Fig. 2

Effect of tgfβ3 knockdown and over-expression on craniofacial chondrogenesis in 4 dpf hatchlings (A–T). Whole-mount lateral (A–H, U–X), and flat-mount dorsal (I–L), ventral (M–P) and lateral (Q–T) views are shown. In the uninjected and STD-MO injected hatchlings, the mouth opening (arrow) is located anteriorly to both eyes (A, B), and the craniofacial cartilages (E, F) including the neurocranium (I, J) and pharyngeal arches (M, N) are distinct and normally developed. Lateral flat-mount of the first pharyngeal arch shows that the Meckel’s cartilage, palatoquadrate and hyosymplectic are normally formed (Q, R). In the i1e2 + e1i1 double morphant hatchling, the mouth opening is ventrally rotated (C), and the craniofacial cartilages appear under-developed (G), including a smaller neurocranium (K), hypoplastic posterior pharyngeal arches (O) and the absence of the basihyal (inset in O). Lateral flat-mount of the first pharyngeal arch shows that the Meckel’s cartilage, palatoquadrate and hyosymplectic are under-developed (S). In the tgfβ3 over-expressed hatchlings, no obvious abnormalities could be detected in the mouth opening (D) or the craniofacial cartilages (H, L, P, T). Insets in M-P show the zoom-in view of the dashed box area. bh, basihyal; cb1-5, ceratobranchial arches 1–5; ch, ceratohyal; e, eye; ep, ethmoid plate; hs, hyosymplectic; ht, heart; m, Meckel’s cartilage; nt, notochord; ov, otic vesicle; pa, pharyngeal arches; pc, polar cartilage; pch, parachordal; pf, pectoral fin; pp, pterygoid process of palatoquadrate; pq, palatoquadrate; tr, trabecula. Black horizontal scale bars, 200 μm.