Formation of Myocardium after the Initial Development of the Linear Heart Tube

Developmental Biology

Roger R. Markwald¹  Andy Wessels¹  Boudewijn P.T. Kruithof¹  Maurice J.B. van den Hoff¹  Antoon F.M. Moorman¹ 

[1] Experimental and Molecular Cardiology Group, Cardiovascular Research Institute Amsterdam, Academic Medical Center, Amsterdam, The Netherlands

关键词: cardiovascular development;    chicken embryos;    endocardial cushion;    myocardialization;    cardiac neural crest;    cardiogenesis;   

DOI  :  10.1006/dbio.2001.0449

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Wellafterformationoftheprimarylinearhearttube,themesenchymalcardiacseptabecomelargelymyocardial,andmyocardialsleevesareformedalongthecavalandpulmonaryveins.Thissecondwaveofmyocardiumformationcanbeenvisionedtobetheresultofrecruitmentofcardiomyocytesbydifferentiationfromflankingmesenchymeand/orbymigrationfromexistingmyocardium(myocardialization).Asafirststeptoelucidatetheunderlyingmechanism,westudiedinchickenheartdevelopmenttheformationofmyocardialcellswithinintra-andextracardiacmesenchymalstructures.Weshowthatthesecondwaveofmyocardiumformationproceedsinacaudal-to-cranialgradientinvivo.Atthevenouspole,looselyarrangednetworksofcardiomyocytesareobservedinthedorsalmesocardiumfromH/H19onward,intheatrioventricularcushionregionfromH/H26onward,andintheproximaloutflowtract(conus)fromH/H29onward.TheprocessiscompletedatH/Hstage43.Subsequently,wedeterminedthepotentialofthedifferentcardiaccompartmentstoformmyocardialnetworksina3Dinvitrocultureassay.Thisanalysisshowedthatthecompetencytoformmyocardialnetworksinvitroisacharacteristicofthemyocardiumthatisflankedbyintra-orextracardiacmesenchyme,i.e.,theinflowtract,atrioventricularcanal,andoutflowtract.Thesecardiaccompartmentscanbeinducedtoformmyocardialnetworksbyatemporallyreleasedorsecretedsignalthatissimilarthroughouttheentireheart.Atrialandventricularcompartmentsarenotcompetentanddonotproducetheinducer.Moreover,cardiaccushionmesenchymewasfoundtobeableto(trans-)differentiateintocardiomyocytesintheinvitrocultureassay.Thecombinedobservationssuggestthatacommonmechanismandmolecularregulatorypathwayunderliestherecruitmentofmesodermalcellsintothecardiogeniclineageduringthissecondwaveofmyocardiumformationthroughtheentireheart.

【 授权许可】

Unknown