Sexual dimorphism in epidermal stem cell dynamics [scRNA-Seq]

Conflicting theories have been proposed regarding the heterogeneity of basal cell layer, with some studies proposing that all proliferative cells have self-renewal potential during homeostasis while others posit a model in which stem cell differentiation occurs through an intermediate progenitor state with strictly limited proliferative potential.

To elucidate the heterogeneity and pattern of cell fate, we performed intravital timelapse imaging to track the fate of individual lineage-labeled cells over the long term in the ear skin interfollicular epidermis. Quantitative analysis of clonal dynamics supports a two-compartment model of epidermal homeostasis, with basal cells organized in a stem-progenitor cell hierarchy. Critical to these conclusions was the discovery of a sexual dimorphism in epidermal fate, with female mice showing a highly synchronized pattern of differentiation and delamination.