• Molecules and Cells
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• 제37권6호
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• pp.473-479
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• 2014

Spermatogonial stem cells (SSCs, also called germline stem cells) are self-renewing unipotent stem cells that produce differentiating germ cells in the testis. SSCs can be isolated from the testis and cultured in vitro for long-term periods in the presence of feeder cells (often mouse embryonic fibroblasts). However, the maintenance of SSC feeder culture systems is tedious because preparation of feeder cells is needed at each subculture. In this study, we developed a Matrigel-based feeder-free culture system for long-term propagation of SSCs. Although several in vitro SSC culture systems without feeder cells have been previously described, our Matrigel-based feeder-free culture system is time- and cost-effective, and preserves self-renewability of SSCs. In addition, the growth rate of SSCs cultured using our newly developed system is equivalent to that in feeder cultures. We confirmed that the feeder-free cultured SSCs expressed germ cell markers both at the mRNA and protein levels. Furthermore, the functionality of feeder-free cultured SSCs was confirmed by their transplantation into germ cell-depleted mice. These results suggest that our newly developed feeder-free culture system provides a simple approach to maintaining SSCs in vitro and studying the basic biology of SSCs, including determination of their fate.

• 한국동물생명공학회지
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• 제35권1호
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• pp.65-72
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• 2020

Fish ovarian germline stem cells (OGSCs) that have the abilities to self-renew and differentiate into functional gametes can be used in various researches and applications. A main issue to be solved for effective utilization of fish OGSCs is the development of their stable in vitro culture condition, but only few researches about fish OGSC culture have been reported so far. In this study, in order to find the clues to develop the culture condition for OGSCs from Japanese medaka (Oryzias latipes), we tried to establish somatic cell lines as a candidate for the feeder cells and evaluated its supporting effects on the culture of ovarian cell populations from O. latipes. As the results, the somatic cell lines could be established only from the embryonic tissues among three tissues derived from embryos, fins and ovaries. Three embryonic cell lines were tested as a feeder cell for the culture of ovarian cell population and all three cell lines induced cell aggregation formation of the cultured ovarian cells whereas the feeder-free condition did not. Furthermore, a significant cellular proliferation was observed in the ovarian cells cultured on two of three cell lines. As a trial to increase the capacity of the cell lines as a feeder cell that supports the proliferation of the cultured ovarian cells, we subsequently established a stable line that expresses the foreign O. latipes fibroblast growth factor 2 (FGF2) from an embryonic cell line and evaluated its effectiveness as a feeder cell. The ovarian cells cultured on FGF2 expressing feeder cells still formed cell aggregates but did not show a significant increase in cellular proliferation compared to those cultured on non-transformed feeder cells. The results from this study will provide the fundamental information for in vitro culture of medaka OGSCs.

• 한국발생생물학회지:발생과생식
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• 제19권3호
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• pp.119-126
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• 2015

The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group. Although there were no differences to colony formations and AP activities, interestingly, the transcripts level of pluripotency marker genes, Pou5f1 and Nanog were highly expressed in D3/MEF (79 and 93) than D3/STO (61and 77) or D3/- (65 and 81). Also, pluripotency marker proteins, NANOG and SOX-2, were more synthesized in D3/MEF ($72.8{\pm}7.69$ and $81.2{\pm}3.56$) than D3/STO ($32.0{\pm}4.30$ and $56.0{\pm}4.90$) or D3/- ($55.0{\pm}4.64$ and $62.0{\pm}6.20$). These results suggest that MEF feeder cell layer is more suitable to mES cell culture.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.291-294
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• 2012

Embryonic stem cell classically cultured on feeder layer with FBS contained ES medium. Feeder-free mouse ES cell culture systems are essential to avoid the possible contamination of nonES cells. First we determined the difference between ES cell and MEF by Oct4 population. We demonstrate to culture and to induce differentiation on feeder free condition using a commercially available mouse ES cell lines.

• Molecules and Cells
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• 제41권7호
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• pp.631-638
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• 2018

Spermatogonial stem cells (SSCs) derived from mouse testis are unipotent in regard of spermatogenesis. Our previous study demonstrated that SSCs can be fully reprogrammed into pluripotent stem cells, so called germline-derived pluripotent stem cells (gPS cells), on feeder cells (mouse embryonic fibroblasts), which supports SSC proliferation and induction of pluripotency. Because of an uncontrollable microenvironment caused by interactions with feeder cells, feeder-based SSC reprogramming is not suitable for elucidation of the self-reprogramming mechanism by which SSCs are converted into pluripotent stem cells. Recently, we have established a Matrigel-based SSC expansion culture system that allows longterm SSC proliferation without mouse embryonic fibroblast support. In this study, we developed a new feeder-free SSC self-reprogramming protocol based on the Matrigel-based culture system. The gPS cells generated using a feeder-free reprogramming system showed pluripotency at the molecular and cellular levels. The differentiation potential of gPS cells was confirmed in vitro and in vivo. Our study shows for the first time that the induction of SSC pluripotency can be achieved without feeder cells. The newly developed feeder-free self-reprogramming system could be a useful tool to reveal the mechanism by which unipotent cells are self-reprogrammed into pluripotent stem cells.

• 식물조직배양학회지
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• 제25권2호
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• pp.81-88
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• 1998

Southeast Asian javanica 벼 품종 Tinawen의 진탕 배양세포로부터 나출된 원형질체의 효과적인 배양과 식물체 재분화가 조사되었다. Lolium multiforum과 Oryza ridleyi의 진탕 배양세포들을 feeder cell로 사용했고 여러가지 재분화 배지를 이용하여 원형질체로부터 유도된 colony들을 재분화 시켰으며, 또한 식물체 재분화율을 높히기 위해 원형질체로 부터 유도된 colony들을 dehydration 시켜 재분화율을 조사하였다. L multiflorum 또는 O. ridleyi의 진탕 배양세포들을 feeder cell로 사용했을 때 원형질체의 평판효율은 feeder cell type과 age에 따라 차이가 났지만 0.09%에서 1.48% 범위로 나타났고, L. multiflorum을 feeder cell로 사용했을 때가 O. ridleyi cell을 사용했을때 보다 6배 높게 원형질체 평판효율을 얻었다. Feeder cell로 L. multiflorum을 사용하여 배양된 원형질채로부터 유도된 colony들을 dehydration 시킨 경우는 19.3-31.7%, O. ridleyi을 사용한 경우는 13.0-18.0%, 또한 이들 두 진탕 배양세포들을 혼합한 것을 사용한 경우는 18.0-22.0%의 식물체 재분화율을 얻은 반면에, dehydration을 시키지 않았을 때는 각각 2.0-7.0%, 3.0-5.0%, 0-4.0%의 재분화율을 얻었다. 원형 질체에서 재분화된 식물체의 flow cytometry를 이용한 배수성 분석 결과 대부분의 식물체가 이배체로 나타난 반면, 단지 34개중 두 식물체에서만이 4배체로 나타났다. 재분화된 식물체들은 온실에 옮겨 기른 결과 정상적인 임성을 나타내었다.

• 한국동물생명공학회지
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• 제35권1호
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• pp.86-93
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• 2020

The establishment of porcine embryonic stem cells (ESCs) from porcine somatic cell nuclear transfer (SCNT) blastocysts is influenced by in vitro culture day of porcine reconstructed embryo and feeder cell type. Therefore, the objective of the present study was to determine the optimal in vitro culture period for reconstructed porcine SCNT embryos and mouse embryonic fibroblast (MEF) feeder cell type for enhancing colony formation efficiency from the inner cell mass (ICM) of porcine SCNT blastocysts and their outgrowth. As the results, porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days showed significantly increased efficiency in the formation of colonies, compared to those for 7 days. Moreover, MEF feeder cells derived from outbred ICR mice showed numerically the highest efficiency of colony formation in blastocysts produced through in vitro culture of porcine SCNT embryos for 8 days and porcine ESCs with typical ESC morphology were maintained more successfully over Passage 2 on outbred ICR mice-derived MEF feeder cells than on MEF feeder cells derived from inbred C57BL/6 and hybrid B6CBAF1 mice. Overall, the harmonization of porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days and MEF feeder cells derived from outbred ICR mice will greatly contribute to the successful establishment of ESCs derived from porcine SCNT blastocysts.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.161-163
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• 2008

The paper deals with a inverter control scheme to apply feeder flow control in the hybrid system consisted of a photovoltaic system and a fuel-cell system. The inverter operation modes and a feeder control reference is changed by changing of the loads. Simulation results using the PSCAD/EMTDC are presented to establish a inverter control method for a Feeder flow control mode.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.141-149
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• 2008

This study was conducted to develop an efficient cryopreservation method of human embryonic stem (ES) cells using vitrification. In an initial experiment, sub-clumps of human ES cells (CHA-hES3 and CHA-hES4) were vitrified using grids after incubation with STO feeder cells for 1 or 16 h (Groups 1-1 and 1-2, respectively). After storage for $2{\sim}4$ months, thawed clumps were re-plated on a fresh feeder layer. The survival rates of warmed CHA-hES3 and CHA-hES4 cells of Group 1-2 were significantly higher than those of the corresponding Group 1-1 cells. In the second experiment, human ES cells were vitrified after incubation with feeder or feeder-conditioned medium (Groups 2-1 to -7). Relative mRNA expression of BM proteins and survival rates were increased following incubation of ES cells with fresh feeder cells for 16 h. In conclusion, increasing of tight adhesion between ES cells by extended incubation with feeder could reduce cryoinjury after vitrifying/warming.

• 식물조직배양학회지
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• 제24권5호
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• pp.295-303
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• 1997

Japonica 벼 품종 Taipei 309 성숙 종자의 배반에서 유도된 캘러스로부터 유기 시킨 세포 현탁 배양체에서 원형질체를 분리하여 filter membrane과 feeder 세포를 이용한 여러가지 조건에서 배양하였다. 이러한 조건들은 gelling agents, feeder 세포와 원형질체 밀도, feeder 세포의 종류 및 heat shock 처리 등이며 이들이 filter membrane 배양 방법에서 원형질체 평판 효율에 미치는 효과들을 조사하였다. 원형질체 평판 효율은, Lolium multiflorum을 feeder 세포로 사용하고 (10 mL의 원형질체 배양 배지당 0.5 mL pcv) 원형질체를 mL 당 $5\;\times\;10^{5}$개로 하여 Sea Plague agarose 배지에 원형질체를 배양 했을때 최고치를 얻었다. 원형질체에 heat shock 처리를 했을 때 원형질체 평판 효율은 변화가 없었다. carbohydrate source로서 sucrose로서 sucrose 대신에 maltose를 사용했을 때 식물체 재분화율이 높았으며 원형질체로부터 재분화된 이들 식물체들은 임성을 나타내었다.