• Reproductive and Developmental Biology
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• 제38권2호
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• pp.85-91
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• 2014

Despite many researches related with in-vitro culture of porcine spematogonial stem cells (SSCs), adherent culture system widely used has shown a limitation in the maintenance of porcine SSC self-renewal. Therefore, in order to overcome this obstacle, suspension culture, which is known to have numerous advantage over adherent culture, was applied to the culture of porcine SSCs. Porcine SSCs retrieved from neonatal testes were suspension-cultured for 5 days or 20 days, and characteristics of suspension-cultured porcine SSCs including proliferation, alkaline phosphatase (AP) activity, and self-renewal-specific gene expression were investigated and compared with those of adherent-cultured porcine SSCs. As the results, the suspension-cultured porcine SSCs showed entirely non-proliferative and significantly higher rate of AP-positive cells and expression of self-renewal-specific genes than the adherent-cultured porcine SSCs. In addition, long-term culture of porcine SSCs in suspension condition induced significant decrease in the yield of AP staining-positive cells on post-day 10 of culture. These results showed that suspension culture was inappropriate to culture porcine SSCs, because the culture of porcine SSCs in suspension condition didn't stimulate proliferation and maintain AP activity of porcine SSCs, regardless of culture periods.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.21-26
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• 2012

Suspension culture is a useful tool for culturing embryonic stem (ES) cells in large-scale, but the stability of pluripotency and karyotype has to be maintained $in$ $vitro$ for clinical application. Therefore, we investigated whether the chromosomal abnormality of ES cells was induced in suspension culture or not. The ES cells were cultured in suspension as a form of aggregate with or without mouse embryonic fibroblasts (MEFs), and 0 or 1,000 U/ml leukemia inhibitory factor (LIF) was treated to suspended ES cells. After culturing ES cells in suspension, their karyotype, DNA content, and properties of pluripotency and differentiation were evaluated. As a result, the formation of tetraploid ES cell population was significantly increased in suspension culture in which ES cells were co-cultured with both MEFs and LIF. Tetraploid ES cell population was also generated when ES cells were cultured alone in suspension regardless of the existence of LIF. On the other hand, the formation of tetraploid ES cell population was not detected in LIF-free condition, in which MEFs were included. The origin of tetraploid ES cell population was turned out to be E14 ES cells and not MEFs by microsatellite analysis and the basic properties of them were still maintained despite ploidy-conversion to tetraploidy. Furthermore, we identified the ploidy shift from tetraploidy to near-triploidy as tetraploid ES cells were differentiated spontaneously. From these results, we demonstrated that suspension culture system could induce ploidy-conversion generating tetraploid ES cell population. Moreover, optimization of suspension culture system may make possible mass-production of ES cells.

• Journal of Microbiology and Biotechnology
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• 제8권5호
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• pp.461-465
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• 1998

The suspension culture of an anchorage-dependent cell line (Bok-l) from Bombina orientalis was successful in respects of cost and efficiency. The amount of cells obtained from the suspension culture was almost equivalent to that from the anchorage-dependent culture. This result shows the possibility of suspension culture for scale-up. The cells in suspension produced an antibacterial peptide as much as anchorage-dependent cells did. The cell growth ($6.0\times10^6cells/m\ell$) and viability (>80%) at 10 rpm were higher than that at 0 rpm ($1.9\times10^6cells/m\ell$, 65~80%) and 30 rpm ($1.8\times10^6cells/m\ell$ 40~76%). The size of cells became smaller at the agitation rate of 30 rpm. The antibacterial activities of cell extracts from suspension cultured cells were confirmed against gram-negative and gram-positive bacteria by the inhibition zone assay and the liquid growth inhibition assay.

• 한국환경과학회지
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• 제15권12호
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• pp.1193-1197
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• 2006

This study was to examine the variations of chromosome number and the ranges of variety in the suspension culture of ginseng (Panax ginseng C. A. Meyer) callus cell, and the effect of plant hormones for the chromosome aberration. Plant hormones added with MS medium in the suspension culture were 2,4-D, kinetin, and 2,4-D+kinetin and concentration of the plant hormones were $1000{\mu}M$ and $0.1\;{\mu}M$ respectively. As a result of these experiment the following conclusion has been obtained. Media contained with 2,4-D+kinetin in $10{\mu}M$ concentration was very effective in the suspension culture result from 26.4% mitosis frequency, and found the various variation of chromosome number. Variety of chromosome number was diversed ($9\sim110$), espicially frequency of hypohaploid and hyperhaploid cells were very higher than hyperdiploid cells. In this experiments, it is suggested that $10{\mu}M$ 2,4-D+kinetin added with medium in the suspension culture of ginseng callus was effect in the variations of chromosome number.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.154-159
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• 2006

Interleukin-18 (IL-18), otherwise known as interferon-gamma-inducing factor (IGIF), is one of several well characterized and important cytokines that contribute to host defenses. The complementary DNA (cDNA) of mature human interleukin-18 gene (hIL-18) was fused with the signal peptide of the rice amylase 1A gene (Ramy1A) and introduced into the plant expression vector under the control of a duplicated CaMV 35S promoter. The recombinant plasmid was transformed into tobacco (Nicotiana tabacum L. cv Havana) using the Agrobacterium-mediated transformation method. The integration of the hlL-18 gene into the genome of transgenic tobacco plants was confirmed by polymerase chain reaction (PCR) amplification and its expression was observed in the suspension cells that were derived from the transgenic plant callus by using Northern blot analysis. The hlL-18 protein was detected in the extracts of the transgenic callus and in the medium of the transgenic tobacco suspension culture by using immunoblot analysis. Based upon enzyme-linked immunosorbant assay (ELISA) results, the expression level of the hlL-18 protein approximated $166{\mu}g/L$ in the suspension culture medium. Bioassay results from the induction of $interferon-{\gamma}$ from a KG-1 cell line indicated that the hlL-18 secreted into the suspension culture medium was bioactive.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.171-173
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• 2003

본 연구에서는 생분해성 고분자 나노입자를 이용하여 부착성 세포의 세포군집 (cell aggregates) 형성을 촉진시켜 무혈청 배지에서 3차원적 부유 배양하는 방법을 개발했다. 생분해성 고분자 나노입자의 사용은 무혈청 배지 부유배양에서 부착성 동물세포인 HEK 293 세포의 세포군집 형성과 세포증식(나노입자를 사용하지 않은 대조군과 비교하여 2배 이상)을 촉진하였다. 일반적으로 무혈청배지 부유배양에 세포를 적응(adaptation)시키는 데에는 시간이 오래 걸리고 많은 비용이 드는데, 이 연구에서 개발된 방법은 이러한 세포적응 공정이 필요없다. 이 배양법은 여러 부착성 동물세포의 산업적 대량배양에 유용하게 사용될 수 있을 것이다.

• 식물조직배양학회지
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• 제27권3호
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• pp.181-184
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• 2000

Friable callus와 compact callus를 배양 단계별로 단백질을 정량한 결과 friable callus가 가장 낮았고 배양 0주째부터 단백질 함량이 서서히 증가하여 배양 3주째 최대함량이 되었으며, 4주째부터는 감소하기 시작했다. 전기영동법으로 단백질의 패턴을 조사한 결과 compact callus와 friable callus간에 특징적인 차이를 보이는 단백질 밴드가 관찰되었다. Friable callus는 약 28 KD, 31 KD과 35 KD에서 특이적으로 나타났으며. compact callus에서는 30 KD부근의 밴드에서 많은 변화가 일어났다. 전체 단백질의 구성 아미노산은 배앙 2∼3주에 가장 높은 함량을 보였고, friable callus에서 그 함량이 가장 낮았다.

• 한국약용작물학회지
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• 제3권2호
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• pp.96-99
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• 1995

본 실험은 쪽 세포의 현탁배양에서 indirubin 생산을 위한 indole의 처리 시기와 처리 기간 및 첨가량을 찾기 위하여 수행하였으며 얻어진 결과는 다음과 같다. 1. Indole 첨가시 세포 생장량은 억제되었다. 2. Tryptophan 첨가시 세포 생장량의 증가는 크지 않았다. 3. Indole과 L-tryptophan을 고체레지에 첨가한 경우 indole을 첨가한 배지에서 만 indirubin이 검출되었다. 4. Indirubin 생산에 적절한 indole 첨가 농도는 고체배지에서 200mg으로 나타났다. 5. 현탁배양 중 indole 첨가시기를 달리한 결과 배양 20일 후 indole을 첨가한 배지에서 세포와 배지내 indirubin 농도가 높았다. 6. 고체배양보다 현탁배양에서 세포내에 축적된indirubin이 많았으며 배지 내 로 상당량의 indirubin이 유출되었다.

• Journal of Plant Biology
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• 제36권3호
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• pp.211-218
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• 1993

Plant regeneration was accomplished from protoplast culture of rice (Oryza sativa L. cv. Taebaeg). Embryogenic callus was induced from mature seed on MS medium containing 5 mM proline, 2.5 mg/L 2,4-D, 30 g/L sucrose in the dark at 28$^{\circ}C$ and used to establish embryogenic cell suspension culture. Suspension cells were subcultured every one week in N6 medium supplemented with 5 mM proline, 200 mg/L casein hydrolysate, 2.5 mg/L 2,4-D and amino acids of AA medium. Suspension cultures were composed of cells that were densely cytoplasmic, potentially embryogenic and were at least maintained for more than 6 months in liquid medium. Protoplasts were isolated from fast-growing suspension culture cells and cultured in a slightly modified KpR medium by mixed nurse culture. Isolated protoplasts began to divide within 5~7 days and thereafter, protoplast-derived calli were sequentially transferred to callus proliferating medium that soft agar MS medium contained 2 mg/L 2,4-D and produced distinct embryogenic cells. Microcolonies were then transferred to solid medium which consisted of MS medium containing 5 mg/L kinetin, 1 mg/L NAA, 1 mg/L ABA, 30 g/L sucrose and 10 g/L sorbitol under fluorescent light. Mulitple shoots of 4~5 per callus emerged and were transferred to hormone-free MS medium for root initiation. Thereafter, The plantlets were transferred to pots of soil to mature in the culture room.

• 한국초지조사료학회지
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• 제20권1호
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• pp.7-12
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• 2000

오차드그래스의 종자배양에서 형성된 캘러스를 현탁배양하여 배양기간별 부정배 형성정도와 식물체 재분화율 등에 대한 몇 가지 실험을 수행하여 얻은 결과를 요약하면 다음과 같다. 종자유래의 캘러스를 현탁배양하였을 때, 세포 모양이 둥근것과 그들의 세포괴는 배양 50일 후에 최대치를 나타내었고 그 이후는 감소하였다. 현탁배양 기간에 따른 갤러스의 부정배 형성과 식물체 분화율은 배양 60일째 가장 높았으며, 그 이후는 감소하는 경향이었다. 현탁배양에서 배지 내에 첨가되는 casein hydrolysate (CH)의 적정농도는 $4\;g/{\ell}$인 것으로 나타났다.