• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1149-1153
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• 2006

In this study, nuclease-resistant RNA aptamers that are specific for Jurkat T leukemia cells were selected by a subtractive systemic evolution of ligands by exponential enrichment (SELEX) method. A randomized nuclease-resistant RNA library was incubated with normal peripheral blood mononuclear cells (PBMC) in each round to preclude RNAs that recognize the common cellular components on the surface of normal and cancer cells. The precluded RNAs were used for the selection of Jurkat T cell-specific aptamers, and the specific RNAs were then gradually enriched from start to the following selections. After 16 rounds of the subtractive SELEX, the selected aptamers were found to preferentially bind to Jurkat T cells, but not to the normal PBMC, evidenced by fluorescence-activated cell sorting analysis. Thus, the subtractive SELEX can be used to identify ligands to cancer-specific biological markers without prior knowledge of the nature of markers. The aptamers could be applied to specific cell sorting, tumor therapy, and diagnosis, and moreover, to find cancer cell-specific markers.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.263-268
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• 2002

Acifluorfen-tolerant callus lines of Solanum ptycanthum were isolated by stepwise selection. Growth of the unselected line was completely inhibited at 0.5 uM. while some selected lines grew at 8 uM acifluorfen. Twenty-two of twenty-five acifluorfen-tolerant callus lines regenerated shoots. Many of the regenerated somaclones were variants, differing in leaf shape, leaf color, number of flower parts, flower color, and fertility. The acifluorfen tolerant S. ptycanthum callus lines differed.

• Plant Resources
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• v.6 no.3
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• pp.170-174
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• 2003

The important component for medical effect in ginseng is ginsenoside. Korea Ginseng & Tobacco Research Institute contains approximately 200 lines produced by inbred selection. It is assumed that ginseng lines containing high level of ginsenoside should be included in those lines. Besides, new breeding methods such as cell line selection in vitro and hairy root were recently developed. Therefore, this study was carried out to detect genes related to ginsenoside, and to use it for selection marker to select and distribute lines containing high level of ginsenoside. DNA was extracted from both ginseng roots and hairy roots, and the difference between the line containing high ginsenoside(KG101) and normal ginsenoside(KG103) were analysed. As a result, 28 out of 36 primers showed bands, and many primers showed band difference between ginseng lines. It is considered that the bands should be analysed using DNA sequence comparison to check if those are related to ginsenoside. In case of hairy roots of ginseng, almost no differences were found between two lines.

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.1-6
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• 1996

다배란 수정란이식(MOET)과 체외수정(IVF)기술을 이용한 육종체계에서 예상되는 유전적 개량량을 여러 집단의 크기에서 비교한 결과 체외수정기술이 MOET육종기술보다 특히 개량대상 유전력이 낮을때 훨씬 효율적으로 나타났다. 그러나 유전력이 높아지면 (h$^2$=0.3, 0.5), MOET와 IVF간의 상대적 차이는 미진하게 나타났다. 체외수정을 이용한 육종기술에서 암컷의 선발 강도는 대단히 높일 수 있는 반면 난자의 회수율이 많을수록 상대적으로 수컷에 대한 선발 강도는 낮아진다. 그 이유는 한 가계에서 근친을 피하기 위해 한 마리의 수컷만 선발해야 하므로 수소의 선발강도는 난자의 회수율이 높을수록 상대적으로 낮아진다. 여러 수준의 난자회수율(10, 20, 30, 50, 100)중에서 30일 때 가장 높은 유전적 개량을 나타내었다. (Key word: MOET, IVF,selection responses)

• Genomics & Informatics
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• v.3 no.2
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• pp.77-80
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• 2005

Targeting of complex system such as human cells rather than biochemically pure molecules will be a useful approach to massively identify ligands specific for the markers associated with human disease such as cancer and simultaneously discover the specific molecular markers. In this study, we developed in vitro selection method to identify nuclease-resistant nucleic acid ligands called RNA aptamers that are specific for human cancer cells. This method is based on the combination of the cell-based selection and subtractive systematic evolution of ligands by exponential enrichment (SELEX) method. These aptamers will be useful for cancer-specific ligands for proteomic research to identify cancer-specific molecular markers as well as tumor diagnosis and therapy.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.883-890
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• 2015

The soilborne fungus Fusarium oxysporum f. sp. lilii (Fol) is a serious threat to all lily cultivars, especially infecting bulbs and flowers. It has become increasingly important to develop varieties resistant against the bulb rot disease. Genetic diversity of cultivars and reliable screening methods are required for this purpose. Here, an efficient in vitro screening system for evaluating resistance to Fol in 38 in vitro-grown lily plants was investigated. Various factors including culture conditions of Fol, inoculum density, appropriate plant materials, inoculation method and duration, and incubation period of plant materials after inoculation were combined to optimize the screening method. As a result, we suggest optimal conditions for an in vitro screening system for the selection of Fol-resistant lily cultivars as follows. Fol was grown on potato dextrose agar (PDA) medium for 6 days at $25^{\circ}C$ in darkness and used as working inoculation. Spore suspensions were prepared (inoculum density: $1.0{\times}10^4$ $spores{\cdot}mL^{-1}$), and then leaf segments $1.5{\times}2.0cm^2$ were inoculated by dipping for 22 hours at $25^{\circ}C$ in dark. Later, leaves were cultured on 0.6% agar plates at $25^{\circ}C$ and 50% humidity with a photoperiod of 16 hours light/8 hours dark (fluence rate of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) to examine the progress of bulb rot. After 7 days, disease levels were classified into indices 1 (no symptom) to 6 (serious bulb rot). Soil inoculation of Fol carried out with resistant or susceptible lily cultivars that had been selected through in vitro screening confirmed the reproducibility of results. Therefore, the in vitro screening method established in this study is efficient and reliable for selection of lily cultivars resistant against bulb rot disease.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.1071-1086
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• 2003

Reproductive biotechnologies continue to be developed for genetic improvement of both river and swamp buffalo. Although artificial insemination using frozen semen emerged some decades back, there are still considerable limitations. The major problem appears to be the lack of efficient methods for estrus detection and timely insemination. Controlled breeding experiments in the buffalo had been limited and similar to those applied in cattle. Studies on multiple ovulation and embryo transfer are essentially a replica of those in cattle, however with inherent problems such as lower number of primordial follicles on the buffalo ovary, poor fertility and seasonality of reproduction, lower population of antral follicles at all stages of the estrous cycle, poor endocrine status and a high incidence of deep atresia in ovarian follicles, the response in terms of transferable embryo recovery has remained low with 0.51 to 3.0 per donor and pregnancy rates between 15 to 30%. In vitro production of buffalo embryos is a valid alternative to recovery of embryos by superovulation. This aspect received considerable attention during the past decade, however the proportion of embryos that develops to the blastocyst stage is still around 25-30% and hence the in vitro culture procedures need substantial improvement. Embryo cryopreservation procedures for direct transfer post thaw need to be developed for bubaline embryos. Nuclear transfer and embryo cloning is a technique that has received attention in various species during recent years and can be of immense value in buffaloes as they have a low rate of embryo recoveries by both in vitro and in vivo procedures. Gender pre-selection, genome analysis, gene mapping and gene transfer are a few of the techniques that have been studied to a limited extent during recent years and are likely to be included in future studies on buffaloes. Very recently, reproductive biotechnologies have been applied to feral buffaloes as well, but the results obtained so far are modest. When fully exploited they can play an important role in the preservation of endangered species.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.26-26
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• 2003

Hyaluronic acid (HA)-binding sites have been shown the diagnostic potential fur assessment of sperm maturity, which is related to male fertility. This study was designed to evaluate chromosomal patterns in porcine embryos produced by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) with non- or HA-binding sperm (HABS). For binding of sperm with HA, sperm incubated in 10 ${mu}ell$ drop containing HA (0.8 mg/ml)-agarose (0.8%) mixture for 15 min. IVF and ICSI with non- or HA-bound sperm examined with matured oocytes at 44 hr after in vitro maturation. Embryos were cultured in 50 ${mu}ell$ of NCSU 23 containing 0.5% BSA for 5 days and then in 50 ${mu}ell$ of NCSU 23 containing 10% FBS for 2 days. For the evaluation of chromosomal aneuploidies, chromosome 1 sub-metacentric specific probe was used in sperm and embryos by fluorescence in situ hybridization (FISH). The frequency of aneuploidy sperm for chromosome 1 was 6.25%. The significant differences following IVF and ICSI with non- or HA-bound sperm were not observed in blastocyst formation rates (18.6, 23.5, and 23.8%) and cell number (61.8 $\pm$ 12.5, 55.5 $\pm$ 7.3, and 59.3 $\pm$ 9.6). Moreover, the percentage of diploidy in 4-cell stage embryos was 57.1% (IVF), 68.8% (ICSI), and 76.3% (ICSI-HABS). These results suggest that HA-binding sites may be a material for selection of normal sperm for ICSI. Therefore HA selection of normal sperm may be reduce the loss to embryonic mortality prior to embryo transfer in pig.

• Research in Plant Disease
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• v.16 no.2
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• pp.158-162
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• 2010

Four promising biocontrol agents against Phytophthora capsici were selected from 507 bacterial isolates collected from rhizosphere soils and roots of pepper plants. In vitro experiment, these four biocontrol agents inhibited mycelial growth, germination of cystospores, and formation of zoosporangia and zoospores of Phytophthora capsici. In the pot experiment, the four biocontrol agents showed control efficiency higher than 70%. In greenhouse experiment, the isolates G28-6 gave the control value of 79.4%. These four biocontrol agents successfully colonized in the population density beyond 105 cfu/g on roots of pepper in vitro. The isolates G28-6 was identified as Pseudomonas aurantiaca, based on its cultural, morphological, and biochemical characterization and 16S rRNA gene sequence analysis.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.88-92
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• 2005

Phosphorylation of amino acid residues in proteins, plays a major role in biological mechanism. Phosphorylation acts as a process regulating the protein activity in variable pathways such as metabolism, signal transduction and cell division. Therefore the development of ligands for phosphoamino acids are an important work for protein analysis and proteomics studies. In this study, RNA aptamers for o-phosphoserine, o-phosphotyrosine and o-phosphotyrosine which appears frequently in nature were developed by in vitro evolution method. We could obtain similar sequences from random RNAs of 40 mer by SELEX method through 10 cycles. As result, the aptamers for o-phosphoserine and o-phosphothreonine among phosphoamino acids aptamers showed high affinity of Kd=2.60 nM and 2.65 nM for their target molecules, respectively. In addition, these aptamers could be confirmed the high selectivity for their target.