title: Wnt signaling balances specification of the cardiac and pharyngeal muscle fields.
abstract: Canonical Wnt/β-catenin (Wnt) signaling plays multiple conserved roles during fate specification of cardiac progenitors in developing vertebrate embryos. Although lineage analysis in ascidians and mice has indicated there is a close relationship between the cardiac second heart field (SHF) and pharyngeal muscle (PM) progenitors, the signals underlying directional fate decisions of the cells within the cardio-pharyngeal muscle field in vertebrates are not yet understood. Here, we examined the temporal requirements of Wnt signaling in cardiac and PM development. In contrast to a previous report in chicken embryos that suggested Wnt inhibits PM development during somitogenesis, we find that in zebrafish embryos Wnt signaling is sufficient to repress PM development during anterior-posterior patterning. Importantly, the temporal sensitivity of dorso-anterior PMs to increased Wnt signaling largely overlaps with when Wnt signaling promotes specification of the adjacent cardiac progenitors. Furthermore, we find that excess early Wnt signaling can cell autonomously promote expansion of the first heart field (FHF) progenitors at the expense of PM and SHF within the anterior lateral plate mesoderm (ALPM). Our study provides insight into an antagonistic developmental mechanism that balances the sizes of the adjacent cardiac and PM progenitor fields in early vertebrate embryos.
authors.affiliation: Heart Institute, Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Molecular and Developmental Biology Graduate Program, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45208, USA.
authors.forename: Amrita
authors.initials: A
authors.lastname: Mandal
authors.affiliation: Heart Institute, Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Holowiecki
authors.affiliation: Heart Institute, Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Molecular and Developmental Biology Graduate Program, University of Cincinnati College of Medicine and Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45208, USA.
authors.forename: Yuntao Charlie
authors.initials: YC
authors.lastname: Song
authors.affiliation: Heart Institute, Molecular Cardiovascular Biology Division, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. Electronic address: joshua.waxman@cchmc.org.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Waxman
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D000072576:Homeobox Protein Nkx-2.5 / Q000235:genetics / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010609:Pharyngeal Muscles / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D058125:Transcription Factor 7-Like 1 Protein / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051153:Wnt Proteins / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D000072576:Homeobox Protein Nkx-2.5; C528182:Nkx2.5 protein, zebrafish; C556397:Tcf21 protein, zebrafish; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C544914:tcf7l1a protein, zebrafish; C544915:tcf7l1b protein, zebrafish; C094521:wnt8a protein, zebrafish
keywords: Cardiac; Mesoderm patterning; Organ fields; Pharyngeal muscle; Wnt signaling; Zebrafish