title: The extracellular matrix protein TGFBI promotes myofibril bundling and muscle fibre growth in the zebrafish embryo.
abstract: The extracellular matrix protein Tgfbi has been shown to localise to myotendinous junctions in mouse and postulated to interact with the transmembrane protein Integrin alpha7beta1, which, in parallel with the Dystrophin-associated protein complex, is critical for linkage between the extracellular matrix and the cytoskeleton of muscle fibres. Here we use a GFP-tagged form of Tgfbi to analyse its distribution in the developing skeletal muscle of the zebrafish embryos and antisense morpholino oligonucleotides to investigate the function of the endogenous protein. We find that although tagged Tgfbi accumulates at the myosepta, the attachment of muscle fibres to the myosepta is established and maintained normally in morphant embryos; however, the fibres show a marked reduction in their growth and a disruption of their myofibril bundles.
authors.affiliation: MRC Centre for Developmental and Biomedical Genetics, University of Sheffield, Sheffield, United Kingdom.
authors.forename: H Rosemary
authors.initials: HR
authors.lastname: Kim
authors.forename: Philip W
authors.initials: PW
authors.lastname: Ingham
mesh_terms: D000818:Animals; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000502:physiology*; D009210:Myofibrils / Q000502:physiology* / Q000648:ultrastructure; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000033:anatomy & histology / Q000196:embryology; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*; D000099222:betaIG-H3 Protein
chemical_list: D016326:Extracellular Matrix Proteins; D016376:Oligonucleotides, Antisense; D011993:Recombinant Fusion Proteins; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins; D000099222:betaIG-H3 Protein