Allogeneic and xenogeneic transplantation of cryopreserved ovarian tissue to athymic mice

Cryopreserved ovarian tissue has major applications for female oncology patients and for the development of genome resource banks. The objective of the present study was to develop a bioassay of cryopreserved ovarian tissue function after allogeneic and xenogeneic transplantation to ovariectomized athymic nude (nu/nu) Balb/C mice. Transplant function was assessed by examination of vaginal smears, number of live births, and posttransplant histology. Animals were sham operated (group I; n = 4) or ovariectomized (group II; n = 5) or were given transplants of either fresh (group III; n = 3) or cryopreserved (group IV; n = 4) Institute of Cancer Research-strain mouse ovarian tissue or cryopreserved sheep ovarian tissue (group V; n = 7). Vaginal smears were examined 5-7 times per week; the number of days between visualizations of epithelial cells in smears was 4.3 +/- 0.6 for group I, 8.6 +/- 3.8 for group II, 3.4 +/- 0.4 for group III, 3.3 +/- 0.5 for group IV, and 4.6 +/- 0.6 for group V Epithelial cells were seen for 1.2-1.7 consecutive days; this value was significantly different between groups III and V. Live births were recorded from 3 of 4 animals from group I, 0 of 5 animals from group II, 2 of 3 animals from group III, and 1 of 4 animals from group IV. In vivo function and longterm survival of cryopreserved ovarian tissue after allogeneic or xenogeneic transplant were confirmed by the examination of vaginal cytology, and offspring were derived from allografts.