title: A threshold of GATA4 and GATA6 expression is required for cardiovascular development.
abstract: The zinc-finger transcription factors GATA4 and GATA6 play critical roles in embryonic development. Mouse embryos lacking GATA4 die at embryonic day (E) 8.5 because of failure of ventral foregut closure and cardiac bifida, whereas GATA6 is essential for development of the visceral endoderm. Although mice that are heterozygous for either a GATA4 or GATA6 null allele are normal, we show that compound heterozygosity of GATA4 and GATA6 results in embryonic lethality by E13.5 accompanied by a spectrum of cardiovascular defects, including thin-walled myocardium, ventricular and aortopulmonary septal defects, and abnormal smooth muscle development. Myocardial hypoplasia in GATA4/GATA6 double heterozygous mutant embryos is associated with reduced proliferation of cardiomyocytes, diminished expression of the myogenic transcription factor MEF2C (myocyte enhancer factor 2C), and down-regulation of beta-myosin heavy chain expression, a key determinant of cardiac contractility. These findings reveal a threshold of GATA4 and GATA6 activity that is required for gene expression in the developing cardiovascular system and underscore the potential of recessive mutations to perturb the delicate regulation of cardiovascular development.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Xin
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Davis
authors.forename: Jeffery D
authors.initials: JD
authors.lastname: Molkentin
authors.forename: Ching-Ling
authors.initials: CL
authors.lastname: Lien
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Duncan
authors.forename: James A
authors.initials: JA
authors.lastname: Richardson
authors.forename: Eric N
authors.initials: EN
authors.lastname: Olson
mesh_terms: D000818:Animals; D002319:Cardiovascular System / Q000196:embryology*; D050991:GATA4 Transcription Factor / Q000502:physiology*; D050993:GATA6 Transcription Factor / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D006579:Heterozygote; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D024723:Ventricular Myosins / Q000378:metabolism
chemical_list: D050991:GATA4 Transcription Factor; D050993:GATA6 Transcription Factor; C484171:Gata4 protein, mouse; C494760:Gata6 protein, mouse; D024723:Ventricular Myosins