Owen W J Prall, Mary K Menon, Mark J Solloway, Yusuke Watanabe, Stéphane Zaffran, Fanny Bajolle, Christine Biben, Jim J McBride, Bronwyn R Robertson, Hervé Chaulet, Fiona A Stennard, Natalie Wise, Daniel Schaft, Orit Wolstein, Milena B Furtado, Hidetaka Shiratori, Kenneth R Chien, Hiroshi Hamada, Brian L Black, Yumiko Saga, Elizabeth J Robertson, Margaret E Buckingham, Richard P Harvey
During heart development the second heart field (SHF) provides progenitor cells for most cardiomyocytes and expresses the homeodomain factor Nkx2-5. We now show that feedback repression of Bmp2/Smad1 signaling by Nkx2-5 critically regulates SHF proliferation and outflow tract (OFT) morphology. In the cardiac fields of Nkx2-5 mutants, genes controlling cardiac specification (including Bmp2) and maintenance of the progenitor state were upregulated, leading initially to progenitor overspecification, but subsequently to failed SHF proliferation and OFT truncation...
March 9, 2007: Cell