Fig. 5. bapx1 is required for jaw joint expression of chd and gdf5. (A-B) Lateral views of wild-type wholemounted embryos at 56 hpf. (A) In uninjected animals, chd is expressed at the jaw joint (arrow) and (B) this domain appears to be absent in bapx1-MO-injected animals (asterisk). The jaw-closer muscle, the adductor mandibulae, which connects the upper and lower jaw, is present and grossly unaffected in bapx1-MO-injected animals. (C,D) Ventral views of wild-type wholemounted embryos at 78 hpf. (C) In uninjected animals, gdf5 is expressed at the first arch joint (arrows) and (D) these domains are severely downregulated in bapx1-MO-injected animals. Second arch midline expression of gdf5 (arrowheads) is also downregulated in bapx1-MO-injected animals. am, adductor mandibulae; M, Meckel's; pq, palatoquadrate. Scale bars: 50 µm.