Notch-1, c-kit and GFRalpha-1 are developmentally regulated markers for premeiotic germ cells

Culture, transfection and immortalization of mouse germ line stem cells, germ cell transplantation and grafting of testicular tissue are milestones of recent biotechnological breakthroughs. Alone and in combination they offer new pathways to explore the cellular mechanisms responsible for pluripotency and the requirements of cells to enter the germ line. Efficient markers, isolation and culture systems as well as transfection approaches are developed to elucidate the molecular and cellular mechanisms leading to the development of male germ line cells. Here, we describe the localization pattern of c-kit, Notch-1 and GFRalpha-1 in postnatal, immature and adult testes. All three proteins are potentially useful markers for spermatogonial characterization and enrichment. First attempts and various future perspectives to use spermatogonial stem cells as pathway for the introduction of transgenes are discussed.