Review Volume 16, Issue 9 pp 8378—8395

Figure 3. Gastrulation. (A) Cell movement during the gastrulation process. The yellow layer depicts the epiblast, and the blue layer — the hypoblast. The cells in brown are migrating to form, first, the endoderm, and later, the mesoderm layers. (B) Axis specification within a gastrulating embryo which corresponds to the ultimate body plan of a human being.