A hydro-osmotic coarsening theory of biological cavity formation - PLoS Comput. Biol.
M. Verge-Serandour and H. Turlier*, PLoS Computational Biology 2021
Fluid-filled biological cavities are ubiquitous and the formation of apical lumens is widely studied. But the physical mechanism underlying basolateral cavity emergence, such as blastocoels or cysts, remains unclear. We propose a model where a single cavity results from the coarsening of a network of micrometric lumens interconnected through the intercellular space. Cavity formation is found to be primarily controlled by hydraulic exchanges, with a minor influence of osmotic heterogeneities. The coarsening dynamics is self-similar with a dynamic scaling exponent reminiscent of dewetting films over a large range of ion and water permeabilities. Adding active ion pumping to account for lumen growth enriches the dynamics: it prevents from collective collapse and leads to the emergence of a novel coalescence-dominated regime exhibiting a distinct scaling law. Finally, we prove that spatially biasing ion pumping may be sufficient to position the cavity, suggesting a novel mode of symmetry breaking for tissue patterning.
