Fig. 7. Defects in pharyngeal arch development in low^ts213 mutants. Whole-mount in situ hybridization with riboprobes to dlx2 (A-D) and hoxa2 (E,F) at 28 hpf, as well as gsc (G-J) at 40 hpf. Wild type (A,C,E,G,I); mutant (B,D,F,H,J). Lateral views, anterior towards the left. Arrows in C-F indicate the hyoid arch. Arrows in I and J indicate the dorsal expression domain of gsc, which is absent in low^ts213. b, branchial arches, fb, forebrain, h, hyoid arch, hb, hindbrain, m, mandibular arch, mb, midbrain, ot, otic vesicle. Scale bars: 100 µm.