Smart-seq analysis comparing melanocytes from Spry1flox/flox mice tail epidermis to the melanocytes derived from Spry1 epidermis specific knockout mice tail and back epidermis

The function and survival of melanocytes is regulated by an elaborate network of paracrine factors synthesized mainly by epidermal keratinocytes. Keratinocytes and melanocytes respond to UV exposure by eliciting a tanning response. However, how keratinocytes and melanocytes interact in the absence of UV exposure is unknown. Here, we demonstrate that after Spry1 knockout in epidermal keratinocytes, melanocyte stem cells (McSCs) in the hair follicle exit the stem cell niche without depleting the pool of these cells. We also found that McSCs migrate to the epidermis in a Scf/C-kit-dependent manner induced by a tanning-like response resulting from Spry1 loss in epidermal keratinocytes. Once there, these cells differentiate into functional melanocytes. These findings show the potential for developing therapies for skin pigmentation disorders by manipulating McSCs. Cell type: FACS purified melanocytes from mouse epidermis; 3 conditions:Spry1flox/flox mice tail epidermis vs Spry1flox/flox k14-Cre-ERT2 mice tail epidermis vs Spry1flox/flox k14-Cre-ERT2 mice back epidermis ; 3 replicate for each condition.