- Polarized cells in embryos organize into patterns based on their orientation, influenced by tissue boundary shapes.
- Topological defects in cell orientation arise from geometric constraints and determine where fluid-filled cavities (lumina) form, such as the pro-amniotic cavity.
- Theoretical physics and experiments show that boundary geometry alone controls defect number and type, guiding tissue organization in 3D.
- Altering embryo shape induces additional lumina at predicted sites, confirming shape as a key control parameter for development.
- Interdisciplinary collaboration reveals general physical principles where shape drives order in biological systems, beyond microscopic details.