title: Somitic origin of limb muscle satellite and side population cells.
abstract: Repair of mature skeletal muscle is mediated by adult muscle progenitors. Satellite cells have long been recognized as playing a major role in muscle repair, whereas side population (SP) cells have more recently been identified as contributing to this process. The developmental source of these two progenitor populations has been considerably debated. We explicitly tested and quantified the contribution of embryonic somitic cells to these progenitor populations. Chick somitic cells were labeled by using replication-defective retroviruses or quail/chick chimeras, and mouse cells were labeled by crossing somite-specific, Pax3-derived Cre driver lines with a Cre-dependent reporter line. We show that the majority of, if not all, limb muscle satellite cells arise from cells expressing Pax3 specifically in the hypaxial somite and their migratory derivatives. We also find that a significant number of, but not all, limb muscle SP cells are derived from the hypaxial somite. Notably, the heterogeneity in the developmental origin of SP cells is reflected in their functional heterogeneity; somitically derived SP cells are intrinsically more myogenic than nonsomitically derived ones. Thus, we show that the somites, which supply embryonic and fetal myoblasts, are also an important source of highly myogenic adult muscle progenitors.
authors.affiliation: Howard Hughes Medical Institute, Program in Genomics, Children's Hospital, Boston, MA 02115, USA.
authors.forename: Jaclyn
authors.initials: J
authors.lastname: Schienda
authors.forename: Kurt A
authors.initials: KA
authors.lastname: Engleka
authors.forename: Susan
authors.initials: S
authors.lastname: Jun
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hansen
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Epstein
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Tabin
authors.forename: Louis M
authors.initials: LM
authors.lastname: Kunkel
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Kardon
mesh_terms: D000818:Animals; D019070:Cell Lineage; D002465:Cell Movement; D002478:Cells, Cultured; D002642:Chick Embryo; D002678:Chimera; D004622:Embryo, Mammalian / Q000166:cytology; D004625:Embryo, Nonmammalian; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D008856:Microscopy, Fluorescence; D032342:Muscle Cells / Q000166:cytology*; D009132:Muscles / Q000166:cytology / Q000378:metabolism; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D011784:Quail; D012190:Retroviridae / Q000235:genetics; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology*; D019170:Somites / Q000166:cytology; D013045:Species Specificity; D013234:Stem Cells / Q000166:cytology*
chemical_list: D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; C068686:Pax3 protein, mouse; D049452:Green Fluorescent Proteins