Genetic and epigenetic control of the proliferation and differentiation ofmouse epidermal melanocytes in culture

Serum-free culture of epidermal cell suspensions from neonatal skin of mice of strain C57BL/10JHir (B10) showed that a-melanocyte-stimulating hormone (cr-MSH) was involved in regulating the differentiation of melanocytes by i nducing tyrosinase activity, melanosome formation, and dendritogenesis, Dib utyryl adenosine 3':5'-cyclic monophosphate (DBcAMP) similarly induced the differentiation of melanocytes, On the other hand, DBcAMP induced the proli feration of epidermal melanocytes in culture in the presence of keratinocyt es, Basic fibroblast growth factor (bFGF) was also shown to stimulate the s ustained proliferation of undifferentiated melanoblasts in the presence of DBcAMP and keratinocytes, These results suggest that the proliferation and differentiation of mouse epidermal melanoblasts and melanocytes in culture are regulated by the three factors; namely, cAMP, bFGF, and keratinocyte-de rived factors. Moreover, serum-free primary culture of mouse epidermal mela nocytes derived from B10 congenic mice, which carry various coat color gene s, showed that the coat color genes were involved in regulating the prolife ration and differentiation of mouse epidermal melanocytes by controlling th e proliferative rate, melanosome formation and maturation, and melanosome d istribution.