Fig. 4

Altered posterior neurulation in early dlx5a/6a zebrafish morphants.

(A-H) Dorsal views of whole-mount in situ hybridization for ncad, ncam3, msx1b and foxd3 in controls (injected with water) and dlx5a/6a morphants at 16 hpf (n>8 for each condition). (A’-H’) In situ hybridization for ncad, ncam3, msx1b and foxd3 on coronal cryosections of 16 hpf controls and dlx5a/6a morphants at levels indicated by lines in (A, H). During neural keel-rod transition, the dlx5a/6a morphants show a decrease or loss of ncad, ncam3 and msx1b in aberrant protruding foxd3-positive NCC at the dorsal midline of the neural keel (black arrowhead in B’-H’). The morphants also present a delay in neural keel-rod transition characterized by bifid stripes of expression caudally (F-H, grey arrowheads). Abbreviations: nc, notochord; ncc, neural crest cells; nk, neural keel; psm, presomitic mesoderm; sm; somitic mesoderm. Scale bar in H for A-H 100 μm, for A’-H’ 25 μm.