• Journal of Embryo Transfer
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• v.20 no.1
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• pp.55-62
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• 2005

This study was undertaken to access the effect of collection methods on the collection efficiency, blastocyst rate and pregnancy rate after IVP embryo transfer. The ovaries of Hanwoo were obtained from an abattoir and kept on 25 to $28^{\circ}C$ and transported to laboratory within 4 hrs. The oocytes were collected by aspiration of follicles $(2\~6\;mm)$ with or without slicing of ovaries after aspiration. The oocytes were matured in vitro (IVM) for 20 to 24 hrs in TCM-199 supplemented with $10\%$ fetal bovine serum at $39^{\circ}C$ under $5\%\;CO_{2}$ in air. Following routine IVM/IVF procedure, the oocytes and presumed zygotes were cultured for three day in CRlaa medium with BSA. The cumulus cells at 2 to 8-cell stage of embryos removed then the embryos and were cultured in CRlaa medium containing $10\%$ fetal bovine serum in $5\%\;CO_{2}$ at $39^{\circ}C$. The fresh blastocysts cultured for 7 to 9 days were transferred into recipients. The numbers of oocytes recovered form two different methods, the aspiration and slicing after aspiration, were compared to know what. The number of oocytes per ovary was 8.2 and 6.5 in aspiration combining slicing, and aspiration groups, respectively (p<0.05). The cleavage rate in aspiration method are significantly (p<0.05) high than those in slicing post aspiration $(27.9\%)$, and aspiration $(25.5\%)$. The pregnancy .ate in aspiration method $(62.5\%)$ was high than that in slicing method after aspiration $(54.4\%)$. The pregnancy rates of aspiration method and slicing method after aspiration in nullipara $(58.1\%\;vs\;68.2\%)$ was high than that in pluripara $(49.5\%\;vs\;53.2\%)$. The results obtained that the increased number of oocytes per ovary in slicing method after aspiration could be better than that in aspiration method. Pregnancy rate in aspiration method was slightly higher in than that in slicing method after aspiration.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.21-27
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• 2004

This study was conducted to investigate the developmental ability of caprine embryos after somatic cell interspecies nuclear transfer. Recipient bovine and porcine oocytes were obtained from slaughterhouse and were matured in vitro according to established protocols. Donor cells were obtained from an ear-skin biopsy of a caprine, digested with 0.25% trypsin-EDTA in PBS and primary fibroblast cultures were established in TCM-199 with 10% FBS. The matured oocytes were dipped in D-PBS plus 10% FBS ＋ 7.5 $\mu$ g/ml cytochalasin B and 0.05M sucrose. Enucleation were accomplished by aspirating the first polar body and partial cytoplasm which containing metaphase II chromosomes using a micropipette with an out diameter of 20∼30 $\mu$m. A Single donor cell was individually transferred into the perivitelline space of each enucleated oocyte. The reconstructed oocytes were electric fusion with 0.3M mannitol fusion medium. After the electrofusion, embryos were activated by electric stimulation. Interspecies nuclear transfer embryos with bovine cytoplasts were cultured in TCM-199 medium supplemented with 10% FBS including bovine oviduct epithelial cells for 7∼9 day. And porcine cytoplasts were cultured in NCSU-23 medium supplemented with 10% FBS for 6 ∼8 day at $39^{\circ}C, 5% CO_2 $in air. Interspecies nuclear transfer by recipient bovine oocytes were fused with electric length 1.95 kv/cm and 2.10 kv/cm. There was no significant difference between two electric length in fusion rate(47.7 and 44.6%) and in cleavage rate(41.9 and 54.5%). Using electric length 1.95 kv/cm and 2.10 kv/cm in caprine-porcine NT oocytes, there was also no significant difference between two treatments in fusion rate(51.3 and 46.1%) and in cleavage rate(75.0 and 84.9%). The caprine-bovine NT oocytes fusion rate was lower(P＜0.05) in 1 pulse for 60 $\mu$sec(19.3%), than those from 1 pulse for 30 $\mu$sec(50.8%) and 2 pulse for 30 $\mu$sec(31.0%). The cleavage rate was higher(P＜0.05) in 1 pulse for 30 $\mu$sec(53.3%) and 2 pulse for 30 $\mu$sec(50.0%), than in 1 pulse for 60 $\mu$sec(18.2%). The caprine-porcine NT oocytes fusion rate was 48.1% in 1 pulse for 30 $\mu$sec, 45.2% in 2 pulse for 30 $\mu$sec and 48.6% in 1 pulse for 60 $\mu$sec. The cleavage rate was higher(P＜0.05) in 1 pulse for 30 $\mu$sec(78.4%) and 1 pulse for 60 $\mu$sec(79.4%), than in 2 pulse for 30 $\mu$sec(53.6%). In caprine-bovine NT embryos, the developmental rate of morula and blastocyst stage embryos were 22.6% in interspecies nuclear transfer and 30.6% in parthenotes, which was no significant differed. The developmental rate of morula and blastocyst stage embryos with caprine-porcine NT embryos were lower(P＜0.05) in interspecies nuclear transfer(5.1%) than parthenotes(37.4%).

• 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.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.289-295
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• 2005

This study was performed to investigate the relationship between Heat shock protein 70 (HSP70) gene polymorphism and in vitro fertilization(IVF) embryo development in the pigs. The single strand conformation polymorphism(SSCP) genotypes from HSP70 K1, K3 and K4 PCR products were detected different patterns. In cleavage rate of oocyte fertilized in vitro, HSP70 K1-AA genotype($73.1\%$) and K1-AB genotype($62.3\%$) showed significantly higher oocyte cleavage rate than HSP70 K1-BB genotype($49.3\%$)(p<0.05). And HSP70 K3-AA genotype ($72.4\%$) and K3-AB($62.2\%$) also showed significantly higher oocyte cleavage rate than HSP70 K3-BB genotype($49.1\%$)(p<0.05). The IVF embryo development of 2-cell stage according to HSP70 genotypes of sperm and pig breeds also showed a significant difference. The number of embryos developed to 2-cell stage in Landrace(28.8) and Duroc(29.8) were significantly higher than in Yorkshire(10.9)(p<0.05). And also HSP70 K4-AB genotype group(29.6) higher than HSP70 K4-AA genotype group(10.6)(p<0.05). However, the number of embryos developed to blastocyst stage did not showed significant differences among breeds as well as HSP70 genotypes. These resrults suggest that in vitro development in porcine early embryos may be affected by HSP70 genotypes and breeds.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.101-107
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• 2006

The objective of this study was to investigative the effects of retinol supplement to IVM and/or IVC medium on maturation, fertilization and development of pig oocytes. North Carolina State University (NCSU) 23 medium containing porcine follicular fluid (pFF) was used as base medium. Each 1 uM, 5 uM and 10 uM concentration of retinol was supplemented to IVM and /or IVC medium. When the retinol was supplemented to maturation medium, the maturation rates were not different (p>0.05) among treatment groups ($66.7{\pm}6.0{\sim}69.2{\pm}5.3%$), but the developmental rate to blastocyst stage was higher (p<0.05) in $5{\mu}M$ group ($20.4{\pm}2.6%$) than in 0 uM ($13.6{\pm}2.1%$) and 10 uM groups ($9.7{\pm}1.7%$). Moreover, total cell number was significantly greater (p<0.05) in the 5 uM group ($37.0{\pm}1.6$) than in the other groups ($29.8{\pm}1.0{\sim}33.2{\pm}1.0$). Retinol supplement to maturation medium did not significantly affect the rates of fertilization and polyspermy (p>0.05). When the retinol was supplemented to culture medium or both maturation and culture medium, the rates of cleavage, and develop to morula and blastocyst stage were not affected, while those of 10 uM group were significantly decreased (p<0.05). These results indicate that 5 uM retinol supplement in maturation medium significantly stimulates embryo development, also improves the total cell number of blastocyst stage in pig.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.131-138
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• 2017

In most mammals, metaphase II (MII) oocytes having high maturation promoting factor (MPF) activity have been considered as good oocytes and then used for assisted reproductive technologies including somatic cell nuclear transfer (SCNT). Caffeine increases MPF activity in mammalian oocytes by inhibiting p34cdc2 phosphorylation. The objective of this study was to investigate the effects of caffeine treatment during in vitro maturation (IVM) on oocyte maturation and embryonic development after SCNT in pigs. To this end, morphologically good (MGCOCs) and poor oocytes (MPCOCs) based on the thickness of cumulus cell layer were untreated or treated with 2.5 mM caffeine during 22-42, 34-42, or 38-42 h of IVM according to the experimental design. Caffeine treatment for 20 h during 22-42 h of IVM significantly inhibited nuclear maturation compared to no treatment. Blastocyst formation of SCNT embryos was not influenced by the caffeine treatment during 38-42 h of IVM in MGCOCs (41.1-42.1%) but was significantly improved in MPCOCs compared to no treatment (43.4 vs. 30.1%, P<0.05). No significant effects of caffeine treatment was observed in embryo cleavage (78.7-88.0%) and mean cell number in blastocyst (38.7-43.5 cells). The MPF activity of MII oocytes in terms of p34cdc2 kinase activity was not influenced by the caffeine treatment in MGCOCs (160.4 vs. 194.3 pg/ml) but significantly increased in MPCOCs (133.9 vs. 204.8 pg/ml). Our results demonstrate that caffeine treatment during 38-42 h of IVM improves developmental competence of SCNT embryos derived from MPCOCs by influencing cytoplasmic maturation including increased MPF activity in IVM oocytes in pigs.

• Journal of Embryo Transfer
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• v.8 no.2
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• pp.143-149
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• 1993

The objective of this study was to produce calves derived from in vitro fertilization of in vitro matured follicular oocytes. Oocytes aspirated from small antral folicles of ovaries obtained at a local slaughter house were matured and fertilized in vitro. At l8hrs after insemination with Korean native cattle semen, oocytes were co-cultured for 6~7 days by utilizing co-culture system with bovine oviduct epithelial cell. After co-culture, good or excellent quality late morulae or early blastocysts were selected by morphological criteria under stereo microscope. Selected embryos were transferred to recipients on day 6 or 7 (estrus = day 0). Recipients were monitored by observation for estrus and rectal palpation after 60 days from embryo transfer. One of them went to term with the birth of a calf. This case is the first production of calf derived from in vitro fertilization in Korea.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.225-231
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• 1996

This study was conducted to investigate the effects of preincubation time, concentration and exposure time of sperm on in vitro fertilization of porcine follicular oocytes rnatured in in vitro. The results obtained are as follows ; 1. Effect of preincuhation time for porcine sperm capacitation on in vitro fertilization in medium with heparin was investigated. Normal fertilization rate was highest in 15 min(26.4%). However, there were no significant differences among preincuhation times of 5~90 min, 2. Normal fertilization rates of sperm concentrations were 17.0~26.5%, and normal fertilization rate from l$\times$ l05cell /ml concentration was also higher than those of other sperm concentration. 3. Normal fertilization rates of sperm exposure time of 4, 8, 12, 16 and 20 hours were 6.1, 20.8, 27.8, 25.0 and 26.7%, respectively. Normal fertilization rate from sperm exposure time of 12 hours was also higher than that of other sperm exposure times.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.33-38
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• 2000

This study was undertaken in an effort to select the sire bull in Hanwoo through in vitro fertilization of proven bull semen. It was used for in vitro fertilization that of the 20 proven bull semen with follicular oocytes derived from slaughterhouse ovaries of Hanwoo. The stage of maturation on the time course of bovine cumulus-enclosed oocytes incubated for 24 hours was found the highest(96.4%) than hose of other maturationi time. In vitro fertilization rate of bovine oocytes with proven bull sperm showed from 61.5 to 88.9%. Polyspermy of in vitro fertilized oocytes according to proven bulls were the highest KP 491(61.5%) nothing but KP 486, KP 491 and KP 497.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.41-46
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• 2001

This study was carried out to evaluate the effect of culture methods on development of embryos with each developmental stage after heat shock in bovine oocytes. The results obtained were as fellows. 1. The culture method after heat shock on development of embryos was better drop-culture than co-culture. 2. The medium without amino acids were not effect of heat sock on development of embryos but it was in need of amino acid during formation of blastocyst.