[Stem cell factor/c-kit interaction in primordial germ cell, melanoblast and hematopoietic progenitors]

Mutation at S1 or W loci are characterized by lacks of pigmentation, gametogenesis and hematopoiesis. Stem cell factor and its receptor, which is encoded by c-kit proto-oncogene, play an important role in the survival and proliferation of these primitive cells. Primordial germ cell is maintained and expanded on cells transfected with membrane-bound SCF gene. Pigmentation of mouse embryo is influenced by administration of monoclonal antibody for c-kit product, ACK 2, because of inhibition of melanoblast migration to epidermal tissue. Moreover, hematopoietic progenitors are considered to be maintained and expanded in liquid culture in the presence of SCF and other growth factors. All of these primitive cells express c-kit product and the direct action of SCF is expected. However, two types of SCF, soluble form and membrane-bound form, exist and the physiological significance of these forms in vivo remain unsolved.