In mammal, oocytes are arrested at the metaphase Ⅱ until fertilization. However, unfertilized oocytes that remain in the oviduct or under in vitro culture, which is called "oocyte aging". Asynchrony negatively affects fertilization, pre- and post-implantation embryo development. Caffeine is known to phosphodiesterase inhibitor that rescues oocyte aging in several species. Nevertheless, the effect of caffeine was not clear in bovine aging oocytes. In this study investigated the cytoskeleton distribution in aged oocytes and the embryo development ability of aged oocytes from treated with or without caffeine during maturation. The cumulus and oocyte complexes (COCs) were cultured in 10% FBSTCM199 for up to 22h at 38.5℃ in 5% CO₂. For oocyte aging study, the COCs were cultured in 10% FBS-TCM199 supplemented with or without 10 mM caffeine for 40hs. And then oocytes underwent in vitro fertilization using highly motile sperm recovered from frozen and than thawed bull semen. As a result normal cytoskeleton percentage of caffeine treatment group more than the aging group (67.57%±4.11 VS 44.61%±6.40) and no significantly different compared to control group. Aged oocytes derived from addition of caffeine to the in vitro maturation medium significantly increased the percentage of 2- cell that developed to the blastocyst stage compared to the aging group. Blastocysts derived from caffeine treatment group significantly increased the total cell number compare aging (90.44%±10.18 VS 67.88%±7.72). Apoptotic fragmenting of genomic DNA was measured in individual embryos using the TUNEL assay. Blastocyst derived from caffeine treatment group significantly decereased the apoptotic index compared to blastocyst derived from aging group. In conclusion, we inferred that the caffeine treatment during oocytes aging periode can improved the develpmental rate and quaility in bovine embryos developing in vitro.

These studies were carried out to improve the reproductive efficiency through embryos transfer of Hanwoo IVM/IVF embryos. Following routine IVM/IVF procedure, Oocytes and zygotes were cultured for 40 to 44 h in CR1aa medium with BSA. Then 2 to 8-cell embryos were removed the cumulus cell and were cultured in CR1aa medium containing 10% fetal bovine serum and 2.5 mM taurine in 5% O2 and 5% CO2 at 38.5℃. The fresh and frozen thawed embryos of the morulae and blastocysts cultured for 6 to 9 days in vitro were transferred into recipients. The pregnancy rates of the blastocyst produced for 6, 7, 8, and 9 days in in vitro culture were 41.9, 48.6, 57.9 and 47.4%, respectively. In the developmental stage, pregnancy rates of early blastocysts (41.7%), blastocysts (57.6%) and expanded blastocysts (50.0%) were higher than that of morulae stage (00.0%). Fresh and frozen embryos on the pregnancy rates were 48.9 and 50.0%, respectively. These results indicate that the pregnancy rate after transfer were affected on embryonic stage of in vitro embryos and in vitro culture periods.

본 연구는 1997년 IMF 이후 급격히 감소된 한우의 두수를 증가시키고, 최근 젖소 송아지 가격이 현저히 낮게 형성되고 있어 양축가의 사기가 떨어지고 있는데 가임 젖소 암소에 한우 수정란을 이식시켜 한우 송아지를 생산케 함으로서 농가 소득을 증대시키고 실시하였다. 1. 체외수정 후 6, 7, 8 및 9일째의 수정란을 이식하여 59.4%, 68.2%, 66.0% 및 100%의 수태율을 나타냈으며, 상실배기(20.0%) 수정란이 배반포기(61.1%∼69.

This study was conducted to examine the condition of in vitro culture system and the viability after embryo transfer of in vitro matured-in vitro fertilized (IVM-IVF) bovine embryos. The in vitro development to the blastocyst stage was enhanced by supplying bovine serum albumin(BSA) to co-culture medium with bovine oviduct epithelial tissue(BOET) compared with that in medium supplemented with fetal bovine serum(FBS) (41.2% vs. 26. 3%, P<0.05). After transfer of IVM-IVF blastocysts into the uterine horn of recipient females (Aberdeen Angus), one was pregnant to term and produced a head of male Korean native calf. These results confirm that the in vitro development of IVM-IVF bovine embryos is affected with different protein source in co-culture with BOET, and IVM-IVF embryos can develop to term after in vitro culture and embryo transfer.