The brilliant cresyl blue (BCB) has been used to select the developmental competent oocytes in pigs, goats and cows. Growing oocytes have a higher level of active glucose-6-phosphate dehydrogenase(G6PDH) compare to mature oocytes and are rarely stained compared to mature oocytes, because G6PDH converts BCB to colorless. First polar body extrusion regard as a guideline of meoisis completion. Selection of polar body extrude oocyte is more developmental competent to blastocyst than unselected. This study was conducted to compare the BCB test to the polar body extrusion on selection of developmental competent porcine oocytes for the production of blastocyst. Cumulus-Oocytes complex were exposed to 26uM BCB stain diluted in NCSU-23 for 90 min. There was no significant difference embryo development to blastocysts between BCB treated and not treated(19.58±1.99 vs 18.75±2.27 %), which means there was no detrimental effect of BCB exposure to oocytes. Normal fertilization is not differed among treatment groups from 70.0 to 78.4% development to blastocyst, beside polyspermy did not. To compare two different selection methods, BCB test and polar body extrusion, evaluate the developmental competent of IVP embryos. BCB+PB+(blue stained and polar body extruded, 20.71±0.45%) and BCB－PB+(colorless and polar body extruded, 20.04±1.29%) groups are significantly (p<0.05) higher developed than those of BCB+PB－(blue stained and no polar body, 13.24±0.73%) and BCB－PB－(colorless and no poladbody, 7.25±0.77%). These results showed that selection of polar body extruded oocytes method is more efficient than that of BCB test.

본 연구는 돼지 수정란의 체외 성숙 및 체외 배양액의 retinol 첨가 효과를 규명하기 위하여 체외 성숙 및 체외 배양액에 retinol을 첨가하여 수정란의 체외 발달에 미치는 영향을 구명하고자 수행되었다. 체외 성숙 배양액에 retinol을 첨가한 결과 성숙율은 으로 각 처리구 간의 유의적인 차이가 없었다(p>0.05). 체외 수정 후 배반포로의 발달율은 첨가구에서 의 발달율을 나타내어 타 처리구에 비하여 유의적으로(p<0.05) 높게 나타났으며,

본 연구는 아미노산의 첨가가 돼지 수정란의 체외 발달율에 미치는 영향을 구명하고자 PEF가 함유된 NCSU-23을 기본배지로 체외성숙 및 체외배양액을 조성한 후 EA(Essential amino acid), NA(Non-essential amino acid) 및 EANA(EA+ NA)를 첨가하여 체외성숙, 체외수정 및 체외발달에 미치는 영향을 조사하였다. 체외성숙 배지에 아미노산을 첨가한 결과 MH 단계까지의 체외성숙율은 NA 첨가군이 83.3%로 대조구 70.0%에 비하여 유의적으로(p<0.05) 높았다. 그러나 체외 수정 이후의 배 발달율과 수정율에서는 아미노산 첨가군과 무첨가군 사이에 유의적인 차이는 없었다. 체외배양액에 아미노산을 첨가한 후 배반포의 내부세포괴(ICM) 세포와 영양배엽(TE) 세포의 발달에 미치는 영향을 조사한 결과, ICM에서는 유의차를 발견할 수 없었으나 TE 세포는 EANA 처리구가 18.0±0.5개로 대조구 16.09±0.56개에 비해 유의적(p<0.05)으로 많았다. 총세포수에서도 EANA 처리구가 50.0±1.0개로 대조구 44.2±1.1개보다 유의적(p<0.05)으로 많았다. 이상의 결과를 종합할 때, 돼지의 체외수정란 생상에 있어서 아미노산의 첨가는 배반포로의 발달율에는 영향을 미치지 못하였으나 체외성숙율을 높이고 배반포의 세포수 향상에 도움을 주는 것으로 판단된다. 특히, 영양배엽(W) 세포의 발달율이 높은 것으로 보아 아미노산의 첨가는 돼지수정란의 착상에 도움을 줄 것이라 기대된다.

도축장에서 채취한 돼지난자를 직경별로 간격으로 나누어, 난자의 크기에 따른 체외성숙과 발육능을 구명코자 체외성숙과 체외수정 후의 배 발달율을 조사하였다. 채취한 난자의 투명대를 제외한 평균직경은 이었으며, 직경별 분포는 < 105, 105~110, 110~115,115~120, 120~125, <이 각각 3.0, 11.0, 31.2, 41.5, 13.0 및 0.4%로 72.7%가 110부터 사이였다. 체외성숙율에 있어서 직경 미만난자는 66.7%인 반면

To improve the efficiency of production of cloned embryos and animals by nuclear transplantation in the rabbit, the effect of cell cycle of donor nuclei and type of recipient cytoplasm on the in vitro developmental potential and production efficiency of offspring was determined. The embryos of 16-cell stage were collected from the mated does at 48h post-hCG injection and they were synchronized to G phase of 32-cell stage. The oocytes collected at 14h post-hCG injection were freed from cumulus cells and then enucleated. One group of the enucleated cytoplasms was activated by electrical stimulation prior to injection of donor nucleus, and the other group was not pre-activated. The separated Gphase blastomeres of 32-cell stage embryos were injected into the perivitelline space of recipient cytoplasms. After culture for 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation and the fused nuclear transplant embryos were co-cultured for 120h and the nuclear transplant embryos developed to blastocyst stage were stained with Hoechst 33342 dye and their blastomeres were counted. Some of the nuclear transplant embryos developed in vitro to 2- to 4-cell stage were transferred into the oviducts of synchronized recipient does. The electrofusion rate was similar between the types of donor nuclei and recipient cytoplasms used. However, the nuclear transplant embryos using G phase donor nuclei were developed to blastocyst at higher rate(60.3%) than those using S phase ones(24.7%). Also, when non-preactivated oocytes were used as recipient cytplasms, the develop-mental rates of nuclear transplant embryos to blastocysts were significantly(P< 0.05) higher(57.1%) than those using preactivated ones(20.8%). The cell counts of nuclear transplant embryos developed to blastosyst stage were increased signficantly(P<0.05) more in the non-preactivated recipient cytoplasm(163.7 cells), as compared whit the preactivated recipient cytoplasm(85.4 cells), A total of 49 nuclear transplant embryos were tranferrid into 5 recipient does, of which two offsprings were produced from a foster mother 31 days after embryo transfer. these results showed that the blastomeres of G1 phase and non-preactivated oocytes might be utillzed efficiently as donor nuclei and recipient cytoplasms in the nuclear transplant procedure, thought the offspring production remained still low.

To improve the efficiency of in vitro production of embryos with follicular oocytes in Korean Native cows, the recovery rates, in vitro maturation, fertilization and development, and the time required for collecting and processing oocytes by aspiration with or without slicing were evaluated comparatively. The ovaries were obtained from a local abattoir and placed in physiological saline at 25~28 and brought to the laboratory within 3 hrs. The oocytes were collected by aspiration of follicles(2~6mm) with or without slicing ovaries after aspiration, and classified into Grade I, Grade II, Denuded, Expanded oocytes by the morphology of cumulus cells attached and the homogeneity of cytoplasmic granules. Also the time required for each step of collecting and processing oocytes were measured. The cumulus cells were removed in some Grade I oocytes to measure their size and nuclear configuration before and after in vitro maturation. The Grade I oocytes were matured in vitro(IVM) for 24 hrs. in TGM-199 supplemented with 35g /ml FSH, 10g /ml LH, 1 g /ml at 39 under 5% C02 in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24hrs. and then the zygotes were cocultured in vitro (IVC) with bovine oviductal epithelial cells for 10 days. The results obtained were as follows: The number of oocytes recovered per ovary was averaged 6.6 by aspiration and 11.2 by slicing post aspiration, which summed to 17.8. The number of Grade I oocytes recovered per ovary was averaged 3.1 by aspiration and 3.6 by slicing, which summed to 6.7. The percentage of Grade I to total oocytes recovered was significantly(P<0.05) higher as 48.0 % in aspiration than 31.6% in slicing post aspiration. The time requlred for recovering a Grade I oocyte by aspiration and slicing was 1.1 and 2.5 min, respectively. The mean diameter of Grade I oocytes by aspiration and slicing was similar as 148.7 and 151.5m, respectively. The percentage of Metaphase II stage oocytes after IVM for 24 hours was significantly (P

The purposes of this study were to produce cloned rabbit embryos and offsprings by nuclear transplantation(NT) using in vitro matured oocytes as nuclear recipient cytoplasm and to determine the effect of frozen nuclei donor embryos on the production efficiency of cloned embryos. The 8cell embryos were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline containing 10% fetal calf serum(FCS) at 40 hours after hGG injection. A portion of collected embryos were preserved at 4 for 24 hours and a portion of them were frozen by vitrification method. The embryos used for donor nuclei were synchronized in the phase of Gi /S transition. The in vitro matured oocytes were used as recipient cytoplasm following removing the nucleus and the first polar body. The synchronized blastomeres from fresh, cooled or frozen embryos were injected into the enucleated oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 sec at 1.0 W /cm in 0.28 M mannitol solution. The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39 in a 5% incubator. Following in vitro culture of the NT embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The nuclear transplant embryos developed in vitro to 2- to 4-cell stage were transferred into the oviducts of synchronized recipient does. The results obtained were summarized as follows: 1. The fusion rates of the blastomeres from fresh, cooled and frozen embryos with the in vitro matured and enucleated oocytes were 100, 95.8 and 64, 3%, respectively. 2. Development in vitro to blastocyst was significantly(p<0.05) different between the cloned embryos with the blastomeres from fresh, cooled or frozen embryos as 39.0, 20. 9 and 15.7%, respectively. 3. The mean numbers of cell cycle per day during in vitro culture of cloned embryos blastomeres from fresh, cooled or frozen embryos was 1.31, 1.29 and 1.16, respectively. 4. A total of 77 nuclear transplant embryos were transferred into 6 recipient does, of which two offsprings were produced from a foster mother 31 days after embryo transfer.

The suitable electric stimulation is essential for activation and fusion of oocytes before or after nuclear transplantation The present study was undertaken to determine the optirnal condition for the parthenogenetic activation of in vitro rnatured(IVM) bovine oocytes by electric stimulation. Different direct current(DC) electric voltage of 1.0, 1.5 and 2.0 kV/cm and pulse duration of 30, 60 and 120 sec were applied to the JVM nocytes in 0.3 M mannitol solution containing each 100 M CaCl and MgCl. IVM occytes at 24, 28 and 32 hours Post-maturation(hpm) were also electrically stimulated at 1.5 kV /cm, for 60 sec. The stimulated nocytes were then co-cultured in TCM-199 solution containing 10% fetal calf serum with bovine oviductal epithelial cells for 7~9 days in a 5% incubator at 39 ~ Their activation and in vitro development to morula and blastocyst were assessed under an inverted microscope. The higher activation rates 62.8 and 63.4% and in vitro de- velopment rates to morula and blastocyst 5.1 and 10.9% were shown in the oocytes stimulated at the voltage of 1.0 and 1.5 kV/cm than 2.0 kV/cm, respectively. No signifi- cantly(P<0.05) different activation rate was shown in JVM oocytes stimulated for 30, 60 and 120 sec, but developmental rates to morula and blastocyst was significantly(P<0.05) higher in the oocytes stimulated for 30 sec(6~3%) and 60 sec(10~0%) than 120 sec(0~ 0%). The aged oocytes at 28 and 30 hpm showed significantly(P<0.05) higher activation rates(72~7 and 79.7%) than the oocytes at 24 hpm(50~9%)~ Also, their developmental rates to morula and blastocyst were significantly(P<0.05) higher in the nocytes at 28(14.3%) and 32 hpm(15.9%) than 24 hpm(3.6%). From these results, it can be suggested that the optimal electric stimulation for IVM bovine occytes is a DC voltage between 1.0 and 1.5 kV/cm, pulse duration of 30 or 60 sec, and the optimal age of IVM oocytes for electric activation is at 32 hpm.

This experiment was investigated the effect of cell stage of embryos at 48 hours post-insemination On in vitro development of IVF embryos. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28 and transported to laboratorty within 2 hrs. The oocytes were matured in vitro(IVM) for 24 hrs. in TGM-199 supplemented with 35 g/ FSH, 10 g/ LH, 1 g/ estradiol-17 and granulosa cells at 39 under 5% in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs. , and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. At 48 hrs. post-insemination, the embryos were classfied into 5 to 8-cell, 3 to 4-cell or 2-cell stage and then were co-cultured in vitro(IVC) with bovine oviductal epithelial cells until the embyos reached blastocyst stage. Embryos developed to blastocyst stage were stained with Hoechst 33342 for cell counting. The embryos of 5 to 8-cell stage at 48 hrs. post-insemination with grade I oocytes were significantly (P<0.05) better developed to blastocysts(63.0%) than 3 to 4-cell(42.0%) and 2-cell stage(2.7%) embryos which delayed in the early cleavage, and those embryos cleaved faster in the very early stage seemed to develop to blastocysts earlier. These results indicate that the embryos cleaved faster at 48 hrs. post-insemination seemed to develop to blastocysts earlier.

This experiment was investigated the effect of presence of granulosa cells from follicles of different size on bovine oocyte maturation, cleavage and development to late stage. The nuclear and cytoplasmic maturation of oocytes in the IVM-IVF system are critical for subsequent embryo development. Granulosa cells when the co-cultured with oocytes may interact with cumulus-oocytes complexes and influence the development competence of the oocytes. Granulosa cells from medium (2~6 mm) and large(>1O mm) size follicles were recovered by aspiration, washed 3 times by centrifugation at 500 x g for 5 min. and used for co-culture at a concentration of 2~3 x 106 cells/mi. The oocytes were matured in vitro (IVM) for 24 hrs. in TCM-199 supplemented with 35 g/ml FSH, 10 g/ml LH, 1 g/ml estradiol-17 and granulosa cells at 39 under 5% in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (I VC) with bovine oviductal epithelial cells for 7 to 9 days. The assessment of maturation revealed that Grade J oocytes showed significantly(P

To investigate the effect of extracellular matrix proteins on the in vitro development of ethanol-induced parthenogenetic eggs of ICR strain mice, those were cultured in vitro in fibronectin, gelatin, or collagen precoated culture dishes containing 1.5 ml of NaH-C03-BMOC-3 medium at 37 for 96 hrs. under the atmosphere of 5% and 95% air. Fibronectin, gelatin, or collagen significantly(P1.4, 45.4i1.4, and 44.8O.9, respectively. And the diameter of those eggs ranged 104.61.9, 102.82.3, and 103.4O.8 m, respectively.

To investigate the effect of EDTA on the in vitro development of blastomeres isolated from 2, 4, and 8-cell embryos(termed 1 /2, 1 /4 and 1 /8 blastomeres, respectively) of ICR strain mice, those were cultured in vitro in 35 mm culture dishes containing NaHCO-BMOC-3 medium supplemented with 10, 50, 100, or 500 M of EDTA at 37 for 72hrs. under the atmosphere of 5% and 95% air. EDTA supplementation of 10, 50, or 100 M to medium significantly(P<0.01) increased blastocyst formation rate compared with controls in 1 /2(58.3, 63.7, and 61.3% vs 21.6%), 1 /4(54.7, 57.5 and 62.2% vs. 2L3%), and 1 /8 blastomeres(46.2, 48.7, and 57.7% vs. 19.1%). Whereas, it was significantly(P<0.01) decreased to 4.5, 2.3, and 2.0% for 1 /2, 1 /4 and 1 /8 blastomeres, respectively by the EDTA supplementation of 500 M Both the nuclear number(P<0.05) and diameter of blastocysts(P<0.01) developed from balstomeres were significantly affected by the origin of blastomeres. The nuclear number of blastocysrs developed from 1/2, 1/4, and 1/8 blastomeres ranged 28.3i1.3, 24.18i1.2, and 19.840.9, respectively. And the diameter of those blastocysts was 87.21.1, 56.40.9, and 39.20.8 M, respectively.

The post-thaw survival of mouse embryos of the various developmental stages was determined after cryopreservation by vitrification in a solution containing ethylene glycol, Ficoll and sucrose (EFS). All the embryos were equilibrated for 2 minutes just prior to freezing. The number of blastomeres during in vitro development was counted by nuclei higher rates of post-thaw survival were obtained from the embryos of 2-cell(92.2%), 8-cell(77.2%) or morula stage(90.0%) than those of blastocyst stage(62.7%). The number of blastomeres per embryo following in vitro culture for 24 hours was significantly(P<0.05) smaller as 66.0f22.3 in vitrified and thawed morulae than fresh morulae(91.712.2).