• Korean Journal of Medicinal Crop Science
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• v.16 no.1
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• pp.39-43
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• 2008

The effect of colchicine treatment on the agronomic performance and polyploid formation of Bupleurum falcatum using flow cytometry technique was investigated. The roots of 4-leaf stage plants were treated with colchicine (0.5%) for 3, 6, 12, and 24 hours and then transplanted in the field. Agronomic characters (survival rate, plant height, chlorophyll content, bolting rate) were recorded at 4 weeks and 6 months after transplanting while flow cytometry technique was conducted for determination of polyploid formation. Flow cytometry technique revealed polyploid nuclear DNA formation in colchicine treated plants. The highest number of polyploids was obtained at the shortest colchicine treatment time indicating an inverse relationship between colchicine treatment time and polyploid formation. Results also showed that survival and bolting rates were inversely related with the treatment time while plant height and chlorophyll were not significantly affected by the treatment. This study showed a convenient method for determination of colchicine-induced polyploid in B. falcatum and its superior agronomic performance at shorter treatment time.

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.268-269
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• 2010

• Journal of Plant Biology
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• v.37 no.1
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• pp.69-76
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• 1994

The present work was conducted to examine the effect of tobacco smoke solution, and its components such as nicotine and catechol treated separately on the root tip cells of Allium cepa L The mitotic abnormalities in root tip cells treated with those three components were increased linearly, while the mitotic index was decreased following concentrations of the components. Chromosomal abnormalities showed 29.7%, 15.8% and 13.0% in the treatment of tobacco smoke solution, nicotine, and catechol, respectively. The abonormalities were included polyploid, c-mitosis, stickness at metaphase, laggard, bridge formation at anaphase or telophase, and micronucleus, abnormal nucleus at interphase, after the treatment of the components for 24 hours. hours.

• Journal of Life Science
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• v.26 no.3
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• pp.376-386
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• 2016

Apoptosis induction has been proposed as an efficient mechanism by which malignant tumor cells can be removed following chemotherapy. The intrinsic mitochondria-dependent apoptotic pathway is frequently implicated in chemotherapy-induced tumor cell apoptosis. Since DNA-damaging agent (DDA)-induced apoptosis is mainly regulated by the tumor suppressor protein p53, and since more than half of clinical cancers possess inactive p53 mutants, microtubule-damaging agents (MDAs), of which apoptotic effect is mainly exerted via p53-independent routes, can be promising choice for cancer chemotherapy. Recently, we found that the apoptotic signaling pathway induced by MDAs (nocodazole, 17α-estradiol, or 2-methoxyestradiol) commonly proceeded through mitotic spindle defect-mediated prometaphase arrest, prolonged Cdk1 activation, and subsequent phosphorylation of Bcl-2, Mcl-1, and Bim in human acute leukemia Jurkat T cells. These microtubule damage-mediated alterations could render the cellular context susceptible to the onset of mitochondria-dependent apoptosis by triggering Bak activation, Δψm loss, and resultant caspase cascade activation. In contrast, when the MDA-induced Bak activation was inhibited by overexpression of anti-apoptotic Bcl-2 family proteins (Bcl-2 or Bcl-xL), the cells in prometaphase arrest failed to induce apoptosis, and instead underwent mitotic slippage and endoreduplication cycle, leading to formation of populations with 8N and 16N DNA content. These data indicate that cellular apoptogenic mechanism is critical for preventing polyploid formation following MDA treatment. Since the formation of polyploid cells, which are genetically unstable, may cause acquisition of therapy resistance and disease relapse, there is a growing interest in developing new combination chemotherapies to prevent polyploidization in tumors after MDA treatment.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1017-1025
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• 2006

Hantaviruses possess three RNA segments of negative sense. Co-infection of closely related hantaviruses may result in generation of a progeny virus with genomic polyploidy, containing a partial or complete set of genome originated from more than one parental virus. To characterize the formation of viral genomic polyploidy, cultured Vero-E6 cells were co-infected with two closely related hantaviruses, Hantaan and Maaji, and the progeny viruses examined. The genotype of plaque-purified viruses was analyzed by a virus-specific RT-PCR. Seventy percent (67/96) of the progeny virus was categorized as Hantaan and 3.3% (2/96) was classified as Maaji, whereas 20% (21/96) was considered polyploidy as they contained both types of the S RNA segment. Most of the polyploidy progeny viruses were unstable and gave rise to either one of the parental viruses or a reassortant after several rounds of plaque purification. No recombination between the heterologous pair of S RNA was observed for those polyploid viruses during three consecutive plaque-to-plaque passages. These data suggest that the viral polyploidy formation constitutes a primary mechanism underlying the generation of a newly emerged hantavirus.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.9-12
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• 2002

The agronomic characteristics and fertility of Morus tiliaefolia growing wild in Korean peninsula are as follows. The possibility of seed formation is 46∼80% and that of germination is 19∼28%. The height period of making flower is April 4-May 3, it means that is later than Morus bombycis, faster than Kaeryangppong. Green tip sprouting stage in spring is April 21∼24. This is later than Morus bombycis and faster than Kaeryangppong. The leaf has very big width and the ratio of leaf length to leaf width is 1.05. The thickness of leaf is thicker than Morous bombycis. There are a lot of matter of soluble nitrogen free, crude ash, and are little crude protein, crude fat and crude fiber in chemical contents of maturation leaf. The attitude of low cutting is spread out type and the branch is long type. The internord length is long. It is weak against cold and die-back.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.617-622
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• 2011

The study was conducted to determine the efficiency in producing spontaneous polyploids in some mandarin hybrids with different seed embryony. Seed formation by open pollination, frequency of spontaneous polyploids, and plant growth characteristics were evaluated in four mandarin hybrids with polyembryony such as 'Amakusa', 'Haruka', 'Hayaka', and 'Seminole' and two with monoembryony such as 'Benibae' and 'Harehime'. The mean number of the developed seeds per fruit was 10.0 and frequency of small seeds was 25.1%. Polyploids were selected from plants germinated in vitro by a flow cytometry and confirmed by chromosome analysis. One triploid was produced from 'Harehime', one tetraploid, 'Amakusa', and one tetrapoid, 'Benibae'. There were little differences in leaf shape, thickness, petiole length, and internode length between diploids and polyploids such as tri- or tetraploid. However, polyploids had larger stomata and lower density of stomata in abaxial epidermis than diploids. SPAS indicating chlorophyll content and photosynthetic rate were significantly affected by ploidy level. The results indicated that spontaneous polyploids might be produced by open pollination in some mandarin hybrids and monoembryony had higher frequency in polyploid occurrence than polyembryony.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.996-1002
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• 2010

Flow cytometry (FCM) was used to measure the ploidy level of three different sports from 'Campbell Early' ($Vitis$ $labruscana$) grape. Results of the study showed different ploidy levels. FCM analysis for 'Campbell Early' grape which contains 2C DNA diploid cells showed single peak around 35-40 while 'Kyoho' grape with 4C DNA tetraploid cells had a different level of 70-80. However, analysis of the sports displayed a histogram with 2 peaks containing both 2C and 4C nuclei. There was no difference in histograms of 2C DNA flesh and pericarp; on the other hand, 4C DNA flesh type of sports had a different histogram from that of the 2C DNA pericarp. Chromosome numbers of diploid ('Campbell Early'), tetraploid ('Kyoho'), and three sports were counted under the microscope. 'Campbell Early' and 'Kyoho' have 38 and 76 chromosomes, respectively. Three different sports are mixoploids with mixtures of diploid and tetraploid cells. Microscopic observations of shoot apical meristems in sports from 'Campbell Early' grape were carried out to determine the type of plant chimera. 'Campbell Early' grape (diploid) and 'Kyoho' grape (tetraploid) showed that both had 2 tunica layers covering corpus cells, while the three different sports had tunica layers showing mostly oblique division. Most cells from 'Kyoho' grape were larger than 'Campbell Early' grape. Cells from L-2 and L-3 layers of the three sports were similar to 'Kyoho' grape in size, although all cells in L-1 surface layer were uniform in size like 'Campbell Early' grape. Results of FCM analysis indicated that both normal and polyploid cells could be intermixed in sports and could become mixoploidy consisting of diploid and tetraploid. All sports used in the tests were periclinal chimera plants with two distinct L-1 and L-2 cell layers. The result of this study suggests that all three sports which originated from 'Campbell Early' grape might be 2-4-4 type chimera formation.