title: Wnt4 is required for ostia development in the Drosophila heart.
abstract: The Drosophila ostia are valve-like structures in the heart with functional similarity to vertebrate cardiac valves. The Wnt/β-catenin signaling pathway is critical for valve development in zebrafish and mouse, but the key ligand(s) for valve induction remains unclear. We observed high levels of Wnt4 gene expression in Drosophila ostia progenitor cells, immediately prior to morphological differentiation of these cells associated with ostia formation. This differentiation was blocked in Wnt4 mutants and in flies expressing canonical Wnt signaling pathway inhibitors but not inhibitors of the planar cell polarity pathway. High levels of Wnt4 dependent activation of a canonical Wnt signaling reporter was observed specifically in ostia progenitor cells. In vertebrate valve formation Wnt signaling is active in cells undergoing early endothelial-mesenchymal transition (EMT) and the Wnt9 homolog of Drosophila Wnt4 is expressed in valve progenitors. In demonstrating an essential role for Wnt4 in ostia development we have identified similarities between molecular and cellular events associated with early EMT during vertebrate valve development and the differentiation and partial delamination of ostia progenitor cells in the process of ostia formation.
authors.affiliation: Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA.
authors.forename: Jun-Yi
authors.initials: JY
authors.lastname: Zhu
authors.affiliation: Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Richman
authors.affiliation: Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA; Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC 20010, USA. Electronic address: ZHan@childrensnational.org.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Han
mesh_terms: D000818:Animals; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000502:physiology*; D006023:Glycoproteins / Q000502:physiology*; D006321:Heart / Q000196:embryology; D009024:Morphogenesis; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology; D051153:Wnt Proteins / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; D006023:Glycoproteins; D051153:Wnt Proteins; C454442:Wnt4 protein, Drosophila
keywords: Development; Drosophila; Heart; Ostia; Wnt4