• Journal of Life Science
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• v.27 no.1
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• pp.95-99
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• 2017

A previous study demonstrated that four kinds of natural compounds, Corydaline, (${\pm}$)-Car-3-ene-2,5-dione, cinobufagin, and corilagin, enhanced the gene expression of ERAP1 and FOXO1 (DFA16) more than two-fold in a cell culture system. In this study, the experimental food was made finally 30 ml in which included 1% agar, 5% sucrose, and each natural compound $20{\mu}l$. A fruit fly of Drosophila melanogaster fed a natural product for 4 hr after 4 hr starvation. Both natural compounds of Cinobufagin and Corilagin induced 6-8 days more survival comparing than it controls group. The resulting fruit flies were estimated the gene expression of ERAP1 and FOXO1 by RT-PCR that also demonstrated meaningful results with the same lifespan results. Cinobufagin from BufonisVenennumis has $C_{26}H_{34}O_6$ molecular formula and 442 kDa molecular weight. Corilagin from Euphorbiapekinensisis has $C_{27}H_{22}O_{18}$ molecular formula and 634 kDa molecular weight. The two types of natural products screened in this study will be used in the early diagnosis and treatment of insect industry in the near future. In addition, the natural products will be used in longevity experiments in a mouse model. The results may give one of the clues for studying new drug development candidates of the longevity.

• Journal of Life Science
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• v.19 no.12
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• pp.1685-1689
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• 2009

Phytochelatins (PCs) are small polypeptides synthesized by PC synthase (PCS). They are present in various living organisms including plants, fission yeast, and some animals. The presumed function of PCs is the sequestration of cytosolic toxic heavy metals like cadmium (Cd) into the vacuoles via vacuolar membrane localized heavy metal tolerance factor 1 (HMT-1). HMT-1 was first identified in fission yeast (SpHMT-1), and later in Caenorhabdtis (CeHMT-1). Recently, its homolog has also been found in PC-deficient Drosophila (DmHMT-1), and this homolog has been shown to be involved in Cd detoxification, as confirmed by the heterologous expression of DmHMT-1 in fission yeast. Therefore, the dependence of HMT-1 on PC in Cd detoxification should be re-evaluated. I heterologously expressed SpHMT-1 in cytosolic PC-deficient yeast, Saccharomycea cerevisiae, to understand the dependence of HMT-1 on PC. Yeast cells expressing SpHMT-1 showed increased tolerance to Cd compared with control cells. This result indicates that SpHMT-1 is not strictly correlated with PC production on its function. Moreover, yeast cells expressing SpHMT-1 showed increased tolerance to exogenously applied glutathione (GSH) compared with control cells, and the tolerance to Cd was further increased by exogenously applied GSH, while tolerance in control cells was not. These results indicate that the function of SpHMT-1 in Cd detoxification does not depend on PCs only, and suggest that SpHMT-1 may sequester cytosolic GSH-Cd complexes into the vacuole.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.9
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• pp.1432-1438
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• 2004

This study investigated the inhibitory effect of methanol extracts and several solvent fractions from doen-jang on mutagenicity using in vitro SOS chromotest and in vivo Drosophila mutagenic system. In order to determine an antimutagenic effect of doenjang methanol extracts, other soybean fermented foods and original materials were compared. The treatment of doenjang methanol extracts (100 ${\mu}$/assay) to SOS chromotest system inhibited N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced mutagenicity by 87~97% and showed higher antimutagenic effect than other fermented foods. Among solvent fractions from doenjang methanol extracts, the ethylacetate and dichloromethane fractions showed the stronger antimutagenic effect (91% and 95%, respectively) in SOS chromotest. In Drosophila mutagenic system, the treatment of ethylacetate fraction (5%/bottle) significantly inhibited aflatoxin $B_1$ induced mutagenicity by 97%. These results demonstrated that doenjang had an inhibitory effect to mutagenic agents in both in vitro and in vivo mutagenic systems, suggesting that its antimutagenic effect may be due to active compounds in the ethylacetate fraction from doenjang methanol extracts.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.706-714
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• 2021

Chemical scavenging of reactive oxygen species (ROS) is considered a major mechanism of antioxidant effects, but preventing ROS generation can be more efficient in attenuating oxidative damage. In this study, the extracts of plants, Solanum lycopersicum, Ailanthus altissima, Equisetum arvense, and Oenothera biennis, were tested to determine whether their antioxidative effects are driven by the prevention of superoxide generation from mitochondria, a major ROS generator. While all the extracts efficiently attenuated the elevation of ROS levels in human fibroblasts and inflammation-induced mice, those of S. lycopersicum, A. altissima, and O. laciniata only suppressed mitochondrial ROS generation and reduced levels of lipofuscin and lipid peroxidation. Furthermore, the extracts of A. altissima and O. laciniata extended the lifespan of fruit flies. Our results suggest that plant extracts with anti-oxidative effects differ in their ability to prevent ROS generation, which may be associated with the attenuation of oxidative damage in cells and animal tissues.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.218-224
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• 1988

Restriction endonucleases were used to search for intraspecific variation at 32 cleavage sites in mitochondrial DNA(mtDNA) purified from fourteen strains of Drosophila melanogaster helonging to different localities of the world. mtDNA of D. melanogaster was displayed site variation(Hpall, Haelll and Seal endonucleases) and length variation(maxirnum 550bp). Six genotypes, Ml, M2, M3, M4, M6 and M7, could be distinguished based on ihe site types witti a low average of intraspecific substitution rate (1.88%),but M5 type of Ogasawara strain in Japan was not detected in this study. A possible explanation for the low divergence was that mtDNA variation of fourteen strains in D. melanogaster could not he accumulated sufficiently owing to recent divergence of few individuals, and that sequence divergence was prevented by frequent migration in spite of the geographical isolation.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.719-722
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• 2007

IgA nephropathy(IgAN) is considered to be a multifactorial disease with genetic and environmental factors contributing to its pathogenesis. The genes involved in susceptibility and progression of the disease have not yet been clearly elucidated. Megsin is an important candidate gene, predominantly expressed in glomerular mesangium and upregulated in IgAN. To understand biological function of megsin, in this work we have produced transgenic D. melanogaster fly over-expressing human megsin(actin-gal4>UAS-Megsin fly). Introduced human megsin was confirmed by RT-PCR and Western blotting, respectively. Its phenotype is melanin deficiency-abdomen and the megsin gene is stably transferred to the next generations.

• The Korean Journal of Zoology
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• v.18 no.1
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• pp.1-8
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• 1975

The experiment has been analyzed for genetic architecture of behavioral trait in strains selected for positive and negative phototaxis in Drosophila melanogaster. Response to selection for two different directions was rapidly diverged in their phototactic scores. Realized heritabilities for the first teh generations of selection in the positive and negative strains calculated to be 3.08% and 2.86%, respectively in both sexes. The frequency of deleterious chromosomes(lethal and semilethal chromosomes) in the positively selected strain(43%) was higher than that of negatively selected one (18%). The unselected strain(27%) was intermediate frequency between both selected strains. The correlated relationship between deleterious genes and photopositive polygenes was confirmed by the phototactic behavior of the lethal heterozygotes($1_i/1_j$). Form the results, the deleterious genes induced by long term selection for phototaxis would be considered some linkage relationship with photopositive polygenes.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.85-90
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• 2022

Insulin and insulin-like growth factor-1 (IGF-1) are hormones that play an important role in the physiological regulation of metabolism, growth, and longevity in vertebrates. Likewise, insulin-like peptides (ILPs), which are structurally similar to insulin and IGF-1, are crucial in insect physiology. In this review, we present an integrated summary of insect ILPs and their receptor signaling, which has been shown to be comparable to insulin and IGF-1 receptor signaling in vertebrates based on genetic studies of Drosophila melanogaster. Additionally, we review the control of ILP synthesis and secretion in the brain in response to nutrition, as well as the ILPs' physiological role in insect metabolism. Moreover, we discuss the contribution of ILPs to growth, development, reproduction, and diapause. Finally, we consider the possibility of targeting ILP receptor signaling in pest management.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.10-22
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• 2022

This study investigated field data to understand the spatio-temporal distribution of pollinating insects and buckwheat flowers. We set the in-situ observation sites in different locations to get altitude and cropping system distribution data for five years (2016 to 2020) in Korea. Twenty-five different insect species, belonging to 8 orders, were recorded. Over the past five years, species from the orders Diptera and Hymenoptera were the principal visitors. Hymenoptera was mainly represented by honey bees (Apis cerana), while Diptera was represented by bean seed fly (Delia platura) and several other species. Some bees and other Hymenoptera species could, however, act as co-pollinators because of their high relative frequency and activity. Compared with open-field cultivation (conventional), the pollination mediating effect of flies and bees was superior in net house, so the yield was high, and it was also found to be slightly higher in the mixed treatment of flies and bees than in the single treatment. Based on the above results, flies and bees were found to be the most active pollinating insects in buckwheat and it is necessary to actively utilize the selected insects to improve buckwheat productivity. This relationship will be utilized in establishing the system of seed production on pollinating regulation of a primary plant.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.662-669
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• 2012

The effect of aspect ratio (AR) on the aerodynamic characteristics of a flapping wing was examined to analyze the design parameters of an insect-based MAV. The experimental model constructed with 4-bar linkages was operated in a water tank with the condition of a low Reynolds number. A water-proof micro-force load cell was fabricated and installed at the root of the wing which is made of a plexiglas. The wing shapes were based on the planform of a fruit fly wing. The ARs selected were 1.87, 3.74 and 7.48 and the Reynolds number was fixed at $10^4$. For AR=1.87 and 3.74, distinct lift peaks which indicate unsteady effects such as 'wake-capture' were observed at the moment of the start of the wing-stroke. However, for AR=7.48, no unsteady effects were observed. These phenomena were also observed in the delayed rotation case. The results indicate that a larger AR provides better aerodynamic performance for the insect-based flapping wing which can be applied in MAV designs.