title: Prdm1 functions in the mesoderm of the second heart field, where it interacts genetically with Tbx1, during outflow tract morphogenesis in the mouse embryo.
abstract: Congenital heart defects affect at least 0.8% of newborn children and are a major cause of lethality prior to birth. Malformations of the arterial pole are particularly frequent. The myocardium at the base of the pulmonary trunk and aorta and the arterial tree associated with these great arteries are derived from splanchnic mesoderm of the second heart field (SHF), an important source of cardiac progenitor cells. These cells are controlled by a gene regulatory network that includes Fgf8, Fgf10 and Tbx1. Prdm1 encodes a transcriptional repressor that we show is also expressed in the SHF. In mouse embryos, mutation of Prdm1 affects branchial arch development and leads to persistent truncus arteriosus (PTA), indicative of neural crest dysfunction. Using conditional mutants, we show that this is not due to a direct function of Prdm1 in neural crest cells. Mutation of Prdm1 in the SHF does not result in PTA, but leads to arterial pole defects, characterized by mis-alignment or reduction of the aorta and pulmonary trunk, and abnormalities in the arterial tree, defects that are preceded by a reduction in outflow tract size and loss of caudal pharyngeal arch arteries. These defects are associated with a reduction in proliferation of progenitor cells in the SHF. We have investigated genetic interactions with Fgf8 and Tbx1, and show that on a Tbx1 heterozygote background, conditional Prdm1 mutants have more pronounced arterial pole defects, now including PTA. Our results identify PRDM1 as a potential modifier of phenotypic severity in TBX1 haploinsufficient DiGeorge syndrome patients.
authors.affiliation: Department of Developmental & Stem Cell Biology, Institut Pasteur, CNRS URA 2578, Paris, France, stephane.vincent@igbmc.fr.
authors.forename: Stéphane D
authors.initials: SD
authors.lastname: Vincent
authors.affiliation: Department of Developmental & Stem Cell Biology, Institut Pasteur, CNRS URA 2578, Paris, France.
authors.forename: Alicia
authors.initials: A
authors.lastname: Mayeuf-Louchart
authors.affiliation: Department of Developmental & Stem Cell Biology, Institut Pasteur, CNRS URA 2578, Paris, France.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Structural Biology, University of Washington, Seattle, WA, USA.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Brzezinski
authors.affiliation: Division of Cardiovascular Development and Differentiation, Department of Pediatric Cardiology, Tokyo Women's Medical University, Tokyo, Japan and.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Miyagawa-Tomita
authors.affiliation: Aix-Marseille Université, Developmental Biology Institute of Marseille, CNRS UMR 7288, Campus de Luminy, Marseille, France.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Kelly
authors.affiliation: Department of Developmental & Stem Cell Biology, Institut Pasteur, CNRS URA 2578, Paris, France.
authors.forename: Margaret
authors.initials: M
authors.lastname: Buckingham
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D001934:Branchial Region / Q000098:blood supply / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D004622:Embryo, Mammalian; D004843:Epistasis, Genetic; D005260:Female; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D055786:Gene Knockout Techniques; D005838:Genotype; D006321:Heart / Q000196:embryology*; D008297:Male; D008648:Mesoderm / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D009024:Morphogenesis / Q000235:genetics*; D009154:Mutation; D038081:Organogenesis; D000074462:Positive Regulatory Domain I-Binding Factor 1; D013234:Stem Cells / Q000378:metabolism; D020825:T-Box Domain Proteins / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C513258:Prdm1 protein, mouse; D020825:T-Box Domain Proteins; C491573:Tbx1 protein, mouse; D014157:Transcription Factors; D000074462:Positive Regulatory Domain I-Binding Factor 1