Fig. 9.

Schematic view of Xenopus laevis embryo during early and mid-gastrula: a dorsal view, b and c midline sagittal view. Labeling: red axial mesoderm, aqua blue—midline neuroectoderm, dark blue—shh expression domain, gray—bottle cells; blc—blastocoel, bl—blastopore, dotted arrows—direction of proposed induction, blue arrows—directions of morphogenetic movements, dotted curve in a—dorsal blastopore lip