title: Homozygous Ft embryos are affected in floor plate maintenance and ventral neural tube patterning.
abstract: Sonic hedgehog (Shh), produced by the notochord and floor plate cells of the neural tube, plays a critical role in organizing dorsal-ventral patterning in the developing neural tube. We have investigated neural tube development in mouse embryos homozygous for the Fused toes (Ft) mutation, a deletion composed of genes of the Iroquois B (IrxB) cluster and of Fts, Ftm, and Fto. In Ft mutants starting from embryonic day 10.5, the floor plate appeared to degenerate and the notochord failed to undergo ventral displacement from the spinal cord. Consistent with the loss of Shh signalling from the floor plate, V3 neuron generation was reduced in Ft/Ft embryos and the domain of motor neuron generation expanded ventrally at the expense of V2 neurons. These data support the idea that Ft genes play an important role in dorsal-ventral patterning of the neural tube acting to define the extent of motor neuron generation; moreover, the data reveal a previously unanticipated function for Ft genes in the maintenance of the floor plate.
authors.affiliation: Institut für Entwicklungs- und Molekularbiologie der Tiere (EMT), Heinrich-Heine-Universität, Düsseldorf, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Götz
authors.forename: James
authors.initials: J
authors.lastname: Briscoe
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rüther
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins; D019521:Body Patterning / Q000235:genetics*; D004622:Embryo, Mammalian / Q000196:embryology* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006720:Homozygote; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009436:Neural Tube Defects / Q000235:genetics*; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C109729:Fts protein, mouse; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D011506:Proteins; C465570:Shh protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors