MOESM3 of Divergent axial morphogenesis and early shh expression in vertebrate prospective floor plate

Additional file 3: Fig. 3. Schematic transversal view of a chicken embryo at the level of the posterior notochord. A: ventral to dorsal floor plate induction in the classical view—shh is first expressed in the notochord and induces shh in floor plate. Shh protein from both sources forms a gradient. B: modified model demonstrating early shh expression and shh gradient formation in the floor plate. Labeling: pink—notochord, blue—floor plate, green—hypoblast/endoderm, brown—paraxial mesoderm, arrows—gradient formation and induction