title: Analysis of Mlc-lacZ Met mutants highlights the essential function of Met for migratory precursors of hypaxial muscles and reveals a role for Met in the development of hyoid arch-derived facial muscles.
abstract: The Pax3 and c-met genes are necessary for the development of tongue, diaphragm, and limb muscles. These hypaxial muscles derive from precursors that migrate out of the ventrolateral lip of the somites at occipital, cervical, and limb levels. In this work, we re-examined primary myogenesis in c-met signaling mutants using a skeletal muscle-specific lacZ transgene (Mlc3f-nlacZ-2E). This strategy allowed us to identify precisely the shoulder, limb, tongue, and dermal muscles that need Met for development and to confirm that the morphological structure of epaxial and body wall muscles was normal, even in the most severe c-met mutant. Surprisingly, however, X-gal staining showed that, in this mutant, hyoid arch-derived facial muscles were either reduced or absent, thus revealing that Met also contributes to the development of muscles in the head.
authors.affiliation: Department of Anatomy, Pharmacology and Forensic Medicine, University of Torino, Corso Massimo d'Azeglio 52, 10126 Turin, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Prunotto
authors.forename: Tiziana
authors.initials: T
authors.lastname: Crepaldi
authors.forename: Paolo E
authors.initials: PE
authors.lastname: Forni
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ieraci
authors.forename: Robert G
authors.initials: RG
authors.lastname: Kelly
authors.forename: Shahragim
authors.initials: S
authors.lastname: Tajbakhsh
authors.forename: Margaret
authors.initials: M
authors.lastname: Buckingham
authors.forename: Carola
authors.initials: C
authors.lastname: Ponzetto
mesh_terms: D000818:Animals; D019070:Cell Lineage; D002465:Cell Movement; D005152:Facial Muscles / Q000196:embryology* / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007700:Kinetics; D007763:Lac Operon; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D024510:Muscle Development; D009132:Muscles / Q000196:embryology*; D009154:Mutation; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics*; D019076:Transgenes; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D019859:Proto-Oncogene Proteins c-met; D001616:beta-Galactosidase