Folliculogenesis following syngeneic transplantation of young murine ovaries into the testes

Abstract

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).

Successful pregnancy in ovariectomized mice using a combination of heterotopic autotransplantation of ovarian tissues and embryo transfer

“…Similar results have been reported in rats, 29 rabbits 30 and sheep 31 . Furthermore, it has been reported that various stages of folliculogenesis were shown in young murine ovaries transplanted syngeneically into the testes 32 . Thus, the site of transplantation of ovarian tissues might be insignificant for the restoration of ovarian function after heterotopic ovarian transplantation.…”

Functional Recovery of a Whole Ovary Transplanted Into Syngenic Testis in Mice

“…In this study, we improved the previously used method for intratesticular grafting of a juvenile ovary [12], and demonstrated that the grafted ovary still possesses the ability to ovulate oocytes when placed under a normal environment via ovary transplantation. Intratesticular grafting of an ovary was first performed by Sand [16,17], who found that the grafted ovary developed mature follicles, although the procedure remained unclear regarding the age of animal most suitable for obtaining donors and recipients and the most optimum stage of follicle maturation.…”

“…Improvement of testicular grafting of an ovary appears to be one of the factors leading to improved recovery of function in the ovaries grafted within the host testis. In our previous experiments [12], only about 40%-50% of STs were removed, which created a limited space, thus allowing the grafted ovary to grow normally. In this study, we removed about 80% of STs by suction by using 20-gauge needle, which gave rise to a larger space wherein the grafted juvenile ovary could grow well (Figure 2e).…”

“…Intratesticular grafting of a juvenile mouse ovary was performed according to the method described by Sato et al [12] with some modifications. Briefly, 2-week-old ovaries from homozygous female Tg mice of the MNCE-39 line, which systemically over expresses EGFP [13], were transplanted into 2-week-old non-Tg MNCE-39 male mice.…”

“…In contrast, intratesticular transplantation of a juvenile ovary (about 2 weeks after birth) into the environment of an adult testis does not appear to affect the quality of the graft itself. In our previous study in which young ovaries isolated from 2-week-old Enhanced Green Fluorescence Protein (EGFP)-expressing transgenic (Tg) females were transplanted into 4-week-old non-Tg male testes, no obvious adverse effects were noted in the ovarian grafts [12]. In these grafts, normal folliculogenesis in the grafts was recovered 2 months after grafting occurred.…”