Fig. 6
Exogenous Edn1 rescues BMP deficiency and vice versa. (A-D,F-K) Alcian Blue stained cartilages of 5 dpf larvae, anterior towards the left. (A-D) Dissected cartilages, lateral views, of a control (A), Tg(hsp70I:dnBmpr1a-GFP) transgenic heat shocked at 16-18 hpf (B) and similarly treated transgenics in which 0.5 μg human recombinant EDN1 protein was microinjected into the arches at 25 hpf (C) and 31 hpf (D). (E) Histogram depicting percentages of Tg(hs:dnBmpra1-GFP)+ embryos with severe ventral arch defects without and with EDN1 protein injected. (F-H) Ventral view of neurocranial cartilage in control (F), dnBmpr+ (G) and dnBmpr+ with 0.5 μg EDN1 injected (H). (I-K) Whole-mount cartilages, ventral views, of non-transgenic wild-type control (I), non-transgenic edn1–/– mutant (J) and edn1–/–; Tg(hsp70I:Gal4;UAS:Bmp4) (K) embryos subjected to a 1-minute heat shock at 21 hpf. Arrows show rescued ventral Mc; arrowheads show rescued ventral Ch cartilages; asterisks indicate fused Mc-Pq joints. Ch, ceratohyal; e, ethmoid plate; Hm, hyomandibular; Mc, Meckels cartilage; Pq, palatoquadrate; Sy, symplectic; t, trabeculae. Scale bars: 100 μm.