Flatmounts of mandibular and hyoid cartilage from 5 dpf alcian-blue stained larvae (A,C,E,G); corresponding schematics (B,D,F,H). The joint between Meckel's and palatoquadrate is fused in alcama morphants and furinA-/- and edn1-/- mutants. Similarly, the interhyal is absent in alcama morphants and furinA-/- mutants leading to a fusion of the ceratohyal and hyosymplectic cartilages. alcama morphants and furinA-/- mutants have misshapen Meckel's cartilage and ceratohyal, but edn1-/- mutants have the most severe defect with a lack of ceratohyal and severely misshapen Meckel's cartilage. DV joint regions are indicated with arrows in A and B. Fusions at joints are indicated with asterisks in (C-H). Cartilages are labeled as followed: pq (palatoquadrate), mc (Meckel's cartilage), hm (hyomandibula), ch (ceratohyal), sy (symplectic), and ih (interhyal). Scale bar: 50 μm.