Melanocytes and Pigmentation
Melanocytes are neural crest-derived cells that are found primraily in the basal layer of the epidermis.
Melanocyte progenitors are known as melanoblasts. These cells are proliferative, express little melanin, and frequently display a bi-polar phenotype with two dendrites.
In response to differentiation signals, melanoblasts form membrane bound vesicles known as melanosomes in which melanin granules form, and increase dendricity. To complete pigmentation of the epidermis, melanosomes (and their melanin granules) are transferred to neighbouring keratinocytes via the dendrites.
In vitro melanocyte pigmentation is commonly investigated by quantifying either: