Sexual dimorphism in epidermal stem cell dynamics.

Intravital time-lapse imaging of lineage-labelled cells in mouse interfollicular epidermis supports a two-compartment model of epidermal homeostasis, with basal cells organized in a stem cell-transit-amplifying hierarchy. Female mice showed synchronized cell division, differentiation and delamination, linked to accelerated wound healing, while analyses of castrated mice showed male sex hormones promote stem cell differentiation and delamination. The work identifies sex-specific regulation of epidermal stem cell fate.