• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.325-333
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• 1997

The use of hormonal stimulation in human in vitro fertilization and embryo transfer (IVF-ET) leads to increased production of embryos for ET. So to avoid high pregnancies and to allow conception in future, unstimulated cycles, cryopreservation of spare embryos is desirable. One of the improvement of cryopreservation methods is vitrification. We cryopreserved mouse day 3 embryos by vitrification using the three different vitrification solution (EFS40, VS11 and VS3a). EFS40 solution is consisted of 40% (v/v) ethylene glycol, Ficol170 30% (w/v) and 0.5M sucrose and VS11 is 6.0M ethylene glycol and 1.8M glycerol. And VS3a is 6.5M glycerol and 6% (w/v) BSA (bovine serum albumin). First we tested the toxicity of three vitrification solution by exposure to these solution during 3 min. After washing by thawing solution, the survival rates of each groups are 95.5%, 90.9% and 84.4% (EFS40, VS11 and VS3a). High percentages of them developed to expanded blastocyst and hatching embryos in culture 48hrs 94.2%, 97.7%, 100% and 97.4% (no treatment group, EFS40, VS11 and VS3a). So there is no significant differences among the each group. Second, after thawing of vitirfied embryos, the survival rates of each groups are 96.8% (slow freeze), 94.1% (EFS40), 85.5% (VS11) and 80.0% (VS3a, P vs. no freeze or EFS40 is 0.01). Vitrified embryos exhibited a high rate of development in vitro after 48hrs culture. The percentages of each group to blastocyst and hatching embryos are 88.7% (no freeze), 91.8% (slow freeze), 93.4% (EFS40), 87.7% (VS11) and 73.0% (VS3a, P vs. other group is 0.01). The results suggest that there is no significant differences in exposure of various vitrification solution and day 3 mouse embryos can be vitrified in solution EFS40 and VS11 by simple procedure.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.52-52
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• 2003

Granulocyte-macrophage colony stimulating factor (GM-CSF) is synthesized in the female reproductive tract and has been shown to play an important role in human and murine embryo development and implantation. However, the mechanism of GM-CSF on the embryo development is unknown. Recent studies suggested that GM-CSF may be increase the expression of implantation relented genes, such as interleukin-1 (IL-1) system. Our aim of this study was to compare the interleukin-1$\alpha$ (IL-1$\alpha$), interleukin-1$\beta$ (IL-1$\beta$) and interleukin-1 receptor antagonist (IL-lra) mRNA between the GM-CSF supplemented group and control group in mouse embryos. Mouse 2-cell embryos were cultured in P-1 medium supplemented with or without mouse GM-CSF (10 ng/ml). The number of total and apoptotic cell in blastocyst were assessed by TUNEL. And then, the expression of IL-1$\alpha$, IL-1$\beta$ and IL-1ra mRNA in blastocyst were examined by RT-PCR.

• 한국동물생명공학회지
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• 제39권1호
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• pp.48-57
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• 2024

Background: Cadmium (Cd) is toxic heavy metal that accumulates in organisms after passing through their respiratory and digestive tracts. Although several studies have reported the toxic effects of Cd exposure on human health, its role in embryonic development during preimplantation stage remains unclear. We investigated the effects of Cd on porcine embryonic development and elucidated the mechanism. Methods: We cultured parthenogenetic embryos in media treated with 0, 20, 40, or 60 µM Cd for 6 days and evaluated the rates of cleavage and blastocyst formation. To investigate the mechanism of Cd toxicity, we examined intracellular reactive oxygen species (ROS) and glutathione (GSH) levels. Moreover, we examined mitochondrial content, membrane potential, and ROS. Results: Cleavage and blastocyst formation rates began to decrease significantly in the 40 µM Cd group compared with the control. During post-blastulation, development was significantly delayed in the Cd group. Cd exposure significantly decreased cell number and increased apoptosis rate compared with the control. Embryos exposed to Cd had significantly higher ROS and lower GSH levels, as well as lower expression of antioxidant enzymes, compared with the control. Moreover, embryos exposed to Cd exhibited a significant decrease in mitochondrial content, mitochondrial membrane potential, and expression of mitochondrial genes and an increase in mitochondrial ROS compared to the control. Conclusions: We demonstrated that Cd exposure impairs porcine embryonic development by inducing oxidative stress and mitochondrial dysfunction. Our findings provide insights into the toxicity of Cd exposure on mammalian embryonic development and highlight the importance of preventing Cd pollution.

• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.319-326
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• 1996

본 연구는 인간의 체외수정 program으로 부터 생산된 여분의 배반포기 배를 이용하여 현미경에 의한 형태학적 판정과 differential labelling 기법을 이용한 세포 수의 상관관계를 조사하고자 실시하였다. 공시된 인간 배반포기 배는 체외수정 후 5일째에 36명의 환자로부터 76개를 얻어 배반포강의 확대와 투명대 두께의 감소를 기준으로 early (ErB), early expanding (BEB), middle expanding (MEB) 및 expanded blastocyst (EdB)로 구분하였다. 분류된 배반포기 배의 크기와 투명대의 두께를 micrometer로 측정하였을 때, 그 크기는 각각 $148.8-217.6{\mu}m$, $1.2-14.4{\mu}m$로 나타나 같은 배양조건에서 생산된 배아라도 그 차이는 크게 나타났다. Hoechst 염색을 이용하여 배반포기 배의 총 세포수를 조사하였을 때, 체외수정 후 5일째 생산된 배반포기 배는 ErB $(39.1{\pm}3.6)$ 에서 EdB $(89.6{\pm}3.3)$ 로 진행되는 동안 두배에서 세배정도 증가되는 양상을 나타내었다. 또한, differential labelling기법 을 이용한 배반포기 배의 inner cell mass (ICM) 와 trophectoderm (TE) 세포수 조사 결과, 각각 $11.9{\pm}1.8-22.2{\pm}4.3$, $24.5{\pm}3.6-70.0{\pm}7.7$을 나타내어 발달이 진행될수록 ICM과 TE세포수도 증가되는 것을 알 수 있었다. 특히, 형태학적으로 약한 ICM으로 판정된 EdB의 경우 differential labelling 후, 역시 적은 ICM 세포수를 나타내어 형태학적 판정과 세포수간에 밀접한 상관관계가 있음을 알 수 있었다. 따라서, ICM과 TE를 differential labelling하는 기법은 인간 배반포기 배의 quality를 평가하는데 매우 유용한 기법으로 형태학적인 구분과 병용된다면 인간 배반포기 배 이식 program의 임신율 증진을 위한 배아 선별의 중요한 자료로서 이용될 수 있다는 것을 시사한다.

• Reproductive and Developmental Biology
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• 제34권4호
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• pp.283-288
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• 2010

During normal early embryonic development in mammals, the global pattern of genomic DNA methylation undergoes marked. changes. The level of methylation is high in male and female gametes. Thus, we cloned the cDNA of the porcine DNA methyltransferase 1 (Dnmt1) gene to promote the efficiency of the generation of porcine clones. In this study, porcine Dnmt1 cDNA was sequenced, and Dnmt1 mRNA expression was detected by reverse transcription-polymerase reaction (RT-PCR) in porcine tissues during embryonic development. The porcine Dnmt1 cDNA sequence showed more homology with that of bovine than human, mouse, and rat. The complete sequence of porcine Dnmt1 cDNA was 4,774-bp long and consisted of an open reading frame encoding a protein of 1611 amino acids. The amino acid sequence of porcine DNMT1 showed significant homology with those of bovine (91%), human (88%), rat (76%), and mouse (75%) Dnmt1. The expression of porcine Dnmt1 mRNA was detected during porcine embryogenesis. The mRNA was detected at stages of porcine preimplantation development (1-cell, 2-cell, 4-cell, 8-cell, morula, and blastocyst stages). It was also abundantly expressed in tissues (lung, ovary, kidney and somatic cells). Further investigations are necessary to understand the complex links between methyltransferase 1 and the transcriptional activity in cloned porcine tissues.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.123-129
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• 2011

The pig has been considered to serve as an appropriate model of human disease. Therefore, establishment of porcine embryonic stem cell lines is important. The purpose of the present study was to further work in this direction. We produced porcine parthenogenetic embryos, and separately aggregated two of each of two-cell ($2{\times}2$), four-cell ($2{\times}4$), and eight-cell ($2{\times}8$) embryos derived by parthenogenesis. After culture for 4 days, the developmental ability of the aggregates and total blastocyst cell numbers were evaluated. The percentage of blastocysts was significantly higher in both $2{\times}4$- and $2{\times}8$-aggregated embryos ($58.3{\pm}1.9%$ and $37.2{\pm}2.8%$, respectively) than in the control or $2{\times}2$-aggregated embryos ($23.6{\pm}1.1%$ and $12.5{\pm}2.4%$, respectively). Total blastocyst cell numbers were increased in the $2{\times}4$- and $2{\times}8$-aggregated embryos (by $44{\pm}3.0%$ and $45{\pm}3.3%$, respectively) compared with those of control or $2{\times}2$-aggregated embryos ($30.5{\pm}2.1%$ and $30.7{\pm}2.6%$, respectively; p<0.05). The levels of mRNA encoding Oct-4 were higher in both the $2{\times}4$- and $2{\times}8$-aggregated embryos than in the control. When blastocysts derived from $2{\times}4$- aggregated embryos or intact normal embryos were cultured on mouse embryonic fibroblast feeder cells to obtain porcine stem cells, blastocysts from aggregated embryos formed colonies that were better in shape compared with those derived from intact blastocysts. Together, the data show that aggregation of porcine embryos not only improves blastocyst quality but also serves as an efficient procedure by which porcine embryonic stem cells can become established.

• Clinical and Experimental Reproductive Medicine
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• 제27권1호
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• pp.39-46
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• 2000

Objective: A number of studies to improve in vitro culture conditions have been tried over past ten years by using co-culture system with helper somatic cells. However, the mechanism of coculture is poorly understood. This study was designed to understand the mechanism for the mode of actual action of co-culture using co-culture system of ICR strain's 1-cell embryos with human oviduct epithelial cells by examining the effect of conditioned medium and contactless coculture using a cell culture insert on the embryo development and by measuring the level of superoxide anion from conditioned medium after co-culture. Methods: ICR strain's zygote embryos were cultured in medium alone (control), coculture, conditioned medium, or contactless coculture system for 6 days. Conditioned media (CM) were prepared as following 5 groups. All CM were collected after culturing oviduct cells for 2 days. CM-1 was stored at $-20^{\circ}C$ until use, and CM-2 was prepared just before use as a culture medium. CM-3 was cocultured with embryos and retrieved just before use. CM-4 and CM-5 were derives from the microfilteration of CM-2 and CM-3, respectively, using Microcon-10 (10 kDa molecular weight cut-off). The percentage of the embryos developed to hatched blastocyst stage and the level of superoxide anion in supernatant from medium alone culture (control), coculture, and contactless coculture were measured. Results: The rates of embryo development to the hatched blastocyst stage were significantly higher in coculture (43%) than in control (0%) (p<0.05). The CM-1 group had no embryo development since 2-cell embryonic stage, whereas the CM-2, CM-3, CM-4 and CM-5 groups had the improved development to 4 or 8 cell embryo stage, but the similar rate of development to hatched blastocyst compared to control. The effect of coculture on embryo development was disappeared in the contactless coculture group. The level of superoxide anion was significantly reduced in coculture group compared to control. Conclusion: It is concluded that the present coculture system overcomes the 2-cell block in vitro and improves the embryo development. This beneficial effect may be due to the direct cell-cell contact between embryo and helper cells or the removal of deleterious components from medium rather than the embryotrophic factors.

• Clinical and Experimental Reproductive Medicine
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• 제24권3호
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• pp.377-383
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• 1997

The effects of embryo number and incubation volume on the development of mouse embryos were evaluated. The growth rate of two-cell mouse embryos to attached blastocyst stage and the growth rate of blastocysts to early somite stage were assessed after culture in different incubation volumes and embryo densities. Embryos were collected from ICR female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by ICR males. In experiment 1, groups of one, five, ten, twenty 2-cell embryos were cultured in 10-, 50-, 500-, 1000-${\mu}l$ drops of BWW media under mineral oil at $37^{\circ}C$ in a humidified atmosphere of 5% $CO_{2}$ and 95% air. As the incubation volume decreased, significantly (p<0.05) higher rates of embryos reached morular and blastocyst stage on day 3 and 4 culture, respectively. In experiment 2, groups of one, five, ten, twenty blastocysts were cultured in 1- and 2-ml volumes of CMRL 1066 media under same condition as in experiment 1. However the reverse was the result. Decreasing the number of embryos incubated per volume from 1 to 20 significantly (p<0.05) increased the number of blastocysts reaching the late egg cylinder (LEC) and early somite (ES) stage on day 6 and 8 culture, respectively, regardless of incubation volume. Blastocysts cultured in 2ml had higher (p<0.05) development rates to LEC and ES stage on day 6 and 8 culture, respectively, than embryos cultured in 1ml. Our results suggest that the effects of embryo number and incubation volume on the development of mouse embryos are stage specific and the shifting point was between hatching and EEC stage.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 춘계학술세미나 및 워크숍
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• pp.19-25
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• 2002

Researches on manipulation pluripotent stem cells derived from blastocysts or promordial germ cells (PGCs) have a great advantages for developing innovative technologies in various fields of life science including medicine, pharmaceutics, and biotechnology. Since the first isolation in the mouse embryos, stem cells or stem cell-like colonies have been continuously established in the mouse of different strains, cattle, pig, rabbit, and human. In the animal species, stem cell biology is important for developing transgenic technology including disease model animal and bioreactor production. ES cell can be isolated from the inner cell mass of blastocysts by either mechanical operation or immunosurgery. So, mass production of blastocyst is a prerequisite factor for successful undertaking ES cell manipulation. In the case of animal ES cell research, various protocol of gamete biotechnology can be applied for improving the efficiency of stem cell research. Somatic cell nuclear transfer technique can be applied to researches on animal ES cells, since it is powerful tool for producing clone embryos containing genes of interest. In this presentation, a brief review was made for explaining how somatic cell nuclear transfer technology could contribute to improving stem cell manipulation technology.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.258-264
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• 2000

Production systems for cloned pigs are very important not only for an increase in production of superior animals but also for the production of knockout animals with organs that do not contain antigens for xenotransplantation or to analyze functions of isolated human genes. At present, however, effective systems have not been developed. We have tried to produce cloned pigs by transfering cultured cells into enucleated oocytes and obtained some cloned embryos. To develop a production system for cloned pigs, the basic technologies needed to support such an effort must be improved.