This study was conducted to examine the effects of human follicular fluid and gonadotropin (FSH+HCG+rhEGF) on in vitro maturation, fertilization and development of human immature oocytes. Cumulus-oocyte complexes (COCs) were collected following for in vitro fertilization and embryo transfer (IVF-ET) cycles of the patients. At the time of oocytes collection, oocytes were classified into MII, MI and GV in accordance with their appearance (MII: Fully mature oocyte at metaphase II of meiosis; MI: Nearly mature oocytes at metaphase I of meiosis; GV: Immature oocytes at prophase I of meiosis). After controlled ovarian stimulation using gonadotropin(FSH) and human chorionic gonadotropin (HCG) in 70 ICSI cycles, 158 MI to MII matured oocytes were intracytoplasmic sperm injection (ICSI) h after in vitro culture and 553 MII oocytes were ICSI after denudation. The aspirated MI and GV oocytes were cultured in culture medium containing 10% (v/v) serum protein substitute (SPS), 10% (v/v) human follicular fluid (hFF) and 10% (v/v) serum protein substitute (SPS)+1 IU/ml FSH+10 IU/ml HCG+10 ng/ml recombinant human epidermal growth factor (rhEGF). The maturation rate of immature oocytes was similar among the three group. When maturation medium was supplemented with 10% SPS, 10% hFF or gonadotropins, the fertilization rate of in vitro matured oocytes was higher in 10% SPS (80.0%), but there was no statistical significance (78.2%; hFF, 76.9%; gonadotropin, p>0.05). The development rate of human embryos developed to cells were not significant difference in the medium containing SPS, hFF and gonadotropins (65.6%, 65.9% and 66.7%). The results of these study suggest that human follicular fluid and gonadotropins supplemented in the culture medium was not effected on the in vitro maturation, fertilization and development of human immature oocytes.

본 연구는 배양액의 종류에 따른 돼지 난자의 성숙 및 단위발생란의 배반포 형성율을 검토하였으며, 배양액의 삼투압과 발달 시기에 따른 배양액의 삼투압 변화가 돼지 단위발생란의 발달에 미치는 영향을 검토하였다. 실험 1에서 난포란을 NCSU-23 mWM 및 mKRB에 각각 성숙배양한 결과 성숙률은 62.1~71.3%로 배양액에 따른 차이가 없었다. 실험 2에서는 각각의 배양액으로 성숙된 난자를 활성화 처리 후 동일한 배양액으로 6일간 배양하여 발달율을 검토한 결과, 배반포 발육율은 NCSU-23에 배양 시 22.9%로 타 그룹(0~0.6%)보다 유의적으로 높게 나타났다(P<0.05). 실험 3에서는 단위발생란을 NaCl 안에 의해 256, 280 및 300 mOsmol(mOsm)로 조정한 NCSU-23에 6일간 배양한 결과, 배반포 발육율은 11.0~14.4%로 실험군 간에 유의적인 차이는 없었으나 삼투압이 낮을수록 난자의 fragment 비율이 높게 나타났다(P<0.05). 실험 4에서는 단위발생란을 삼투압이 조정된 세 종류의 NCSU-23에 48시간 배양한 후 삼투압이 높거나 낮은 NCSU-23으로 옮겨 4일간 추가 배양한 결과 배반포 형성율은 배양 48시간 후에 배양액의 삼투압을 낮춰 주었을 때(21.0%)가 높여 주었을 때 (11.8%) 보다 유의적으로 높게 나타났다(P<0.05).본 실험의 결과는 돼지 단위발생란의 발육이 배양액의 종류 및 삼투압에 의해 영향을 받으며, 배양액의 삼투압은 돼지 단위발생란의 발육 단계별로 영향을 주어, 초기에는 높은 삼투압의 배양액에서 배양하고 일정 시간 후 낮은 삼투압의 배양액으로 배양함으로써 발육이 증진될 수 있음을 시사한다.

Supplementation of maturation medium with additional granulosa cells has beneficial effect on in vitro maturation of bovine follicular oocytes and their subsequent cleavage and development in vitro. However, maturation system using granulosa cells have some disadvantages that collection of granulosa cells is cumbersome and metabolic activity of the cells is variable according to ovarian cycle or follicular size. We hypothesized that bovine immsture oocytes matured without granulosa cell coculture can fertilize and develop normally if the medium volume per oocyte is reduced during in vitro maturation. Immature oocytes were matured for 24 hours in a TCM199 containing 10% fetal calf serum, anterior pitultary hormone (0.02 AU /ml Antrinⓡ) and estradiol with or without granulosa cells in vitro. In Group 1, 35 to 40 oocytes were matured in a well of 4-well plastic dish containing 500 l of maturation medium and granulosa cells, and 9 to 10 oocytes were matured in a 50-l drop of maturation medium without granulosa cells in Group 2. After maturation, oocytes were coincubated with sperm for 30 hours in a modified Tyrode's medium (IVF). Inseminated oocytes were cultured in a microdrop (30 l) of a synthetic oviduct fluld medium (SOFM) containing BSA, Minimum Essential Medium essential and non-essential amino acids for 9 days. As a preliminary experiment, we investigated the beneficial effect of granulosa cells during maturation on subsequent cleavage and development using the same type of culturedishes (4-well dish). Granulosa cells could not increase embryo cleavage after fertilization but significantly improved (p<0.05) embryo development to expanding blastocyst (Table1 and 2). In Group 1, 68 and 80% of inseminated oocytes have cleaved at 30 hours and 2 days after IVF, respectively, which is similar (p>0.05) to the result of Group 2 (69% at 30 hours and 78% at 2 days after IVF). The oocytes in Group 2 showed 21 and 11% of developmental rates to expanding and hatching blastocysts, respectively, which was not significantly different (p>0.05) from those (20 and 10%, respectively) of oocytes in Group 1. In conclusion, it has been clarified that a microdrop culture system without granulosa cells for in vitro maturation can support bovine embryonic development to blastocyst in vitro as readily as a granulosa cell coculture system.

This study was conducted to improve the in vitro maturation(JVM), in vitro fertilization (IVF) and in vitro developmental capacity of oocytes derived from slaughtered Korean native cattle. The recoverd oocytes, obtained from a local slaughter house, were used completely surrounded by at least 3 layers of cumulus cells in combination with a homogeneous cytoplasmic pigmentation. In vitro maturation was induced in TCM-199 or Ham's F-10 supplemented with LH(1O g/rnl), FSH(35 g/ml), estradiol-17(1 g/ml) at 39 under 5% in air for 24 hours. Sperm from caudal epididyrnis and previously matured cumulus-oocytes complexes were cultured for 24 hours in 100 l droplets of fertilization media under paraffin oil. The zygotes were cultured with media(TCM-199 with bovine oviductal epithelial cells or CRlaa) for 7 to 10 days. The cleavage rate of IVM-IVF oocytes was significantly (P<0.05) higher following maturation using Ham's F-10 (59.9%) than TCM-199 (51.6%). Development to the blastocysts among cleaved embryos was not signficantly different between maturation media: Ham's F-10 (16.0%) and TCM-199(11.9%). However, the hatching rate was affected significantly (P<0.05) on rnaturation media as 62.9% in Ham's F-10, compared with 41.2% in TCM-199. The cleavage rate of IVM-IVF oocytes was significantly (P<0.05) higher following IVF using m-TALP medium (80.1%) than BO medium (51.6%). The percentage of in vitro developed blastocysts among cleaved embryos was not signficantly different between fertimization media: BO (11.7%) and m-TALP (17.6%). The cleavage and the developmental rate to the blastocysts after IVF in m-TALP or condition medium(CM) with or without oviduct epithelial cell monolayer(OECM) was similar(80.1% and 17.6% in m-TALP, 83.8% and 19.4% in M-TALP with OECM. 82.9% and 18.9% in CM, 87.6% and 16.0% in CM with OECM, respectively). The percentage of in vitro developed blastocysts among cleaved embryos was significantly (P<0.05) higher in TCM-199 medium co-cul tured with bovine oviduatal epithelial cell monolayers(35.2%) than CRlaa medium(1.9%). These results stggest that the most transferable IVF embryos could be produced from Ham's F-10, m-TALP and TCM-199 medium with bovine oviductal epithelial cell monolayers for IVM, IVF and IVC, respectively.