Maternal Vsx1 plays an essential role in regulating prechordal mesendoderm and forebrain formation in zebrafish

摘要

Prechordalmesendoderm(PME)isaderivativeofgastrulaorganizerunderlyingtheanteriorneuralplateofvertebrateembryos.IthasbeenfirmlyestablishedthatPMEiscriticalforheadinductionandanteriorndash;posteriorpatterning.Therefore,theestablishmentofPMEinadesiredshapeandsizeatacorrectpositionduringearlyembryogenesisiscrucialfornormalheadpatterning.However,itremainslargelyunclearhowthedesiredformandsizeofPMEisgeneratedatapredestinedpositionduringearlyembryogenesis.HereweshowthatinzebrafishamaternaltranscriptionrepressorVsx1isessentialforthisearlydevelopmentalregulation.Knockingdownmaternalemvsx1/emresultedinimpairedPMEformationandprogressionassociatedwithadeficientandposteriorizedforebrain.Loss-andgain-of-functionexperimentsshowedthatmaternalVsx1isessentialforrepressingemntl/emectopicexpressioninmoreanimalregionatearlygastrulastages.ChromatinimmunoprecipitationassayincombinationwithcoreconsensussequencemutationanalysisfurtherrevealedthatmaternalVsx1candirectlyrepressemntl/emtranscriptionbybindingtotheproximalpromoterataspecificsite.Simultaneousinhibitionofemntl/emfunctioncouldsuccessfullysuppressthedefectsofbothPMEandforebrainformationinmaternalVsx1knockdownembryos.OurresultsrevealapivotalroleformaternalVsx1asadirecttranscriptionalrepressorofemntl/emexpressionatthemarginofthezebrafishgastrulatoensuredirectionalcellpolarizationandmigrationofPMEcells./p/div