Fig. 7
From: Divergent axial morphogenesis and early shh expression in vertebrate prospective floor plate
Axial morphogenesis during initial stages of primitive streak regression in the schematic dorsal view of chick embryo between stages 4 + (a), 5 − (b) and 5 + (c). Labeling: aqua blue—shh domain in the epiblast/ectoderm, red—notochord and its proposed progenitor domain, pink—primitive streak. Dotted arrows indicate directions of tissue displacement