title: FGFs, Wnts and BMPs mediate induction of VEGFR-2 (Quek-1) expression during avian somite development.
abstract: Regulation of VEGFR-2 (Quek1) is an important mechanism during blood vessel formation. In the paraxial mesoderm, Quek1 expression is restricted to the lateral portion of the somite and later to sclerotomal cells surrounding the neural tube. By implanting FGF 8b/8c or SU 5402 beads into the paraxial mesoderm, we show that FGF8 in addition to BMP4 from the intermediate mesoderm (IM) is a positive regulator of VEGFR-2 (Quek1) expression in the quail embryo. The expression of Quek1 in the medial somite half is normally repressed by the notochord and Sfrps-expression in the neural tube. Over-expression of Wnt 1/3a also results in an up-regulation of Quek1 expression in the somites. We also show that up-regulation of FGF8/Wnt 1/3a leads to an increase in the number of endothelial cells, whereas inhibition of FGF and Wnt signaling by SU 5402 and Sfrp-2 results in a loss of endothelial cells. Our results demonstrate that the regulation of Quek1 expression in the somites is mediated by the cooperative actions of BMP4, FGF8 and Wnt-signaling pathways.
authors.affiliation: Institute of Anatomy and Cell Biology, Department of Molecular Embryology, University of Freiburg, Albertstrasse 17, D-79104 Freiburg, Germany.
authors.forename: Suresh
authors.initials: S
authors.lastname: Nimmagadda
authors.forename: Poongodi
authors.initials: P
authors.lastname: Geetha-Loganathan
authors.forename: Martin
authors.initials: M
authors.lastname: Scaal
authors.forename: Bodo
authors.initials: B
authors.lastname: Christ
authors.forename: Ruijin
authors.initials: R
authors.lastname: Huang
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000502:physiology*; D002478:Cells, Cultured; D003370:Coturnix / Q000196:embryology* / Q000378:metabolism; D042783:Endothelial Cells / Q000201:enzymology; D004790:Enzyme Induction / Q000235:genetics; D051524:Fibroblast Growth Factor 8 / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D051379:Mice; D017981:Receptors, Neurotransmitter / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology; D019170:Somites / Q000201:enzymology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis* / Q000235:genetics; D051153:Wnt Proteins / Q000502:physiology*; D051155:Wnt1 Protein / Q000502:physiology*; D060508:Wnt3 Protein
chemical_list: D030161:Avian Proteins; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D017981:Receptors, Neurotransmitter; D051153:Wnt Proteins; D051155:Wnt1 Protein; D060508:Wnt3 Protein; D051524:Fibroblast Growth Factor 8; C083131:KDR protein, Coturnix japonica; D040301:Vascular Endothelial Growth Factor Receptor-2