This study was experimented that developmental effects of bovine in vitro fertilized embryos by coculture system and supplementation of energy materials into simple media. With the ovaries from slaughter house in vitro maturation by 24h, in vitro fertilization was performed with sperms collected by Percoll gradient method. Fertilized embryos were cocultured in 15% FCS+CZB medium with BOEC(bovine oviductal epithelial cell), GCM (granulosa cell monolayer) and MEFC(mouse embryonic fihrohlast cell). And also in this study, there was trying to improve the early developmental rate of embryos by addition of concentration-controlled Na-pyruvate, D-glucose which were used as energy sources into CZB medium. In vitro developmental rate was confirmed by the cleavage rate of 48h post-IVF and the embryo development rate at 240h culture. In the coculture system BOEC had 20.0% of blastocysts rate, which was higher than that of other coculture systems. To determine the optimum concentration for early embryo developmental rate rapidly, through the gradient of concentrations of Na-pyruvate and D-glucose, we focused on the cleavage rate at 48h and blastocysts rate at 240h. In case of Na-pyruvate, cleavage rate and developmental rate over 3-cell were lower at the concentration of 1.OOrnM than the other treatment concentrations, otherwise the blastocysts rate was higher as 23.2% than the others. That result showed that as like reported group which had higher develop-mental rate over 3-cell was also higher to the blastocysts rate. In case of D-glucose, there was no effects through the concentration changes. It was the result of this study for which the use of BOEC coculture system and 1.OOmM Na-pyruvate as an energy source had an effect upon embryo development.

The experiments reported here take advantage of the large number of in vitro matured and in vitro fertilized(IVM /IVF) bovine oocytes which can be produced, permitting the design of controlled experiments to establish a simple defined medium for the study of early embryo requirements. A total of 1,386 IVM /IVF oocytes were used to compare a simple defined medium(KSOM) with more complex culture conditions used successfully for culture of bovine embryos but do not permit study of specific requirements. All experiments were extensively replicated factorials. In Experiment 1, KSOM was superior to Menezo B medium in producing morulae plus blastocysts from IVM /IVF oocytes(33 vs 20%, P<0.()5). The yield of morulae plus blastocysts with KSOM was 22% and with BRLC added was 30%. In Experiment 2, (a 2x2 factorial of KSOM with or without BRLC and 0, 1 ng /ml of platelet derived growth factor, PDGF) more morulae plus blastocysts (40%) were produced in KSOM-BRLC co-culture containing 1 ng /ml PDGF than in the control KSOM(12%). In Experiment 3, there was no dose response when 0, 1 and 5 ng /ml of PDGF were added. The results with simple defined KSOM medium are sufficiently promising to indicate that specific requirements of the embryo may be examined in future studies with KSOM as a base.

This experiment was carried out to study the determination of survival of vitrified and thawed mammal follicular oocytes by FDA-test. Oocytes were divided into 3 groups according to attachment of cumulus cell. Group A oocytes were tightly surrounded by cumulus cell, group B oocytes were partially surrounded by cumulus cell, and group C oocytes were poorly surrounded by cumulus cell. Vitrification solution developed by our previous study (Kim et al, 1992) which consisted of permeable agent (20 % glycerol + 10 % ethylene glycol) and nonpermeable agent (30 % Ficoll + 10 % sucrose). Oocytes (7~10) loaded into 0.25 ml straw after 10 min equilibration were plunged into liquid nitrogen (- 196) directly. The FDA-score of vitrified and thawed group A oocytes was higher in rat (4.2) than in rabbit (3.9), cow (3.8), mouse (3.4) and porcine (2.4), however that of cumulus cell was higher in rabbit (4.7) than in rat (4.1), cow (2.9), porcine (2.6) and mouse (1.4). The FDA-score of vitrified and thawed group B oocytes were 3.1 (cow), 2.9 (rabbit), 2.9 (mouse), 2.6 (rat) and 2.5 (porcine), respectively. However that of cumulus cell was higher in rabbit (3.7) than in porcine (2.6), rat (2.3), cow (1.7) and mouse (0.3). The FDA-score of vitrified and thawed group C oocytes was higher in mouse (4.1) than in cow (2.9), rabbit (2.6), rat (1.3) and porcine (1.1). As shown in the above results, The survival rates of oocytes were higher in group A than in group B and C except in mouse and cow. These results suggest that the survival of cumulus cell as well as follicular oocytes can be reliably judged by their fluorescence with FDA-test.

This study was performed to establish the condition and the methods for the techniques of insertion the isolated blastomere cells into cytoplasm, in order to research the develop-mental ability of bovine embryo blastomere cells in vitro produced. After 24h in vitro ovary maturation with the ovaries from a slaughter house, in vitro fertilization was performed to the vital sperms which their mobility were decided by percoll gradient method, with 2~8 cell stage embryos, the blastomeres were isolated in +. +-free PBS, and following that embedded into agar and alginate solution, respectively. The rates of in vitro develop-ment are as follows ; in agar embedded 11 among 120(9.2%) 1 /2~1 /3 blastomers cleaved and 6 among 93(6.5%) 1 /4~1 /8 blastomeres cleaved. In sodium alginate-embedded 14 among 84(16.7%) 1 /2~1 /3 blastomeres cleaved and 6 among 85(7.1%) 1 /4~1 /8 blastomeres cleaved. In case of Na-alginate, the rate of the cells were better than those of agar. The results suggest that the techniques for embeeding the isolated blastomeres into gel may help cloning of bovine early embryo without nuclear transplantation.

10% ethanol에 의한 처녀발생유가 및 체외수정된 돼지 난포란을 CZB와 CRlaa 에서 배양하여 배발달율을 조사하였다. 또한 CZB에 각기 다른 농도의 cholesterol (0g/mL, 2g/mL, 5g/mL, 10g/mL)을 첨가한 후 체외수정된 돼지 난포란을 배양하여 배발달률을 조사하였다. CZB 구는 BOEC와 공배양하였다. 처녀발생유가 48시간 후 2~8세포기로 발달한 난자의 비율은 CZB 구가 32.2%, CRlaa구가 16.8%였으며

Essential and non-essential amino acids supplemented to culture medium stimulate mammalian embryo development in vitro. Amino acids such as glycine, taurine and alanine are concentrated in the lumen of oviduct and uterus and it can he thought that these amino acids may have physiological role on fertilization and embryo development. Our aim of this experiment was to investigate the effects of essential and non-essential amino acids, taurine or glycine supplemented to fertilization medium on the cleavage and subsequent in vitro development of bovine oocytes matured and fertilized in vitro. Immature oocytes were obtained from slaughtered Holstein cows and heifers and matured in TCM199 containing 10% fetal calf serum, 2.5 g /mL of FSH and LH and 1 g / mL of estradiol with granulosa cells in vitro. After maturation, oocytes were coincubated with sperm in fertilization medium supplemented with Minimum Essential Medium (MEM) essential and non-essential amino acids, taurine (3.75 mM) or glycine (10 mM) for 30 hours in vitro. Inseminated oocytes were cultured in synthetic oviduct fluid medium (SOEM) containing MEM essential, non-essential amino acids and 1 mM glutarnine up to 8 days after fertilization.Supplementation of fertilization medium with MEM essential and non-essential amino acids lowered significantly (p<0.05 and p<0.001) the cleavage rate after 30 hours of IVF (53.3%) and at Day 3 (62.7%: Day 0: the day of I VF) compared to control (64.3% and 77.3%, respectively). Subsequent developmental rates to morulae (Mo) and expanding blastocysts (ExBL) also significantly decreased (p<0.001 and p<0.05 for Mo and ExBL) when oocytes were coincubated with sperm in the medium containing MEM amino acids. Taurine added to fertilization medium have not increased the cleavage rate over the control, whereas glycine showed significantly lower (p<0.01) cleavage rate at Day 3 than that of taurine, but there was no significant difference in the developmental rates to Mo and ExBL of bovine embryos irrespective of the supplementation of taurine or glycine to fertilization medium. In conclusion, supplementation of fertilization medium with essential and non-essential amino acids, taurine or glycine has no beneficial effect on in vitro cleavage and development of bovine oocytes matured and fertilization in vitro.

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% in air vs. 5% , 5% , 90% ). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% in air or 5% COi, 5% , 90% . Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% , 5% , 90% (24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% , 5% , 90% . In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% , 5% , 90% . In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

This research was conducted to obtain the basic information on the cell block phenomenon occuring during early development in vitro of mouse embryos. Early embryos were recovered at 3h post-hGG injection(hph). Various chemicals (EDTA, EGTA, DTPA, MA and PRA) were tested to examine the effects of them on the overcoming the 2-cell block phenomenon. One hundreds M of the chelating agents were added to the M16 medium containing embryos. The treated embryos were worked and transferd to fresh M16 medium after 1, 3, 6 and 12h of treatment. Development was examined at 58 and l2Oph injection, respectively. 44.7~68.9% of the treated embryos developed to 4-cell stages at 58hph. Only 17.6~60.3% of the embyos developed upto blastocyst at l20hph. Whereas control embryos showed slightly lower development in M16 medium alone (38.9~42.4%, 4-cell and 3.8~65.5%, blastocyst). Three mitogenic agents were tested. 51.6~63.8% and 43.4~48.1% of embryos developed up to 2-cell and blastocyst stage, respectively when treated in 5 g PHA-M Imi for 5 min, 1, 3 and 6h subsequently cultured in fresh M16 medium. Control embryos only showed 38.8% for 4cell and 5.9% fo blastocyst at 58 and l2Ohph, respectively. 100M PMA was also beneficial for the 2-cell block. Showing better development them that of control (42.4 vs 57.9~59.4% 4cell and 5.9 vs 25.0~55.6% blastocyst, respectively. However 1M butyric acid was toxic to early embryos, thus arresting further development. These result indicate that either chelating or mitogenic agents could be used to overcome the "in vitro 2-cell block" occuring during early development in vitro of ICR embryosCR embryos

This study evaluated the influence of cell stage of donor nucleus on nuclear injection, electrofusion and in vitro development in the rabbit to improve the efficiency of nuclear transplantation in the rabbit. The embryos of 8-, 16- and 32-cell stage were collected from the mated does by flushing viducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FGS) at 44, 54 and 60 hours after hCG injection. The blastorneres separated from these embryos were used as donor nucleus. The ovulated oocytes collected at 14 hours after hCG injection were used as recipient cytoplasm following removing the nucleus and the first polar body. The separated blastomeres were injected into the enucleated oocytes by micromanipulation and were electrofused in 0.28 M mannitol solution at 1.5 kV /cm, 60 sec for three times. The fused oocytes were cocultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FGS for 72~120 hours at 39 in a 5% incubator. The cultured nuclear transplant embryos were stained with Hoechst 33342 solution and the number of cells were counted by fluorescence microscopy. The successful injection rate of 8-, 16- and 32-cell-stageblastomeres into enucleated oocytes was 86.7, 91.0 and 93.9%, respectively. The electrofusion rate of 8-, 16- and 32-cell-stage blastomeres with enucleated oocytes was 93.3,89.3 and 79.0%, respectively. Development of blastomeres to blastocyst was similar with 8-,16- and 32-cell-stage donor nuclei(26.2, 25.8 and 26.6%, respectively, P<0.05). The mean number of cell cycle per day during in vitro culture in nuclear transplant embryos which received 8-, 16- and 32-cell- stage nuclei was 1.87, 1.81 and 1.43, respectively.

This study was carried out to investigate the inhibiting or promoting effect of fetal bovine serum fractionated by the molecular weight and to examine the effect of reconstruction of serum fractions on the development of 1- and 2-cell mouse embryos fertilized in vitro (IVEE) . The serum was separated by ultrafiltration or gel filtration methods and added in m-KRB medium for culture of IVFE. The developemental ability(cavitation and hatching) of embryos following culture of day 4 and 6 was compared among fractions. Small molecular weight fraction( <3 kDa) significantly inhibited the development of 1-and 2-cell IVFE to the blastocyst stages, compared with other fractions. One-cell IVFE were more sensitively damaged than 2-cell embryos by that fraction and arrested mainly at 2~4 cell stages. Moreover, small amount(<3%,v /v) of the inhibiting fraction acted even with protein rich fraction(100~30 kDa) and arrested the embryonic development. On the other hand, 100~30 kDa fraction promoted the embryonic development and no inhibiting effect was observed at the level of 50%(v /v) in culture medium In the experiment of gel filtraton, =30 kDa fraction showed the highest promoting effect on the embryonic development, but <4 kDa fraction inhibited significantly the development. These results suggest that serum contains not only small molecular weight inhibitory component(s) but also promoting one rather than albumin on embryonic development. And serum can be more effectively used in the IVF program after removal of inhibitory component(s) by one of above separation methods.