title: Integrins in the mouse myotome: developmental changes and differences between the epaxial and hypaxial lineage.
abstract: Integrins are cellular adhesion receptors that mediate signaling and play key roles in the development of multicellular organisms. However, their role in the cellular events leading to myotome formation is completely unknown. Here, we describe the expression patterns of the alpha1, alpha4, alpha5, alpha6, and alpha7 integrin subunits in the mouse myotome and correlate them with the expression of several differentiation markers. Our results indicate that these integrin subunits may be differentially involved in the various phases of myogenic determination and differentiation. A detailed characterization of the myogenic cell types expressing the alpha4 and alpha6 subunits showed a regionalization of the myotome and dermomyotome based on cell-adhesion properties. We conclude that alpha6beta1 may be an early marker of epaxial myogenic progenitor cells. In contrast, alpha4beta1 is up-regulated in the intercalated myotome after myocyte differentiation. Furthermore, alpha4beta1 is expressed in the hypaxial dermomyotome and is maintained by early hypaxial myogenic progenitor cells colonizing the myotome.
authors.affiliation: Departamento de Biologia Animal, Centro de Biologia Ambiental, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Bajanca
authors.forename: Marta
authors.initials: M
authors.lastname: Luz
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Duxson
authors.forename: Sólveig
authors.initials: S
authors.lastname: Thorsteinsdóttir
mesh_terms: D000818:Animals; D015415:Biomarkers; D019521:Body Patterning; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D004622:Embryo, Mammalian / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D017403:In Situ Hybridization; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009132:Muscles / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D017570:MyoD Protein / Q000378:metabolism; D011247:Pregnancy; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D017474:Receptors, Laminin / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000502:physiology
chemical_list: D015415:Biomarkers; D016023:Integrins; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D021122:Protein Subunits; D012333:RNA, Messenger; D017474:Receptors, Laminin