Fertility preservation in felids

With an increasing number of endangered feline species, their genome resource banking is of paramount importance. The storage of germplasm (gametes, embryos, gonadal tissues) is crucial to maintain biodiversity and to improve the fertility potential in wild species and domestic valuable breeds. Gamete cryobanking – Semen cryopreservation is the safer choice for male fertility preservation. Ejaculated or epididymal spermatozoa can be frozen with acceptable results (Luvoni 2006, Theriogenology 66:101–11). The female counterpart is more complex, as oocytes are larger and more sensitive cells, which often lose their developmental competence after cryostorage. Protocols still need to be optimized: encouraging results have been obtained in the domestic cat (Luvoni 2012, Reprod Dom Anim 47 Suppl. 6:266–8), but embryo development from cryopreserved oocytes has never been reported in wild felids. Gonadal tissue cryobanking – Testicular and ovarian tissues are abundant sources of gametes. Both freezing and vitrification of the male and female gonads have been achieved and ovarian cryobanking is already performed for some wild felids. Other techniques for fertility preservation – Freeze- drying is an interesting alternative to conventional freezing, but even if already applied to domestic cat and jaguar semen, it is still highly experimental. Oocyte nuclear preservation (germinal vesicle) by air- drying or microwave- assisted drying has been also attempted in cats, but it requires further studies. Conclusion – We are aware that there is still much to do, but also that with the improvement of fertility preservation procedures, the dream of safeguarding threatened felids, as in a modern Noah ’ s Ark, might come true.