Spermatogonial stem cell (SSC) transplantation is a promising technique to circumvent sterility in prepubertal boys undergoing gonadotoxic treatments.While the cryopreservation of spermatogonial stem cells is being introduced in clinical practices worldwide,a lot of unanswered questions remain regarding their eventual transplantation.In this paper autologous and allogeneic SSC transplantations in the testes of sterilized macaques were performed and spermatogenesis could be restored from donor SSCs.The spermatozoa obtained were competent to fertilize oocytes.This report proves the feasability of SSC transplantation in a primate model,hence reinforcing the hope that this strategy will eventually find its way into clinical practice.