• Reproductive and Developmental Biology
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• v.38 no.2
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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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• v.36 no.1
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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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• v.8 no.5
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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.

• Journal of Environmental Science International
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• v.15 no.12
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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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• v.11 no.2
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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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• 2003.10a
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• pp.171-173
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• 2003

Suspension culture in serum-free medium is important for the efficient large-scale culture of anchorage-dependent cells that are utilized to produce therapeutic recombinant protein(e.g., insulin, antibody, vaccine) and virus vector for therapeutic gene transfer. We developed a novel method for the suspension culture of anchorage-dependent animal cells in serum-free medium using biodegradable polymer nanospheres in this study. Poly(lactic-co-glycolic acid) (PLGA) polymer nanospheres (433nm in average diameter) were used to the culture of human embryonic kidney 293 cells in serum-free medium in stirred suspension bioreactors. The use of PLGA nanospheres promoted the aggregate formation and cell growth (3.8-fold versus 1.8-fold growth), compared to culture without nanospheres. Adaptation of the anchorage-dependent cells to suspension culture or serum-free medium is time-consuming and costly. In contrast, the culture method developed in our study does not require the adaptation process. This method may be useful for the large-scale suspension culture of various types of anchorage-dependent animal cells in serum-free medium.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.181-184
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• 2000

Proteins in friable and compact calli of Viola patrinii DC. were analysed. The protein contents in friable calli were lower than those in compact calli. In suspension culture, it increased to the maximum after 3 weeks culture from inoculation and decreased after 4 weeks culture. Several strong lavel signals were detected with the SDS-PAGE analysis. The polypeptides of 28, 31 and 35 KD were observed from the friable cell culture, from the compact cell culture strong band of 30 KD was determined, indicating that these polypeptides may be the major protein occurring during their cultures. Changes in amino acid contents during culture of the viola suspension cells were investigated the amino acid contents were greatest between two and three weeks culture of the viola suspension cells.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.96-99
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• 1995

This experiment was carried out to analyze the effect of indole on the synthesis of indirubin in suspension culture of Polygonum tinctorium. Adding indole and L-tryptophan into culture media was re­vealed that indirubin was synthesized in callus grown on solid medium containing indole and proper concentration of indole for indirubin production was decided as 200mg/1. Indirubin content in suspension culture was higher than in solid medium with considerable amount of indirubin secresed into media in suspension culture and highest quantity of indirubin was obtained when indole was added into medium after 20 days suspension culture.

• Journal of Plant Biology
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• v.36 no.3
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.7-12
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• 2000

This study was carried out to improve the ability of embryo formation and the efficiency of plant regeneration from suspension cultured cells of seed derived calli of orchardgrass (Dactylis glomerata L.). The frequency of formation of round cell and cell colonies was highest at 50 days after suspension culture in $N_6$ medium supplemented with $4\;g/{\ell}$ casein hydrolysate (CH), $20\;g/{\ell}$ sucrose and $30\;g/{\ell}$ sorbitol. The highest frequency of plant regeneration and somatic embryo formation was obtained from suspension cultured cells of 60 days. Addition of CH ($4\;g/{\ell}$) in suspension culture medium gave the highest frequency of embryo formation (39.6%) and plant regeneration (73.0%).