Fig. 6.

Induction of Gq activity rescues the edn1^−/− phenotype and causes ventralization of dorsal structures. (A-D) Representative flat-mounts of the viscerocranium at 4 dpf, shown in ventral view, of heat-shocked larvae for edn1^+/+ (A), edn1^−/− (B), hsp70l:Gq-Q209L;edn1^+/+ (C) and hsp70l:Gq-Q209L;edn1^−/− (D). Transformed pterygoid process of the palatoquadrate (ptp) is indicated by white arrowheads in C and D. Transformed hyomandibular cartilage (hm) is indicated by a black arrowhead in C,D. (E,F) Flat-mounts of the viscerocranium at 4 dpf, in lateral view, of heat-shocked non-transgenic edn1^+/+ (E) and hsp70l:Gq-Q209L; edn1^+/+ larvae (F). Transformed ptp (white arrowhead) and hm (black arrowhead) are indicated in F. (G) Frequency of phenotype rescue for six Edn1/Ednra-dependent structures in heat-shocked hsp70l:Gq-Q209L;edn1^−/− larvae (accounting for sidedness). Phenotype rescue was determined to be statistically significant with a chi-square test (P=0.0001), comparing the number of restored skeletal elements in non-transgenic edn1^−/− larvae (0) to hsp70l:Gq-Q209L;edn1^−/− larvae. (H) Frequency of malformed ptp and hm (accounting for sidedness) in all edn1 genotypes with the hsp70l:Gq-Q209L transgene. Scale bar: 100 μm. ch, ceratohyal; hj, hyoid joint; jj, jaw joint; Mc, Meckel's cartilage; pq, palatoquadrate; sy, symplectic.