title: In vivo cell tracking of mouse embryonic myoblasts and fast fibers during development.
abstract: Fast and slow TnI are co-expressed in E11.5 embryos, and fast TnI is present from the very beginning of myogenesis. A novel green fluorescent protein (GFP) reporter mouse lines (FastTnI/GFP lines) that carry the primary and secondary enhancer elements of the mouse fast troponin I (fast TnI), in which reporter expression correlates precisely with distribution of the endogenous fTnI protein was generated. Using the FastTnI/GFP mouse model, we characterized the early myogenic events in mice, analyzing the migration of GFP+ myoblasts, and the formation of primary and secondary myotubes in transgenic embryos. Interestingly, we found that the two contractile fast and slow isoforms of TnI are expressed during the migration of myoblasts from the somites to the limbs and body wall, suggesting that both participate in these events. Since no sarcomeres are present in myoblasts, we speculate that the function of fast TnI in early myogenesis is, like Myosin and Tropomyosin, to participate in cell movement during the initial myogenic stages. genesis
authors.affiliation: Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas Alberto Sols, C.S.I.C., Madrid, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Guerrero
authors.forename: Pedro
authors.initials: P
authors.lastname: Villar
authors.forename: Lidia
authors.initials: L
authors.lastname: Martínez
authors.forename: Claudio
authors.initials: C
authors.lastname: Badia-Careaga
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Arredondo
authors.forename: Margarita
authors.initials: M
authors.lastname: Cervera
mesh_terms: D000818:Animals; D058948:Cell Tracking / Q000379:methods*; D005121:Extremities / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D024510:Muscle Development / Q000235:genetics; D032446:Myoblasts / Q000378:metabolism*; D009218:Myosins / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms; D014335:Tropomyosin / Q000235:genetics / Q000378:metabolism; D019210:Troponin I / Q000235:genetics* / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D014335:Tropomyosin; D019210:Troponin I; D049452:Green Fluorescent Proteins; D009218:Myosins
keywords: GFP; Troponin I; muscle; transgene