(230ao) Drosophila Melanogaster Embryo As an Active Granular Fluid:Intercellular Coordination Via Mechanical Feedback during Morphogenesis

Embryogenesis hinges on seamlessly proceeding multiple morphogenetic processes that require both local and embryo-wide cellular coordination. Chemical signaling, whose importance to biological processes is incontrovertible, is not capable of controlling the compatibility of cellular shape changes and motions. We believe that the precise coordination occurring during the embryo development is accomplished through communication via mechanical stress fields and feedback. Therefore, we propose an active granular fluid (AGF) modeling platform that describes a tissue as a collection of mechanically active, stress-responsive objects. As a proof of concept, we provide two applications of the AGF approach to Ventral Furrow Formation (VFF) during the gastrulation of a Drosophila embryo. The first application, focused on the ventral face of the embryo during the initiation of VFF, has provided strong evidence that the observed patterns of constricted cells are the result of the cellular sensitivity to tensile stresses. The other application considers a cross-section of the embryo throughout the invagination of the ventral face, which is completed during VFF. Our modeling has revealed that the process is more robust when cells can actively deform to relieve excess stresses or to provide an additional push to help complete a perturbed invagination process.