• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.411-420
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• 2015

Despite of the same species there is a difference in the tree shape and its wood property due to quantitatiVe and qualitatiVe differences in wood cells by the intra-annual cambial actiVity. The purpose of this study was to proVide the fundamental database of intra-annual cambial seasonal actiVity for red pine in Sokwang-ri and Anmyondo for the determination of their wood qualities. As the results of intra-annual cambial actiVity, the initiation of cambial actiVity of red pine in the plots with Age Class V in Sokwang-ri was in the middle of April and it was at the beginning of April in all plots in Anmyondo. Only the plots with Age Class IX in Sokwang-ri showed relatiVely late initiation of cambial actiVity as between middle of May and middle of June. Except one plot with Age Class IX in Sokwang-ri all plots in both sites showed the same cessation of cambial actiVity as between middle and end of October. According to intra-annual cambial actiVity, the duration of cambial actiVity in Sokwang-ri is shorter than that of Anmyondo. On the other hand, the number of cell diVision of cambial actiVity in Sokwang-ri was more than those of Anmyondo. We could establish the database for intra-annual cambial actiVity for Sokwang-ri and Anmyondo to estimate their wood quality.

• Journal of Plant Biology
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• v.28 no.2
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• pp.105-118
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• 1985

This study was carried out to investigate the epidermal structure and types of stomata on the upper and lower surfaces of the leaves in six species and one variety belonging to Korean Crassulaceae. The shape of epidermal cells was polygonal, isodiametric, or elongated. The cell wall was thick, sinuous or deeply sinuous. The subsidiary cell wall was thin or mostly arched. The cytolith-containing cells were found in Orostachys japonicus. The distribution of stomata was more on the upper surface than on the lower surface in the leaves of O. japonicus and Sedum sarmentosum. The stomata in the other species were less on the upper surface than on the lower surface, and stomatal size was different in each species. The great majority of stomatal types was the helico-eumesogenous type. This type was subdivided into two, parahelico-eumesogenous type and diahelico-eumesogenous type by us on the basis of the angle of division of guard mother cell and the long axis of the last-formed subsidiary cells. Sometimes allelo-eumesogenous type as well as aniso-eumesogenous type was found. The tetra-eumesogenous type with four mesogenous subsidiary cells was rarely observed. It was observed that the varieties of aniso-eumesogenous type with one to three subsidiary cells and one helix of subsidiary cells were developed by the secondary division of subsidiary cells of aniso-eumesogenous stoma. The compound shape of helico-eumesogenous stomata was found. Five new kinds of stomatal types were observed as follows; the helico-tetra-eumesogenous type, the coallelohelico-eumesogenous type, the cohelico-allelo-eumesogenous type, the duplotetra-eumesogenous type, and the aniso-euperigenous type. These types were reported here in the vascular plants for the first time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.318-325
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• 2021

The objective of this study was to identify the effect of zebularine, a DNA methylation inhibitor, on the chromosomal association between homoeologous chromosomes in the wheat genetic background. Zebularine at a final concentration of 10 µM was used to treat the spikes of the double monosomic wheat addition line (DMA) with one Leymus mollis chromosome and one Leymus racemosus chromosome, both of which were in a homoeologous relationship. In late prophase, zebularine led to chromosome breakage in the Leymus homoeologous chromosomes. Chromosome breakage caused an increase in the frequency of chromosomal associations between the Leymus homoeologous chromosomes. Ordinary DMA showed 65 cells (35.3%) with chromosomal associations and 119 cells (64.7%) with no association, whereas treated DMA showed 102 cells (60.0%) with chromosomal associations and 67 cells (39.4%) with no association. In diakinesis, the Leymus bivalent showed a chromosomal association in the whole euchromatic region. In metaphase, the Leymus bivalent showed association in the whole chromosomal region, unlike other Leymus bivalents with partial chromosomal association. Chromosomal association by chromosome breakage occurred not only between Leymus chromosomes but also between Leymus and wheat chromosomes. The frequency of other chromosomal association (such as fusion and insert) was increased. Chromosome breakage by zebularine treatment is a useful method at the chromosome level as the spores with others are hereditary stable, although the homologous index (h) was not significantly different between ordinary DMA and treated DMA. It is necessary to study how to control zebularine treatment with a more stable concentration for chromosome breakage during meiosis.

• Journal of Plant Biology
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• v.35 no.4
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• pp.359-364
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• 1992

The vascular cambium in Ginkgo biloba seedling began to differentiate in the cotyledonary node, and then the differentiation proceeded bidirectionally from the cotyledonary node toward the stem and root. In tangential view, procambium at the early developmental stage was a homogeneous structure consisted of almost similar cells in shape, and at the later stage the procambium became a heterogeneous one consisted of long cells and short cells. Such a differentiation pattern in the cotyledonary node was similar to that in the stem. However, it was different from that in the root. Fusiform initials and ray initials consisting the vascular cambium were originated from the long cells and the short cells, respectively. The long cells and the fusiform initials in the cotyledonary node were shorter and wider than those in the first internode.ernode.

• Korean Journal of Weed Science
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• v.16 no.1
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• pp.64-71
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• 1996

This study was conducted to determine the physiological responses of corn plants to chlorsulfuron, CHL, (2-chloro-N-(((4-methoxy-6-methyl-1,3,5- triazin-2-yl)amino)carboxyl) benzenesulfonamide) and/or imazaquin, IMA, (2-(4,5-dihydro-4-methyl-4-(1-methyl)-5-oxo-1H-imidazol-2y1)-3-quinoline carboxylic acid). CHL inhibited the plant growth within 6h after treatment, whereas IMA inhibited the growth more slowly(i.e., 36h). CHL inhibited the cell division of the root tips rapidly, however, little effect was found with IMA treatment. Neither CHL nor IMA had effect on the cell elongation of the shoots. CHL inhibited acetolactate synthase(ALS) activity of the roots within 1h after treatment. Interaction between CHL and IMA in growth inhibition was found to be additive or synergistic with simultaneous or sequential treatment of the two herbicides, respectively. In addition, interaction between CHL and IMA in ALS inhibition was found to be additive when the two herbicides were treated simultaneously.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.45-52
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• 1990

In order to determine whether maturation inhibiting activity(MIA) in the cytoplasm of growing follicular oocytes would suppress the cleavage of the embryonal cells, the growing oocytes were fused with the 2 or 4 cell blastomeres and then examined for the nuclear phase of the fused giant cells 24 hr after culture. A significant number of the giant cells(60%) composed of growing mouse oocyte and 2 cell mouse blastomere(1/2) in interphase has contained 2 nuclei 24 hr after culture and most of the giant cells (90%) composed of the growing oocyte and 4 cell blastomere(1/4) also contained 2 nuclei after culture. The unfused blastomeres or the isolated blastomeres cultured without fusion treatment cleaved one cell cycle under the same culture condition. In contrast, the nucleus of the growing oocytes was disintegrated and the chromosome condensed when fused with 2 cell blastomere in mitosis. The growing rat oocytes also suppressed the nuclear disintegration of the mouse embryonal cells during culture. The data presented here showed that MIA in the growing mammalian oocyte inhibited the cleavage of the embryonal cells in interphase stage, but not in milosis stage.

• Journal of Life Science
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• v.33 no.11
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• pp.950-955
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• 2023

Cell division is an essential process for the survival and development of living organisms. It is critical that duplicated chromosomes are properly segregated into daughter cells during mitosis. The centrosome is the core organelle that forms the microtubule-organizing center (MTOC), which generates the microtubules that make up the mitotic spindle during cell division. The centrosome is also involved in cell signaling and motility. In normal cells, there is one centrosome in G1 that replicates into two in the S phase and matures through G2. During the M phase, duplicated centrosomes move to both ends of the cell, and spindle microtubules that are generated from MTOC move the chromosome to both ends. The cells then split into two to complete the cell division. However, a phenomenon called centrosome amplification (CA), in which the number of centrosomes is higher than normal, is common in cancer cells and can lead to chromosome instability (CIN). This paper discusses the process of centrosome replication and the role of PLK4 in this process. The possible consequences of centrosome amplification and how the PLK4 inhibitor may be able to treat certain types of cancer cells, such as breast cancer and neuroblastoma, will also be discussed.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.124-131
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• 2005

The regulation of gene expression plays an important rolet in cell cycle controls. In this study, a novel $mas3^+$ (mitosis associated protein) gene, a homolog of human SMARCADl, was isolated and characterized from a fission yeast Schizosaccharomyces pombe. The overall homology between the helicase proteins of the two species is $87\%$. This DEAD/H box-containing molecule has seven highly conserved sequence regions that allow us to place it in the SNF2 family of the helicase superfamily. Knock-out cell of $mas3^+$ gene was constructed using kanMX6 as a selection marker. Survival of mas3 null mutant exposed to UV or MMS was similar to those of wild type cells. $mas3^+$ expression was lowest at $G_2$ and gradually increased. Cytokinesis of mas3 null mutant was abnormal at $26^{\circ}C\;and\;35^{\circ}C$ and a large number of multi-septate cells were produced. These results indicate that the $mas3^+$ is involved in cytokinesis and cell shape control.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.2
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• pp.115-123
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• 2006

Objective: To investigate new signal transduction cascade through integrin, FAK and ERK in the suppressed cell proliferation by GnRH-I and -II. Method: Human endometrial cancer cells (HEC1A) were cultured under the following condition: DMEM/F12 (10% FBS). GnRH-I and -II were treated time (0, 5, 10, 15, 20, 30 min; 100 nM) and dose (10 nM or 100 nM; 20 min) dependent manner according to experimental purposes. Cell proliferation was measured using [$^3H$] thymidine incorporation assay. Immunoblotting was utilized to detect proteins. Results: GnRH-I and -II inhibited proliferation of HEC1A cells and induced expression of integrin ${\beta}3$. Phosphorylation of FAK and ERK were induced by GnRH-I and -II. Conclusion: GnRH inhibited cell proliferation via the expression of integrin and FAK, ERK phosphorylation.

• The Korean Journal of Zoology
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• v.37 no.4
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• pp.533-544
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• 1994

정신분열 살인환자로 격리 치료를 받고 있는 집단을 대상으로 이들을 치료하고자 복용시키는 Haloperidol, Perphenazine, Lithium carbonate 등과 같은 항정신질환 치료제가 자매염색분체 교환(Sister Chromatid Exchange SCE)에 미치는 영향을 조사하였다. 항정신질환 치료제를 계속적으로 복용하고 있는 환자 100명(남자: 76명, 여자: 24명)과 치료제를 전혀 복용하지 않은 남자 환자 10명을 대조군으로 하여 SCE의 빈도를 분석한 결과 항정신질환 치료제를 복용한 환자군에서의 SCE 평균빈도는 세포당 12.24$\pm$0.20으로 항정신질환 치료제를 복용하지 않은 대조군에서의 평균빈도인 세포당 8.77$\pm$0.20보다 높아 유의한 차이를 볼 수 있었다 그러나 항정신질환 치료제를 복용하지 않은 대조군에서의 평균빈도는 이미 보고된 바 있는 정상인 한국인 집단에서의 평균빈도인 세포당 8.78$\pm$0.24(Park et al. , 1992)와 별 차이가 없었다 한편 항정신질환 치료제를 장기간 복용하는데 따른 SCI 빈도의 차이가 있는지의 여부를 보기 위하여 1년 미만에서 6년 정도까지의 치료제 복용기간에 따른 SCE의 평균빈도를 비교 분석한 바 복용기간에 따른 SCE 평균빈도의 유의한 차이는 볼 수 없었다. 정신분열환자들이 복용하고 있는 항정신질환 치료제가 SCE에 영향을 줄 수 있다는 결과를 얼었다.