Autologous grafting of cryopreserved prepubertal rhesus testis produces sperm and offspring

Preserving male fertility Before chemotherapy or radiation treatment, sperm from adult men can be cryopreserved for future use. However, this is not possible for prepubertal boys. Fayomi et al. grafted cryopreserved testicular tissue from castrated pubertal rhesus macaques, placing each animal's own testis sections under the skin of the back or scrotum (see the Perspective by Neuhaus and Schlatt). Grafts grew, produced testosterone, and were able to generate sperm that could fertilize oocytes, in one case resulting in a successful pregnancy. The results hold promise for preserving human fertility, for example, after childhood cancer treatments. Science , this issue p. 1314 ; see also p. 1283