Function of Cryopreserved Cat Ovarian Tissue after Autotransplantation

Abstract

The aim of this study was to assess a slow-freezing protocol of cat ovarian tissue cryopreservation using autotransplantation. Four adult queens were ovariohysterectomized and the ovaries were fragmented and cryopreserved. After one week, the grafts were thawed and autografted to the subcutaneous tissue of the dorsal neck of each queen, then randomly removed after 7, 14, 28, 49, and 63 days after transplantation. Percentages of morphologically normal primordial and growing follicles (MNFs) were 88% and 97%, respectively, in fresh tissue samples (fresh controls), and 74% and 100%, respectively, immediately after thawing (cryo D0). No MNFs were found after 49 days of transplantation. In both fresh control and cryo D0 fragments, granulosa cells were frequently in proliferation. Two morphologically normal antral follicles were detected in one queen on Day 28 post-transplantation. Connective tissue fibers increased, suggesting replacement of active ovarian cortex by fibrous tissue. Tissue vascularization was observed at 7 days after grafting, and wide blood vessels were clearly visible on Days 49 and 63. In conclusion, although follicular survival was low after cryopreservation and grafting of cat ovarian tissue, follicles were able to develop up to the antral stage, which is an encouraging outcome.

Ovarian tissue transportation: a systematic review

“…Some studies have used in vitro culture of ovarian fragments, but this system is not very well established for many species, yielding low rates of follicle survival in both short-and long-term culture (Isachenko et al 2006, Smitz et al 2010, Vilela et al 2016. Since ovarian tissue transplantation has already been validated for cryopreservation assessment (Nottola et al 2008, Amorim et al 2011, Luyckx et al 2013, Ayuandari et al 2016, Ruan et al 2019, Vilela et al 2019, it might be a valuable technique to evaluate tissue transport. Indeed, transplantation of mouse ovarian tissue was used to assess ovarian tissue storage and revealed a significant reduction in both implantation and live birth rates, even though the morphology before transplantation did not show any difference in the percentage of morphologically normal follicles (Kamoshita et al 2016).…”

Cryopreservation of African painted dog (Lycaon pictus) ovarian tissue

“…OTC is also being applied to various animal species to preserve genetic material until such a time that in vitro fertilization or allo-or xeno-grafting can be performed. Thus far, transplantation of cryopreserved ovarian tissue has been reported to result in live birth in mice and sheep (4,5), and the return of fertility in cats (6). Xenografting of ovarian tissues into immunocompromised mice has allowed for the successful growth of primordial and antral follicles across a number of species, including the African elephant (Loxodonta africana) (7), common wombat (Vombatus ursinus) (8), and lion (Panthera leo) (9).…”