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        검색결과 134

        81.
        2015.07 서비스 종료(열람 제한)
        In this study we evaluate the informative and efficiency of Simple Sequence Repeat (SSR) and Sequence Specific Amplified Polymorphism (SSAP) markers for genetic diversity, genetic relationship and population structure among 87 super sweet corn inbred lines generated by different origins. The SSR showed relatively higher level of the average gene diversity and shannon’s information index value than that of the SSAP. To assess genetic relationship and to characterize among 87 super sweet corn inbred lines using the SSR and SSAP markers. The dendrogram using SSR marker divided into nine groups of clusters were observed at the genetic similarity value 53.0%. For SSAP marker, Total three main clusters were confirmed in genetic similarity value at 50.8%. Result of combine data for SSR and SSAP markers showed six subgroup were detected in genetic similarity at 53.5%. To confirm population structure, the total 87 super sweet corn inbred lines were divided into groups I, II and admixed group based on membership probability 0.8 for SSR and SSAP markers. However population structure using combine data was K=3 and divided into group I, II, III and admixed group. This study has demonstrated the comparative analysis of SSR and SSAP for the study of genetic diversity and the genetic relationship for super sweet corn inbred lines. Thus, the results of this study will be useful to maize breeding programs in Korea.
        82.
        2014.09 서비스 종료(열람 제한)
        Development of the central nervous system (CNS) occurs normally in mammalian fetus despite lower temperature in the brain region than in the heart. To investigate the effects of temperature niche on the neural differentiation of stem cells in vitro, P19 embryonic carcinoma (EC) stem cells and N2a neuroblastoma stem cells were induced to undergo neural differentiation by retinoic acid and LiCl, respectively. The cells were analyzed for the expression of neural marker genes during 12 days differentiation. Although there were Map2 and NCAM expressions in both groups, no clear difference was found. Similarly, expression patterns of Tuj1 and NF-M were not different in both groups, showing more intensive staining patterns at day 12 than those at days 4 and 8, respectively. However, more cells expressed GFAP markedly at day 12 in 37℃ group. There was little expression of the above markers in N2a cells during differentiation except for Ngn2 and Tuj1. It was found that Ngn2 was expressed more intensely at days 6 and 9 in 33℃ group. Tuj1 expression showed a similar pattern to those of P19 EC cells. RT-PCR analysis also showed that the expressed transcripts did not quite different in both groups, although they were different among the days of differentiation. Thus, it appears that neural differentiation occurs normally with a slight delay and probably less cell death in the cells at 33℃ than that at 37℃.
        83.
        2014.09 서비스 종료(열람 제한)
        Chemoresistance is one of the main problems to treat different kinds of cancers or cancer cells. Therefore, it is necessary to find out the strategies to make the cancer cells sensitive to chemotherapy along with optimal dosage of drugs. We examined sensitivity of MCF7 cells through pretreating with an epigenetic modulator, azacytidine (AzaC) to doxorubicin (Dox). The cells were treated with 5 and 10 mM of AzaC for a week, subsequently with 50, 100 and 500 nM of doxorubicin for 24 and 48h. It was found that pretreatment of AzaC significantly enhance the sensitivity of MCF7 cells to Dox, inducing cell death. After 24h 15% cells underwent apoptosis in 500 nM dox treatment group while 23.4% cells death occurred in AzaC pre treatment group. After 48h MCF7 cells treated with Dox showed 19.0% cell death while AzaC sensitized cells showed 50.0% cells death when exposed to 500 nM of Dox for 48h. Western blot analysis showed the upregulations in the expression of bax, caspase-3, caspase-9 and p53 in AzaC-sensitized MCF7 cells treated with Dox as compared to those treated with only Dox. There was no clear indication for pro-apoptosis genes in the cells treated with individual drugs. These results showed that pretreatment with the epigenetic modulator significantly increased the sensitivity of MCF7 cells to Dox. Therefore it is concluded that demethylation event might enhance the activity of DNA intercalating agents to induce DNA damage in breast cancer cells.
        84.
        2014.07 서비스 종료(열람 제한)
        Watermelon (Citrullus lanatus) is one of the most economically important cucurbitaceous crop over the world. Screening of proper reference genes was needed to reverse transcription quantitative real-time PCR (qRT-PCR), and it is bausic step of many researches including gene expression analysis. However, the reference genes on watermelon has not yet been reported systematically. Therefore, eight candidates of reference genes were selected with reference to Arabidopsis or cucumber papers. They are β-Actin, elongation factor 1-α, glyceraldehy-3-phosphate-dehydrogenase, NADP-isocitrate dehydrogenase, leunig, polypyrimidine tract-binding protein1, ubiquitin-conjugating eznyme E2, and 18S ribosomal RNA. The expression levels of genes were evaluated by qRT-PCR under biotic stress (Colletotrichum orbiculare treatment), plant hormone treatment (100 μM ABA), and abiotic stresses such as drought, cold (4℃), salt (250 mM NaCl) stresses. We founded appropriate reference genes which did not induce or reduce gene expression levels under broad spectrum of stresses by qRT-PCR analysis. These results may provide proper information for the use of appropriate reference genes for gene expression studies in watermelon qRT-PCR analysis.
        85.
        2014.07 서비스 종료(열람 제한)
        Heat shock transcription factors(HSFs) are the major heat shock factors regulating the heat stress response. They participate in regulating the expression of heat shock proteins (HSPs), which are critical in the protection against stress damage and many other important biological processes. In this study, a genome-wide analysis was carried out to identify all HSFs soybean genes. Twenty six nonredundant HSF genes(GmHsf) were identified in the latest soybean genome sequence. Chromosomal location, protein domain and motif organization of GmHsfs were analyzed in soybean genome. The phylogenetic relationships, gene duplications and expression profiles of GmHsf genes were also presented in this study. According to their structural features, the predicted members were divided into the previously defined classes A–C, as described in Arabidopsis. Using RT-PCR, the expression patterns of 26 GmHsf genes were investigated under heat stress. The data revealed that these genes presented different expression levels in response to heat stress conditions. Real-time (q)RT-PCR was performed to investigate transcript levels of five GmHsfs in response to multiple abiotic stresses. Differential expression of five GmHsfs implies their role during abiotic stresses. Subcellular localization using GFP-fusion protein demonstrated that GmHsf12 and GmHsf34 were restricted to the nucleus and GmHsf28 was localized in the nucleus and cytoplasm in plant. The results provide a fundamental clue for understanding of the complexity of the soybean HSF gene family and cloning specific function genes in further studies and applications.
        86.
        2014.07 서비스 종료(열람 제한)
        The plant-specific NAC (NAM, ATAF, and CUC)-domain proteins play important roles in plant development and stress responses. Comparative time-course expression analyses were carried out to analyze the expression levels of 62 soybean NAC genes during drought stress in order to search for the stress-inducible NAC genes. Ten GmSNAC (Glycine max stress-inducible NAC) genes having the significant differential expression in response to the drought stress and abscisic acid (ABA) hormone application were further investigated for their expression profiles with various stresses such as drought, high salinity, cold and with ABA treatments by the quantitative real-time PCR analyses. In this research, the full-length cDNAs of eight GmSNAC were isolated for the further studies. Eight GmSNAC proteins were tested for their transcription activation in the yeast assay system. Two GmSNAC proteins showed the very high transcriptional activities and the other two GmSNAC proteins displayed moderate levels of transactivation while the remaining four GmSNAC proteins lacked transactivation in yeast. Subcellular localization of eight GmSNAC proteins was analyzed via the green fluorescent protein-GmSNAC fusion protein in tobacco plant cell. Three GmSNAC proteins with the C-terminal transmembrane domain were localized to the nucleus and cytoplasmic fractions. The other five GmSNAC proteins were targeted to the nucleus. The function of GmSNAC49 gene was further investigated using the overexpression transgenic Arabidopsis. Germination rate in transgenic plants over-expressing GmSNAC49 was delayed in the media supplemented with mannitol or ABA compared with that of wild-type (WT) plants. The 35S:GmSNAC49 transgenic Arabidopsis displayed improved tolerance to drought stress compared to the WT. The results of this systematic analysis of the GmSNAC family responsive to abiotic stress will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars
        87.
        2014.07 서비스 종료(열람 제한)
        Comparative time-course expression analyses were carried out to analyze the expression levels of 60 soybean WRKY genes during abiotic stress in order to search for the stress-inducible WRKY genes. Five GmWRKY(Glycine max WKRY) genes having the significant differential expression in response to the drought stress and abscisic acid(ABA) hormone application were further investigated for their expression profiles with various stresses such as drought, high salinity, cold and with ABA treatments by the quantitative real-time PCR analyses. In this research, the full-length cDNAs of five GmWRKY were isolated for the further studies. Five GmWRKY proteins were tested for their transcription activation in the yeast assay system. GmWRKY3 proteins showed the very high transcriptional activities and the other two GmWRKY proteins displayed moderate levels of transactivation while the remaining two GmWRKY proteins lacked transactivation in yeast. Subcellular localization of five GmWRKY proteins was analyzed via the green fluorescent protein-GmWRKY fusion protein in tobacco plant cell and all of GmWRKY proteins were targeted to the nucleus. In order to analyze the function of GmWRKY genes in plant, 35S:GmWRKY overexpression(OE) transgenic Arabidopsis were generated. Root growth and germination rates in transgenic OE plants were investigated in the media supplemented with mannitol, NaCl or ABA compared with that of wild-type(WT) plants. The 35S:GmWRKY42 transgenic Arabidopsis displayed reduced tolerance to drought stress compared to the WT. The results of this systematic analysis of the GmWRKY family responsive to abiotic stress will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars
        88.
        2013.12 서비스 종료(열람 제한)
        Neutropenic enterocolitis (NE), the most serious gastrointestinal complication, has been reported as a clinical syndrome that occurs in the setting of disease- or chemotherapy-induced neutropenia. Complications of NE include bowel necrosis with perforation, fistula, stenosis, massive bleeding, abscess formation, and pneumatosis intestinalis (PI). Most physicians recommend initial conservative management with bowel rest, intravenous fluids, total parenteral nutrition, broad-spectrum antibiotics, and normalization of neutrophil counts. Surgical intervention is recommended in the event of obstruction, perforation, persistent gastrointestinal bleeding despite correction of thrombocytopenia and coagulopathy, or clinical deterioration. We experienced a patient whose abdominal computed tomography scan showed pneumoretroperitoneum, intramural gas in the colon, and inferior vena caval gas. Her condition improved after treatment with granulocyte colony-stimulating factor and broad-spectrum antibiotics. We report on this case along with a review of the literature.
        89.
        2013.08 서비스 종료(열람 제한)
        Use of nature-derived matrices of a part of body tissues has been used to repair damaged tissues in practical terms. Recently, the same idea has also been applied to regenerate whole organs including the heart, liver, lung, and pancreas etc. Thus, so-called bio-artificial organ technology becomes a promising way of overcoming the lack of donor organs and immune rejections in organ transplantation if we can obtain recipient stem cells. Although the regenerated heart in vitro so far may demonstrate some typical organ's responses in vitro and vivo, it is still far from a fully functional organ for transplantation. We initiated a study to look at changes occurring during the generation of bio-artificial organ using the mouse model. Adult hearts were dissected out and perfused for acellularization with SDS-containing buffer and washed several times. Enzymatic treatment also evaluated the acellular purity by isolating genomic DNA and total RNA before and after DNase and RNase treatments. For recellularization, differentiating H9C2 cell or cells derived from P19 EC cells along with mesenchymal stem cells were seeded on the finally obtained heart matrix several times before submerging culture for generating the heart. Histological analyses revealed that complete removal of cellular components. The intensive staining of alcian blue (pH 1.5 and 2.5) suggests that acid mucopolysaccharides, glycocomponents and sulfate-containing saccharides are widely spread within the heart matrix. There was little DNA and RNA in the heart matrix after the enzymatic treatments as judging by the DAPI or PI staining. Cell seeding and subsequent submerging culture showed substantial heart tissue development as evidenced by immunocytochemistry and RT-PCR in the recellularized and grown heart. From these results, we suggest that each procedure for bio-artificial organ has to be carefully examined to improve the entire process.
        90.
        2013.07 서비스 종료(열람 제한)
        Gibberellic acid (GA) is a well-characterized plant hormone, which plays a critical role in various plant growth and development. including stem elongation, floral indcution and seed development. GA is known to cause enlargement of ripening fruits and, especially in grapevines, GA shows a unique function: the induction of seedlessness in seeded grape varieties. However, despite extensive previous studies about GA, there has been no clear verification of the mechanism that induces seedlessness in grapes. To understand how GA treatment results in artificial parthenocarpy of seeded grapes at molecular levels, we analyzed transcriptional changes in seeded grapes with and without GA application in various inflorescence developmental stages using RNA-seq. At 14 days before flowering (DBF), seeded grapes were treated with 100 ppm GA and clusters were collected at three developmental stages: 7 DBF, full bloom, and 5 days after flowering (DAF). Of a total of 28,974 genes that were mapped to grape genome reference sequences, 7,013 and 9,064 genes were up- and down-regulated, respectively, in the GA-treated grape as compared to the non-GA-treated control at 7 DBF, full bloom, and 5 DAF. Clustering analysis revealed that these genes could be grouped into 9 clusters with different expression patterns. We also carried out functional annotation based on gene ontology categories. There were significant differences in the expression of the GA and auxin-related gene families. These findings expand our understanding of the complex molecular and cellular mechanisms of GA-induced parthenocarpy of grapes and provide a foundation for future studies on seed development in grapevines.
        91.
        2013.07 서비스 종료(열람 제한)
        Our study is performed to confirm the level of genetic diversity and population structure with 80 maize inbred lines (40 waxy inbred lines and 40 flint inbred lines) and to explain the genetic basis of agronomic traits using an association mapping. The 200 SSR loci are confirmed a total of 1,610 alleles in total 80 maize inbred lines. The average number of alleles per locus was 8.05. The average GD was 0.72. The average PIC value was 0.68. The average MAF was 0.40. Population structure was revealed for K=2. Total 80 maize inbred lines were divided by groups I, II and admixed group. The 14 waxy inbred lines were assigned to group I. The 45 inbred lines include 5 waxy inbred lines and 40 flint inbred lines were contained to group II. The 21 waxy inbred lines were contained in the admixed group with lower than membership threshold 0.8. Association mapping between 200 SSR markers and 10 phenotypic traits of waxy/flint maize inbred lines were performed by Q GLM and Q+K MLM. In significant level at 0.01, 72 SSR markers were associated with 10 phenotypic traits using Q GLM. The 4 marker-trait association were detected in Q+K MLM. The results derived from this study will be used for designing efficient new maize breeding programs.
        97.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        Nitrogen (N) impact directly to growth and yield of plants. N loss has occurred every where in the world, it is not only serious problem in agriculture but also in environment. N loss can be caused by erosion, runoff, leaching or by many other factors. This experiment was conducted in green house as modeling with pots. The pot is 50 cm of height, 30 cm of diameter and with a tap at near the bottom for drainage. All pots were fill up of soil as natural horizontal. We use 3 types of soil as paddy soil, upland soil and sandy upland soil. The plant materials were used such as: hot Pepper, Soybean and Rye. We conducted 3 treatments of fertilizer in this experiment with N: 5; 10; 20kg/10a. Every treatment was recycling with 3 times of all drained water. The uptakes of plant nutrients at the first cycle were low and with small amount, almost nutrient were kept in soil and leaching by drained water. Every recycled nutrients was reduced in content of drained water but plant increasing absorbability, it means nutrient use efficiency has been improved. In this experiment the total N reduction after the first cycle was 50% and decreased to 10% after the third recycle. Nutrient loss by leaching depends on the soil type and recycling time. In this experiment, leaching capacity of sandy upland soil was higher than paddy soil and lowest was upland soil. The nutrient contents of drained water of sandy upland soil were more than 25mg at the 3rd recycle, it is still high compare with paddy soil and upland soil. If only use fertilizer for 1st cycle almost fertilizer would be leached to underground water or by the path way as a cause of environmental pollution and furthermore we could save application amount of N fertilizer.
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