title: A single type of progenitor cell maintains normal epidermis.
abstract: According to the current model of adult epidermal homeostasis, skin tissue is maintained by two discrete populations of progenitor cells: self-renewing stem cells; and their progeny, known as transit amplifying cells, which differentiate after several rounds of cell division. By making use of inducible genetic labelling, we have tracked the fate of a representative sample of progenitor cells in mouse tail epidermis at single-cell resolution in vivo at time intervals up to one year. Here we show that clone-size distributions are consistent with a new model of homeostasis involving only one type of progenitor cell. These cells are found to undergo both symmetric and asymmetric division at rates that ensure epidermal homeostasis. The results raise important questions about the potential role of stem cells on tissue maintenance in vivo.
authors.affiliation: MRC Cancer Cell Unit, Hutchison-MRC Research Centre, Cambridge CB2 0XZ, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Clayton
authors.forename: David P
authors.initials: DP
authors.lastname: Doupé
authors.forename: Allon M
authors.initials: AM
authors.lastname: Klein
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Winton
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Simons
authors.forename: Philip H
authors.initials: PH
authors.lastname: Jones
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D019070:Cell Lineage; D002999:Clone Cells / Q000166:cytology; D000078404:Epidermal Cells; D006706:Homeostasis; D051379:Mice; D008954:Models, Biological; D013234:Stem Cells / Q000166:cytology*