射出精子 및 精巢上體精子의 Caffeine 및 Heparin 處理가 尖體反應과 體外受精의 種杜牛個體差異에 미치는 영향 = Effect of Caffeine and Heparin on Individual Variation in Acrosome Reaction and Fertilization In Vitro of Ejaculated and Epididymal Spermatozoa form Different Bulls

다국어 초록 (Multilingual Abstract)

These studies were designed to identify the effects of sperm treatments and individual Korean native bulls on in vitro acrosome reaction, invitro fertilization and in vitro embryonic development. Sperm samples used were frozen-thawed ejaculated sperm from 9 bulls and epididymal sperm from 6 bulls and the acrosomes of sperm were evaluated at various intervals after the treatment with caffeine, heparin or caffeine-heparin. The treated sperm were fertilized in vitro with zona-free hamster eggs for sperm penetration assay and with in vitro matured bovine follicular oocytes for in vitro embryonic development.
1. When the frozen-ejaculated sperm were treated with caffeine, the percentage of live and dead sperm with detached acrosome increased significantly from 1.5h after preincubation (P<0.05) and these increases were observed at the other sperm treatments. The acrosome reaction of live sperm by each sperm treatment was not significantly different among the individual bulls, but the total sperm with detached acrosome were significantly different among them (P<0.05).
2. The acrosome reaction of epididymal sperm increased significantly from 3h after sperm treatment (P<0.05), but there was no significant difference between the sperm treatments and the time was slightly slower than that of ejaculated sperm. When the frozen-thawed epididymal sperm were treated with caffeine, the percentage of live sperm with detached acrosome ranged from 8.8 to 22.8 and there was significant difference between the individual bulls (p<0.05).
3. When the frozen-thawed ejaculated sperm were preincubated 2h after caffeine treatment, 42.1 to 52.6% of them penetrated into zona-free hamster eggs and the bull of a higher acrosome reaction tended also to show a higher penetration rate, but there was not significantly different between the individual bulls. When the frozen-thawed epididymal sperm were preincubated 3h after caffeine treatment, 41.2 to 59.4% of them penetrated into zona-free hamster eggs, There was no significant difference between the individual bulls and their penetration rates were not similar to their acrosome reaction rates.
4. The embryonic development from bovine follicular oocytes which were fertilized in vitro with 2h-preincubated frozen-ejaculated sperm was not accorded with the acrosome reaction rates of sperm, while the cleavage to above 8-cell was different between the bulls although there was not significant. The embryonic development from bovine follicular oocytes which were fertilized in vitro with 3-h preincubated frozen-epididymal sperm was not related to the acrosome reaction of bulls, but their cleavages to above 8-cell tended to be higher than those with ejaculated sperm. It is concluded that the caffeine treatment was more effective to induce the acrosome reaction of sperm and the effective preincubation time was 2h for ejacuated sperm and 3h for epididymal sperm. The results also indicated that the in vitro fertilization and embryonic development is not accorded with the in vitro acrosome reaction of sperm but can be affected by the individual bulls.