Spermatogonial transplantation technique in spermatogenesis research.

The spermatogonial stem cell is the foundation of spermatogenesis and it continues to divide throughout the lifetime of a male. It divides to renew itself as well as to produce daughter cells that finally differentiate to spermatozoa. Transplantation of spermatogonial stem cells from a fertile mouse to the testis of a sterile mouse results in the development of donor cell derived spermatogenesis. Furthermore, spermatogenesis of the rat and hamster occurs in immunodeficient mouse testes following spermatogonial transplantation. Cryopreservation of spermatogonial stem cells has been shown to be applicable in many species for later transplantation. In addition, certain forms of infertile donor germ cell can be transplanted to produce functional sperm in a recipient testis. These new techniques will be useful for basic research of spermatogenesis and for application to reproductive technology in the future.