Simulated morphogenesis of developmental folds due to proliferative pressure.

We present a simulation that models individual cells as spherical particles that can migrate, interact, divide and differentiate. We simulate the evolution of a progenitor layer of cells that reproduce, leading either to more progenitors or to differentiated daughters. We find that this simplified model produces spontaneous folds whose lengths depend linearly on the ratio of rates of production of progenitors to differentiated daughters. We also find that folds grow approximately exponentially in time, and that larger folds can be placed via patterning events that perturb the positions of selected progenitor cells early in the developmental process.