Fig. 4

Transcription factors important in amniote palatogenesis are expressed during development of the zebrafish palate. A,B: Schematics representing lateral view of 36, 40 hours postfertilization (hpf) and ventral view at 44, 48 hpf RNA in situ hybridizations respectively, asterisks mark palate-forming cranial neural crest cells (CNCC). C,D,G,H,K,L,O,P,S,T,W,X: Lateral views at 36 and 40 hpf and E,F,I,J,M,N,Q,R,U,V,Y,Z: ventral views at 44 and 48 hpf are shown. Arrowheads indicate areas of CNCC expression domains, black for palatal precursor CNCC and white for mandibular CNCC, while arrows mark expression in oral ectoderm. In all images the oral ectoderm is outlined by white dashes to aid in its visualization. C–F: msxe is expressed in frontonasal, maxillary and mandibular cranial neural crest cells (CNCC) from 36 hpf to 48 hpf. G–J: osr1 expression is restricted to maxillary and a small portion of mandibular CNCC from 36 to 40 hpf and then also includes dorsal oral ectodermal cells at 44 to 48 hpf. K–N: osr2 is expressed in the frontonasal and maxillary CNCC at 36 and 40 hpf. At 44 and 48 hpf osr2 expression becomes restricted to a subpopulation of the mandibular CNCC expression. O–R: The expression domain of tbx22 in CNCC increases with time and is limited to the posterior maxillary and mandibular domains, wrapping around the oral ectoderm. S–V: CNCC express lhx6, wrapping around the oral ectoderm. This expression includes both the maxillary and mandibular domains and extends further than tbx22 into more anterior crest cells within each domain. W–Z: pax9a is not expressed at 36hpf in the first arch, but is expressed in the frontonasal and posterior maxillary CNCC from 40 to 48 hpf with a small area of expression in the oral ectoderm. e,eye; mx, maxillary domain; md, mandibular domain; fn, frontonasal CNCC; cf, choroid fissure; oe, oral ectoderm; ea, ear.