Fig. 3

DMH1 treatment at 48hpf for 48 h did not affect formation of most dermal bones, but did rescue early formation of the dentary and quadrate in fam20b mutants. Compared to DMSO-treated controls (A-A″), wild-type zebrafish embryos treated at 48hpf for 48 h with DMH1 at 3 μM (B-B″), 10 μM (C-C″), or 30 μM (D-D″) did not block most dermal bones at 5dpf. Compared to DMSO-treated control embryos (E-E‴), fam20b−/− embryos treated with 10 μM DMH1 at 48hpf for 48 h showed minimal effects on most dermal bones at 5dpf (F-F‴). However, the treatment inhibited early development of the dentary (E′,F′) and quadrate (E″,F″), along with early chondral bones, such as the ceratohyal bone and hyomandibular. Green and red dashed boxes in panels E and F indicate dentary and quadrate regions, respectively, in panels E″ and F’’. n = 10 for each genetic group at each concentration or chemical treatment. Scale bars: A-F‴ = 200 μm. Abbreviations: AB/AR=Alcian blue/Alizarin red; bsr = branchiostegal ray; cb5 = ceratobranchial 5; chb = ceratohyal bone; cl = cleithrum; d = dentary; en = entopterygoid; eo = exoccipital; hm = hyomandibular; mx = maxilla; op = opercle; ot = otolith; pco = perichordal ossification; ps = parasphenoid; q = quadrate. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)