• 한국동물생명공학회지
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• 제34권3호
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• pp.232-239
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• 2019

In general, cloned pigs have been produced using the somatic cell nuclear transfer (SCNT) technique with various types of somatic cells; however, the SCNT technique has disadvantages not only in its low efficiency but also in the development of abnormal clones. This study aimed to compare early embryonic development and quality of SCNT embryos with those of induced pluripotent stem cells (iPSCs) NT embryos (iPSC-NTs). Ear fibroblast cells were used as donor cells and iPSCs were generated from these cells by lentiviral transduction with human six factors (Oct4, Sox2, c-Myc, Nanog, Klf4 and Lin28). Blastocyst formation rate in iPSC-NT (23/258, 8.9%) was significantly lower than that in SCNT (46/175, 26.3%; p < 0.05). Total cell number in blastocysts was similar between two groups, but blastocysts in iPSC-NT had a lower number of apoptotic cells than in SCNT (2.0 ± 0.6 vs. 9.8 ± 2.9, p < 0.05). Quantitative PCR data showed that apoptosis-related genes (bax, caspase-3, and caspase-9) were highly expressed in SCNT than iPSC-NT (p < 0.05). Although an early development rate was low in iPSC-NT, the quality of cloned embryos from porcine iPSC was higher than that of embryos from somatic cells. Therefore, porcine iPSCs could be used as a preferable cell source to create a clone or transgenic animals by using the NT technique.

• 한국가축번식학회지
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• 제26권4호
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• pp.311-320
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• 2002

The objective of this study was to assess the developmental potential in vitro produced embryos frozen-thawed with the various containers, and also examined expression and localization of heat shock protein 70 at these embryos. For the vitrification, 2-cell, 8-cell and blastocyst stage embryos produced by in vitro fertilization (IVF) and nuclear transfer (NT) were exposed the ethylene glycol 5.5 M freezing solution (EC 5.5) for 30 sec, loaded on each containers such EM grid, straw and cryo-loop, and then immediately plunged into liquid nitrogen. Thawed embryos were serially diluted in sucrose solution, each for 1 min. and cultured in CRI-aa medium. Survival rates of the vitrification production were assessed by re-expanded, hatched blastocysts. There were no differences in the survival rates of IVF using EM grid and cryo-loop. However, survival rates by straw were relatively lower than other containers. The use of cryo-loop resulted in only survival of nuclear transferred embryos (43.7%). Also, there embryos after IVF or NT were analysed by semi-quantitive reverse transcription-polymerase chain reaction (RT- PCR) methods for hsp 70 mRNA expression. Results revealed the expression of hsp 70 mRNh were higher thawed embryos than control embryos. Immunocytochemistry used to localize the hsp 70 protein in embryos. Two and 8-cell embryos derived under control condition was evenly distributed in the cytoplasm but appeared as aggregates in some frozen-thawed embryos. However, in the control, blastocysts displayed aggregate signal while Hsp70 in frozen-thawed blastocysts appeared to be more uniform In distribution. Therefore, this result suggests that the exploiting Hsp 70 in the early embryos may be role for protection of stress condition for increase viability of embryos within IVF, NT and there frozen-thawed embryos.

• 한국수정란이식학회지
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• 제25권2호
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• pp.127-131
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• 2010

The objective of this study was to determine the mRNA expression patterns of several putative imprinted genes in in vivo and in vitro fertilized, parthenogenetic, and cloned porcine preimplantation embryos. Both maternally (Dlk1, IGF2, Peg1/Mest and Ndn) and paternally (IGF2r, H19 and Xist) imprinted genes were selected. We have used reverse transcription polymerase chain reaction (RT-PCR) to investigate gene expression patterns in the porcine embryos. IGF2 transcripts were detected in the most of embryos. In nuclear transfer (NT), Peg1/MEST transcripts showed fluctuating pattern. Dlk1 was only expressed partially from the morula and blastocyst stage of NT embryos. Ndn gene expression was started somewhat early for in vivo embryos. However, the expressions of maternally imprinted genes were similar in all types of blastocysts (NT, in vivo and in vitro fertilized, and parthenogenetic embryos). The IGF2R gene expression level was somewhat irregular and varied among samples. However, for the majority samples of all types of embryos, IGF2R expression was diminished after one- to two-cell stages and reappeared at the morulae or blastocyst stage embryos. H19 gene was only expressed early in parthenogenetic and in vivo embryos. For NT embryos, H19 was only expressed in blastocysts. Xist expression was detected in all blastocysts with the earliest being in vivo 8-cell stage embryos and the last one being NT blastocysts. These putative imprinted genes appeared to have stage specific expression patterns with a fluctuating pattern for some genes (Peg/Mest, IGF2r, H19). These results suggest that stage specific presence of imprinted genes can affect the embryo implantation and fetal development.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.73-73
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• 2002

Nuclear transfer (NT) techniques have advanced in the last years, and cloned animals have been produced by using somatic cells in several species including pig. However, it is difficult that the nuclear transfer porcine embryos development to blastocyst stage overcoming the cell block in vitro. Abnormal segregation of chromosomes in nuclear transferred embryos on genome activation stage bring about embryo degeneration, abnormal blastocyst, delayed and low embryo development. Thus, we are evaluated that the correlations of the frequency of embryo developmental rates and chromosome aberration in NT and In viかo fertilization (IVF) derived embryo. We are used for ear-skin-fibroblast cell in NT. If only karyotyping of embryonic cells are chromosomally abnormal, they may difficultly remain undetected. Then, we evaluate the chromosome aberrations, fluorescent in situ hybridization (FISH) with porcine chromosome 1 submetacentric specific DNA probe were excuted. In normal diploid cell nucleus, two hybridization signal was detected. In contrast, abnormal cell figured one or three over signals. The developmental rates of NT and IVF embryos were 55% vs 63%, 32% vs 33% and 13% vs 17% in 2 cell, 8 cell and blastocyst, respectively. When looking at the types of chromosome aberration, the detection of aneuploidy at Day 3 on the embryo culture. The percentage of chromosome aneuploidy of NT and IVF at 4-cell stage 40.0%, 31.3%, respectively. This result indicate that chromosomal abnormalities are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT associated with lower implantation rate, increase abortion rate and production of abnormal fetuses.

• 한국수정란이식학회지
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• 제14권3호
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• pp.195-201
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• 1999

This study was carried out to improve a technique of cloned animal prodcution by preactivation of nuclear recipient oocytes with ionomycin and 6-dimethylaminopurine (6-DMAP) in rabbits. The oocytes were collected from the oviduct of superovulated rabbit at 19∼20 hours post hCG injection. The collected oocytes were preactivated and self-enucleated by treating 5 uM ionoycin for 5 min, and 2.0 mM 6-DMAP for two hours. Microsurgical removel of the chromation complex in the second polar bodies was effectively performd and single blastomere separated from 32-cell stage rabbit embryos was injected into the perivitelline space of the enculeated recipient oocyts. Follwoing electrofusion and in vitro culture for 18 hours, the nuclear transplant(NT) embryos were transferred into the uterine horns of naturally mated or synchronized recipient does. When 32 NT embryous reconstituted with preactivated oocytes were transferred to 2 recipient does, one foster doe delivered two offspring (6.3%), while not a offspring was delivered from three foster does which received 17 NT embryos reconstituted with non-preactivated oocytes. A total of 68 NT embryos reconstituted with preactivated oocytes were transferred into the uterine horns of 7 synchronized ecipient does. Among them, two recipients were pregnant and delivered three offspring(5.9%).

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.64-64
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• 2001

To facilitate the widespread application of somatic cell cloning, improvements in blastocyst production efficiency and subsequent fetal viability are required. Area where technical improvements are needed include donor cell treatments, starvation and passage numbers. This study was carried out to investigate the effect of serum-starvation and passage on the development of ear skin fibroblast cells cloned embryos. A skin biopsy was obtained from the ear of a 2-year-old Korean Hanwoo female. The cells were cultured in 10% FBS＋DMEM up to 2-3 months(up to 10 passages) and then used. In Experiment 1, the Korean bovine Ear Skin Fibroblast cells (KbESF) were either serum starved (culture in 0.05% FBS＋DMEM) or serum fed (10% FBS＋DMEM) for 4-7 days Prior to NT In Experiment 2, the KbESF cells used for nuclear transfer in these experiments were from passages 2 to 10. The development of 208 nuclear transfer (NT) embryos reconstructed from either serum starved or serum fed ear skin fibroblast was assessed. NT embryos reconstructed from serum starved and serum fed cells showed the same developmental rate (cleavage 80.16 vs. 85.37%; blastocyst 20.63 vs. 19,51%). The development of 590 nuclear transfer (NT) embryos reconstructed from passage 2 to 10 was assessed. We observed the same developmental rates for embryos derived from later Passages as compared with those embryos from early passages(blastocyst from 16.69 to 27.91%, average 20.17%). There was no significant difference between serum-fed and serum-starved donor cells. We observed no difference in developmental rates for embryos derived from 2 to 10 passages. These data show that prolonged culture and serum starvation does not affects the cloning competence of adult somatic cells.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.962-968
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• 2009

The aim of this study was to compare the effects of oviductal fluid, porcine zygote medium (PZM)-3, PZM-4 and PZM-5, and modified PZM-5 culture media, and determine the effects of zona pellucida (ZP) removal on the development of nuclear transfer (NT) embryos. There were no significant differences in the rates of fusion and cleavage among the five different oviductal fluid concentrations. However, the rates of blastocyst formation and the cell numbers per blastocyst were high in the embryos at the 14 and 28 $\mu{g}$/ml concentrations of oviductal fluid compared to the 0, 56 and 100 $\mu{g}$/ml concentrations. The rates of cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the PZM-3, PZM-5 and modified PZM-5 media than in the PZM-4 medium. However, there were no significant differences in the fusion rates of oocytes among the four culture media. The cell numbers per blastocyst in the embryos without ZP were significantly greater than those with ZP. However, there were no significant differences in the rates of fusion, cleavage and blastocyst formation between the embryos with and without ZP. In conclusion, we improved blastocyst development and the quality of NT embryos by replacing PVA with 3 mg/ml of BSA in PZM-5 medium and supplementing the PZM-5 medium with 14 $\mu{g}$/ml oviductal fluid. The NT embryos produced by the zona-free NT method had a high rate of blastocyst formation in the modified PZM-5 medium.

• 한국수정란이식학회지
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• 제23권1호
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• pp.31-36
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• 2008

We attempted to control the maturation promoting factors (MPF) activity and nuclear remodeling of somatic cell nuclear transfer (NT) bovine embryos. Bovine ear skin fibroblasts were fused to enucleated oocytes treated with either 5 mM caffeine for 2.5 h or 0.5 mM vanadate for 0.5 h and activated. The nuclear remodeling type of the reconstituted embryos was evaluated 1.5 h after activation. MPF activity was assessed in enucleated and chemical treated oocytes before the injection of a donor cell. Effect of chemicals on the embryonic development was evaluated with parthenogenetic embryos. MPF activity increased significantly by caffeine treatment, but decreased by vanadate treatment (p<0.05). Caffeine or vanadate had no deleterious effect on the parthenogenetic embryo development. In caffeine treated group, premature chromosome condensation (PCC) was occurred in 72.2% of NT embryos (p<0.05). In contrast, vanadate induced the formation of a pronucleus-like structure (PN) in a high frequency (68.9%, p<0.05) without PCC (NPCC). Blastocyst development of NT embryos increased by treating with caffeine (30.3%), whereas decreased by treating with vanadate (11.4%) compared to control (22.1%, p<0.05). The results indicate that caffeine or vanadate can control of MPF activity and remodeling type of NT embryos, resulting in the increased or decreased in vitro development.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.168-173
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• 2004

The ability of frozen-thawed fetal skin was examined to generate viable cell lines for nuclear transfer. Fetal skin frozen at -20$-20^{\circ}C$, $-30^{\circ}C$ or $-80^{\circ}C$ in the presence of 5% DMSO used as tissue explants to generate somatic cells. The resultant confluent cells were then used as donors for nuclear transfer (NT). Of the bovine NT embryos reconstracted from the somatic cells, 62.3%, 76.6% to 65% showed cleavage 70.5%, 81.9% to 78.5% reached the stage of morula formation and 39.7%, 43.2% or 47.6% reached the blastocyst stage. There was no significant difference in development when the NT embryos were compared with those reconstracted from fresh somatic cell derieved skin tissues (72%, 75.3%, and 45.2%, for cleavage, and development to morula and blastocyst stage, respectively). NT embryos were then placed in a portable $CO_2$ incubator and carried to China from Japan by air. After reaching to farm, two NT embryos were transferred to each of 5 recipients. We obtained 2 NT calves which birth weights is 30kg and 36kg female, and gestation periods is 281 and 284 days, respectively. There were no observation any abnormality from those calves. The results indicated that cell lines derieved from bovine fetal skin cryopreserved by a simple method could be used as donors in nuclear transfer using the portable $CO_2$ incubator.

• 한국가축번식학회지
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• 제21권3호
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• pp.293-302
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• 1997

Follicular oocytes of Grade I and II were collected from 2~6 mm ovarian follicles and matured in vitro (IVM) for 24 hrs in TCM-199 su, pp.emented with 35$\mu\textrm{g}$/ml FSH, 10$\mu\textrm{g}$/ml LH, and 1$\mu\textrm{g}$/ml estradiol-17$\beta$ at 39$^{\circ}C$ under 5% CO2 in air. They were fretilized in vitro (IVF) by epididymal spermatozoa capacitated with heparin for 12 hrs. The zygotes were then co-cultured in vitro with bovine oviducted epithelial cells (BOEC) for 7 to 9 days. The optimal time for IVM, the successful enucleation of IVM oocytes by micromanipulation at different oocyte ages after IVM, and the ideal culture system for IVM for effective IVF and in vitro development of IVM-IVF embryos was examined for in vitro production of nuclear recipient oocytes and nuclear donor embryos. To improve the efficiency of nuclear transplantation (NT) of IVF embryo into IVM follicular oocytes, this study evaluated the optimal electric condition and oocytes age for activation of IVM oocytes and in vitro development of NT embryos. In vitro development of NT embryos with preactivation or non-preactivation in enucleation oocytes, cell number of IVN-IVF embryos, and NT embryos wre also examined. The results obtained were as follows; 1. The most suitable enucleation time was at 24 hpm (83.3%) rather than that of 28 hpm(69.6%) and 32 hpm(50.0%). 2. There was no difference among the fusion rates of NT embryos at the voltages of 0.75, 1.0 and 1.5 kV/cm, but the in vitro development rates to morule and blastocyst were significantly (P<0.05) higher at the voltage of 0.75(12.5%) and 1.0kV/cm (12.6%) compared to 1.5kV/cm(0%). 3. No significant difference in activation rates were seen in NT embryos stimulated for 30, 60 and 120 $\mu$sec (71.7, 85.2 and 71.9%, respectively), but the in vitro development rates to morulae and blastocyst were significantly (P<0.05) higher in the oocytes stimulated for 30 $\mu$sec (11.6%) and 60 $\mu$sec(10.7%) than 120 $\mu$sec(0.0%). 4. The fusion rates (71.0 and 87.3%) and the in vitro development rates (9.1 and 12.7%) to morula and blastocyst were seen in the NT embryos stimulated at 28 and 32 hpm under the condition of 1.0 kV/ml, 60 $\mu$sec. However, at 24 hpm the fusion rates were 64.8% and the in vitro development to morula and blastocyst were not seen. 5. The fusion rates between the 8~12, 13~17 and 18~22-cell stage of IVM-IVF embryos were not significantly different. The in vitro development rates of the fused embryos to morula and blastocyst which were received from a blastomere of 8~12, 13~17 and 18~22-cell stages of IVM-IVF embryos were 14.9, 8.3 and 6.5%, respectively. 6. The in vitro development rate of the enucleated recipient oocytes with preactivation (24.2%) to morula and blastocyst was significantly (P<0.05) higher than that of non-preactivation (12.8%). 7. The cell numbers of NT blastocyst and IVM-IVF blastocyst cultured during 7~9 days were 63$\pm$11 and 119$\pm$23, and then their the mean cell cycle number were 5.98 and 6.89, respectively.