A Floor Plate Enhancer of the Zebrafish netrin1 Gene Requires Cyclops (Nodal) Signalling and the Winged Helix Transcription Factor FoxA2

Developmental Biology

Ferenc Müller¹  Nadine Fischer¹  Isabelle Le Roux¹  Stephanie Albert¹  Patrick Blader¹  Uwe Strähle¹  Sepand Rastegar¹ 

[1] Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, B.P. 10142, 67404, Illkirch Cedex, C.U. de Strasbourg, France

关键词: cyclops;    Nodal;    floor plate;    hypochord;    netrin1;    foxA2 (HNF3β;    axial);   

DOI  :  10.1006/dbio.2002.0837

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Thefloorplateisanorganisingcentrethatcontrolsneuraldifferentiationandaxonogenesisintheneuraltube.TheaxonguidancemoleculeNetrin1isexpressedinthefloorplateofzebrafishembryos.Toelucidatetheregulatorymechanismsunderlyingexpressioninthefloorplate,wescannedthenetrin1locusforregulatoryregionsandidentifiedanenhancerthatdrivesexpressioninthefloorplateandhypochordoftransgenicembryos.TheexpressionofthetransgeneisectopicallyactivatedbyCyclops(Nodal)signalsbutdoesnotrespondtoHedgehogsignals.Thewinged-helixtranscriptionfactorfoxA2(alsoHNF3β,axial)isexpressedinthenotochordandfloorplate.Weshowthatknock-downofFoxA2leadstolossoffloorplate,whilenotochordandhypochorddevelopmentisunaffected,suggestingaspecificrequirementofFoxA2inthefloorplate.ThetransgeneisectopicallyactivatedbyFoxA2,andexpressionofFoxA2leadstorescueoffloorplatedifferentiationinmutantembryosthataredeficientinCyclopssignalling.Zebrafishandmouseusedifferentsignallingsystemstospecifyfloorplate.Thezebrafishnetrin1regulatoryregionalsodrivesexpressioninthefloorplateofmouseandchickenembryos.ThissuggeststhatcomponentsoftheregulatorycircuitscontrollingexpressioninthefloorplateareconservedandthatFoxA2—givenitsimportanceformidlinedevelopmentalsointhemouse—maybeonesuchcomponent.

【 授权许可】

Unknown