Fig. 5. Rostrocaudal movement of cells originating from the hindbrain. (A) Lateral view of stage 25 embryo. Neural crest cells populate arches ventral and caudal to the site of injection. b indicates horizontal plane of section in B in which neural crest (nc) cells are also found medial to the mesoderm (m). (C) Pan-Dlx immunolabel of section shown in B. Black arrow indicates Dlx expression co-localizes with DiI labeled cells surrounding the mesodermal core. (D) Stage 23 embryo in which neural crest cells labeled at the hindbrain level have migrated ventrally in both rostral and caudal directions. e indicates plane of section in E, in which rostal labeled cells are segregated into arches while caudal cells are still in a continuous stream; neural crest cells are found medial to the mesodermal core. (F) Section (10 µm) of boxed region in C; arrowhead indicates Dlx positive cells excluded from mesodermal core. Yellow circle, initial position of DiI dorsally; yellow arrows, direction and distance of migration of labeled cells. Scale bars: in B, 200 µm for A-C; in D, 200 µm for D,E.