Hair Follicle Epithelial Stem Cells Contributing to Interfollicular Epidermis during Homeostasis [single-cell RNA-seq]

The mammalian skin is a crucial barrier, with the epidermis as its protective, renewing outer layer. Loss of epidermal function is lethal, so multiple stem cell populations likely support the interfollicular epidermis (IFE) for survival. Using single-cell RNA sequencing, we show that KROX20 marks a diverse stem cell population in the upper and middle mouse hair follicle (HF), partially overlapping with known HF stem cells. Lineage tracing reveals that Krox20-lineage cells migrate from the HF to the IFE, contributing to both basal and suprabasal layers. Epithelial cells from epidermis of five Krox20-GFP mice at P5 were harvested and FACS sorted for GFP-positive (Krox20-expressing) cells. FACS-sorted cells (GFP-positive) were then used for Single Cell Sequencing.