• Clinical and Experimental Reproductive Medicine
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• v.27 no.2
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• pp.165-172
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• 2000

Objective: In vitro fertilization (IVF) and a prolonging the time of culture may be helpful in establishing a viable pregnancy through a selection effect. Some embryos do not develop beyond the 4-cell stage and some may not develop to the blastocyst stage. We have evaluated the safety of SET and the outcomes of pregnancy. Methods: Sperms were treated with Ham's F-10 supplemented with 10% human follicular fluid (hFF). oocytes or fertilized oocytes were cultured in Dulbecco's Modified Eagle Medium (DMEM) with 10% or 20% hFF respectively. Up to five oocytes were inseminated with approximately 200,000 sperm cells/2 ml in each well. Fertilization was examined in the following morning and fertilized oocytes were co-cultured until embryo transfer. Vero cells for co-culture were prepared in Tissue Culture Medium - 199 (TCM-199) with 10% fetal bovine serum. At the two to four cell and blastocyst on day 2 and day 5, embryo and blstocyst grading were evaluated. Pregnancy rate was determined after transfer of human embryos at the two to four cell stage on day 2 (Group I) or subsequent transfer of embryos on day 2 and at the blastocyst stage on day 5 (Group II). For statistical analysis, Student's t-test and Chi-square (${\chi}^2$_test) were used. Results were considered statistically significant when p value was less than 0.05. Results: No differences was found in the fertilization between Group I (81.0%, 98/121) and Group II (81.8%, 180/220). In case of cleavage rate, no difference was found in Group I (95.9%, 94/98) and Group II (97.8%, 174/178). However, the rate of-clinical pregnancy was significantly higher (p=0.014) in Group II (66.7%, 12/18) than in Group I (26.3%, 5/19). Conclusion: The results of this study showed that SET is safe and effective, and significantly increases the pregnancy rate.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.245-249
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• 2007

The aim of present experiment was to examine hatching rate as in vitro indicator of viability of porcine embryos before early stage embryo transfer such as zygotes or 2-cell stage embryos. Cumulus-oocyte complexes (COCs) collected from ovaries were matured in North Carolina State University 23 (NCSU-23) containing 10% porcine follicular fluid (pFF), 10 ng/ml epidermal growth factor (EGF), $10{\mu}g/ml$ follicle stimulating hormone (FSH), $35{\mu}g/ml$ luteinizing hormone (LH), and 1mg/ml cysteine. After 24 hours, the COCs were transferred to the same medium without hormones. After 65h of maturation, oocytes were exposed to phosphate buffered saline (PBS) with 7% ethanol (v/v) for 7 minutes, and then the oocytes were washed and cultured in tissue culture medium (TCM) 199 containing 5 ug/ml cytochalasin B for 5h at $38.5^{\circ}C$ in an atmosphere of 5% $CO_2$ and 95% air with high humidity. After cytochalasin B treatment, the presumptive parthenotes were cultured in porcine zygote medium (PZM)-5 and cleavage of the parthenotes was assessed at 72h of activation, Normally cleaved parthenotes were cultured for an additional 8 days to evaluate their ability to develop to blastocyst and hatching stages. The fetal bovine serum (FBS) were added at Day 4 or 5 with concentrations of 2.5, 5 or 10%. The blastocyst rates were ranged within $39.1{\sim}70%$ in each treatment. However hatching rate was dramatically decreased in non-addition group. In this experiment, embryo viability in female reproductive tract may be estimated before embryo transfer with in vitro culture adding FBS by hatching ability.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.145-151
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• 2002

The aim of these experiments was to investigate in vitro nuclear maturation of canine oocyte collected from various stages of estrus cycles, Ovaries were obtained from 1 to 4 year-old mongrel bitch and minced for oocyte collection in phosphate buffered saline with 100 iu penicillin-G $m\ell$／sup -1／, 50 $\mu\textrm{g}$ streptomycin sulphate $m\ell$／sup -1／ and 0.1％ (w／v) polyvinyl alcohol. Cumulus-oocyte-complexes (COCs) were washed in HEPES buffered tissue culture medium (TCM)199 and in vitro matured in TCM-199 culture medium supplemented with sodium pyruvate 0.028mg/$m\ell$, L-glutamine 0.146mg／$m\ell$, penicillin G 10,000 IU／$m\ell$, streptomycin 0.031mg／$m\ell$ and 10％ (v／v) fatal calf serum. COCs were in vitro matured for 48～72 hrs at 39$^{\circ}C$ in humidified 5％ $CO_2$ in air atmosphere. In vitro matured oocytes were remove the cumulus cells using 0.2％ (v／v) hyaluronidase. After denuding, oocyte were placed in acetic acid : methanol : chlorform solusion (3:6 : 1.5 v／v) for 30 sec and acetic acid: ethanol(1:3 v／v) for 48hrs fixation. Nuclear maturation was classified to GV, GVBD, MI, MII and degenerate oocyte under microscopy after 1％ aceto-orcein stain. In vitro maturation rates at 48hrs were not significantly difference among the oocytes collected from different stage of estrus at 15.9％, 16.3％, 23.7％ and 18.2％ for anestrus, proestrus, estrus and diestrus. However, the oocytes maturation(36.6％) of collected from estrus ovaries were significantly different from oocytes derived from proesturs, diestrus and anestrus ovaries(30.8％, 17.5％ and 22.1％; p＜0.05). The overall in vitro maturation rates were significantly higher (p＜0.05) in 72hrs culture than 48hrs culture system. In summary, there was a tendency for higher in vitro maturation rates with the oocyte collected from estrus ovary than other stages of estrus. Also, for nuclear maturation, in vitro culture of oocyte for 72hrs was better than 48hrs culture.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.189-194
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• 1997

The ovaries of Korean native cows or heifers were obtained from a slaughter house and kept on 28~3O˚C and transported to laboratory within 2 hrs. The follicular oocytes were collected follicles. The oocytes were matured in vitro for 24 hrs. In TCM-199 supplemented with 35 $\pi$g /ml FSH, 10 $\pi$g /ml LH, 1 $\pi$g /ml estradiol-17 and granulosa cells at 39˚C under 5% $CO_2$ in air. The caudal epididymis of Korean native bulls were obtained from a slaughter house and transported to laboratory within 30 minutes. Swim-up of collected spermatozoa and freezing sperm was layered under 2ml fertilization B. 0. medium in two tissue culture tubes and held at a 45˚C angle for 0~2 hrs. They wrer fertilized in vitro by freezing sperm treated with heparin for 24 hrs, and then the zygotes were co-cultured in vitro with bovine oviductal epithelial cells for 7 to 9 days. The follicular oocytes recovered were classified into 41.7% as grade I, 51.5% as grade II and 6.8% as graed III. The number of oocytes recovered per ovary was averaged 8.3 and they were classifed into 2.3 as grade I, 2.5 as grade II and 2.3 as grade III. The cleavage rate of matured oocytes was significantly(P

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.7-13
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• 2007

The present study investigated the effects of follicle stimulating hormone (FSH) and human chorionic gona-dotrophin (hCG) on the nuclear maturation of canine oocytes. Oocytes were recovered from mongrel female ovaries in various reproductive states; follicular, luteal or anestrous stage. Oocytes were cultured in sserum-free tissue culture medium (TCM)-199 supplemented with various concentrations of FSH (Exp. 1: 0, 0.5, 1.0 or 10 IU) or hCG (Exp.2:0, 0.5, 1.0 or 10 IU) or both (Exp. 3:1 IU FSH +1 IU hCG) for 72 hr to determine the effective concentration of these hormones, and to examine their combined effect. After maturation culture, oocytes were denuded in PBS containing 0.1% (w/v) hyaluronidase by gentle pipetting. The denuded oocytes were stained with $1.9\;{\mu}M$. Hoechst 33342 in glycerol and the nuclear state of oocytes was evaluated under UV light. More (p<0.05) oocytes matured to MII stage when follicular stage oocytes were supplemented with 1 IU FSH (6.2%) compared with the control, 0.1 or 10.0 IU FSH (0 to 1.2%). Significantly higher (p<0.05) maturation rate to MII stage was observed in follicular stage oocytes supplemented with 1.0 IU hCG (7.2%) compared with the control or other hCG supplemented groups (0 to 1.5%). However, the combination of FSH and hCG did not improve the nuclear maturation rate of canine oocyte (2.4 %) compared with FSH (6.2%) and hCG alone (7.2%). In conclusion, FSH or hCG alone significantly increased the maturation of canine oocytes to MII stage.

• Journal of Embryo Transfer
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• v.22 no.2
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• pp.89-95
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• 2007

The present study was conducted to examine some factors affecting in vitro development and fecundity of embryos recloned with somatic cell nuclear transfer (SCNT). Fibroblast cells retrieved from the ear of a 3-week-old, cloned Korean goat (Jinsoonny) were used as karyoplast donors and serum-starvation was conducted in tissue culture medium (TCM)-199 supplemented with 0.5% FBS. Recipient oocytes were surgically collected by flushing the oviducts 35 h after hCG injection following FSH priming. The zonae pellucidae of the oocytes were partially perforated with a laser drill and a donor cell was transferred into an enucleated oocyte. The couplets were electrically fused and activated by ionomycin (5 min) and 6-DMAP (4 h). The reconstructed embryos were cultured in mSOF medium containing 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $%O_2$, 90% $N_2$ for 12 to 15 h. Re-cloned embryos (2- to 4-cell stages) were surgically transferred into the oviducts of the recipients and pregnancy was subsequently diagnosed by progesterone assay and ultrasound on Days 21 and 63 of pregnancy. The fusion rate following 1st fusion pulse was higher (p<0.05) in 2nd cloning (65.9%) compared to 1st cloning (51.0%), but it was not different in the other groups. The rate of cleavage after fusion was significantly higher (p<0.05) in 1st (77.7%) than in 2nd cloning (56.0%). A total of 175 re-cloned embryos were transferred into 28 recipients. On day 21 and 60 after transfer, 11 (39.3%) and 4 recipients (17.4%) were pregnancy, respectively. In comparison of pregnancy rate by estrous synchronization, a total of 66 and 109 re-cloned embryos were transferred into 11 recipients in natural estrus and 17 recipients in induced estrus, respectively. Five (45.4%) and 2 recipients (18.2%) in natural estrus were pregnant on days 21 and 63 while 6 (35.3%) and 2 (11.8%) recipients in induced estrus were pregnant, respectively. These results show that recloning of goat can be achieved by SCNT and estrous synchronization between donor and recipient animals may be one of the major factors affecting success rate.