SPERMATOGONIAL STEM-CELL TRANSPLANTATION, CRYOPRESERVATION AND CULTURE

Testis cells of a fertile male mouse can be transplanted to the semini ferous tubules of an infertile male, where the donor spermatogonial st em cells will establish spermatogenesis and produce spermatozoa that t ransmit the donor haplotype to progeny. In addition, stem cells can be cryopreserved for long periods, thereby making male germ lines immort al. Recently, mouse testis cells have been cultured for longer than 3 months and, following transplantation, produced spermatogenesis. These techniques are likely to be applicable to many species, since rat tes tis cells can be cryopreserved and generate spermatogenesis in the sem iniferous tubules of immunodeficient mice.