Xenografting of canine ovarian tissue to ovariectomized severe combined immunodeficient (SCID) mice

Xenografting of ovarian tissue salvaged from valuable dogs to an immunologically incompetent recipient is a possible mechanism to allow the ovarian tissue to be used for recovery of fertilizable oocytes. In this study, follicular development was assessed after xenotransplantation of fresh canine ovarian tissue into immunodeficient mice. Fresh prepubertal canine ovarian tissue was grafted beneath the kidney capsule of 7-week-old ovariectomized severe combined immunodeficient mice. At intervals after grafting, the recipient mice were killed, necropsied and the xenografts were recovered. The number and stage of development of follicles were assessed quantitatively by histological examination of serial sections of the xenografts. By day 56 after grafting, recruitment of primordial follicles had occurred but follicular development to the antral stage was not observed. The recipients showed persistent vaginal cornification and uterine dilation, which indicates that the grafts were producing hormones. However, these changes are not consistent with the oestrous cycle of either bitches or mice, indicating that inappropriate communication may occur between the recipient hypothalamic-pituitary glands and the axis of the xenograft gonad.