Changes in protein kinase C activities are correlated with the metaplastic transformation of Schwann cell precursors of avian embryos into melanocytes.

In previous work, we found that the phorbol ester drug 12-O-tetradecanoyl phorbol acetate (TPA) reverses the developmental restriction of melanogenesis that occurs early in neural crest development, causing Schwann cell precursors to undergo a metaplastic transformation into melanocytes. In this study, we examine whether these effects of TPA may be mediated by changes in endogenous levels of protein kinase C (PKC) activities. We report that low levels of PKC activity are correlated with this adventitious pigmentation in the crest-derived cells of dorsal root ganglia both during normal development and following TPA treatment in culture. These results suggest that regulation of endogenous levels of PKC plays a role in developmental decisions that neural crest cells make during early embryogenesis.