DOI 10.1095/biolreprod.102.009480 Successful Intra- and Interspecific Male Germ Cell Transplantation in the Rat1

The lumen of the seminiferous tubules has hitherto been re-garded as an immunologically privileged site. We report here the birth of young following transplantation of stem spermato-gonia from Long-Evans rats to the seminiferous tubules of Sprague-Dawley rats after treatment with the immunosuppres-sive agent cyclosporin. Follicle-stimulating hormone was also given to stimulate Sertoli cell proliferation, and testosterone to stimulate the recovery of spermatogenesis. Donor germ cells un-derwent normal spermatogenesis, and progeny were repeatedly produced from the donor germ cells as demonstrated by micro-satellite paternity analysis. In addition, donor germ cells from the cryptorchid testes of LacZ mice were also able to colonize the seminiferous tubules of Sprague-Dawley rats using this pro-tocol. Morphologically normal rat and mouse spermatozoa were present in the epididymis and vas deferens of the recipient rats. This highlights the potential for transplantation of male germ cells between different species. developmental biology, immunology, male reproductive tract, spermatogenesis, testi