• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.151-156
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• 1991

Bovine in vitro fertilization experiment was carried out using ovary-derived follicular oocytes and frozen-thawed spermatozoa to determine the optimal preincubation time of spermatozoa and the insemination time for successful in vitro fertilization rate. The possibility of parthenogenetic cell division of unfertilized oocytes during culture without spermatozoa was also examined. There was no significant (p>0.05) difference in percent ratio of embryos developed to blastocyst stage between 0 and 3 h preincubation times of spermatozoa, showing a tendency to have higher percentage for 0 h of preincubation time. The 6 h insemination time seemed to be better for producing higher percentage of ova cleavage compared with those of 1 and 3 h treatments. Approximately 10% of unfertilized oocytes divided into 2 to 4-cell stage, and some of them cleaved to 5 up to 8-cells. The results obtained from this study suggested that 0 h of sperm preincubation time and 6 h of insemination time would be suitable for producing better in vitro fertilization rate of bovine oocytes. It is also likely that unfertilized bovine oocytes probably cleave to some cell stages with irregular divisions of the cells. On the one hand, considerable variation was also found in spermatozoa function among individual bulls.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.757-762
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• 1993

The ovaries of Korean Native cows or heifers were obtained from an abattoir and kept on 20 to $25^{\circ}C$ and transported to laboratory within 2 hrs. The follicular oocystes were collected from 2~6mm follicles in diameter and classified into 3 grades by the morphology of cumulus cells attached. The oocytes were matured in vitro(IVM) for 24 hrs. in TCM-199 supplemented with $23{\mu}g/ml$ FSH, $10{\mu}g/ml$ LH, $1{\mu}g/ml$ estradio-17 ${\beta}$ and granulosa cells at $39^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro(IVF) by incubation for 12 hrs. of epididymal spermatozoa pretreated with heparin, and then the zygotes were co-cultured in vitro(IVC) with oviductal epithelial cells for 7 to 9 days. Assessment of maturation revealed that 93.0%(147/158) of grade I oocytes had expanded of cumulus cells, which was higher(p<0.05) than the 79.4%(85/107) of grade II oocytes. Compared to epididymal sperm(32.9%), the insemination with frozen and thawed sperm resulted in slightly lower(20.5%), but not significant, development to morulae and blastocysts from grade I oocytes. Co-culture of bovine IVF embryos with oviductal epithelial cells improved the development to transferable embryos significantly(38.1%), compared to co-culture with granulosa cells(20.0%). When VF bovine embryos were vitrified at blastocyst, the post-thaw survival rate was obtained higher resulf for 1 min. equilibration time(82.6%) or 2 min.(73.9%) than 3 min.(18.2%) in EFS solution.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.111-117
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• 1996

This experiment was designed to evaluate the effect of transforming growth factor-$\beta$ (TGF-$\beta$) and insulin-like growth factor-I (IGF-I) in bovine oocyte maturation in the presence or absence of serum on subsequent fertilization and embryo development. In addition, various concent rations of these growth factors were evaluated for the ability to promote development of eight-cell stage embryos to the blastocyst stage. Cumulus-oocyte complexes were recovered from 2 to 6 mm follicles obtained from slaughterhouse ovaries and cultured at 38.5$^{\circ}C$ for 24 hours in TCM-199 (HEPES Modification) with or with out 20 % fetal bovine serum (FBS) to which the following growth factors were added TGF$\beta$ IGF-l or TGF $\beta$ + IGF-I, all at 10 ng/ml each. The matured oocytes were fertilized in IVF-TL medium with frozen-thawed semen at a concentration of 1 ${\times}$ 10$^6$ cells/ml of fertilization medium following Percoll separation. After 24 hours of sperm-egg incubation, the embryos were transferred to CZB medium without glucose for 48 hours and then cultured in TCM-199 with 20% fetal bovine serum (FBS) for 96 hours. The addition of growth factors to IVM medium in the presence of serum had no effect on cleavage and subsequent embryo devlopment to blastocyst. In the absence of serum, TGF- improved cleavage and development to blastocyst compared to control's(p<0.05) and no synergistic effeet of IGF-I + TGF-$\beta$ was observed. In the second experiment, eight-cell embryos obtained by in vitro maturation (IVM) in TCM-199 + 20% FBS without growth facrors and in vitro fertil-ization (IVF) were cultured in the in vitro cuiture (IVC) medium supplemented with 5, 10 ng/ml TGF-$\beta$ or 5, 10, 50, 100 ng/ml IGF-I. Cleavage rate and development to the blastocyst stage was observed during seven days of incubation. The supplementation of 10 ng/ml TGF-$\beta$ to lVC medium for eight-cell embryos improved development to blastocyst (p<0.05) compared to control. In conclusion, these data indicate that the supplementation of growth factors to IVM medium in the presence of serum does not influence cleavage and subsequent embryo development. However, significantly more oocytes matured in serum-free TCM-199 and eight-cell embryos cultured in lVC medium developed to blastocyst with supplementation of 10ng/ml TGF-$\beta$.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.287-294
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• 2007

The present study was to conducted the sexing efficiency and accuracy of bovine embryo by LAMP (Loop-mediated isothermal amplification) method, the development of the biopsied embryos into re- reformation and the freezability of these blastocysts by slow-freezing and vitrification. In vivo embryos were superovaluted with gonadotropin(Antorin R-10) for 4 days combined with progestrone releasing intravaginal(CIDR) insertion in Hanwoo donors, and in vitro embryos were used blastocyst embryos at Day 7 or Day 8 after post-insemination in vitro. The biopsy of bovine embryo was carried out in a 80μl drop with Ca2+-Mg2+ free D-PBS and the viability of biopsied embryos were evaluated in IVMD medium at over 12 h culture time in 5% CO2 incubator.For embryo sexing, about five or seven blastomeres were isolated from in vitro and in vivo embryos at blastocysts with microblade. and were then subjected to LAMP. The survivability of biopsied embryos were no difference in the development rate to re-formation of blastocysts between in vivo and in vitro embryos(100% and 90% respectively). The rates of sexed embryos were compared according to two groups, the female rate was lower than that the male in the in vivo and in vitro embryos(46% vs, 54% and 40% vs, 60%, respectively). However, there were no difference in the overall sexing ratio between the two groups. The survivability of frozen-thawed sexed embryos were lower in the in vitro than in vivo embryos in the slow-freezing(Group 1) and vitrification method(Group 2), (41.7% vs. 58.8% and 57.1% vs, 77.8. respectively).

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.67-67
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• 2003

Early development of porcine oocytes fertilized in vitro was examined in different culture conditions. Porcine ovaries were collected from local slaughter-house. Cumulus-oocytes complexes were aspirated from 2 to 6 mm follicles. The collected oocytes were cultured for in vitro maturation in NCSU-23 medium with 5 mM hypotaurine, 0.57 mM cystein, 10% porcine follicle fluid, 10 IU/ml PMSG and 10 IU/ml hCG for 42~44 hrs. The frozen-thawed spermatozoa were washed by centrifigation 2 times at 1, 500 rpm in D-PBS with 5.56 mM glucose, 0.33 mM Na-pyruvate, 100 IU/ml penicillin, 1$\mu\textrm{g}$/ml streptomycin and 1ng/ml BSA. The fertilization medium used mTBM with 2 mM caffeine and 2 mg/ml BSA and adjusted to a pH of 7.2 to 7.4. The final concentration of spermatozoa was adjusted to 2.5$\times$10$^{6}$ cells/ml motile sperm during fertilization in vitro. At 8hrs h after insemination, the oocytes were transferred into NCSU-23 medium with 5.0 mM hypotaurine and 4 mg/ml BSA and cultured for 7 days. In first experiment, the mean numbers of oocytes collected from 20 ovaries were 674.4 oocytes, and 4.1(27.6), 12.5(84.0), 25.4(171.6) and 57.9%(390.8) for A, B, C and D grade in morphological classification. In the second experiment, when culture medium was supplemented with various concentrations of EGF, the proportions of oocytes cleaved were 56.9, 55.7, 61.9 and 54.7% for 0, 5, 10 and 20ng/ml EGF. The higher proportions(15.1%) of oocytes developed to morular stage were obtained at concentration of 10ng/ml than 0 and 5ng/ml EGF (P<0.05). However, the proportions of embryos developed to blastocyst stage were not significantly different among concentrations of EGF. In another experiment, when the medium supplemented with catalase was used, the proportions of oocytes cleaved were higher in the concentration of 0 unit (56.5%, 61/108) than 100 and 1, 000 unit/ml of catalase (P<0.05). Although the developmental capacity of embryos was improved by medium with 0 unit/ml compared with 100, 500 and 1, 000 units/ml of catalase in oocytes developed to morula and blastocyst stages, were not significantly different among concentrations of catalase.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.2
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• pp.117-124
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• 2007

Objective: The aim of this study was to compare the efficacy of slow freezing with vitrification method for cryopreservation of mouse pronuclear stage embryos. Methods: Mouse pronuclear embryos obtained from superovulated mice and classified into 2 groups of slow freezing and vitrification. Slow freezing solution consisted of 1.5 M PROH, 0.1 M sucrose, while vitrification solution consisted of 40% ethylene glycol, 18% Ficoll and 0.5 M sucrose diluted in Dulbecco's phosphate-buffered saline supplemented with 10% SSS. Recovery and survival rates after thawing and development rates to hatching balstocyst stage were compared between two groups. Results: After freezing and thawing, recovery rate of slow freezing group was 93.8%, whereas vitrification group was 66.5% (p<0.01). Survival rate of recovered embryos were similar between two groups as 83.2% in slow freezing and 87.6% in vitrification. Embryo development rates to 2-cell stage after 24 hrs (77.0% vs 59.1%), 4-cell after 48 hrs (72.6% vs 53.3%), blastocyst after 96 hrs (53.1% vs 40.1%) of thawing were significantly higher in vitrification group than those of slow freezing group, respectively. Conclusion: The vitrification method may provide better developmental competence of frozen-thawed embryos than that of slow freezing method for cryopreservation of mouse pronuclear stage embryos.

• Korean Journal of Animal Reproduction
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• v.22 no.1
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• pp.1-9
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• 1998

This study was carried out to confirm whether the developmental capacity of bovine mature oocytes frozen ultra-rapidly using electron microscopic(EM) grids and EFS30 can be obtained, and whether the cryoprotectants and the freezing method used in this study effect detrimentally to the bovine oocytes by indirect immunocytochemistry. As freezing solution, we used EFS30 which consisted of 30% ethylene glycol, 0.5 M sucrose, 18% ficoll and 10% FBS added in D-PBS. The results obtained in this experiment were summarized as follows: When the effects of cryoprotectant and freezing procedure on the microtuble, micrfilament and chromatin morphology of oocytes were evaluated using indirect immunocytochemistry, the results of freezing as well as exposure group were not different with that of the control oocytes. When the fertilization abnormality after ultrarapid freezing of bovine mature oocytes was examined by Hoechst staining, the rates of total penetration(96.7, 9.0%), normal two pronuclei formation(74.6, 68.9%) and mean number of sperm / oocyte(1.50, 1.44) were not different between control and freezing group. In addition, when the developmental capacity of frozen-thawed of oocytes(85.5%) was survived, 74.5% of them were cleaved and 31.4% of cleaved embryos were developed to blastocyst. These data were similar to those of the control(76.0%, 34.6%) and exposure(74.5%, 33.0%) except survival rates. Also, when the total cell number of blastocysts produced from the each treatment at day after IVF was examined by hoechst staining, there were not different among groups. There results demonstrate that developmental capacity of frozen-thawed bovine mature oocytes can be successfully obtained by ultra-rapid freezing method using EM grid and EFS30 solution.

• Journal of Embryo Transfer
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• v.19 no.1
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• pp.1-10
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• 2004

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 far 40 to 44 h in CRlaa medium with BSA. Then 2 to 8-cell embryos were removed the cumulus cell and were cultured in CRlaa medium containing 10% fatal bovine serum and 2.5 mM taurine in 5% $O_2$ and 5% $CO_2$ at 38.5$^{\circ}C$. The fresh embryos of the morulae and blastocysts cultured for 6 to 9 days in vitro or the frozen-thawed embryos were transferred into recipients. The pregnancy rates of the blastocyst produced for 6, 7, 8, and 9 days in vitro culture were 59.4, 68.2, 66.0 and 100%, respectively. In the developmental stage, pregnacy rates of early blastocysts (61.1%), blastocysts(64.7%) and expanded blastocysts(69.5%) were higher than that of morulae stage(20.0%). The pregnancy rates according to the corpus luteum grades of A, B and C in recipients were 73.6, 62.9 and 50.0%, respectively. Effects of donor-recipients synchrony of after day 2, 1 and 0, before day 1 and 2 on the pregnancy rates were 35.7, 65.5, 72.6, 67.9 and 60.0%, respectively. Pregnancy rates of the body condition score of recipients $\leq$2(71.3%) were higher than those of $\geq$3.0 score(40.0%). The pregnancy rates according to the parity of recipients when embryo was transferred to cow(70.6%) was higher than in heifer(59.1%). The pregnancy rates according to hormone treatment before embryo transfer were 69.9% in hCG + GnRH administration group and 63.0% in control group. Fresh and frozen-thawed embryos on the pregnancy rates were 70.6 and 36.4%, respectively. Pregnancy rates in single and AI+single was 90.0% and 64.8%. Pregnancy rates in twin induction was better than in single. These results indicate that pregnancy rates after transfer were affected on the embryo ages, donor-recipient synchrony, body condition score of recipients, corpus luteum status, parity and hormone treatment to recipients.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.980-987
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• 2008

The objective of this study was to investigate the effects of cell status of BOEC on development of bovine IVM/IVF embryos and gene expression in BOEC before or after culturing of embryos. The developmental rates beyond morula stage in the BOEC co-culture group was significantly higher than in the control group (p<0.05). In particular, blastocyst production in the BOEC co-culture group (28.3%) was dramatically increased compared with the control group (7.2%). In the in vitro development of bovine IVM/IVF embryos according to cell status, the developmental rates beyond morula stage in the primary culture cell (PCC) co-culture group were the highest of all experimental groups. Expression of genes related to growth (TGF-${\beta}$ EGF and IGFBP), apoptosis (Bax, Caspase-3 and p53) and antioxidation (CuZnSOD, MnSOD, Catalase and GPx) in different status cells of BOEC for embryo culture was detected by RT-PCR. While EGF gene was detected in isolated fresh cells (IFC) and PCC, TGF-${\beta}$ and IGFBP were found in IFC or PCC after use in the embryo culture, respectively. Caspase-3 and Bax genes were detected in all experimental groups regardless of whether the BOEC was used or not used in the embryo culture. However, p53 gene was found in IFC of both conditions for embryo culture and in frozen/thawed culture cells (FPCC) after use in the embryo culture. Although antioxidant genes examined were detected in all experimental groups before using for the embryo culture, these genes were not detected after use. This study indicated that the BOEC co-culture system used for in vitro culture of bovine IVF embryos can increase the developmental rates, and cell generations and status of BOEC might affect the in vitro development of bovine embryos. The BOEC monolayer used in the embryo culture did not express the growth factors (TGF-${\beta}$ and EGF) and enzymatic antioxidant genes, thereby improving embryo development in vitro.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.647-659
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• 1997

To overcome the difficulties of collecting and culture of primary cell from genital tract on embryonic development, the present study was carried out to investigate the critical effect of cell lines, such as BRL and Vero cell and its conditioned medium on the development of early Korean native cattle embryos in vitro. Oocytes collected from slaughterhouse ovaries were matured in TCM199 containing FSH, estradiol-$17{\beta}$ and FBS with granulosa cell monolayer for 24 hours and then fertilized in vitro using frozen-thawed, heparin-treated spermatozoa in TALP for 30 hours. And then early embryos (1-2cell) were cultured in TCM199 containing 10% FBS with BOEC, Granulosa, BRL, Vera cell monolayers and conditioned medium for 2~3 days. Development to morulae and blastocysts were recorded, also examined the number of blastomeres presented a valuable parameter for the evaluation of embryonic development. The early cleavage rates of in vitro fertilized embryos co-cultured, there was no differences between primary cell and cell lines(p<0.05). The rate of development to the later stage, coculture of BRL cell was significantly higher than that of the primary cell(p<0.05). The rates of development to morula and blastocyst were significantly higher in vero cell than BRL, Granulosa, Oviduct epithelial cell conditioned medium. In the result of effect of serum on development of early bovine embryos, the use of media containing serum were significantly higher than the use of not containing one on development of early and later stage of embryos. The result of number of blastomeres in blastocysts, there is no differences between primary cell and cell lines. The blastocysts from coculture were higher than from conditioned medium in blastomere cells. In summary, these experments have proved that the culture system in TCM199 with BRL, Vero cell monolayers is effective on in vitro development of early bovine embryos, In addition, it is effective to development of bovine embryos that containing serum in conditioned medium, or in co-culture rather than in conditioned medium alone. The use of cell lines opponent to primary cells is effective in bovine embryo culture.