The origin and development of neural crest-derived melanocytes
Melanocytes are specified from pluripotent neural crest cells that delaminate from the developing neural tube and overlying ectoderm early in development. As a subset of these neural crest cells migrate along the dorsal-lateral path, they begin to differentiate into melanocyte precursors (called melanoblasts). While the melanoblasts continue to differentiate, the population expands through proliferation and prosurvival processes. Melanoblasts eventually migrate through the dermis, into the epidermis, and, in mice and humans, into hair follicles, in which they produce melanin. Several classes of proteins, including transcription factors, extracellular ligands, transmembrane receptors, and intracellular signaling molecules regulate these processes. The genes that are currently implicated in melanocyte development and their relationship with each other will be discussed in this chapter. © 2006 Humana Press Inc.