Mechanics of embryonic self-organization

Embryonic development is a largely self-organized process, that can restore its course following perturbations, through cell-cell communication. While this can be mediated by diffusing molecules, it is increasingly appreciated that the mechanical forces that shape an embryo can also function as long-range signals. This dual role of mechanics is illustrated in the early development of birds, which shares many aspects with that of other vertebrates, yet is easily observed and manipulated. I will present a study of avian gastrulation, in which we have shown that the forces driving morphogenesis self-organize and impinge on gene expression in the establishment of the embryonic axis. It is tempting to speculate that mechanical feedback, implicated here in the proportioning of the early embryo, is pervasive in development.