Folliculogenesis following syngeneic transplantation of young murine ovaries into the testes.

To examine the effects of intratesticular transplantation on the growth and maturation of young murine ovaries. Two-week-old ovaries from transgenic mice with enhanced green fluorescent protein expression were transplanted under the testicular capsule of 4-week-old non-transgenic mice. Two months after transplantation all successfully grafted ovaries had survived, based on the presence of bright green fluorescence. The grafts showed various stages of folliculogenesis, including expanded follicles. The neighboring seminiferous tubules had a normal structure and mature sperm in their lumens, indicating active spermatogenesis, and all the recipient males were fertile. There was no evidence of extensive cell migration from the grafted ovaries into the testis. Similar findings were obtained for the grafted ovaries 6 months after surgery, although cell death (as evidenced by yellowish or pale fluorescence) was more frequent. Young murine ovaries can grow and mature autonomously for at least 6 months unaffected by the male hormonal environment. (Reprod Med Biol 2006; : 71-77).