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        검색결과 546

        181.
        2017.10 구독 인증기관·개인회원 무료
        A genus of entomopathogenic Beaveria bassiana has been widely used in pest management, however little studies havebeen given to its virulence-related genes. To identify the roles of virulence genes, AtMT-induced random mutants weregenerated and followed by localization study with TAIL-PCR. Two genes, Complex I intermediated-associated protein30 (CIP30) and Autophagy protein 22 (Atg22), were predicted as virulence-related genes in B.bassiana JEF-007. To validatethe a possible relationship between two genes and fungal virulence, hpRNAi was performed. A hpRNAi plasmid wasconstructed as a model system to knock down of egfp gene in egfp-expressing B. bassiana transformant. A Real-TimePCR showed the knock down of egfp gene expression via hpRNAi. The CIP30 and Atg22 genes in B. bassiana willbe validated by the established RNAi technique. This work can be a strong platform for the functional genetics in B.bassiana.
        182.
        2017.09 구독 인증기관 무료, 개인회원 유료
        Xenotransplantation is proposed as a solution to the problem of organ shortage. However, transplantation of xenogeneic organs induces an antigen-antibody reaction in α-1,3-gal structure that are not present in humans and primates, and thus complement is also activated and organs die within minutes or hours. In this study, we used FasL gene, which is involved in the immune response of NK cell, and US11, which suppresses MHC Class I cell membrane surface expression, to inhibit cell mediated rejection in the interspecific immunity rejection, and also hDAF(CD55) was introduced to confirm the response to C3 complement. These genes were tranfeced into Korean native pig fetal fibroblasts using pCAGGS vector. And cytotoxicity of NK cell and human complement was confirmed in each cell line. The US11 inhibited the cytotoxicity of NK cell and, in addition, the simultaneous expression of US11 and Fas ligand showed excellent suppress to T-lymphocyte cytotoxicity, hDAF showed weak resistance to cytotoxicity of natural killer cell but not in CD8+ CTLs. Cytotoxicity study with human complement showed that hDAF was effective for reducing complement reaction. In this studies have demonstrated that each gene is effective in reducing immune rejection.
        4,000원
        184.
        2017.05 구독 인증기관·개인회원 무료
        Embryo development is very important in reproductive physiology of domestic animal experiments. Therefore, in the above experiment, we want to provide a lot of important information with regard to fertilization breeding by looking at the expression of transcription factor by early embryo development. It is known that mice affect early embryonic development of many transcription factors, many experiments are underway. Different types of mammals showed different expression patterns, thus, we used pigs, which are known to be the most similar to humans, to observe the expression of transcription factors in early embryonic development. Transcription factors were observed using CDX2, OCT4 and E-CADHERIN. CDX2 was expressed in 2 cells, OCT4 and E-CADHERIN were expressed in blastocyst. OCT4 was expressed specifically in ICM (inner cell mass) in blastocyst, and E-CADHERIN was expressed in cell wall and junction of blastocyst. These results show that CDX2, OCT4 and E-CADHERIN play an important role in early embryonic development in pigs.
        186.
        2017.04 구독 인증기관·개인회원 무료
        We performed a survey for flavivirus infection and distribution of Aedes albopictus that known as Zika and Dengue virus vector using black–light trap and BG-sentinel trap around urban area in Korea. Mosquitoes were collected in 27 cities during March to November (twice a month) year 2016. Total numbers of mosquitoes collected 102,102 including 19 species 8 genera during collecting period. Total 21,467 Ae. albopictus was collected that 20,961(24.3%) by BG-sentinel trap and 506 (3.2%) by Black-light trap in urban area. Trap index(trap/night) of Ae. albopictus was showed highest in Hamyang (TI:992.3) and lowest in Taebaek (TI:0.3) there was only collected by Black-light trap. A total of 894 pools from all collecting Ae. albopictus were performed a Flavivirus detection. Flavivirus was not detected during study period. This study may provide basic information for surveillance of imported diseases (include Zika virus) and vectors in Korea.
        187.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi, widely distributed in nature, have been developed as biopesticides of agricultural pests. However, little is known about isolation method for obtaining a variety of highly virulent strains from the soil. In this work, the previously established method using mealworm (larvae of Tenebrio molitor) as a baiting system was used to efficiently isolate fungal strains from soil, and the isolated fungal library in Korea was established. To isolate entomopathogenic fungi, soil samples from 10 regions of Korea such as Iksan, Imsil, Gunsan, Yeosu, Suncheon, Gwangyang, Jinju, Hamyang, Boseong and Jangseong were collected. Of the collected soils, 21 and 34 isolates of entomopathogenic fungi were isolated from Iksan and Gunsan, respectively. The isolates were classified as genera of Metarhizium, Beauveria and Isaria. This work can suggest an effective insect pathogenic fungal isolation method
        188.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been known as promising candidates in biological control. However, a large number of conidia with higher stability should be produced for industrialization. In this work investigated the possibility of several grains for the production of thermotolerant Isaria javanica and I. fumosoroseus conidia. The fungal conidia were produced on ten grains for 14 days in Petri dish conditions. Of the ten granular substrates, millet, perilla seed and barley showed the high conidial production, 15.7 ± 8.4, 17.3 ± 5.2 and 13.5 ± 1.9 × 109 conida/g in I. javanica and 15.9 ± 0.6, 15.0 ± 0.5 and 15.0 ± 0.7 ×109 conida/g in I. fumosoroseus, respectively. However, the two strains showed relatively low thermal stability regardless of substrates, when exposed to 45℃ for 1, 2 and 3 hours. This work suggests a possible substrate for conidial production of entomopathogenic fungi with low cost.
        189.
        2017.04 구독 인증기관·개인회원 무료
        Secondary metabolites isolated from Actinomycete have been studied to find potent pest control agents as their insecticidal and growth inhibitory activities. In order to investigate novel insecticidal compounds, second metabolites from 363 Actinomycete isolates were evaluated for their insect growth regulatory activities. Among them, ethyl acetate extracts from ten Streptomyces spp. showed high level of Juvenile hormone antagonist activity. In addition, their insecticidal activities were tested against larvae of Aedes albopictus, Plutella xylostella and Laodelphax striatellus. These results suggested that secondary metabolites from Streptomyces spp. could be used for development of novel IGR-based insecticides.
        190.
        2017.04 구독 인증기관·개인회원 무료
        Plant essential oils have been reported to show repellent, insecticidal and growth-reducing effect on many insect herbivores. Recently, it has been reported that plants synthesize secondary metabolites regulating insect juvenile hormone (JH) receptor complex as a part of their defense mechanisms. We tested 180 plant essential oil compounds using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system. Among them, we identified 17 compounds that showing high JH agonist (JHA) or antagonist (JHAN) activities. They were grouped into 4 groups by their structural similarity and their insecticidal activity was tested against larvae of Aedes albopictus, Plutella xylostella, Plodia interpunctella and Laodelphax striatellus. These results could provide insights on the plant-insect coevolution and may be useful for the development of insect specific and safe pesticides.
        191.
        2017.04 구독 인증기관·개인회원 무료
        RNA interference (RNAi) is an universal gene-knockdown mechanism in eukaryotic organisms including insects. RNAi has been considered as an alternative strategy to control agricultural pests whereby double-stranded RNA triggers a potent and specific inhibition of its homologous mRNA. Bacillus thuringiensis (Bt) is a spore-forming bacterium that produces a copious amount of crystal proteins δ-endotoxins under the control of sporulation-dependent promoter. In order to develop dsRNA mass-production platform utilizing recombinant Bt, the pHT1K-EGFP which expresses dsRNA against EGFP under the control of Cyt1-Aa sporulation-dependent promoter was constructed and the expression level of transgene (EGFP) was confirmed by qPCR analysis. These results suggested that Bt’s potential of becoming a new platform in dsRNA production.
        192.
        2017.04 구독 인증기관·개인회원 무료
        Insect growth regulators (IGRs) are insecticides that disrupt the normal development of target insects by inducing symptoms such as premature molting or supernumerary larval stages. Juvenile hormone (JH)-based IGRs are of particular interest because they simulate or interfere with the formation of juvenile hormone receptor complex. Insect larvae generally have been poorly susceptible to JH agonists (JHAs) because endogenous JH titer is already high in the larval stage. In contrast, JH antagonists (JHANs) might be more effective for control of target pests in larval stages through interference in the status quo action of JHs. In this study, we tested 2,354 chemical compounds using the yeast-two hybrid system to identify JHANs. Among them, K265674 sample was selected and its insecticidal activity was evaluated against Aedes albopictus larvae. These results may be useful for development of novel IGR insecticide.
        193.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi have been widely studied for their potential as the effective biological control agents. They produce variety of secondary metabolites with insecticidal activities, and it is reasonable to assume that entomopathogenic fungi might produce secondary metabolites modulating juvenile hormone for their survival against defense mechanisms of host insect. In this study, acetone extract of the Lecanicillium spp. cultured on unpolished rice medium showed juvenile hormone antagonist (JHAN) activity in the yeast-two hybrid β-galactosidase assay and high insecticidal activity against Aedes albopictus and Plutella xylostella. In addition, to compare bioactivities of secondary metabolites from solid and liquid culture, the Lecaniciilium spp. strain cultured on unpolished rice medium or PDB medium were serially extracted with acetone and ethyl acetate respectively. Both extracts showed JHAN activity and high insecticidal activity against A.albopictus. Theses results suggested that secondary metabolites of entomopathogenic fungi could be useful for development of novel IGR insecticides.
        194.
        2017.04 구독 인증기관·개인회원 무료
        Rice stripe virus (RSV) is one of the serious plant pathogenic viruses for rice transmitted by small brown planthopper (SBPH), Laodalphax striatellus. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. To disturb transmission of the RSV in SBPH using RNAi pathway, we chose nine genes highly expressed in RSV-viruliferous SBPH by transcriptome sequencing. These SBPH-derived dsRNAs were applied to the insects indirectly through xylem of rice leaves by irrigation. qPCR result demonstrated that five out of nine SBPH-derived dsRNAs successfully reduced the replication of RSV in viruliferous SBPH in dose-dependent manner, suggesting that these five dsRNAs could suppress replication of RSV and provide a new tool for RSV control strategy.
        195.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are expected to play a role as great biological control agents in the global bio-pesticide market in the future. The first step is the collection of fungal isolates and it should be a platform for the development of highly effective biopesticides. In this work, we constructed a fungal library using a mealworm pathogenecity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic tree was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, virulence against several insect, stability of conidia for heat, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.
        196.
        2017.04 구독 인증기관·개인회원 무료
        Many turfgrass pests, Ectinohoplia rufipes, Exomala orientalis and Popillia quadriguttata, cause serious damage to grass fields in Korea. In this study, control of turfgrass pests using entomopathogenic fungi were investigated using Protaetia brevitarsis seulensis as an alternative insect. In a preliminary experiment, some Metathizium sp. showed ca. 60% virulence after 7 days exposure to the entomopathogenic fungi. Compared to the contact-exposure, overall a spray treatment showed lower control efficacy against P. brevitarsis seulensis. Furthermore, mortality of various developmental stages of P. brevitarsis seulensis was investigated under laboratory conditions. This work suggests that when treated with fungi mortality of P. brevitarsis seulensis was closely related with developmental stage. These results provide a basic information for the control of P. brevitarsis seulensis using entomopathogenic fungi
        197.
        2017.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are potential pesticides as biological control agents. However, many previous studies have focused on basic researches to control pest using insect-pathogenic fungi. Herein, the molecular characteristics of insect defense mechanisms against fungal pathogens and fungal pathogenicity to insects were investigated. The whole genome of Beauveria bassiana (Bb) JEF-007 was sequenced (36,538,394 bp) using Pacbio sequencing. Based on this data, the transcriptomes of bean bug and fungus were analyzed using RNA-seq. In the transcriptome analyses, six and five genes were validated to be involved in the fungal pathogenicity and insect defense, respectively. This work can provide an understanding of the insect-pathogen interactions
        198.
        2017.04 구독 인증기관·개인회원 무료
        Dermanyssus gallinae is parasitic to chicken, and they cause many damages such as disturbing sleep reducing for body weight and egg production by blood-sucking. To develop acaricide against D. gallinae, The acaricidal activity of 40 species plant extract were examined. Cnidium officinale extracted by Me-OH showed 82.0% acaricidal activity after treated 48 hrs at 4,000 ppm. The hexane fraction showed 92.4% mortality against D. gallinae at 48 hrs at 2,000 ppm. Purification of the biologically active constituents from the hexane extraction with acaricidal activity was done using silica gel open column chromatography and HPLC. H1122 fraction gave 80.9% mortality to D. gallinae at 400 ppm after treated 48 hrs. H1122 fraction was analyzed by GC-MS and NMR.
        199.
        2017.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We carry out the study of 850 μm sources in a part of the XMM-LSS field. The 850 μm imaging data were obtained by the SCUBA-2 on the James Clerk Maxwell Telescope (JCMT) for three days in July 2015 with an integration time of 6.1 hours, covering a circular area with a radius of 15′. We choose the central area up to a radius of 9.′15 for the study, where the noise distribution is relatively uniform. The root mean square (rms) noise at the center is 2.7 mJy. We identify 17 sources with S/N > 3.5. Differential number count is estimated in flux range between 3.5 and 9.0 mJy after applying various corrections derived by imaging simulations, which is consistent with previous studies. For detailed study on the individual sources, we select three sources with more reliable measurements (S/N > 4.5), and construct their spectral energy distributions (SEDs) from optical to far-infrared band. Redshift distribution of the sources ranges from 0.36 to 3.28, and their physical parameters are extracted using MAGPHYS model, which yield infrared luminosity LIR = 1011.3−1013.4 L⊙, star formation rate SFR = 101.3−103.2 M⊙yr−1 and dust temperature TD = 30−53 K. We investigate the correlation between LIR and TD, which appears to be consistent with previous studies.
        4,600원
        200.
        2016.11 구독 인증기관·개인회원 무료
        Most known species in the Strophariaceae are decomposers and grow on various kind of organic matter. Approximately 18 genera and 1,316 species in the Strophariaceae have been reported worldwide. Through an ongoing survey of indigenous fungi in Korea, 29 specimens belonging to the Strophariaceae were collected from 2012 to 2016. These specimens were identified based on morphological characteristics and molecular analysis of internal transcribed spacer sequences. Fifteen taxa were confirmed, with eight species matching those previously recorded. Seven species in five genera were shown to be new records in Korea: Galerina marginata, Gymnopilus crociphyllus, Gymnopilus picreus, Hebeloma birrus, Hebeloma cavipes, Pholiota multicingulata, and Psilocybe thaizapoteca. In this study, we provide detailed morphological descriptions of these species and investigate their evolutionary relationships by constructing phylogenetic trees.