Induction of melanogenesis by tetradecanoylphorbol-13 acetate and endothelin 3 in embryonic avian peripheral nerve cultures

In this study, me have analyzed the melanogenic potential of Schwann cells using in vitro cell cultures of embryonic quail peripheral nerves. It is sh own that in Schwann cells, two factors, 12-O-tetradecanoylphorbol-13 acetat e (TPA) and endothelin 3, trigger a differentiation pathway toward melanocy tes, and that Steel factor has no effect on these cells unless treated simu ltaneously with TPA. In these cultures, TPA induces the expression of c-kit , whereas Steel factor enhances the development of melanocytes. In the assa y system we employed, neither neuronal nor catecholaminergic phenotypes wer e obtained, regardless of various combinations of related factors added to the culture medium. These data support our previous observations indicating tla existence of bipotent progenitors that are capable of differentiating into Schwann cells or into melanocytes, and the regulatory role of endothel in 3 on those precursors, as revealed by the clonal culture of neural crest cells.