Fetal myoblast clones contribute to both fast and slow fibres in developing rat muscle.
Retroviral cell lineage marking was used to investigate the role of cell lineage in fetal and neonatal rat muscle development. Clusters of infected cells, presumably myoblast clones, contribute cells to both slow primary and fast secondary fibres. Moreover, single clusters of marked cells contain both slow and fast primary fibres, suggesting that, at least during fetal life, single clones contribute nuclei to both fibres that are committed to remain slow and those that convert to a fast phenotype. The majority of fibres in individual fascicles of fetal muscle could be infected by a self-inactivating retroviral vector. Retroviral gene expression was markedly lower in non-muscle tissues, suggesting that fetal retroviral infection might target exogenous genes to mammalian muscle fibres during later life.
Hughes
S M
SM
MRC Muscle and Cell Motility Unit and Developmental Biology Research Centre, The Randall Institute, King's College London, United Kingdom. simon.hughes@kcl.ac.uk
D000367:Age Factors; D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D015316:Genetic Therapy; D018878:Limb Buds / Q000378:metabolism; D024510:Muscle Development; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000502:physiology*; D009132:Muscles / Q000196:embryology*; D051381:Rats; D017208:Rats, Wistar; D012190:Retroviridae; D013997:Time Factors; D014018:Tissue Distribution