Mechanics of epithelial tissue formation. (7th October 2018) - van Drongelen, Ruben
Highlights: In the epithelial blastoderm, cellular boundaries exactly coincide with the Voronoi tessellation of their nuclei. We find the same behavior in a simple mechanical model of the tissue, based on cell growth and mechanical interaction. The model faithfully reproduces key properties of the experimental data, without the need of fine-tuning any parameters. Our results suggest that once the blastoderm has formed, it sits in a state just on the liquid side of jamming. Graphical abstract: Abstract: A key process in the life of any multicellular organism is its development from a single egg into a full grown adult. The first step in this process often consists of forming a tissue layer out of randomly placed cells on the surface of the egg. We present a model for generating such a tissue, based on mechanical interactions between the cells, and find that the resulting cellular pattern corresponds to the Voronoi tessellation of the nuclei of the cells. Experimentally, we obtain the same result in both fruit flies and flour beetles, with a distribution of cell shapes that matches that of the model, without any adjustable parameters. Finally, we show that this pattern is broken when the cells grow at different rates.