LGR5 is a Conserved Marker of Hair Follicle Stem Cells Across Species and is Present Early and Throughout Follicle Morphogenesis

Abstract Hair follicle stem cells are key for driving growth and homeostasis of the hair follicle niche and have remarkable regenerative capacity throughout hair cycling and display fate plasticity during cutaneous wound healing. Due to the need for a transgenic reporter, essentially all observations related to LGR5+ hair follicle stem cells have been generated using transgenic mice, which have significant differences in anatomy and physiology from the human. Using a transgenic pig model, a widely accepted model for human skin and human skin repair, we demonstrate that LGR5 is a marker of hair follicle stem cells across species in homeostasis and development. We also report the strong similarities and important differences in expression patterns, gene expression profiles, and developmental processes between species. This information is important for understanding the fundamental differences and similarities across species, and ultimately improving human hair follicle regeneration, cutaneous wound healing, and skin cancer treatment.