title: Morphogenesis of outflow tract rotation during cardiac development: the pulmonary push concept.
abstract: BACKGROUND
  Understanding of cardiac outflow tract (OFT) remodeling is essential to explain repositioning of the aorta and pulmonary orifice. In wild type embryos (E9.5-14.5), second heart field contribution (SHF) to the OFT was studied using expression patterns of Islet 1, Nkx2.5, MLC-2a, WT-1, and 3D-reconstructions. Abnormal remodeling was studied in VEGF120/120 embryos.
  
  
  RESULTS
  In wild type, Islet 1 and Nkx2.5 positive myocardial precursors formed an asymmetric elongated column almost exclusively at the pulmonary side of the OFT up to the pulmonary orifice. In VEGF120/120 embryos, the Nkx2.5-positive mesenchymal population was disorganized with a short extension along the pulmonary OFT.
  
  
  CONCLUSIONS
  We postulate that normally the pulmonary trunk and orifice are pushed in a higher and more frontal position relative to the aortic orifice by asymmetric addition of SHF-myocardium. Deficient or disorganized right ventricular OFT expansion might explain cardiac malformations with abnormal position of the great arteries, such as double outlet right ventricle.
authors: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Roderick W C
authors: RW
authors: Scherptong
authors: Monique R M
authors: MR
authors: Jongbloed
authors: Lambertus J
authors: LJ
authors: Wisse
authors: Rebecca
authors: R
authors: Vicente-Steijn
authors: Margot M
authors: MM
authors: Bartelings
authors: Robert E
authors: RE
authors: Poelmann
authors: Martin J
authors: MJ
authors: Schalij
authors: Adriana C
authors: AC
authors: Gittenberger-De Groot
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D003198:Computer Simulation; D004622:Embryo, Mammalian; D005865:Gestational Age; D006321:Heart / Q000033:anatomy & histology / Q000196:embryology*; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000196:embryology / Q000378:metabolism / Q000502:physiology*; D055595:Mechanical Phenomena; D051379:Mice; D008822:Mice, Transgenic; D008955:Models, Cardiovascular; D009024:Morphogenesis / Q000235:genetics / Q000502:physiology; D012399:Rotation; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C484469:Nkx2-5 protein, mouse; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse