• Development and Reproduction
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• v.4 no.1
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• pp.7-12
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• 2000

At fertilization, sperm penetrates into oocyte, male and female pronuclei are fused together, and mitotic division follows. However, little information is available on the interactive roles and dynamic processes between cytoplasmic and nuclear components during the pronuclear formation, migration and cell division. The assisted reproductive technologies such as, intracytoplasmic sperm injection (ICSI) and round spermatid injection(ROSI) could provides new treatments for the male infertility as well as tools for the study of basic mechanism during fertilization. Nuclear transfer can also provide a mechanism on the interactive roles between nucleus and cytoplasm since the process includes nuclear reprogrammming of differentiated cells in the enucleated oocytes. Recently, I have investigated developmental processes in porcine oocytes following fertilization parthenogenesis, ICSI, ROSI and nuclear transfer using indirect immunocytochemical and electron microscopic studies. The results could provide an insight into biological questions related with epigenesis as well as strategies for the enhancement of embryology in general such as ICSI and nuclear transfer.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.225-228
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• 2015

Understanding the behavior of transgenes introduced into oocyte or embryos is essential for evaluating the methodologies for transgenic animal production. To date, many studies have reported the production of transgenic pig embryos with, however, low efficiency in environment of blastocyst production. The aim of present study was to determine the expression and duration of transgene transferred by intracytoplasmic sperm injection-mediated gene transfer (ICSI-MGT). Embryos obtained from the ICSI-MGT procedure were analysed for the expression of GFP and then for the transmission of the transgene. Briefly, fresh spermatozoa were bound to exogenous DNA after treatment by Triton X-100 and Lipofectin. When ICSI-MGT was performed using sperm heads with tails removed, the yield of blastocyst (25.3%), treated with Lipofectin (18.8%) and Triton X-100 (19.2%) were observed. Treatments of Lipofectin or Triton X-100 did not further improve the rates of blastocysts. Moreover, the apoptosis rates of embryos were obtained from the control and LIpofectin groups (8.7%, 9.7%, respectively), but were significantly higher in the Triton X-100 group (13.0%). Our results demonstrated that ICSI-MGT caused minimal damage to oocytes that could develop to full term. Moreover, the embryos derived by ICSI-MGT have shown prolonged exogenous DNA expression during preimplantation stage in vivo. However, more efforts will be required to improve the procedures of both sperm treatments cause of high frequency of mosaicisms.

• Journal of Embryo Transfer
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• v.26 no.1
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• pp.19-25
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• 2011

This study was carried out to evaluate the effect of early pregnant cow as donor for Ovum Pick-Up (OPU) derived oocyte aspiration and embryo production in Holstein heifers. Four non-pregnant and 2 pregnant Holstein heifers were used as donor and then carried out total 17 OPU session for 10 weeks (2 times per week). Recovered cumulus-oocyte-complexes (COCs) were classified into 4 grade by oocyte cytoplasm and cumulus cells and matured in vitro in TCM-199 supplemented with 10% FBS, 10 mg/ml FSH and 1 mg/ml estradiol in 5% $CO_2$ and over 99% humidity for 24 h. After 24 h co-incubation with post-thaw sperm, the presumed zygotes were cultured in CR1aa medium with 4 mg/ml BSA for 3 days and then changed CR1aa medium with 10% of FBS for another 3~4 days. The Mean number of aspirated follicles and collected oocytes in the early stage pregnant and non-pregnant heifers were $13.0{\pm}4.3$ and $10.6{\pm}3.9$, $5.4{\pm}3.4$ and $7.7{\pm}3.6$ per session, respectively. Rate of collected oocyte from aspirated follicles were 59.2% and 50.5%, respectively. The average number of good quality oocytes (Grade I and II) in the early stage pregnant and non-pregnant heifers was $3.7{\pm}2.7$ and $4.9{\pm}2.6$ (Mean${\pm}$SD). Cleavage and blastocyst developmental rates in Grade I and II were 22.2% and 25.5%, and then $1.7{\pm}0.9$ and $1.4{\pm}1.1$ blastocyst per session, respectively. In conclusion, OPU technology can be used in early stage pregnant and non-pregnant heifers without any problem and so applied OPU derived embryo production to maximize the ability of genetically valuable females.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.469-481
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• 1993

Gametic biotechnologies involve the procedures which are utilized for procuring reproductive success through the mimicry of in vivo events as in in vitro fertilization, embryo transfer etc. With the realization that the oviduct performs most of the procedures mimicked in vitro under normal in vivo situations, the need to master the oviduct therefore, becomes paramount. The oviduct being an exocrine gland (with its output of glycoproteins) and possibly an ecdocrine gland must be implicated in all the preimplantational procedures of reproduction, which include ovulation, oocyte maturation, sperm capacitation, gametic and embryonal nutrition, fertilization, and implantation. The evidences in the literature for the implication of the oviduct in these processes are examined. It is concluded that there is a need for the mastery of oviductual activity in order to maximize the successes of the procedures in vitro, and provide gametic manipulations which will have high success rates in implantation that is the ultimate after of in vitro fertilization for reproductive success.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.966-975
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• 1999

Technologies on preimplantation porcine embryos have been developed quickly and significantly. Successful development of systems for culture of porcine zygotes to the blastocyst stage has made it possible to utilize follicular oocytes for in vitro production of embryos and thus stimulated research on various embryo technologies. Recent technological development of embryo cryopreservation, separation of X- and Y-bearing spermatozoa and non-surgical embryo transfer has also made it easy to utilize in vivo- and in vitro-produced embryos for artificial manipulation to produce clones and transgenic pigs. Further progress in overcoming various problems associated with each embryo technology will result in acceptable efficiency to utilize porcine embryos with a high or increased quality. Combining these technologies will accelerate further expansion of the swine industry not only for meat production but also for the production of therapeutic recombinant proteins and xonografts.

• BMB Reports
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• v.52 no.8
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• pp.482-489
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• 2019

Reproductive biotechnology has developed rapidly and is now able to overcome many birth difficulties due to infertility or the transmission of genetic diseases. Here we introduce the next generation of assisted reproductive technologies (ART), such as mitochondrial replacement technique (MRT) or genetic correction in eggs with micromanipulation. Further, we suggest that the transmission of genetic information from somatic cells to subsequent generations without gametes should be useful for people who suffer from infertility or genetic diseases. Pluripotent stem cells (PSCs) can be converted into germ cells such as sperm or oocytes in the laboratory. Notably, germ cells derived from nuclear transfer embryonic stem cells (NT-ESCs) or induced pluripotent stem cells (iPSCs) inherit the full parental genome. The most important issue in this technique is the generation of a haploid chromosome from diploid somatic cells. We hereby examine current science and limitations underpinning these important developments and provide recommendations for moving forward.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.15-15
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• 2001

We recently demonstrated that satellite regions exhibit an aberrant DNA methylation in cloned bovine embryos. Here, we examined, using bisulfite -sequencing technology, whether the inefficient demethylation of cloned donor genomes could be rescued by the presence of oocytic nuclei. Both AciI digestion and sequencing analyses showed that satellite sequence was demethylated more efficiently in cloned tetraploid blastocysts than in diploid clones. When methyl -CpG density (the number of methyl-CpG sites per string) was scored, a significant decrease was observed In tetraploids (P<0.001). These results suggest that unknown mechanisms provided by oocytic nuclei could assist the demethylation of satellite sequences in tetraploid clones.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.153-160
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• 1989

The effect of antisperm antibodies (ASA) on the human in vitro fertilization (lVF) process was evaluated by analyzing the IVF data between October and December 1988 at Seoul National University Hospital prospectively. The immunobead test (IBT) was used to identify Ig G, Ig A, and Ig M in the serum, semen, and follicular fluid from 93 couples undergoing in vitro fertilization-embryo transfer (lVF-ET ) . The fertilization rate in couples with ASA to sperm head of at least one isotype in female serum (n= 10) was significantly less than that in couples without ASA to sperm head (n=83; 28.5% versus 45.3% , p=0.028). The presence of ASA to sperm head in follicular fluid (n=8) also reduced fertilization rate from 45.3% to 24.4% (p=O.0l3). However, ASA binding to sperm head in male serum and semen did not predict fertilization. Similarly, ASA binding to sperm tail and tail-tip did not reduced the oocyte fertilization rate significantly in any of the fluids tested. The zygote cleavage rate was not reduced in the presence of ASA. These results suggest that the presence of ASA to sperm head in female serum and follicular fluid is associated with reduced fertilization in IVF-ET. Another observation is that the oocyte that do fertilize in the presence of antisperm antibodies can subsequently proceed with normal cleavage. The results of this investigation therefore suggest that the IBT is a useful test forscreening of women participat.ing IVF-ET program.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.1
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• pp.40-46
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• 2017

Objective: To describe in vitro development of human embryos derived from an individual with a homozygous pathogenic variant in NLRP7 (19q13.42) and recurrent hydatidiform mole (HM), an autosomal recessive condition thought to occur secondary to an oocyte defect. Methods: A patient with five consecutive HM pregnancies was genomically evaluated via next generation sequencing followed by controlled ovarian hyperstimulation, in vitro fertilization (IVF) with intracytoplasmic sperm injection, embryo culture, and preimplantation genetic screening. Findings in NLRP7 were recorded and embryo culture and biopsy data were tabulated as a function of parental origin for any identified ploidy error. Results: The patient was found to have a pathogenic variant in NLRP7 (c.2810+2T>G) in a homozygous state. Fifteen oocytes were retrieved and 10 embryos were available after fertilization via intracytoplasmic sperm injection. Developmental arrest was noted for all 10 embryos after 144 hours in culture, thus no transfer was possible. These non-viable embryos were evaluated by karyomapping and all were diploid biparental; two were euploid and eight had various aneuploidies all of maternal origin. Conclusion: This is the first report of early human embryo development from a patient with any NLRP7 mutation. The pathogenic variant identified here resulted in global developmental arrest at or before blastocyst stage. Standard IVF should therefore be discouraged for such patients, who instead need to consider oocyte (or embryo) donation with IVF as preferred clinical methods to treat infertility.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.639-645
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• 1997

The objectives of the present study were improvements in the efficiency of developmental rates to morula and blastocyst stages to produce a large number of genetically identical nuclear transplanted embryos. The oocytes collected from slaughterhouse ovaries were matured 24h in TCM199+10% FBS and exposed to $39^{\circ}C$ or room temperature to allow cytoplasmic maturation and gain activation competence. Donor embryos were treated for 12h with $10{\mu}g/ml$ nocodazole or $0.05{\mu}g/ml$ demicolcine to synchronize the cell cycle stage at 26h after the onset of culture. The blastomeres and recipient oocytes were fused by electrofusion. The cloned embryos were then cultured in various conditions to allow further development. In the treatment of oocyte activation and cell cycle regulation of donor nuclei, the room temperature exposure and nocodazole treatment group had significant effect on the developmental rates to morula/blastocyst(21.7% vs 12.1~16.7%), but had no significant effect on the fusion rates between donor blastomeres and recipient oocytes. The developmental rates of bovine nuclear transplanted embryos appeared to be higher significantly in mTALP medium under 5% $O_2$ condition and in TCM199 with bovine oviduct epithelial cell under 20% $O_2$ condition(22.2%) than other groups. In embryo transfer of nuclear transplanted embryos, there were no significant differences in calving rates between the use of excellent and good grade donor embryos.