Fig. 4. Early development of the visceral sensory ganglia is affected in tfap2a mutant embryos. (A,B) In situ hybridization at 24 hpf reveals a strong reduction in dlx2-expressing neural crest cells in branchial arches of tfap2a mutant embryos. (C,D) By 24 hpf, ret1 expression in the branchial arches is reduced in tfap2a mutant embryos. (E,F) At 4 dpf, ret1 expression reveals a complete loss of epibranchial placode-derived sensory ganglia in tfap2a mutant embryos. (G,H) Expression of phox2a, which marks placodal-derived neurons, is also missing in tfap2a mutant embryos. (I,J) Alcian Blue staining of cartilage combined with anti-acetylated-tubulin immunohistochemistry in 4 dpf embryos. The axon bundles of the cranial nerves are missing in tfap2a mutant embryos. (A-H) Lateral views, anterior towards the left. (I,J) Ventral views, anterior towards the left. (A,C,E,G,I) wild-type; (B,D,F,H,J) tfap2a mutant embryos. allg, anterior lateral line ganglion; b, branchial stream, cb, ceratobranchials; ch; ceratohyal; fs, facial sensory ganglion; gs, glossopharyngeal sensory ganglion; h, hyoid stream; m, mandibular stream; pllg; posterior lateral line ganglion; vs, vagal sensory ganglia; V, axons of the facial cranial nerve; VII, axons of the glossopharyngeal cranial nerve; X axons of the vagus cranial nerve. Scale bars: 50 µm.

Return to article