Speaker: Professor Arezki Boudaoud (École Normale Supérieure de Lyon (ENS de Lyon))

Abstract: How do organs reach reproducible sizes and shapes in the face of substantial variability at the cellular level? The current belief is that a morphogen gradient spanning the organ provides cells with positional information that controls organ size. Nevertheless, recent evidence suggests that the simple interpretation of a global morphogen gradient is insufficient for size control. We built a mechanical model for growth variability during the formation of 2D organs. This model consists of a set of coupled  stochastic PDEs describing a viscous medium with spatially variable density and local nematic order, each of which are coupled to mechanical stress. We determined how variability changes across scales, to understand how heterogeneous cells yield robust organs. These results may be compared to available experimental data.