Blastocyst Development After Cryopreservation and Subcutaneous Transplantation of Mouse Ovarian Tissue

Abstract

Purpose : To investigate follicle survival and developmental potential with IVF of cryopreserved, subcutaneously transplanted mouse ovarian tissue. Methods : Fresh and frozen mouse ovarian tissue was autologously transplanted into subcutaneous tissue. Two weeks after the transplantation, the morphology and histology of the fresh and frozen grafts were compared. Superovulation and IVF was performed to evaluate the fertility potential of the frozen ovarian graft. Results : Both fresh and frozen grafts of ovarian tissue survived in 14 of 16 mice (88%). Morphologically, both types of grafts resembled fresh ovarian tissue and contained follicles at all stages of folliculogenesis. A total of 73% of follicles in fresh grafts and 62% in frozen grafts survived after transplantation compared with fresh ovarian tissue. Sixteen ICR mice underwent superovulation. A total of 56 oocytes from antral follicles were recovered from the subcutaneously transplanted cryopreserved ovarian tissue. Fourteen (25%) oocytes were in metaphase II stage, 6 were fertilized by IVF, and 2 progressed to the blastocyst stage. Conclusions : Cryopreservation and subcutaneous transplantation of ovarian tissue provides a possible means of fertility preservation. The main loss of follicles occurred during grafting rather than during freezing and thawing.

Abnormally low expression of connexin 37 and connexin 43 in subcutaneously transplanted cryopreserved mouse ovarian tissue

“…It has been hypothesized that poor folliculogenesis in cryopreserved ovaries is attributable to dysfunction of granulosa cells but not of oocytes [17,30]. Previously, we have shown that oocytes survive in adequate numbers in subcutaneously transplanted cryopreserved ovarian tissue [17]. Granulosa cells are reportedly more vulnerable to ischemia than primordial follicles [31], and in this study, we demonstrated a higher than normal rate of apoptosis in granulosa cells from cryopreserved ovaries (Fig.…”

“…Injury to granulosa cells may affect further folliculogenesis [19]. It has been hypothesized that poor folliculogenesis in cryopreserved ovaries is attributable to dysfunction of granulosa cells but not of oocytes [17,30]. Previously, we have shown that oocytes survive in adequate numbers in subcutaneously transplanted cryopreserved ovarian tissue [17].…”

“…Pregnant mare's serum gonadotropin (PMSG, China Chemical and Pharmaceutical Co., HsinChu, Taiwan) 400 IU was injected intraperitoneally, and human chorionic gonadotropin (hCG, China Chemical and Pharmaceutical Co.), 200 IU, was given 48 h later following the previous method [17]. The mice were killed by cervical dislocation 10 h after hCG administration.…”

“…In humans, a 4-cell embryo was produced from subcutaneously transplanted cryopreserved ovarian tissue, but it did not result in conception [16]. We have reported blastocyst development from cryopreserved, subcutaneously transplanted mouse ovarian tissue [17]. However, there were few good quality embryos, and successful pregnancy did not occur.…”

“…In a previous study, we showed that only 25% of metaphase II oocytes could be recovered from the antral follicles of the subcutaneously transplanted cryopreserved mouse ovarian tissue, while 66% of the collected oocytes were in the germinal vesicle (GV) stage [17]. More primordial follicles die from hypoxia and delayed revascularization than from freezing-thawing injuries.…”