Figure 3.

Developmental EMT. a During gastrulation, ectodermal cells (yellow) at the primitive streak undergo EMT (blue) as a result of signals produced by the Spemann-Mangold organizer. These cells ingress through the primitive streak and migrate into the underlying tissue. The newly ingressed cells either remain mesenchymal becoming the primary mesoderm (red) or undergo MET forming the endoderm (green) and together establish the trilaminar embryo. b The neural crest cells (blue) are formed from an EMT of cells at the border of the embryonic ectoderm and the neuroectoderm during closure of the neural tube. After invading from their site of origin, neural crest cells migrate throughout the developing embryo giving rise to diverse tissue including craniofacial structure, the adrenal medulla and the peripheral nervous system.