Gastrulation as a self-organized symmetry breaking process

Among the stages a fertilized egg undergoes until reaching its final shape, gastrulation represents the first step in breaking its initial symmetry. This process is of enormous importance in development of the embryos sagittal symmetry plane or dorso-ventral axis. Gastrulation also results in the appearance of three regions, the germ layers, from which all of the organs and systems of the organism originate. In this paper, following the hypothesis which affirms that pattern formation at some stages of organism development are due to morphogens gradient, we introduce a model which mimics the early stages of gastrulation of many multicellular organisms. In this model, the cause of symmetry breaking is given by the intrinsic dynamics of the system.