Graded interference with FGF signalling reveals its dorsoventral asymmetry at the mid-hindbrain boundary.
Signalling by fibroblast growth factors (FGFs) at the mid-hindbrain boundary (MHB) is of central importance for anteroposterior neural patterning from the isthmic organiser. Graded suppression of FGF signalling by increasing amounts of a dominant negative FGF receptor provides evidence that in addition to anteroposterior patterning, FGF signalling is also involved in patterning along the dorsoventral axis at the MHB. FGF signalling at the MHB is required for the activation of the HH target gene spalt at the MHB. Our results indicate that FGF signalling mediates the competence of the MHB to activate spalt in response to SHH. This interdependence of the two signalling pathways is also found in the outbudding optic vesicle where HH requires functional FGF signalling to activate spalt in the proximal eye region.
Carl
M
M
Developmental Biology Programme, European Molecular Biology Laboratory, Meyerhofstrasse 1, PO Box 10.2209, Germany.
Wittbrodt
J
J
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning; D029721:Drosophila Proteins; D005123:Eye / Q000196:embryology; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins / Q000235:genetics; D008636:Mesencephalon / Q000196:embryology; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics; D009990:Oryzias / Q000196:embryology; D011505:Protein-Tyrosine Kinases; D011506:Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051498:Receptor, Fibroblast Growth Factor, Type 3; D051499:Receptor, Fibroblast Growth Factor, Type 4; D017468:Receptors, Fibroblast Growth Factor / Q000096:biosynthesis / Q000235:genetics; D012249:Rhombencephalon / Q000196:embryology*; D015398:Signal Transduction; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein
D029721:Drosophila Proteins; D005346:Fibroblast Growth Factors; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D011505:Protein-Tyrosine Kinases; D011506:Proteins; D011518:Proto-Oncogene Proteins; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051498:Receptor, Fibroblast Growth Factor, Type 3; D051499:Receptor, Fibroblast Growth Factor, Type 4; D017468:Receptors, Fibroblast Growth Factor; D015534:Trans-Activators; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D000099266:Engrailed 2 Protein; C085793:salm protein, Drosophila