703 Tracing the proliferative dynamics of dermal papilla (DP) progenitors during adult hair follicle (HF) regeneration

Abstract

The dermal papilla (DP) instructs the cyclical regeneration of the adult hair follicle (HF). The HF grows in anagen, regresses in catagen and rests in telogen. The DP expands in cell number as the HF regenerates, which is critical for HF growth and regulating hair shaft size. Currently how the DP expands is not clear. As the DP is considered to be a quiescent population, the prevailing theory is that the DP expands from proliferative cells that reside outside the DP. We performed EdU pulse chase experiments to track when and where DP progenitors divide and contribute to the expanding DP.