• The Korean Journal of Zoology
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• v.27 no.1
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• pp.1-12
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• 1984

In order to investigate the alkaline phosphtase activities in the mouse oocytes in matuation and preimplantation embryos in developing in culture, the enzyme activities were measured by means of biochemical method. The in vitro effect of levamisole which is known as an inhibitor of the lakaline phosphatase was also observed on the oocyte in maturation and the embryos in early embryogenesis. The results obtained were as follows: The enzyme activity was not detected in the embryos unitl the stage of 4-cell, but it appeared first in the 4-cell embryos and the level of the activity was steady through up to the blastocyst. Levamisole inhibited the alkaline phosphatase activity in the blastocyst, and the activity decreased by almost 70% at 10 mM and 50% at 1 mM as compared with the control. In addition, levamisole inhibited completely the formation of polar body by the oocytes. and induced degeneration of the preimplantation embryos at the dose of 0.5 mM or higher.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.205-205
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• 2004

최근에 개발된 real time RT-PCR 방법은 소량의 시료에서 특정 유전자의 mRNA 발현 양상을 분석하는데 효율적으로 이용되고 있다. 특히, 난자 또는 배아와 같이 성숙과 발생단계에 따라 유전자의 발현 양상이 현저하게 변화되는 경우에는, 각각의 시료에서 발현 양상이 크게 변하지 않는 대조군으로 사용할 수 있는 유전자를 이용한 비교, 분석이 중요하다. 본 연구에서는 생쥐의 난자와 초기 배아를 이용한 real time RT-PCR에서 mRNA의 추출방법과 형광 probe의 사용 유무 그리고 대조군으로 사용되고 있는 유전자들에 대한 검증을 시행하였다. (중략)

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.234-242
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• 2014

In this study, gametotoxicity and embryotoxicity experiments using Hemicentrotus pulcherrimus were carried out to investigate the ecotoxicological effects of bisphenol A (BPA). We examined the effects of BPA on fertilization and normal embryogenesis at various concentrations (0, 300, 500, 800, 1000, and 1500 ppb). The results demonstrated that the fertilization rates were not changed. The normal embryogenesis rates were gradually decreased in a dose-dependent manner, and were significantly lowered following 800 ppb BPA treatment ($EC_{50}$=1056.1 ppb, 95% Cl=981.8~1163.9 ppb). The observed effective concentration and the lowest observed effective concentration of the normal embryogenesis rate were 500 ppb and 800 ppb, respectively. The embryos showed retarded development at each tested concentration, indicating the fact the embryonic development was delayed due to the increasing concentrations of BPA. Furthermore, we examined the expression of glutathione S-transferase (GST) mRNA at various concentrations of BPA in H. pulcherrimus. Interestingly, it was found that the expression level of GST mRNA was significantly increased in the experimental group exposed to BPA. Based on these results, we suggested that BPA at greater than 800 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and GST mRNA may be used as a biomarker for risk assessment of BPA contamination.

• Development and Reproduction
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• v.15 no.4
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• pp.385-391
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• 2011

Human in vitro fertilization and embryo transfer (IVF-ET) program is a general procedure for infertile couples since first successful delivery on 1978 in UK and Korean first on 1985. Recently in Korea, more than 42,000 cases per year of IVF-ET were performed and showed good pregnancy rates compared worldwide data. The human IVF-ET procedure use many consumables, such as ovum pick-up (OPU) needles, centrifuge tubes, culture dish, ICSI pipette, culture media and ET catheters. Major of these materials are supported by the global companies. Thus, Korean IVF-ET program might be placed unstable situation by global economical risks. These uncertain problems could be overcome by the domestic production of IVF-ET materials and consumables. Two times questionnaires for Korean clinicians and researchers about the domestic production were performed and analyzed. Many of them requested domestic OPU needles, ET catheters, culture media and ICSI pipettes under good quality control and quality assurance system. This trial may be contributed to industrialization and to global competence of Korean IVF-ET program. The results of this survey can be provide a fundamental base for development and production of domestic materials and consumables for human IVF-ET program.

• Development and Reproduction
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• v.13 no.4
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• pp.305-312
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• 2009

Multipotent spermatogonial stem cells (mSSCs), derived from uni-potent SSC, are a type of reprogrammed cells with similar characteristics to embryonic stem cells (ESCs). The aim of this study was to evaluate the potential for transgenesis of mSSC derived from outbred mice and the production of transgenic animal by the mSSC-insertion into embryo. mSSCs, established from outbred mice (ICR strain) in the previous study, were maintained and then transfected with a lenti-viral vector expressing green fluorescent protein (GFP), CS-CDF-CG-PRE. Embryonic stem cells (ESCs) were derived from inbred transgenic mice (C57BL/6-Tg (CAG-EGFP)) and were used as an experimental control. Transfected mSSCs were well proliferated in vitro and maintained their characteristics and normal karyotype. Ten to twelve mSSCs and ESCs were collected and inserted into perivitelline space of 8-cell mouse embryos, and then transferred them into uteri of poster mothers after an additional 2-days of culture. Percentage of mSSC-derived offsprings was 4.8% (47/980) and which was lower than those (11.7% (67/572)) of ESC-derived ones (P<0.05). However, even though different genetic background of mSSC and ESC origin, the production efficiency of coat-colored chimeric offspring in mSSC group was not different when compared it with ESC (6.4% (3/47) vs. 7.5% (5/67)). From these results, we confirmed that mSSC derived from outbred mice has a pluripotency and a potential to produce chimeric embryos or mice when reaggregatation with mSSC is performed.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.34-35
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• 1998

• Korean Journal of Environment and Ecology
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• v.18 no.3
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• pp.340-345
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• 2004

The embryotoxic effects of PCB (Aroclor 1248) on a Korean frog, Rana dybowskii was deter-mined by using the FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol. The rates of mortality and malformed larvae were investigated by probit analysis. The results showed that PCB is highly embryolethal. From LC$_{50}$ of 1.48ppb and from EC$_{50}$ of 0.25ppb and TI of 5.7 were derived, which indicates PCB is to be considered a teratogenic compound. Specific malformations occurred in 62.0% as edema at the 0.1ppb, in 32.0% as tail deformations at the 1ppb, and in 68.0% as profound deformations at the 5ppb of PCB concentration which living embryos were exposed to. PCB suppressed the growth of head-tail length at a relatively low concentration (1.0ppb), and therefore growth inhibition as assessed by embryo length can be used as a sensitive indicator to evaluate the toxicity of pollutants in the environment. In conclusion, PCB must be considered highly embryotoxic to Rana dybowskii.

• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.42-43
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• 1999

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.311-319
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• 2009

Objective: Human embryonic stem cells (hESCs) have the capacity to differentiate into all of the cell types and therefore hold promise for cell therapeutic applications. In order to utilize this important potential of hESCs, enhancement of currently used technologies for handling and manipulating the cells is required. The cryopreservation of hESC colonies was successfully performed using the vitrification and slow freezing-rapid thawing method. However, most of the hESC colonies were showed extremely spontaneous differentiation after freezing and thawing. In this study, we were performed to rapidly collect of early passage hESCs, which was thawed and had high rate of spontaneously differentiation of SNUhES11 cell line. Methods: Four days after plating, partially spontaneously differentiated parts of hESC colony were cut off using finely drawn-out dissecting pipette, which is mechanical separation method. Results: After separating of spontaneously differentiated cells, we observed that removed parts were recovered by undifferentiated cells. Furthermore, mechanical separation method was more efficient for hESCs expansion after thawing when we repeated this method. The recovery rate after removing differentiated parts of hESC colonies were 55.0%, 74.5%, and 71.1% when we have applied this method to three passages. Conclusion: Mechanical separation method is highly effective for rapidly collecting and large volumes of undifferentiated cells after thawing of cryopreserved early passage hESCs.

• 대한생식의학회:학술대회논문집
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• 1999.11a
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• pp.57.2-58
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• 1999