| There are abundant follicles in domestic cat ovary but majority of them undergo atresia in preantral stage, and only a few follicles are destined to mature and ovulate. Reseach on isolation and in vitro maturation of preantral follicles can retrieval and utilize effectively these latent genetic and breeding sources, and provide sufficient supper quality oocytes for the in vitro production of the felid embryos, animal cloning and transgenesis and associated researches. There is an important theoretical and practical value for relevant studies on endangered wildlife, such as Giant Panda. In present experiment, the preantral follicles were isolated from domestic cats ovaries by mechanical and enzyme digestion combined with mechanical treatments. The average number of preantral follicles, collected by mechanical treatment, were 16.89 with 2~-.4 layers of granulosa cells and obtained many primordial follicle. Enzyme digestion combined with mechanical treatments resulted in 20.07 preantral follicles per pair of ovaries (P>0.05). the preantral follicles from one-month, prepubertal and adult cats were collected by enzyme digestion combined with mechanical treatments.the average number of preantral follicles were 9.43 21.50 and 18.90 respectively. There were significant differences between one-month and prepubertal and adult group (P<0.05). In order to indentif~?the preantral follicles from domestic cat ovaries morphologically, the morphological research was conducted in this experiment. The criteria of preantral follicles from cat ovaries has been developed by mesurement and analysis of related data. There was no cavity in preantral follicle, Its oocyte was enclosed by no more than 4 layers of granulosa cells. The follicular diameter was less than 21 Ouin and diameter of its oocyte was less than I lOum(including ZP). DMEM and EMEM medium were used for the culture of preantral follicles from cat. It has been found that diameter of follicular in these two groups increased 33.67 and 14.26uni on S 36 days of culture. There were no significant differences between two kinds of media (P>0.05). The degeneration rates of oocytes were 73.33% and 71 .370/orespectively,without difference(P>0.05). Eight culture systems have, been established in the experiment. (1)DMEM+0.S%BSA, (2)EMEM+0.5%BSA, (3)DMEM+0.5%BSA+40nglmlHydrocortisone, (4)DMEM+ 10%FCS, (5) DMEM+10%FCS+4Ong/mlHydrocortisone, (6) DMEM+10%FCS+SOng/mIITS+SOng/mIEGF +4Ong/mlHydrocortisone, (7) DMEM+0.5%BSA+5Ong/mIITS+SOng/m1EGF+4Ong/ml Hydroc- ortisone, (8) DMEM+HEPES+0.5%BSA+SOng/mIITS+SOng/mIEGF+4Ong/ml Hydrocortisone. After 7 days of culture of preantral follicles (>1 OOum) with these eight culture systems, the increments of follicular diameter were 33.67,5.26,14.67,51.25,34.04,54.87,57.62 and 64.O8um, respectively. The degeneration rate of eight culture systems were 93.35,100,83.33,75,70,66.50, 85.11 and 64.41%, there was significant differences between (2) and (8) group (P<0.05). As far as growth rate of follicle was concered, (6), (7) and (8) groups were best medium for culture cat follicles (>lOOum). After 7 days of culture of preantral follicles ( |
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