• Journal of Embryo Transfer
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• v.9 no.3
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• pp.213-220
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• 1994

생쥐 배반포로부터 내부세포괴(inner cell mass, ICM)를 outgrowth로 분리하여 증식 시킴으로써 배아주(embryonic stem, ES)세포를 확립하고자 본 실험을 실시하였다. 과배란처리와 교미에 의해 생산된 ICR 생쥐의 3.5일 배반포를 sDMEM내의 배아성 섬유아단흥배양층에 배양하여 ICM세포의 증식을 조사한 결과, 3.5일부터 분리한 ICM세포들은 배양 7, 8일에 각각 1,500 및 3,200세포의 미분화세포로 증식하였다. 이들 세포의 계대배양에 의해 잠정적인 ES세포 colony를 얻었으며 10회의 계대배양후에도 그 형태가 변하지 않았다. 이들 세포는 다능성의 분화능을 보여 전형적인 ES세포 형태를 보였다. 이 같은 결과는 ICR배반포에서 outgrowth로 분리한 ICM으로부터 ES세포 확립이 가능함을 보여준 것이다.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.684-689
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• 2005

Parametric calculation were conducted to estimate performance of variable geometry of hydrogen recirculation blower for fuel cell vehicle. The pressure rise and efficiency are effected by change of the geometric parameter of impeller and casing, and stripper clearance under various mass flow. Hydrodynamic performance were evaluated, and also the inner flow fields were investigated by CFD. Calculated results show good coincidence with experimental test results of total pressure performance. Performance of model designed by parametric calculations satisfied experimental data of verification model.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.164.2-164.2
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• 2003

Human embryonic stem (ES) cell lines derived from the inner cell mass of human blastocysts have potential to differentiate into any cell types. We have established in vitro neural differentiation of human ES cells. After the formation of embroid bodies (EBs), the differentiating EBs formed neural tube-like rosettes in the presence of basic fibroblast growth factor (bFGF). The rosettes were selectively isolated by the treatment of dispase and cultured in a medium for human neural precursors in the presence of bFGF. (omitted)

• Clinical and Experimental Reproductive Medicine
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• v.29 no.2
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• pp.129-138
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• 2002

Objective: This study was to compare the characteristics between parthenogenetic mES (P-mES) cells and in vitro fertilization mES cells. Materials and Methods: Mouse oocytes were recovered from superovulated 4 wks hybrid F1 (C57BL/6xCBA/N) female mice. For parthenogenetic activation, oocytes were treated with 7% ethanol for 5 min and $5{\mu}g$/ml cytochalasin-B for 4 h. For IVF, oocytes were inseminated with epididymal sperm of hybrid F1 male mice ($1{times}10^6/ml$). IVF and parthenogenetic embryos were cultured in M16 medium for 4 days. Cell number count of blastocysts in those two groups was taken by differential labelling using propidium iodide (red) and bisbenzimide (blue). To establish ES cells, b1astocysts in IVF and parthenogenetic groups were treated by immunosurgery and recovered inner cell mass (ICM) cells were cultured in LIF added ES culture medium. To identify ES cells, the surface markers alkaline phosphatase, SSEA-1, 3,4 and Oct4 staining were examined in rep1ated ICM colonies. Chromosome numbers in P-mES and mES were checked. Also, in vitro differentiation potential of P-mES and mES was examined. Results: Although the cleavage rate (${\geq}$2-cell) was not different between IVF (76.3%) and parthenogenetic group (67.0%), in vitro development rate was significantly low in parthenogenetic group (24.0%) than IVF group (68.4%) (p<0.05). Cell number count of ICM and total cell in parthenogenetic b1astocysts ($9.6{\pm}3.1,\;35.1{\pm}5.2$) were signficantly lower than those of IVF blastocysts ($19.5{\pm}4.7,\;63.2{\pm}13.0$) (p<0.05). Through the serial treatment procedure such as immunosurgery, plating of ICM and colony formation, two ICM colonies in IVF group (mES, 10.0%) and three ICM colonies (P-mES, 42.9%) in parthenogenetic group were able to culture for extended duration (25 and 20 passages, respectively). Using surface markers, alkaline phosphatase, SSEA-l and Oct4 in P-mES and mES colony were positively stained. The number of chromosome was normal in ES colony from two groups. Also, in vitro neural and cardiac cell differentiation derived from mES or P-mES cells was confirmed. Conclusion: This study suggested that P-mES cells can be successfully established and that those cell lines have similar characteristics to mES cells.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.239-248
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• 2015

The nature of molecular mechanisms governing embryonic cell block is largely unknown, but recent reports have demonstrated that proper execution of programmed cell death is crucial for this process. The main objective of this study is to determine effects of programmed cell death on porcine oocytes development in vitro after parthenogenesis. Among the blastocysts matured in 3MA, MAP1LC3A and ATG5 RNA gene expression level increased in the order of Cyst < 3MA < RP. However, Casp-3 and TNF-r RNA gene expression level decreased in the order of RP < 3MA < Cyst. Expression of mTOR within the RP-cultured blastocyst was the most highly to the inner cell mass, while 3MA-cultured blastocyst showed very lowest expression in inner cell mass. The expression of mTOR showed a pattern opposite to that of MAP1LC3A. That is, its expression was the lowest in Cyst group. When the enzymatic activity of MMP-2 and MMP-9 was assessed in culture, the level of active MMP-9 was higher expression in the medium of each RP treatment group, with the level of another treatment group being relatively higher. Analyses of TIMP-2 and TIMP-3 revealed that their expression was higher in groups that did not receive RP treatment. More specifically, the level of TIMP-2 was not affected by Cyst treatment, while the level of TIMP-3 was higher in 3MA and RP treatment group. There was highly cell division activation efficiency of parthenogenesis on cultured system of RP supplement IVC medium. Therefore, these results suggest that embryo development was significantly increased in conditional culture medium with active autophagy as compared to common cultured condition. Further investigation of this distinction may enable the development of innovative improvements for the production of porcine somatic cell nuclear transfer.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.11-15
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• 2004

Embryonic stem (ES) cells are derived from the inner cell mass of the blastocyst-stage embryos that can be propagated indefinitely and, at the same time, can be differentiated into all the cell types that constitute the body. Current research using ES cells is mainly focused on the efficient generation of specific cell types by employing optimal differentiation conditions, which often requires the genetic manipulation of ES cells. As a way of developing an efficient system to regulate foreign gene expression in ES cells, we have inserted the gene encoding Corynebacterium diphtheria toxin-A (DTA) into an autonomously induced plasmid under positive doxycycline control ('Tet-on' system). In this study, we demonstrate that this system can lead to the cell death of mouse ES cells by the induction of DTA expression when exposed to the tetracycline derivative, doxycycline. MTT assay showed that this induction resulted in the apoptosis of ES cells.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.157-165
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• 1997

포유류 배반포배의 epiblast는 내세포괴에 포함되어 있으며, 이 epiblast cells이 배 및 태아의 생식세포와 일반 체세포로 분화된다 (Beddington, 1986; Lawson 등, 1991). 그런데 조기에 발달된 부화배반포기 배가 지연발생된 부화배반포기 배보다도 많은 epiblast cells을 가지고 있다고 한다(Talbot 등, 1995). 그래서 본 연구에서는 체외수정 유래의 배반포배의 발육속도에 따른 내세포괴/영양배엽세포의 비율 및 배아간세포 확립 효율을 비교하여 발달일령 간에 차이가 있는지를 규명하고자 하였다. 공시한 소의 난포란을 TCM-199에 0.5$\mu\textrm{g}$/ml FSH, 5$\mu\textrm{g}$/ml LH, 10% FBS, 100 units/ml penicilin, 및 100$\mu\textrm{g}$/ml streptomycin을 첨가하여 39$^{\circ}C$, 5% CO2 조건하에서 24시간 동안 체외성숙한 후, 5$\mu\textrm{g}$/ml heparin으로 수정능이 획득된 1$\times$106 sperm/ml의 정자로 체외수정을 유도하였다. 체외수정 후 18~20시간에 과립막세포를 vortexing으로 제거하여 얻은 모든 체외수정란을 3mg/ml BSA, 20${\mu}\ell$/ml NEM amino acids, 40${\mu}\ell$/ml BME amino acids, 10mM glycine 및 1mM alanine이 함유된 CR1aa 배양액에서 BRL 단층세포와 공배양을 실시하였다. 수정후 7, 8 및 9일재 (체외수정일 : 0일)에 확장배반포기까지 발달한 수정란을 이중염색 및 배아간세포의 확립 실험에 공시하였다. 체외수정후 24시간에 분할된 총 1,145개의 수정란이 7, 8 및 9일째에 후기 배반포기까지 각각 222(15.6%), 103(7.2%) 및 52(3.6%)로 발달하여 총 377개 (26.4%)가 발달하였다. 내세포괴/영양배엽세포의 비율은 7일 및 8일째 배반포배에서 각각 47.2$\pm$11.9/95.1$\pm$24.4개 (33/67%) 및 40.3$\pm$12.4/83.3$\pm$26.9개 (33/67%)로서 9일째 배반포배의 19.3$\pm$8.1/62.3$\pm$23.1개 (24/76%) 보다 유의적(P<0.05)으로 높았다. ES-like cells을 확립하기 위하여 후기배반포기 배를 mouse embryonic fibroblast 단층 공배양기에 옮긴 후 5일에 내세포괴의 부착 여부를 판정하고, 10일에 배아간세포의 확립 여부를 판정하였다. 그 결과 7, 8 및 9일째의 배반포기배의 각각 47.7% (82/172), 30.9%(22/71) 및 15.6%(5/32)에서 배아간세포가 확립되었다. 이상의 결과에서 배반포기까지의 발육이 빠른 수정란에서 영양배엽에 대한 내세포괴세포의 비율이 높았고 배아간세포의 확립율도 높다는 사실을 입증할 수 있었으며, 이와 같은 결과에서 체외수정란 유래 배반포배의 질을 결정할 수 있을 것으로 생각된다.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.4
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• pp.237-243
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• 2002

Objective : The aim of this study was to evaluate the influence of different media on blastulation, mean cell number, percentage of inner cell mass (ICM) of total cells and ICM : trophectoderm (TE) ratio in mice. Materials and methods: A total 552 two cell embryos were retrieved from ICR female mice (4 weeks old) at 48 hr after hCG injection (mated just after hCG injection) and cultured in MEM (n=276) or TCM (n=276) supplemented with 20% hFF. The grading of blastocysts from zona-intact (ZiB) to -escape (hatching and hatched, ZeB) was performed at 72 hours after culture. Total, TE and ICM cell numbers were analyzed by differential staining of blastocyst. Statistical analysis was performed using t-test with SigmaPlot-2001. P-values < 0.05 were accepted as statistically significant. Results: The blastulation rate in MEM ($64.9{\pm}4.95%$) was significantly higher (p=0.0031) than that in TCM ($57.2{\pm}5.22%$). No differences were found in the number of ZiB and ZeB between MEM ($31.9{\pm}2.62$, $33.0{\pm}4.58%$), and TCM ($27.2{\pm}4.28$, $30.1{\pm}4.58%$). A total 314 blastocysts (MEM=166; TCM=148) were stained differentially. Mean cell number of blastocysts was significantly higher (p=0.0002) in TCM ($73.1{\pm}3.3$) than in MEM ($61.7{\pm}2.5$). Differential staining was successfully performed in 155 blastocysts (MEM=77; TCM=78). The percentage of ICM was significantly higher in MEM than in TCM ($20.9{\pm}1.3$ vs. $17.1{\pm}1.2%$, p=0.0281). The ICM : TE ratio was higher in TCM than in MEM (1 : $4.85{\pm}0.68$ vs. 1 : $3.78{\pm}0.78$, NS). Conclusion: These results show that MEM increase the blastocyst formation and percentage of ICM of total cells comparing with TCM in mice.

• Animal Bioscience
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• v.36 no.8
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• pp.1180-1189
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• 2023

Objective: Discovering the mechanism of cell specification is important to manipulate cellular lineages. To obtain lineage-specific cell lines, the target lineage needs to be promoted, and counterpart lineages should be suppressed. Embryos in the early blastocyst stage possess two different cell populations, the inner cell mass (ICM) and trophectoderm. Then, cells in the ICM segregate into epiblasts (Epi) and primitive endoderm (PrE). PrE cells in embryos show specific expression of platelet-derived growth factor (PDGF) and its receptor, PDGF receptor A (PDGFRA). In this study, we suppressed PDGF signaling using two methods (CRISPR/Cas9 injection and inhibitor treatment) to provide insight into the segregation of embryonic lineages. Methods: CRISPR/Cas9 RNAs were injected into parthenogenetically activated and in vitro fertilized embryos. The PDGF receptor inhibitor AG1296 was treated at 0, 5, 10, and 20 µM concentration. The developmental competence of the embryos and the number of cells expressing marker proteins (SOX2 for ICM and SOX17 for PrE) were measured after the treatments. The expression levels of the marker genes with the inhibitor were examined during embryo development. Results: Microinjection targeting the PDGF receptor (PDGFR) A reduced the number of SOX17-positive cell populations in a subset of day 7 blastocysts (n = 9/12). However, microinjection accompanied diminution of Epi cells in the blastocyst. The PDGF receptor inhibitor AG1296 (5 µM) suppressed SOX17-positive cells without reducing SOX2-positive cells in both parthenogenetic activated and in vitro fertilized embryos. Within the transcriptional target of PDGF signaling, the inhibitor significantly upregulated the Txnip gene in embryos. Conclusion: We identified that PDGF signaling is important to sustain the PrE population in porcine blastocysts. Additionally, treatment with inhibitors was a better method to suppress PrE cells than CRISPR/Cas9 microinjection of anti-PDGF receptor α gene, because microinjection suppressed number of Epi cells. The PDGF receptor might control the number of PrE cells by repressing the proapoptotic gene Txnip. Our results can help to isolate Epi-specific cell lines from blastocysts.

• Journal of Embryo Transfer
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• v.26 no.2
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• pp.111-115
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• 2011

In general, zona pellucida (ZP) of the blastocyst has to be removed first, then either isolated the inner cell mass (ICM) or ZP-removed whole blastocyst, which is then cultured on the feeder layer to induce ICM outgrowth for the generation of embryonic stem cells (ESC). However, it is unclear whether ICM isolation before seeding on feeder layer is beneficial or not because the interaction between ICM and trophoblasts may affect cellular growth and/or pluripotency during the culture on the feeder. In the present study, two ZP removal methods (mechanically by splitting with a 28-gauge needle versus chemically by the treatment of acid-Tyrode's solution) and two ICM isolation methods (ZP-free whole blastocyst seeding versus mechanical isolation of ICM) were evaluated for the efficient isolation and culture of putative parthenogenetic bovine ESC. The number of maintained outgrown colonies was counted in each experimental group. As the result, mechanical removal of ZP with a needle and followed by whole ZP-free blastocyst seeding on feeder cells tended to attach more on the feeder layer and resulted in more outgrown colonies with its simple and less time-costing benefits. Currently we are generating ESC lines in HanWoo cattle by using this method for initial outgrowth of the parthenogenetic bovine blastocysts.