Spermatogonial transplantation - an update for the millennium

Spermatogonial transplantation as developed in the laboratory of Ralph Brinster has been a technological breakthrough in the study of Sertoli-germ cell interactions. For the first time, germ cells can be transferred from one animal to another and from one species to another. The transfer technology combined with developments in freezing germ cells, long-term culture of germ cells, and enrichment of stem cell populations portend even more significant breakthroughs in the new millennium. The ultimate application of germ cell transfer would allow the in vitro genetic manipulation of cultured stem cells that could then be transplanted into recipient syngeneic or xenogeneic recipients and give rise to functional male gametes. Clearly, this achievement would have applications in basic science, human medicine, and domestic and wild animal reproduction. While progress in this direction has been significant and swift, significant barriers such as immunological response and mechanisms for introducing genetic material into the stem cells remain to be examined. This report is a chronological review of the technological advances made and conceptual insights gained since the first report of successful transplantation in 1994