Fig. 3. Migration of cranial neural crest cells from hindbrain. (A) Lateral view of stage 23 embryo showing initial hindbrain position of DiI-labeled cells and migration into the hyoid arch (hy). b and c indicate horizontal planes of section shown in B and C, respectively. (B) Migration of cells caudal to the initial site of labeling in the dorsal pharyngeal region. Arrow indicates position of labeled cells caudal to the original position of the DiI label. (C) Ventral section through developing branchial arches. Two most rostral arches containing labeled cells, the hyoid and first branchial arch, have been segregated by the outpocketing of the pharyngeal endoderm in these regions. Labeled cells in the caudal presumptive branchial arch region (pbar) are in a contiguous stream. DiI-labeled cells surround the mesodermal core of the hyoid arch (arrow pointing from white asterisk). (D) Lateral view of stage 23 embryo shown in cross-section in E. (E) Cross-section through hyoid arch of D at position marked e. Labeled neural crest cells have migrated ventrally beneath the ectoderm. (F) Lateral view of stage 25 embryo labeled in the hindbrain region. Neural crest cells have migrated ventrally into the hyoid arch. g indicates plane of section shown in G. (G) Horizontal section of stage 25 embryo shows neural crest cells in the hyoid arch are located in a lateral position beneath the ectoderm (arrow). A few cells can still be seen adjacent to the endoderm. Yellow circle indicates the initial position of the DiI injection. Yellow arrow indicates the direction and distance of migration along the rostrocaudal axis. Scale bar: 200 µm.

Return to article