Figure 4.
Craniofacial morphogenesis in L. laevis. The embryonic head is shown in lateral (A,D,G,J; anterior to the left) and frontal views (B,E,H,K). Arrows indicate the location of the stomodeum (stom), or mouth. Higher magnification views (C,F,I,L) detail the gradual maturation of the mouth, including the perforating buccopharyngeal membrane (bm). The face and mouth widen dramatically as development proceeds, and the cement gland (cg), which initially forms a horseshoe shape (B), becomes bifurcated as the face widens (K). Gosner Stages (GS) are as indicated. Scale bars in A–B, D–E, G–H and J–K = 500μm; scale bars in C,F,I,L = 250μm. Other abbreviations: gb=gill buds; n=nasal pits; op=optic cup; ot=otic vesicle, pa=pharyngeal arches; so= somites.