Requirement for FGF signaling in neural crest contribution to the heart.
(A) Experimental design and results for FGF inhibition using SU5402. NC contribution to cardiac chambers was not affected by FGF inhibition at any time point, while NC contribution to the VA and BA was reduced by FGF inhibition. +, mCherry cells present; -, mCherry cells absent; +/-, drastically reduced mCherry cells. (B) Percent coverage of the ventral aorta by NC-derived cells for DMSO-treated control embryos, and embryos treated with SU5402 from 42-48 hpf. Cartoon illustrates the 50µm area of the VA assessed for coverage by mCherry positive cells. Red represents mCherry cells and green represents the endothelium of the VA and BA. (C-D’’) Confocal projections of the BA and VA in DMSO-treated control (C-C’’) and SU5402-treated NC:mCherry; kdrl:GFP embryos (D-D’’). (E-F’’) Confocal projections of DMSO-treated control (E-E’’) and SU5402-treated NC: mCherry; myl7:GFP embryos. VA, ventral aorta; BA, bulbus arteriosus, A, atrium; V, ventricle. Scale bars = 20µm. ***, p < 0.001.