title: Evidence for novel fate of Flk1+ progenitor: contribution to muscle lineage.
abstract: Flk1 is one of the specific cell surface receptors for vascular endothelial growth factor and one of the most specific markers highlighting the earliest stage of hematopoietic and vascular lineages. However, recent new evidence suggests that these Flk1(+) mesodermal progenitor cells also contribute to muscle lineages. All evidence is based on the experiments using in vitro differentiation and in vivo transplantation systems. Although this approach revealed a differentiation potential range of Flk1(+) cells that is wider than previously expected, it fails to determine whether Flk1(+) cells contribute to muscle lineage as part of the normal developmental process. To obtain direct evidence for the fate of Flk1(+) cells in development, we used a knock-in mouse line where Cre is expressed in Flk1(+) cells. Studies with these Cre lines provide direct evidence that Flk1(+) cells are progenitors for muscles, in addition to hematopoietic and vascular endothelial cells.
authors.affiliation: The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-8573, USA.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Motoike
authors.forename: David W
authors.initials: DW
authors.lastname: Markham
authors.forename: Janet
authors.initials: J
authors.lastname: Rossant
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Sato
mesh_terms: D000818:Animals; D017930:Genes, Reporter; D008040:Genetic Linkage; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D024510:Muscle Development / Q000502:physiology*; D009132:Muscles / Q000196:embryology* / Q000378:metabolism; D042787:Receptor, TIE-2 / Q000235:genetics / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D042787:Receptor, TIE-2; D040301:Vascular Endothelial Growth Factor Receptor-2; C045073:Cre recombinase; D019426:Integrases