title: Analysis of muscle fibre input dynamics using a myog:GFP transgenic trout model.
abstract: The dramatic increase in myotomal muscle mass in teleosts appears to be related to their sustained ability to produce new fibres in the growing myotomal muscle. To describe muscle fibre input dynamics in trout (Oncorhynchus mykiss), we generated a stable transgenic line carrying green fluorescent protein (GFP) cDNA driven by the myogenin promoter. In this myog:GFP transgenic line, muscle cell recruitment is revealed by the appearance of fluorescent, small, nascent muscle fibres. The myog:GFP transgenic line displayed fibre formation patterns in the developing trout and showed that the production of new fluorescent myofibres (muscle hyperplasia) is prevalent in the juvenile stage but progressively decreases to eventually cease at approximately 18 months post-fertilisation. However, fluorescent, nascent myofibres were formed de novo in injured muscle of aged trout, indicating that the inhibition of myofibre formation associated with trout ageing cannot be attributed to the lack of recruitable myogenic cells but rather to changes in the myogenic cell microenvironment. Additionally, the myog:GFP transgenic line demonstrated that myofibre production persists during starvation.
authors: INRA, UR1037 LPGP Fish Physiology and Genomics, Rennes F-35000, France pierre-yves.rescan@rennes.inra.fr.
authors: Pierre-Yves
authors: PY
authors: Rescan
authors: INRA, UR1037 LPGP Fish Physiology and Genomics, Rennes F-35000, France.
authors: Cécile
authors: C
authors: Rallière
authors: INRA, UR1037 LPGP Fish Physiology and Genomics, Rennes F-35000, France.
authors: Veronique
authors: V
authors: Lebret
authors: INRA, UR1037 LPGP Fish Physiology and Genomics, Rennes F-35000, France.
authors: Maxence
authors: M
authors: Fretaud
mesh_terms: D000375:Aging; D000818:Animals; D030801:Animals, Genetically Modified; D049109:Cell Proliferation / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D024510:Muscle Development; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D018008:Myogenin / Q000235:genetics / Q000378:metabolism*; D017686:Oncorhynchus mykiss / Q000196:embryology* / Q000235:genetics / Q000254:growth & development*; D011401:Promoter Regions, Genetic
chemical_list: D018008:Myogenin; D049452:Green Fluorescent Proteins
keywords: Muscle hyperplasia; Myogenesis; Myogenic regulatory factor; Myogenin; Oncorhynchus mykiss; Teleost; Transgenesis