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        검색결과 143

        101.
        2016.10 서비스 종료(열람 제한)
        Background : Some of invasive plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plants in Korea, particularly in Jeju Island, invade farmland, and autochthonous forest, establishing monocultures and modifying the ecosystem structure. This invasive species has become a serious environmental problem because they displace the indigenous plant species. This study was conducted to evaluate the antioxidantive effects of ethanolic extracts from different parts (root, stem, seed and leaf) of the invasive exotic species Hypochaeris radicata L. Methods and Results : The aim of present study was to estimate the total phenolic and flavonoid contents and to investigate in vitro antioxidant potential of ethanolic leaf, root, seed, and stem extracts of the Hypochaeris radicata. Antioxidant activity was assessed by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, reducing power activity, [2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] ABTS+ assay and ferrous ion chelating activity. The total phenolic and flavonoid contents were also determined and expressed in gallic acid and quercetin equivalent respectively. The results of the study indicate that the ethanolic extracts of the leaf, root, seed, and stem of H. radicata posses significant scavenging activity against DPPH (21.25% for leaf, 34.98% for root, 60.76% for seed and 45.25% for stem at 250 μg/ml each) and ABTS+ radical scavenging activity (14.85% for leaf, 17.40% for root, 35.91% for seed and 24.70% for stem at 250 μg/ml each), reducing power activity (0.178 absorbance at 300 μg/ml for leaf, 0.211 absorbance at 300 μg/ml for root, 0.447 absorbance at 300 μg/ml for seed, 0.276 absorbance at 300 μg/ml for stem). The free radical scavenging and antioxidant activities may be attributed to the presence of adequate phenolic (gallic acid content is 361.92.98 μg/g in leaf, 356.59μg/g in root, 719.72 μg/g in seed and 512.08 μg/g stem) and flavonoid compounds (219.52 μg/g in leaf, 75.67μg/g in root, 281.39 μg/g in seed and 215.66 μg/g stem). This study revealed that the ethanolic extracts of both leaf, root, seed and stem of H. radicata has demonstrated significant antioxidant activity. Conclusion : In conclusion, the present study has demonstrated that Hypochaeris radicata seed ethanol extracts are rich in phenolics and have a strong antioxidant activity and a radical-scavenging action in all of the tested methods. This suggests that Hypochaeris radicata is a good source of natural antioxidants.
        102.
        2016.10 서비스 종료(열람 제한)
        Background : More than 1250 bamboo species, belonging to 75 genera, are distributed all over the world. Sasa quelpaertensis Nakai is a type of bamboo grass widely distributed in Halla mountain, Jeju Island, which has been used as antidiabetic, anti-cancer and anti-inflammatory drugs. In this study, we investigated the antioxidant and antimicrobial activities of Sasa quelpaertensis Nakai leaf extracted with different ethanol concentration and demonstrated the potent bioactivities of the extracts suitable to be used as natural antioxidant compounds or pharmaceutical supplements. Methods and Results : Antioxidant and anti-microbial activities of Sasa quelpaertensis Nakai extracts were studied. At first, different ethanol concentrations (0, 20, 40, 60 and 80%) were compared for determining of the best solvent for extraction of phenolic compounds from Sasa quelpaertensis Nakai. Forty percent Ethanol extract with 990.01±28.9 (mg of gallic acid equivalents/g sample) were the best solvent in the extraction of phenolic compounds. But, 60% ethanolic extracts were highest antioxidant activity appeared such as DPPH radical scavenging (IC50 21.20±0.42 μg/ml), ABTS radical scavenging (IC50 49.85±1.27 μg/ml) and reducing power. However, 80% ethanol extracts showed the strongest SOD like activity. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and yeast. Sixty percent and 80% ethanol extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 125 μ g/ml and 250 μg/ml for the 60% and 80% extracts, respectively. Conclusion : The results of this study show that the extract of Sasa quelpaertensis Nakai can be used as easily accessible source of natural antioxidants and as a possible food supplement or in pharmaceutical industry. However, the components responsible for the antioxidant and antimicrobial activities of both extracts of Sasa quelpaertensis Nakai are currently unclear. Therefore, it is suggested that further works should be performed on the isolation and identification of the antioxidant components in Sasa quelpaertensis Nakai.
        103.
        2016.10 서비스 종료(열람 제한)
        Background : Panax ginseng C. A. Meyer is a slow-growing perennial herb that is cultivated in shading condition. Climate change occur around the world that make a lot of problem such as damage of high temperature, drought, salinity and disease. The problems lower the ginseng productivity that cause income reduction of farmers. To achieve stable ginseng production, development of elite varieities resistant to abiotic and biotic stresses is consistently required. It is very time consuming process in order to develop new ginseng varieties because ginseng flowers after 3 years of growth. So, early selection system of elite line must be established. This study was conducted to develope efficient ginseng breeding techniques for early identification of heat or salinity resistance. Methods and Results : Ginseng petioles was soaked in mixed salts solution consisting of KNO3, KH2PO4, MgSO4․H2O in order to test resistant or susceptible salinity. The degree of resistance was quantified according to damage size. Also, ginseng lines transplanted in pot were treated 46℃ for 1 hour and then chlorophyll fluorescence reaction were measured in order to test resistant or susceptible high-temperature. The measured values such as Fm/Fo, Fv/Fm, Rfd were differentiated between resistant and susceptible line. Conclusion : Several lines showed that they are resistance to high temperature or salinity. The selected lines will be utilized for parents to develop new varieties.
        104.
        2016.05 서비스 종료(열람 제한)
        Background : Water uptake and flow across cellular membranes is a fundamental requirement for plant growth and development, and plant water status is important not only for plant growth under favorable conditions but also for ability of a plant to tolerate adverse environmental conditions. Thus identification of plasma membrane water channel genes (aquaporins) in ginseng provides extensive information for functional studies and the development of markers for salinity stress tolerance. Methods and Results : For salinity treatment, the plants were grown for 4 weeks in culture medium gelled with 0.8% Phytoagar, and the old media were replaced with the fresh medium containing NaCl at 0, 50, 100, 200 and 400 mM, respectively. The samples for stress treated and non-stressed plants were collected from 6h to 72h, and frozen immediately into liquid nitrogen. According to the sequence information from the assembled transcripts, four primer pairs were designed from the aquaporin gene regions. In order to determine the pattern of aquaporins expression in ginseng seedlings to salinity stress, we conducted semi-quantitative RT-PCR. Conclusion : A tonoplast intrinsic protein 1 (TIP1)-type aquaporin is not only believed to be essential for plant life, but also to be beneficial for growth under salinity stress. Therefore, a deeper understanding of aquaporin genes in ginseng will be essential for crop improvement, which could help us to understand the molecular genetic basis for the ginseng genetic improvement and also provide the functional genetic resources for selective breeding and transgenic research.
        105.
        2016.05 서비스 종료(열람 제한)
        Background : This study was carried out to understand the effect of seedling weight (SW) on growth and flowering in Panax ginseng. Methods and Results : The testing materials were Chunpoong (CP), Yunpoong (YP) and Jakyeongjong (JK). The increase of seedling (1yr) weight led to an increase in ratio of flowering plant and in number of flower per plant. The seed setting rate of two year-old plant (CP, YP, JK) increased with increase of SW at the planting time (PT) and number of flower per plant of three year-old plant (CP, YP) increased also. In the two year-old plant (JK), the ratio of three leaves per plant was 8.8, 19.6, 31.0, 42.0, 44.7 and 58.2%, respectively, in the SW of >0.6, 0.6~0.8, 0.8~1.0, 1.02~1.2, 1.2~1.4 and 1.4g<. The growth of ginseng plant was good with increase of SW at the PT. Conclusion : There was a highly positive correlation between seedling weight and flowering characteristics.
        106.
        2016.05 서비스 종료(열람 제한)
        Background : Due to immature development of embryo in ripened berries, dehiscence process is required for the proper germination of ginseng seeds. Such process involves the preparation of the container with alternating layers of seed and moist sand. In order to make sand fully moist, water sprayer has been usually used by farmers, which is labor intensive, time consuming and causing uneven sand moisture. Methods and Results : In this study, we investigated the effects of different stratification methods on dehiscence ratio of ginseng seeds. Ginseng seeds were stratified for 90 days in a total of 12 different treatments and the dehiscence ratios were compared; drainage methods, drainage time, the ratio between ginseng seeds and sand, and etc. Seed stratification process was performed according to the guideline of ginseng GAP. One thousand ginseng seeds were used for each treatment. It was found that the average of dehiscence of the 12 treatments was 84.6 %. The highest dehiscence ratio (90.3 %) was observed in the seeds that were treated with water soaking, immediately followed by drainage. Higher ratio was also observed in the seeds that were soaked for 60 min, followed by drainage. Therefore, our findings indicate that ginseng seeds soaked in water less than 60 min could dehisce more efficiently than traditional method. Conclusion : Our study demonstrated that ginseng seeds that are subjected to water soaking and then drainage showed better ration of dehiscence. This method will eventually decrease the time and labor used for seed stratification.
        107.
        2016.05 서비스 종료(열람 제한)
        Background : This study was conducted to determine the impact of temperature elevated and the effect of transplanting times based on climate change scenario on growth of 2-year-old korean ginseng (Panax ginseng C. A. Meyer.) in temperature gradient chambers (TGC). Methods and Results : As a plant materials, ‘Yunpoong’ was cultivated in TGC at ambient temperature(Amb), Amb+2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng was also transplanted on March 29, April 12 and 26 respectively. Investigation on characteristic of aerial parts were carried out on 28, 56, 84 and 112 days after transplanting and characteristic of roots were conducted on October 19. As transplanting time was faster and temperature was higher, the growth of aerial parts were increased. Compared with those of ginseng transplanted on March 29 with Amb, the root weight which tend to decrease depending on late transplanting time and high temperature decreased about 11.1%, 35.4% and 42.4% in Amb+ 2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng transplanted on April 12 and 26 decreased about 20.9%, 33.9% respectively. Conclusion : Consequently, the more transplanting time extend, the more quantity increased in all temperature treatment. So, it is possible to increase in quantity to advance transplanting time although high temperature will be caused by the climate change.
        108.
        2016.05 서비스 종료(열람 제한)
        Background : When ginseng seeds were gathered, the seeds were unripe. To grow immature embryo definitely, special treatment called dehiscence must be performed. Even though dehiscence is completed, most ginseng seeds are on enforced dormancy. The breaking seed dormancy is generally achieved using cold treatment. Also it is reported that gibberellin treatment can replace the treatment. It is very time consuming process in order to develop new ginseng cultivar because ginseng flowers after 3 years of growth. To shorten the ginseng breeding period, it is necessary to establish fast generation progress. Therefore, this study examined the possibility of breaking seed dormancy of ginseng using GA3 treatment and alternating temperature. Methods and Results : Seeds were obtained from local variety fruit which is not inbred. Gibberellin of 100 ppm was treated at seeds for 24 hours. Fixed cold condition was treated on both –2℃ and 2℃. Alternating cold condition was treated on 2℃ and then –2℃, finally 2℃. Fixed and alternating temperature was continued for 15, 30, 45, 60, 90 days that 15 days of alternating temperature is first 2℃ for 5days and then -2℃ for 5days, finally 2℃ for 5days. The other treatment periods such as 30, 45, 60, 90 days mean 10, 15, 20, 30 days respectively. Each of 48 seeds were sowed on tray in greenhouse at 3 replication. Experimental plot was completely randomized. Conclusion : Seeds untreated with GA3 were germinated little and there is no difference between 2℃ and –2℃. Alternating temperature until 60days made no difference with fixed temperature but germination rate increased up to 70.8% when seeds were treated for 90days. Germination of seeds treated with GA3 is much higher than untreated seeds especially combined with alternating temperature.
        109.
        2015.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        We estimated the orbit of the Communication, Ocean and Meteorological Satellite (COMS), a Geostationary Earth Orbit (GEO) satellite, through data from actual optical observations using telescopes at the Sobaeksan Optical Astronomy Observatory (SOAO) of the Korea Astronomy and Space Science Institute (KASI), Optical Wide field Patrol (OWL) at KASI, and the Chungbuk National University Observatory (CNUO) from August 1, 2014, to January 13, 2015. The astrometric data of the satellite were extracted from the World Coordinate System (WCS) in the obtained images, and geometrically distorted errors were corrected. To handle the optically observed data, corrections were made for the observation time, light-travel time delay, shutter speed delay, and aberration. For final product, the sequential filter within the Orbit Determination Tool Kit (ODTK) was used for orbit estimation based on the results of optical observation. In addition, a comparative analysis was conducted between the precise orbit from the ephemeris of the COMS maintained by the satellite operator and the results of orbit estimation using optical observation. The orbits estimated in simulation agree with those estimated with actual optical observation data. The error in the results using optical observation data decreased with increasing number of observatories. Our results are useful for optimizing observation data for orbit estimation.
        110.
        2015.07 서비스 종료(열람 제한)
        To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the salt tolerance of adapted cells was memorized. Salt-adapted and stress memorized cells were densely aggregated and formed multi-layered cell lump. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. The results provide new insight into metabolic level mechanisms of plant adaptation to saline stress as well as stress memory.
        111.
        2015.07 서비스 종료(열람 제한)
        To identify novel signaling components involved in regulation of plant responses to phosphate (Pi) starvation, we screened an Arabidopsis T-DNA activation tagging library for mutants with altered Pi-starvation responses. Here, we report the identification and characterization of novel activation-tagged mutant involved in Pi starvation signaling in Arabidopsis. The hpd (hypersensitive to Pi deficiency) mutant exhibits enhanced phosphate uptake and altered root architectural change under Pi starvation compared to wild type. Expression analysis of auxin-responsive DR5::GUS reporter gene in hpd mutant indicated that both auxin biosynthesis and auxin translocation under Pi starvation are suppressed in hpd mutant plants. Impaired auxin translocation in roots of hpd mutant was attributable to abnormal root architecture changes in Pi starvation conditions. Mis-regulation of auxin translocation in hpd mutant was further confirmed by analysis of expression patterns of auxin efflux carrier proteins, PIN-FORMED (PIN) 1, 2, and 3 fused with GFP. Not only expression levels but also expression domains of PIN proteins were altered in hpd mutant in response to Pi starvation. Molecular genetic analysis of hpd mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’-end processing. The results propose that mRNA processing plays crucial roles in Pi homeostasis as well as developmental reprograming in response to Pi deprivation in Arabidopsis.
        112.
        2014.09 서비스 종료(열람 제한)
        We determined intravitreal levels of vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in patients with early phase rhegmatogenous retinal detachment (RRD). Twenty five eyes of 25 RRD patients with symptom onset from one day to 21 days prior to vitrectomy were selected. Concentrations of VEGF and PEDF in vitreous were determined by enzyme-linked immunosorbent assay and relationships between these concentrations and durations and involved quadrants were analyzed. Duration of RRD was found to show significant correlation with PEDF concentration. However, number of involved quadrants did not show correlation with PEDF concentration in vitreous.
        113.
        2014.09 서비스 종료(열람 제한)
        The aim of this study was to analyze the effect of antifreeze proteins (AFPs) on vitrification of mouse mature (MII) oocytes. We studied about 3 types of AFPs from different origins (FfIBP, LeIBPand Type III AFP). The MII oocytes were obtained from 4-week-old BD-F1 mice. Vitrification of oocyte was performed by 2 steps using the Cryotop (equilibration: 7.5% EG + 7.5% PROH for 5 min, vitrification: 15% EG + 15% PROH + 0.5M sucrose for 1 min). The concentrations of AFPs added to these solutions were 0.05 mg/ml for FfIBP and 0.1 mg/ml for LeIBP and Type III AFP. After fertilization, embryo development was assessed up to 5 days. Through immunostaining of vitrified-warmed oocytes, we assessed the normal meiotic spindle. Also, intracellular ROS and mitochondrial activity was analyzed. In the developmental stages, FfIBP and LeIBP groups showed significantly higher survival rates. In the blastocyst and apoptotic blastomere rates were significant differences in AFPs treated groups. AFPs treated groups were significantly higher in blastocyst cell numbers than control group. Among the AFPs treated groups, FfIBP, LeIBP groups were significantly higher rates. And, in cleavage rates, FfIBP group was significantly higher rates than the other groups. In vitrified-warmed MII oocytes, the normal meiotic spindle organization and chromosome alignment rate was significantly higher in FfIBP and LeIBP groups. And in intracellular ROS levels, control group was significantly increased than AFPs treated groups. However, in the mitochondrial activity, LeIBP group was significantly higher than control, FfIBP and LeIBP groups. AFPs treated groups were significant differences in development, meiotic spindle organization and intracellular ROS levels. And in the AFPs treated groups, FfIBP and LeIBP groups were significantly higher rates in normal meiotic spindle and mitochondrial activity than Type III AFP group respectively. In conclusion, FfIBP and LeIBP can be thought to improve oocyte cryopreservation efficiency.
        114.
        2014.09 서비스 종료(열람 제한)
        The follicle loss of transplanted ovarian tissue (OT) is caused by ischemia and slow revascularization. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been treated for transplanted tissues. Angiopoietin-2 (ANG-2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in the ischemic and/or hypoxic environment. So, this study was designed to assess the impact of ANG-2 on follicle integrity and revascularization of mouse OT grafts. The 5-week-old B6D2F1 female mice were divided into 3 groups (a control and 2 ANG-2 groups) followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without ANG-2 injection (50 or 500 ng/kg), and then killed at day(D)2, 7, 21 and 42 after transplantation. Total 2,437 follicles in OT grafts were assessed for the follicular density, integrity and classification by H&E staining. Apoptosis, revascularization, and serum FSH levels were evaluated by TUNEL assay, CD31 immunohistochemistry, and ELISA respectively. All the ANG-2 groups showed remarkable increase of morphologically intact follicle ratio across all the grafting duration except D21 (no statistical difference). The numbers of CD31(+) vessels (the sum of 3 fields at ×400 magnification) were significantly increased in both ANG-2 groups compared with the control group at all the grafting duration. Especially at D42, the 500ng ANG-2 group showed significantly more vessels than the 50 ng ANG-2 group as well as the control group. However the mean follicle numbers of grafts, apoptosis ratio and serum FSH levels showed no significant difference among the groups. In this study, remarkably well preserved follicles and larger amount of vessels were appeared in ANG-2 treated groups. So we thought that ANG-2 treatment is effective for OT transplantation and improve transplantation outcomes.
        115.
        2014.09 서비스 종료(열람 제한)
        Polyethyleneglycol-adsorbed–superoxide dismutase (PEG-SOD), has been proposed as an effective agent for reducing free radical-mediated injury. The objective of this study was to investigate a protective effect of PEG-SOD supplementation on ovarian tissue during transplantation. Ovaries from F-1 mice were collected and vitrified. After warming, ovaries were autotransplanted under kidney capsule. Mice were randomly divided into four groups according to dose of PEG-SOD, (0 U/ml, 100 U/ml, 1,000 U/ml and 10,000 U/ml respectively). Grafted ovaries were retrieved 2, 7 and 21 days later. PEG-SOD was treated by intraperitoneal injection once every 48 hours and especially for 21 days group, after first week treatment, PEG-SOD was treated once every 4 days. Morphology of ovaries was assessed histological analysis and ELISA for FSH was performed to evaluate restoration of ovarian function. In 2 days groups, morphologically intact follicle ratio of 10,000 U/ml group was significantly higher than other groups. In 7 days groups, morphologically intact follicle ratio was significantly higher in all treatment groups. In 21 days groups, there was no significant difference of intact follicle ratio in total follicles in all groups but intact primordial, primary and secondary follicles ratio was higher in 10,000 U/ml group. FSH levels in blood serum were decrease as time goes on, but there is no statistical difference in each groups. In conclusion, the data of the present study show that PEG-SOD has a beneficial effect on preservation of the morphologically intact follicle.
        116.
        2014.09 서비스 종료(열람 제한)
        Ovarian tissue cryopreservation and transplantation causes follicle depletion. To overcome this problem, we investigate the effect of Anti-Müllerian hormone (AMH), a follicle recruitment control hormone, supplementation before and/or after mouse ovarian transplantation. A total of 120 5-week-aged BD F-1 female mice were used. The mice were randomly divided into four groups according to AMH doses (0, 5, 25, 125 μg/mL, respectively). AMH was injected intraperitoneally on every other day for a week before, after, or before and after transplantation of ovaries under kidney capsules was performed. One week after transplantation, follicular normality was evaluated by histological analysis and TUNEL assay. In Group A and C, morphologically intact follicle (G1) ratios of AMH treated groups showed no statistically significant difference. In Group B, G1 ratios of 25 and 125 μg/mL of AMH treated groups were higher than those of 5 μg/mL treated group, but there was no improvement in G1 ratio after AMH treatment. In every group, apoptotic follicle ratios did not show any trend according to AMH treatment. Proportions of primordial follicle were not significantly different according to AMH treatment in all groups. The result of the present study demonstrated that AMH treatment during on transplantation of cryopreserved ovaries has no significant effect on follicle survival and prevention of follicle depletion.
        117.
        2014.09 서비스 종료(열람 제한)
        Objective : To investigate the effects of Simvastatin and Methylprednisolone on ovarian tissue cryopreservation and transplantation using mouse models. Methods : The mice were randomly distributed into 1 control and 3 experimental groups. The B6D2F1 mice were given oral Simvastatin (5 mg/kg), intravenous Methylprednisolone (15 mg/kg), or a combination of both at 2 hours before ovariectomy. Same volume of normal saline was given perorally in the control group at 2 hours before ovariectomy. The ovarian tissues were vitrified accrording to our protocols. The vitrified ovaries were warmed 1 week later and auto-transplanted under bilateral kidney capsules. The ovaries and blood sera were collected at 2, 7 or 21 days after transplantation. Histological analysis, TUNEL assay, immuno-histochemistry for CD31, serum AMH level and embryonic development after in vitro fertilization were assessed for evaluation. Results : With regard to the total grade 1 follicle rate, both Simvastatin or Methylprednisolone treated groups were significantly increased at 2, 7 or 21 days after transplantation (except Simvastatin treated group at 7 days). A combination of Simvastatin and Methylprednisolone group was significantly improved in terms of the total G1 follicle rate, apoptotic follicle rate, CD31 positive area and serum AMH after ovarian tissue transplantation. However, there were no statistically difference with respect to the oocyte maturation rate, blastulation rate, and the other embryonic development parameters after in vitro fertilization procedure among the four groups. Conclusion : Our results suggest that combined donor Simvastatin and Methylprednisolone have beneficial effects on the quality and function of transplanted ovarian tissues.
        118.
        2014.09 서비스 종료(열람 제한)
        Study question: What is the optimal vitrification protocol according to the cryoprotective agent (CPA) for ovarian tissue (OT) cryopreservation? Summary answer: The two-step protocol with 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 10 min then 20% EG, 20% DMSO and 0.5 M sucrose for 5 min showed the best results in mouse OT vitrification. What is known already: Establishing the optimal cryopreservation protocol is one of the most important steps to improve OT survival. However, only a few studies have compared vitrification protocols with different CPAs and investigated the effect of in vitro culture (IVC) on vitrified–.warmed OT survival. Some recent papers proposed that a combination of CPAs has less toxicity than one type of CPA. However, the efficacy of different types and concentrations of CPA are not yet well documented. Study design, size, duration: A total of 644 ovaries were collected from 4-week-old BDF1 mice, of which 571 ovaries were randomly assigned to 8 groups and vitrified using different protocols according to CPA composition and the remaining 73 ovaries were used as controls. After warming, each of the eight groups of ovaries was further randomly divided into four subgroups and in vitro cultured for 0, 0.5, 2 and 4 h, respectively. Ovaries of the best two groups among the eight groups were autotransplanted after IVC. Participants/materials, setting, methods: The CPA solutions for the eight groups were composed of EDS, ES, ED, EPS, EF, EFS, E and EP, respectively (E, EG; D, DMSO; P, propanediol; S, sucrose; F, Ficoll). The IVC medium was composed of a-minimal essential medium, 10% fetal bovine serum and 10 mIU/ml follicle-stimulating hormone (FSH). Autotransplantation of vitrified–.warmed OTs after IVC (0 to 4 h) using the EDS or ES protocol was performed, and the grafts were recovered after 3 weeks. Ovarian follicles were assessed for morphology, apoptosis, proliferation and FSH level. Main results and the role of chance: The percentages of the morphologically intact (G1) and apoptotic follicles in each group at 0, 0.5, 2 and 4 h of IVC were compared. For G1 follicles at 0 and 4 h of IVC, the EDS group showed the best results at 63.8 and 46.6%, respectively, whereas the EP group showed the worst results at 42.2 and 12.8%, respectively. The apoptotic follicle ratio was lowest in the EDS group at 0 h (8.1%) and 0.5 h (12.7%) of IVC. All of the eight groups showed significant decreases in G1 follicles and increases in apoptotic follicles as IVC duration progressed. After autotransplantation, the EDS 0 h group showed a significantly higher G1 percentage (84.9%) than did the other groups (42.4–.58.8%), while only the ES 4 h group showed a significant decrease in the number of proliferative cells (80.6%, 87.6–.92.9%). However, no significant differences in apoptotic rates and FSH levels were observed between the groups after autotransplantation. Limitations, reasons for caution: The limitation of this study was the absence of in vitro fertilization using oocytes obtained from OT grafts, which should be performed to confirm the outcomes of ovarian cryopreservation and transplantation. Wider implications of the findings: We compared eight vitrification protocols according to CPA composition and found the EDS protocol to be the optimal method among them. The data presented herein will help improve OT cryopreservation protocols for humans or other animals.
        119.
        2014.07 서비스 종료(열람 제한)
        Genome sequencing researches for considerable numbers of crops and wild plants are being developed. Cytogenetic researches according to chromosome number and size are essential to confirm and comprehend ploidy level and genome size before genome sequencing project is actually conducted. Cytogenetic researches on six food crop plants were carried out by DAPI staining and fluorescence in situ hybridization (FISH) method. Fagopyrum esculentum Moench showed 2n=2x=16, each chromosome length of 1.42㎛ to 1.77㎛, total chromosome length of 13.31㎛, and karyotypic formula of 2n=8m; Phaseolus angularis W.F. Wight, 2n=2x=22, 2.01㎛ to 3.84㎛, total 28.03㎛, 2n=9m+2sm, Perilla frutescens var. japonica Hara, 2n=2x=40, 1.73㎛ to 2.76㎛, total 44.36㎛, 2n=5m+13sm+2st. Chromosome sizes of the other three species such as, Panicum miliaceum L., 2n=2x=36, total chromosome length of 30.83㎛, Sesamum indicum L., 2n=2x=26, 27.39㎛, lpomoea batatas L., 2n=2x=30, total 33.51㎛ were too small for each chromosome type to be identified and analyzed. The result of FISH analysis using 5S and 45S rDNA probe showed species-specific chromosome locations in the genome. These preliminary analyses were carried out to decide which food crop to prioritize for genome sequencing. This work was supported by the “Cooperative Research Program for Agriculture Science & Technology Development (No.PJ009837), Rural Development Administration, Republic of Korea.
        120.
        2012.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.
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