title: Ectopic Pax-3 activates MyoD and Myf-5 expression in embryonic mesoderm and neural tissue.
abstract: To understand how the skeletal muscle lineage is induced during vertebrate embryogenesis, we have sought to identify the regulatory molecules that mediate induction of the myogenic regulatory factors MyoD and Myf-5. In this work, we demonstrate that either signals from the overlying ectoderm or Wnt and Sonic hedgehog signals can induce somitic expression of the paired box transcription factors, Pax-3 and Pax-7, concomitant with expression of Myf-5 and prior to that of MyoD. Moreover, infection of embryonic tissues in vitro with a retrovirus encoding Pax-3 is sufficient to induce expression of MyoD, Myf-5, and myogenin in both paraxial and lateral plate mesoderm in the absence of inducing tissues as well as in the neural tube. Together, these findings imply that Pax-3 may mediate activation of MyoD and Myf-5 in response to muscle-inducing signals from either the axial tissues or overlying ectoderm and identify Pax-3 as a key regulator of somitic myogenesis.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Maroto
authors.forename: R
authors.initials: R
authors.lastname: Reshef
authors.forename: A E
authors.initials: AE
authors.lastname: Münsterberg
authors.forename: S
authors.initials: S
authors.lastname: Koester
authors.forename: M
authors.initials: M
authors.lastname: Goulding
authors.forename: A B
authors.initials: AB
authors.lastname: Lassar
mesh_terms: D000818:Animals; D015415:Biomarkers; D002454:Cell Differentiation / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics*; D004475:Ectoderm / Q000166:cytology / Q000502:physiology; D004627:Embryonic Induction / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D053823:Hedgehog Proteins; D008648:Mesoderm / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D051379:Mice; D008934:Mitogens / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000166:cytology / Q000196:embryology; D017570:MyoD Protein / Q000235:genetics*; D051787:Myogenic Regulatory Factor 5; D009420:Nervous System / Q000737:chemistry / Q000196:embryology; D009672:Notochord / Q000737:chemistry / Q000196:embryology / Q000502:physiology; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D011506:Proteins / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics; D013116:Spinal Cord / Q000737:chemistry / Q000196:embryology; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics; D051153:Wnt Proteins; D029961:Zebrafish Proteins
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; D053823:Hedgehog Proteins; D008934:Mitogens; D009124:Muscle Proteins; C497418:Myf5 protein, mouse; D017570:MyoD Protein; D051787:Myogenic Regulatory Factor 5; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; D011506:Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C489412:pax3a protein, zebrafish; C068686:Pax3 protein, mouse