cells. In this paper, we review the mechanisms of cell arrangement with a focus on geometric constraints, drawing from interdisciplinary perspectives. We also review mathematical models developed to enhance our understanding of these mechanisms and discuss future directions for theoretical approaches in exploring geometric effects on cell arrangement in various tissues of various species.