The cell-, tissue-, and organism-scale dynamics that underlie robust embryonic development

Embryonic development depends keenly on the dynamics of the underlying biological tissues, which themselves arise from cellular properties such as: cortical tension, cell-cell adhesion, elasticity, and viscosity. These properties are influenced by protein levels and localization, which result from fixed pre-patterning of the embryo. But development is also surprisingly robust to perturbations. Drosophila embryos, for instance, can consistently develop even under profound genetic mutations and over a wide range of temperatures.

In this talk, I will present the results of live imaging Drosophila embryogenesis to understand how cell-scale properties lead to the robust organism-scale tissue flows that underlie development. I will describe how the shape of the embryo can direct how tissues flow in response to local changes in cortical tension and how this inherent geometric cue can lead to robustness of developmental dynamics in the face of genetic mutations. I will also discuss the developmental robustness of cold-blooded organisms (like the Drosophila) to temperature changes. Up to a point, increasing the temperature of the environment increases the speed at which the embryo develops without impacting the final adult form. I will present how changes in developmental speed depend on tissue flow and cell-scale dynamics, and how changes to these localized dynamics coordinate to maintain the correct sequence and form of global morphogenetic events.