Fig. 9. Disturbance of cranial neural crest cell (NCC) migration upon injection of p120 morpholino (MO) or RNA-encoding JMD-deleted E-cadherin. (A) Tracing of cranial NCCs migrating into the branchial arches. Embryos were injected at the 4-cell stage with caged Fluorescein-dextran in combination with control MO (a,b), p120 MO (c,d) or mE-cadhJMD RNA (e,f). At stage 14, the Fluorescein was activated with UV light in the region where the NCCs originate. Embryos injected with control MO show the three wide streams of migrating cranial NCCs (a,b). Depletion of p120 (c,d) or overexpression of mE-cadhJMD (e,f) leads to disturbance in the migration of the NCCs. The three streams do not go as deep as in the control MO-injected embryos and they are not as wide (c,d and e,f, respectively). Dotted lines (b,d and f) show a projection of the three streams (a,c and e, respectively). (B) Transverse histological sections of the head of stage 26 embryos. Embryos were injected with mE-cadhJMD at the 4-cell stage and fixed for sectioning at stage 26. Transverse section of the head of a non-injected embryo (a), showing the neural tube (NT), the notochord (N), the eyes (EY), the pharynx (PH) and the cement gland (CG). Embryos injected with mE-cadhJMD (b,c) show clumps of intimately associated cells in close proximity to the neural tube or still attached to the neural tube (arrowheads).