Cryopreservation Of Domestic Cat Ovaries Tissues

There are millions of follicles in the ovary of domestic cat. But a large number of them undergo atresia during their preantral stage, which leads to a serious waste of genetic and breeding resource. Storing mammalian ovaries tissues with cryopreservation technology can effectively solve this problem. It also offers an effective method to retrieval and utilizes these latentgenetic and breeding resources of some endangered species.The objective of this paper was to find a method to store mammalian ovaries tissues with cryopreservation technology, as well as to do some basic research for preserving the genetic and breeding resources of some endangered species, such as the wild felid and the giant panda.In this research, the ovaries tissues of domestic cats were dealt with 4 different kinds of methods and cryoprotectors. The method of vitrification could save natural follicles with fewer traumas. After cryopreservation, the ultrastructures of some follicles were destroyed. The average number of preantral follicles, collected by combining enzyme digestion method with mechanical treatments method, was 33.78 per domestic cat. The method of vitrification could keep higher livability of follicles after cryopreservation by judging the result of vigor-dye.All the follicles processed by these 4 different kinds of freezing methods preserved the growth ability in vitro culture. One of these follicles produced its first polar. During culture period, the diameters of the follicles processed by these 4 different kinds of freezing methods increased respectively by 6.75μm, 7.33μm, 8.45μm and 6.68μm. There was no obvious difference between them (p>0.05). The degeneration rates of oocytes were respectively 86.88%, 65.63%, 68.45% and 56.86%, without significant difference (p>0.05) either.The amounts of estradiol contained in the used culture medium were mensurated with ELISA method. All the test results were positive. We gained 3 sets of data: 5.882pg/50nL, 2.951 pg/50|iL and 1.299 pg/5OjiL. The ovaries tissues reserve the ability of incretion and excreting estradiol.The results prove that after cryopreservation the ovaries tissues of domestic cat still reserved their vitality.