title: A dynamic analysis of muscle fusion in the chick embryo.
abstract: Skeletal muscle development, growth and regeneration depend upon the ability of muscle cells to fuse into multinucleated fibers. Surprisingly little is known about the cellular events that underlie fusion during amniote development. Here, we have developed novel molecular tools to characterize muscle cell fusion during chick embryo development. We show that all cell populations arising from somites fuse, but each with unique characteristics. Fusion in the trunk is slow and independent of fiber length. By contrast, the addition of nuclei in limb muscles is three times more rapid than in trunk and is tightly associated with fiber growth. A complex interaction takes place in the trunk, where primary myotome cells from the medial somite border rarely fuse to one another, but readily do so with anterior and posterior border cells. Conversely, resident muscle progenitors actively fuse with one another, but poorly with the primary myotome. In summary, this study unveils an unexpected variety of fusion behaviors in distinct embryonic domains that is likely to reflect a tight molecular control of muscle fusion in vertebrates.
authors.affiliation: EMBL Australia; Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, VIC 3800, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sieiro-Mosti
authors.affiliation: EMBL Australia; Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, VIC 3800, Australia.
authors.forename: Marie
authors.initials: M
authors.lastname: De La Celle
authors.affiliation: EMBL Australia; Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, VIC 3800, Australia.
authors.forename: Manuel
authors.initials: M
authors.lastname: Pelé
authors.affiliation: EMBL Australia; Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, VIC 3800, Australia christophe.marcelle@monash.edu.
authors.forename: Christophe
authors.initials: C
authors.lastname: Marcelle
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002459:Cell Fusion; D002642:Chick Embryo; D018274:Electroporation; D007150:Immunohistochemistry; D007211:Indoles; D018613:Microscopy, Confocal; D009024:Morphogenesis / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology*; D018482:Muscle, Skeletal / Q000196:embryology*; D010957:Plasmids / Q000235:genetics; D019170:Somites / Q000196:embryology*
chemical_list: D007211:Indoles; C007293:DAPI
keywords: Chick embryo; Electroporation; Limb; Muscle fusion; Myotome