Arch expression of predicted domain-specific genes. Whole-mount fluorescent in situ hybridizations for select genes were performed in sox10:GFPCAAX embryos at 36 hpf, with anti-GFP staining (green) showing CNCCs of the mandibular and hyoid arches. (A) foxf1, foxf2a, fzd9b, smad6a and skp2 are expressed in ventral domains of both arches, pitx1 only in the ventral mandibular arch, and sema3bl and twist1b in ventral and dorsal CNCCs. (B) fgfbp2a and shox are expressed in ventral-intermediate CNCCs, stmn1a in ventral-intermediate and dorsal CNCCs, tmem107I in ventral mandibular and posterior dorsal hyoid arches, and her6 in a more dorsal domain. (C) fsta, ctgfb, foxd1, emx2 and igfbp5b show specific intermediate domain expression; igfbp5b is also expressed in arch mesoderm. (D) cdh11, cd248a, kctd15a, pou3f3a, pou3f3b and postnb are expressed in dorsal CNCCs, sfrp2 in dorsal arch mesoderm, rassf10a in epithelia, and osr2 between the dorsal first arch and eye. Arrows point to expression in predicted domains, and arrowheads to other arch domains. Single optical sections are shown. Scale bar: 20 μm.