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Fig. 10. Ihh participates in the formation of neural crest derivatives. (A–F) Craniofacial cartilages, Alcian blue staining. (A) IhhMO-injected side of stage 45 embryos (arrowhead) present a marked reduction of Meckel's, ceratohyal and ceratobranchial cartilages. (B) The coinjection of IhhMO and specific Snail2 promoter-driven (α3000) expression of CRIhh rescues normal cartilages morphology. (C) Schematic representation of IhhMO effects on Xenopus head cartilages. (D) Stage 23 embryos were grafted on the right branchial arch region with 20 μM cyclopamine-soaked beads, cultured until stage 46 and stained with Alcian blue. The ceratobranchial cartilage was the most affected by this treatment. (E) Control BSA-soaked beads grafted in the branchial region of stage 23 embryos produced no effect on craniofacial cartilages. (F) Control morpholino (CoMO)-injected embryos show no changes in cartilage morphology. (G–I) IhhMO produced no effects on pigment cell development (G–H) or Trp2 expression (I) compared with their respective non-injected sides (G’, J and K). (A–F) Anterior side is at the top. M, Meckel's cartilage; Ir, infrarrostral cartilage; CH, ceratohyal cartilage; BH, basihyal cartilage; CB, ceratobranchial cartilage. |