Generic principles of space compartmentalization in protocell patterns

Self-organization of cells into higher-order structures is key for multicellular organisms, e.g. during embryonic epithelium formation via repetitive replication of template-like founder cells. Yet, very similar spatial arrangements of cell-like compartments (’protocells’) are also seen in cell extracts in the absence of template structures and genetic material. Here we show that protocell patterns are highly organized, featuring a spatial arrangement and coarsening like two-dimensional foams but without signatures of disordered hyperuniformity. These features even remain unaffected when enforcing smaller protocells by stabilizing microtubule filaments. Comparing our data to generic models, we conclude that protocell patterns emerge by simultanous formation of randomly placed seeds that grow at a uniform rate until fusion of adjacent protocells drives coarsening. The strong similarity of our observations to the recently reported organization of epithelial monolayers suggests common generic principles for space allocation in living matter.