Fig. 1

Fig. 1 foxd3^zdf10;tfap2a^low double mutant embryos lack NC derivatives. (A) Live larvae at 4 days post-fertilization (dpf), lateral views with either transmitted (left) or reflected (right) light. Wild-type zebrafish exhibit three NC-derived pigment cell types: black melanophores (left, arrows), yellow xanthophores (left, arrowheads) and iridescent iridophores (right, white arrows). foxd3^zdf10 and tfap2a^low single mutants develop essentially normal pigment patterns by 4 dpf. Jaw structures protrude ventrally in both foxd3^zdf10 and tfap2a^low single mutants (asterisks). foxd3^zdf10;tfap2a^low double mutants completely lack NC-derived pigment cells except for occasional head xanthophores. Jaw structures appear to be missing (asterisk). (B) Craniofacial cartilage development revealed by Alcian Blue staining at 4 dpf, ventral views with anterior to the left. The wild-type larval head skeleton of zebrafish consists of the dorsal neurocranium (ne), as well as upper (mandibular, m) and lower (hyoid, h, and ceratobranchial, ce) jaw structures. In both foxd3^zdf10 and tfap2a^low single mutants, mandibular and hyoid structures are disorganized and the ceratobranchial elements are absent, whereas the neurocranium remains intact. Double mutants lack upper and lower jaw structures, and all but the most posterior portion of the neurocranium. (C) Immunostaining with 16A11 monoclonal (anti-Hu) antibody at 3 dpf, lateral views, anterior to the left. DRG neurons are found in each trunk segment of wild-type embryos (arrowheads) and enteric neurons populate the gut tube (arrows). DRG neurons are absent in foxd3^zdf10 single mutants (asterisks) and present in reduced numbers in tfap2a^low single mutants (arrowheads), whereas enteric neurons are reduced in number in both backgrounds (arrows). DRG and enteric neurons are absent in double mutant embryos (asterisks). (D) tyrosine hydroxylase (th) expression in sympathetic neurons at 48 hpf in wild-type embryos (arrowhead). Sympathetic neurons are absent in foxd3^zdf10 and tfap2a^low single mutants, as well as in double mutants (asterisks).