In vivo fate mapping of cryopreserved murine ovarian grafts

Background: Cryopreservation of ovarian tissue has been suggested as an alternative to restore fertility for ovarian failure before chemotherapy. Methods: Ovaries of donor FVB/N-Tg (PolII-Luc) Ltc transgenic mice (n = 5) were cryopreserved and transplanted to the back muscles of recipient FVB/NJNarl wild-type mice that had undergone bilateral oophorectomy. We evaluated the fate of cryopreserved murine ovarian grafts by in vivo bioluminescent imaging (BLI), AMH mRNA expression and follicle counts. Results: There were significantly stronger BLI signals in the fresh ovaries than in the frozen-thawed ones. The number of primordial follicles was significantly lower in frozen-thawed ovaries at 10 days after transplantation (P < 0.001). The AMH mRNA expression was significantly lower in the frozen-thawed ovaries (P < 0.001), showing that unavoidable harm occurs after transplantation. Conclusions: Ovarian cryopreservation by slow freezing compromises ovarian reserve by cryoinjury and ischemia, evident at an early stage after transplantation.