The ordered architecture of murine ear epidermis is maintained by progenitor cells with random fate.
Typical murine epidermis has a patterned structure, seen clearly in ear skin, with regular columns of differentiated cells overlying the proliferative basal layer. It has been proposed that each column is a clonal epidermal proliferative unit maintained by a central stem cell and its transit amplifying cell progeny. An alternative hypothesis is that proliferating basal cells have random fate, the probability of generating cycling or differentiated cells being balanced so homeostasis is achieved. The stochastic model seems irreconcilable with an ordered tissue. Here we use lineage tracing to reveal that basal cells generate clones with highly irregular shapes that contribute progeny to multiple columns. Basal cell fate and cell cycle time is random. Cell columns form due to the properties of postmitotic cells. We conclude that the ordered architecture of the epidermis is maintained by a stochastic progenitor cell population, providing a simple and robust mechanism of homeostasis.
MRC Cancer Cell Unit, Hutchison-MRC Research Centre, Cambridge CB2 0XZ, UK.
David P
DP
Doupé
Allon M
AM
Klein
Benjamin D
BD
Simons
Philip H
PH
Jones
D053687:Adult Stem Cells / Q000166:cytology*; D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D004431:Ear, External / Q000033:anatomy & histology / Q000166:cytology*; D000078404:Epidermal Cells; D004817:Epidermis / Q000033:anatomy & histology; D006706:Homeostasis; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013269:Stochastic Processes
D008164:Luminescent Proteins; D011994:Recombinant Proteins