Fig. 1. Craniofacial and aortic arch phenotype in vgo (tu285 allele, AB* background). (A) Alcian Blue cartilage preparation of a 5 dpf wild-type larva, ventral view. (B) Schematic drawing of the cartilages in A (blue, pharyngeal skeleton; red, neurocranium). (C) Dissected pharyngeal cartilages of a 5 dpf vgo larva. The cartilages in the mandibular (m, pq) and hyoid (ch, hm) arches are drastically reduced and the pharyngeal arches 3-7 (cb1-5) are completely absent. (D) Ventral view of the dissected neurocranium in a vgo larva. The mesodermally derived parachordalia (pc) are malformed and the anterior pole of the notochord (nc) extends almost to the point where the trabeculae (t) fuse. cb1-5, ceratobranchial cartilages 1-5; ch, ceratohyal cartilage; hm, hyomandibula; m, Meckel's cartilage of mandibular arch; nc, notochord; oa, occipital arch; pq, palatoquadrate; pc, parachordalia; t, trabeculae. (E-G) Aortic arches of 2.5 dpf larvae visualized with fluorescent microbeads. (E) Wild-type larva. At this stage, five aortic arches are visible (arrows). (F,G) vgo mutants showing variable reductions of the aortic arches. (F) Only one interrupted aortic arch is present (arrow). (G) Only three aortic arches formed but are much smaller in diameter than wild-type aortic arches (arrows).