• 보건행정학회지
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• 제14권3호
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• pp.97-121
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• 2004

Recently, human embryonic stem cell research raises exciting public expectation on medical possibilities as well as ethical debate. Embryo management has become an integral part of the management of infertility treatment, researches on embryo and human embryonic stem cells and so on. Britain has permitted the research on stem cells derived from human embryo which made the first nation to allow the cloning of human embryo for the stem cell research. However, new technologies such as the assisted reproductive technologies and human embryonic stem cell research continue to pose an increasing source of ethical dilemmas for physician, scientists, legislators, religious authorities and the general publics to deal with. None the less, the United Kingdom has adopted the most liberal policies regarding human embryo and human embryonic stem cell research. The implication of the British embryo management system are as follows: 1) the development of reproductive technologies and new stem cell research technologies continue to pose legal and ethical debates, since those involve several parties; 2) the UK has taken the legal and institutional approaches to cope with those serious issues; 3) the UK adopted most liberal policies regarding embryonic and human embryonic stem cell researches; 4) the British HFE Act is consistent with the existing Acts related to human embryo management and researches; 5) through amending the HFE Act to accomodate the changes of technologies, the UK try to minimize the legal and ethical burden on undertaking research regarding embryo. The debates about the researches on human embryo and human embryonic stem cells is likely to continue in the Korean society. Because of the controversy and competing ethical values, as well as the evolving technologies, so far no consensus exists in our society. It suggest that it is premature to bring closure by ruling out any particular approaches. Thus our society needs to make an efforts to find a basis which could resolve the societal controversies through enriching the societal conversation about the profound ethical issues regarding embryo management.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.319-327
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• 2009

Follicular fluid meiosis-activating sterol (FF-MAS) has been suggested as a positive factor which could improve the oocyte quality and subsequent embryo development after in vitro fertilization. However, FF-MAS is a highly lipophilic substance and is hard to detect in studying the relationship between MAS and quality of oocyte maturation. The present study focused on the expression of lanosterol 14${\alpha}$-demethylase (LDM), a key enzyme that converts lanosterol to FF-MAS, on mouse oocyte maturation and its potency on development. LDM expression was strong in gonadotropin-primed germinal vesicle stage oocytes, weak after germinal vesicle breakdown (GVBD), and then strong in MII stage oocytes. The LDM-specific inhibitor azalanstat significantly inhibited oocyte fertilization (from 79.4% to 68.3%, p<0.05). Also, azalanstat (5 to 50 ${\mu}M$) decreased the percentage of blastocyst development dosedependently (from 78.7% to 23.4%, p<0.05). The specific inhibition of sterol ${\Delta}14$-reductase and ${\Delta}7$-reductase by AY9944 accumulates FF-MAS and could increase blastocyst development rates. Additionally, in the AY9944 group, the rate of inner cell mass (ICM)/ total cells was similar to that of in vivo development, but the rate was significantly decreased in azalanstat treatment. In conclusion, LDM, the key enzyme of FF-MAS production, may play an important role in fertilization and early development of the mouse embryo, especially in vitro.

• 한국수정란이식학회지
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• 제13권1호
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• pp.43-52
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• 1998

The embryogenesis stimulating activity(ESA) had been shown in co-culture of embryos with bovine oviduct epithelial cell(BOEC) and culture in BOEG-conditioned medium. The present study was undertaken to purify and quantify the embryotropic proteins and to determine the optimum concentration of the embryotropic protein for the proper development of embryos. In BOEC-conditioned medium, five major bands of proteins were detected(66, 53, 40, 32 and 24 kDa) by SDS-PAGE. From these proteins, 288pg of protein that had a 32kDa molecular weight was purified by gel filtration column and perfusion chromatography ion-exchange column. When purified protein was supplemented to the in vitro culture media at various concentrations in protein-free media, 2.5$\mu$g /ml supplement group showed significantly higher rates of embryo development into morula /blastocyst stages than other groups(p<0.05). In conclusion, we purified 32kDa protein from BOEC-conditioned medium and this protein showed optimum embryogenesis stimulating effect at 2.5$\mu$g /ml.

• 한국수정란이식학회지
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• 제16권1호
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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.

• 한국동물학회지
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• 제35권2호
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• pp.144-148
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• 1992

Insulin and transfenin (Tf) were found to be essential for suwival and differentiation of brain neuroblasts obtained from chick embryo. This requirement, however, is Changed from insulin to Tf upon neuronal development of the embryo, and this phenomenon is due to the changes in the levels of corresponding receptors. Using cultured neuroblasts, the level of Tf receptor is also found to increase Lvhile that of insulin receptor falls dramatically during the course of the cell differentiation. These results suggest that the development-specific changes in the levels of insulin and Tf receptors in embryo can be reproduced in the culture system during the differentiation period. Because the culture system used was a defined medium and contained no other macromolecules than insulin and Tf, it appears possible that insulin and Tf may act as signalling molecules in the control of neuronal development.

• Asian-Australasian Journal of Animal Sciences
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• 제24권11호
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• pp.1541-1546
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• 2011

This study was carried out to examine the influence of minimum essential medium (MEM) vitamins supplementation to in vitro maturation medium and in vitro culture medium on the development of porcine embryos. Porcine embryo development was investigated following cultivation in both in vitro maturation and culture medium with the supplementation of MEM vitamins (0, 0.1, 0.2 and 0.4%) using immature oocytes collected from the ovary of prepubertal gilts. Embryo development was observed and the total cell number in each blastocyst generated under the culture conditions was quantified following supplementation of the medium. The embryonic development rate of the blastocyst and hatched blastocyst was higher, but not significantly so, when 0.4% MEM vitamins were supplemented to the in vitro maturation medium of the porcine oocyte. Interestingly, the total number of cells in the blastocyst was significantly higher in the in vitro maturation MEM vitamins supplemented group compared to either the untreated group or the group which had MEM vitamins supplemented to both in vitro maturation and in vitro culture medium simultaneously (p<0.05). Therefore, the supplementation of 0.4% MEM vitamins to the in vitro mature medium has a beneficial effect on the embryonic development of in vitro produced blastocysts derived from the immature porcine oocytes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.87-87
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• 2003

Taurine (2-aminoethanesulfonic acid, $^{+}NH_3CH_2CH_2{SO_3}^{-}$) is endogenous $\beta$-amino acid which is essential in fetal nutrition and development and is present in abundant quantities in several tissues of fetus. In utero, taurine deficiency causes abnormal development and abnormal function of brain, retina, kidney and myocardium. Thus, transfer of taurine into fetus is important during embryonic development. Taurine transporter (TauT) has 12 hydrophobic membrane -spanning domains, which is typical of the $Na^{+}$- and $Cl^{-}$-dependent transporter gene family. Among the various biosynthetic enzymes of taurine, cysteine sulfinic acid decarboxylase (CSD) is the rate-limiting enzyme for biosynthesis of taurine. However, the enzyme activities of taurine biosynthesis are limited in early stage of embryonic development. To analyze the expression period of TauT and CSD during embryonic development, we have investigated the gene expression of TauT and CSD using reverse transcriptase polymerase chain reaction (RT-PCR) in mouse and chicken embryos. RT-PCR anaylsis revealed that both TauT and CSD mRNAs were already expressed at Day-4.5 in mouse embryo. In chicken whole embryo, TauT and CSD mRNAs began to appear on developing times of 48 hrs and 12 hrs, respectively. TauT mRNA was detected in the organs of heart, brain and eye of the day-3 chicken embryo. Our data show that TauT and CSD mRNAs were expressed in early stage of embryonic development.

• 한국수정란이식학회지
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• 제30권1호
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• pp.33-43
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• 2015

Successful somatic cell nuclear transfer (SCNT) has been reported across a range of species using a range of recipient cells including enucleated metaphase II (MII) arrested oocytes, enucleated activated MII oocytes, and mitotic zygotes. However, the frequency of development to term varies significantly, not only between different cytoplast recipients but also within what is thought to be a homogenous population of cytoplasts. One of the major differences between cytoplasts is the activities of the cell cycle regulated protein kinases, maturation promoting factor (MPF) and mitogen activated protein kinase (MAPK). Dependent upon their activity, exposure of the donor nucleus to these kinases can have both positive and negative effects on subsequent development. Co-ordination of cell cycle stage of the donor nucleus with the activities of MPF and MAPK in the cytoplast is essential to avoid DNA damage and maintain correct ploidy. However, recent information suggests that these kinases may also effect reprogramming of the somatic nucleus and preimplantation embryo development by other mechanisms. This article will summarise the differences between cytoplast recipients, their effects on development and discuss the potential role/s of MPF and or MAPK in nuclear reprogramming.

• Animal Bioscience
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• 제35권2호
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• pp.177-183
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• 2022

Objective: The present study evaluated the efficiency of embryo development and pregnancy of somatic cell nuclear transfer (SCNT) embryos using different source-matured oocytes in Camelus dromedarius. Methods: Camelus dromedarius embryos were produced by SCNT using in vivo- and in vitro- matured oocytes. In vitro embryo developmental capacity of reconstructed embryos was evaluated. To confirm the efficiency of pregnancy and live birth rates, a total of 72 blastocysts using in vitro- matured oocytes transferred into 45 surrogates and 95 blastocysts using in vivo- matured oocytes were transferred into 62 surrogates by transvaginal method. Results: The collected oocytes derived from ovum pick up showed higher maturation potential into metaphase II oocytes than oocytes from the slaughterhouse. The competence of cleavage, and blastocyst were also significantly higher in in vivo- matured oocytes than in vitro- matured oocytes. After embryo transfer, 11 pregnant and 10 live births were confirmed in in vivo- matured oocytes group, and 2 pregnant and 1 live birth were confirmed in in vitro- matured oocytes group. Furthermore, blastocysts produced by in vivo-matured oocytes resulted in significantly higher early pregnancy and live birth rates than in vitro-matured oocytes. Conclusion: In this study, SCNT embryos using in vivo- and in vitro-matured camel oocytes were successfully developed, and pregnancy was established in recipient camels. We also confirmed that in vivo-matured oocytes improved the development of embryos and the pregnancy capacity using the blastocyst embryo transfer method.

• Clinical and Experimental Reproductive Medicine
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• 제49권1호
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• pp.26-32
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• 2022

Objective: We investigated the effect of supplementing fertilization medium and/or culture medium with astaxanthin (AST) on the two phases of in vitro fertilization: gamete fertilization and embryo development. Methods: Mouse cumulus-oocyte complexes were divided into four groups with 5 µM AST added to the fertilization medium (group 3, n=300), culture medium (group 2, n=300), or both media (group 4, n=290). No AST was added to the control group (group 1, n=300). Results: The fertilization rate was significantly higher (p<0.001) in the groups using AST supplemented fertilization medium (group 3, 79.0%; group 4, 81.4%) than those without AST (group 1, 56.3%; group 2, 52.3%). The blastocyst rate calculated from the two-cell stage was significantly lower (p<0.001) in the groups using AST-supplemented embryo culture medium (group 2, 58.0%; group 4, 62.3%) than in those without AST (group 1, 82.8%; group 3, 79.8%). The blastocyst rate calculated from the number of inseminated oocytes was highest in group 3 (189/300, 63.0%) and lowest in group 2 (91/300, 30.3%) with statistical significance compared to other groups (p<0.001). There were significantly higher numbers of cells in the inner cell mass and trophectoderm, as well as significantly higher total blastocyst cell counts, in group 3 than in the control group. Conclusion: An increased blastocyst formation rate and high-quality blastocysts were found only in the fertilization medium that had been supplemented with AST. In contrast, AST supplementation of the embryo culture medium was found to impair embryo development.