Restoration of fertility by orthotopic transplantation of frozen adult mouse ovaries

BACKGROUND: Successful thawing and orthotopic transplantation of ovarian tissue has produced live offspring in mice, but until now has only been successful for very young ovary donors. METHODS: Whole and half ovaries from adult C3H/HeNCrlBR (C3H) and whole ovaries from B6129SF1/J were frozen-thawed and then grafted orthotopi-cally into B6C3F1/CrlBR (B6C3F1) and B6129SF1/J recipients, respectively. In bilateral transplant groups (bilat-eral), recipients underwent a bilateral ovariectomy, followed by orthotopic grafting. In unilateral groups recipients either underwent bilateral ovariectomy followed by unilateral grafting (unilateralovx) or had only one ovary removed and replaced with a graft (unilateral) along with complete transection of the remaining oviduct. RESULTS: Ovary size and number of follicles decreased dramatically in grafted compared with control groups, but the loss in the unilateralovx group was significantly less than in the unilateral group. Similar numbers of litters and litter size were obtained in bilateral and unilateral grafts of fresh ovary. However, a much lower number of litters and litter size were derived from unilateral grafts than from unilateralovx grafts of frozen ovary. CON-CLUSIONS: Normal fertility can be restored by orthotopic grafting of fresh or frozen adult mouse ovaries and no significant difference between fresh and frozen ovaries was found. Grafting of half ovaries does not alter the overall fertility rate. Unilateralovx grafting is an efficient procedure to produce live pups and removes the negative effect of recipient native ovaries on post-grafting fertility