검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 679

        424.
        2010.10 구독 인증기관·개인회원 무료
        Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus within the family Reoviridae, is the causative agent of maize rough dwarf and rice black-streaked dwarf diseases, both of which can lead to severe yield losses in east Asia. Although molecular approaches such as RT-PCR have potential for detection and diagnosis of this virus infections, their impact on high throughput certification is still limited. Therefore, the development of an antibody-based assay for rapid and effective diagnosis of RBSDV is preferable. In this study, we collected RBSDV from rice with rough dwarf disease and its complete nucleotide sequences of 10 genomic segments encoding 12 non-overlapping ORFs were determined. Among 12 ORFs, ORF1, 2 and 12 showed high level of similarities with the RdRp, major core protein and major outer shell protein, respectively. These ORFs were expressed as polyhedrin fusion protein or full-length soluble protein using baculovirus expression system for the preparation of specific antibody against RBSDV, which could be useful for the detection and diagnosis of this virus.
        425.
        2010.10 구독 인증기관·개인회원 무료
        We isolated two baculoviruses, Spodoptera litura granulovirus (SlGV) and S. litura nucleopolyhedrovirus (SlNPV) in the dead larvae of S. litura. The granule of SlGV were ovoidal shape with an approximate measure of 240-340 nm×140-180 nm, and each granule contained one single rod-shape virion with a mean size of 180-200 nm×20-40 nm. Whereas, the polyhedra of SlNPV were irregular in shape with a approximate diameter of 1.0-1.5 ㎛, and numerous virions comprised of the multinucleocapsid were contained in each polyhedra. The major component of occlusion bodies produced by SlGV and SlNPV were about 29 and 30 kDa, respectively. When the phylogenic relationship between these viruses were analyzed using the nucleotide sequences of granulin gene from SlGV and polyhedrin gene from SlNPV, they were not closely related to each other. We also found that the two viruses showed similar insecticidal activity against 2nd instar larvae of Spodotera litura in terms of dose-response, but SlGV showed much longer LT50 than that of SlNPV. The two baculoviruses might be cooperatively be applied as biological control agent for the control of S. litura
        426.
        2010.10 구독 인증기관·개인회원 무료
        Glutathione S-transferases (GSTs) are multifunctional enzymes that are mainlyinvolved in the xenobiotic metabolism and protection against oxidative damage. Most studies of GSTs in insects have been focused on their role in detoxifying exogenous compounds in particular insecticides. Here, we show the expression profiles of GSTs of the bumblebee Bombus ignitus in response to oxidative stress. We identified a sigma-class GST from B. ignitus (BiGSTS). The BiGSTSgene consists of 4 exons that encode 201 amino acids. Comparative analysis indicates that the predicted amino acid sequence of BiGSTS shares a high identity with the sigma-class GSTs of hymenopteran insects such as Apis mellifera (70% protein sequence identity) and Solenopsis invicta (59% protein sequence identity). Tissue distribution analyses showed the presence of BiGSTS in all tissues examined, including the fat body, midgut, muscle and epidermis. The oxidative stress responses analyzed by quantitative real-time PCR showed that under H2O2 overload, BiGSTS and BiGSTD (identified in our previous study) were upregulated in all tissues examined, including the fat body and midgut of B. ignitus worker bees. Under uniform conditions of H2O2 overload, the expression profile of GSTs and other antioxidant enzyme genes, such as phospholipid-hydroperoxide glutathione peroxidase (Bi-PHGPx) and peroxiredoxins (BiPrx1 and BiTPx1), showed that other antioxidant enzyme genes are acutely induced at 3 h after H2O2 exposure, whereas BiGSTS and BiGSTD are highly induced at 9 h after H2O2 exposure in the fat body of B. ignitus worker bees. These findings indicate that GSTs and other antioxidant enzyme genes in B. ignitusare differentially expressed in response to oxidative stress. Taken together, our findings indicate that BiGSTS and BiGSTD are oxidative stress-inducible antioxidant enzymes that may play a role in oxidative stress response.
        427.
        2010.10 구독 인증기관·개인회원 무료
        Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and harbors 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, 55 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells, 16 of them were found affecting viral replication since they defected in producing polyhedra. Furthermore, to verify the pathogenicity of the single ORF-truncated mutants, the remaining 39 mutants were subjected to bioassay to Spodoptera exigua 3rd instar larvae. Among them, ac9-, ac49-, ac103- and ac105-knockout mutants showed higher mortality compared to that of bAc-MK. These results suggested that these ORFs could be related to pathogenicity of AcMNPV.
        428.
        2010.10 구독 인증기관·개인회원 무료
        The Bacillus thuringiensis strain K4 was isolated from fallen leaves, sampled in a forest region of the city of Mungyeong, Korea. The flagellated vegetative cells of B. thuringiensis strain K4 were agglutinated with the H3 reference antiserum and further, agglutinated with 3b and 3d monospecific antisera but non-reactive for 3c and 3e factor sera. These results create a new serogroup with flagellar antigenic structure of 3a3b3d, designated serovar mogi. The strain K4 showed high activity against dipteran larvae, Anopheles sinensis and Culex pipiens pallens while no lepidopteran toxicity. It produced a single ovoidal-shaped parasporal crystal whose SDS-PAGE protein profile consisted of several bands ranging from 75 to 30 kDa. Through the protein identification by nano-LC-ESI-IT MS analysis, the putative peptides of Cry19Ba, Cry40ORF2, Cry27Aa and Cry20Aa were detected. In contrast to the plasmid profile of B. thuringiensis H3 serotype strains, the strain K4 contained only a large plasmid (~100 kb) and we cloned partial cry27Aa, cry19Ba and cry40ORF2 genes from it by thermal asymmetric interlaced PCR. Sequencing analysis showed 87%, 88% and 88% homologous with known cry27Aa, cry19Ba and cry40ORF2 genes, respectively. The new type strain, B. thuringiensis subsp. mogi (H3a3b3d) will be a good resource for new mosquitocidal cry genes.
        429.
        2010.10 구독 인증기관·개인회원 무료
        The Northeast of China, which covers an area of 124'1400 km2, comprises HeiLongjiang, JiLin, LiaoNing province, and northeast of inner Mongolian. The annual mean temperature is 5 centigrade below zero in the north, and 10 centigrade above zero in the south. The annual precipitation range from 300 mm to 1200 mm. Moreover, northeast China is an important forest area in China, and hundreds of forest disease and pests occurred every year. Among these pests, the Lepidoptera account for a big part, accordingly, the research on diversity of Lepidoptera is the basis of taxonomy and pests control. According to 「List of Chinese Insects」(Hua, 2005), there are about 20,692 species in China, and 2,934 in Northeast China, for instance, Noctuidae 1,400 spp. (Hua, 2005), Notodontidae 128 spp. (Hua, 2005), Tortricidae 267 spp. (Hua, 2005), Pyralidae 146 spp. (Hua, 2005), Geometridae 233 spp. (Zheng, 1999), Hesperiidae 54 spp. (Zhou, 2000), Parnassiidae 32 spp. (Zhou, 2000), Papilionidae 26 spp. (Zhou, 2000), Pieridae 59 spp. (Wang, 1998), Nymphalidae 188 spp. (Zhou, 2000), Lycaenidae 150 spp., etc. (Wang, 2002).
        430.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PAN precursor fibers were produced via wet-spinning process, and effects of polymerization and spinning processes, especially the stretching process, were investigated on mechanical properties and micro-morphologies of precursor fibers. An increase in molecular weight, dope solid and densification and a decrease in surface defects were possible by controlling polymerization temperature, the number of heating rollers for densification and the jet stretch ratio, which improved the mechanical properties of precursor fibers. The curves for strength, modulus, tensile power and diameter as a function of stretch ratio can be divided into three stages: steady change area, little change area and sudden change area. With the increase of stretch ratio, the fiber diameter became smaller, the degree of crystallization increased and the structure of precursor fibers became compact and homogeneous, which resulted in the increase of strength, modulus and tensile power of precursor fibers. Empirical relationship between fiber strength and stretch ratio was studied by using the sub-cluster statistical theory. It was successfully predicted when the strengths were 0.8 GPa and 1.0 GPa under a certain technical condition, the corresponding stretch ratio of the fiber were 11.16 and 12.83 respectively.
        4,000원
        432.
        2010.05 구독 인증기관·개인회원 무료
        Bee venom contains a variety of peptides and enzymes, including serine proteases. Here we describe the molecular cloning and characterization of a serine protease (Bt-VSP) isolated from the venom of the bumblebee Bombus terrestris. The Bt-VSP gene consists of six exons encoding a 358-amino acid protein. The form of Bt-VSP detected in bee venom was the 34-kDa mature protein, which is created by cleavage of the catalytic domain of Bt-proVSP between Arg111 and Val112. Bt-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, defining roles for Bt-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. The finding that Bt-VSP acts as a fibrin(ogen)olytic enzyme is similar to a previous finding that Bi-VSP, a venom serine protease of B. ignitus, exhibits fibrin(ogen)olytic activity. We also compared major venom components in honeybee and bumblebee, and found that bumblebee venom contains a larger amount of serine protease. Furthermore, unlike bumblebee venom, which exhibits fibrin(ogen)olytic activity owing to the presence of a serine protease, it is likely that honeybee venom lacks fibrin(ogen)olytic activity.
        433.
        2010.05 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are widely available as biological control agents for controlling insect pests in agriculture and forestry. The fungal culture broth contains various pathogenesis-related components such as blastospores, mycelium and insecticidal enzymes such as chitinase, Pr1- and Pr2-proteases, which have been reported to play an important role in penetrating insect cuticles. In this study, we tried to evaluate the utility of culture broth from Beauveria bassiana SFB-205 to control lepidopteran pests. High level of insecticidal activity correspond to over 90% of mortality were observed when the culture broth of B. bassiana SFB-205 was inoculated to the Spodoptera litura larvae together with the B. thuringiensis K1. The freeze-dried culture broth showed synergistic effects in insecticidal activity against larvae of S. exigua and S. litura when treated with corresponding baculoviruses, SeNPV and SlNPV. Active ingredient of the B. bassiana SFB-205 culture broth was identified to chitinase, which have truncated form by insertional mutation compared to previously reported chitinases.
        434.
        2010.05 구독 인증기관·개인회원 무료
        Bacillus thuringiensis 1-3 (Bt 1-3) which was isolated from a Korean soil sample showed high insecticidal activity against Aedes aegypti as well as Plutella xylostella. The isolate was determined to belong to ssp. aizawai (H7) type by an H antiserum agglutination test and produced bipyramidal-shaped crystal proteins with a molecular weight of 130 kDa. PCR analysis with cry gene specific primers showed that Bt 1-3 contained cry1Aa, cry1Ab, cry1C, cry1D and cry2A gene, differing from spp. aizawai (reference strain) which contains cry1Aa, cry1Ab, cry1C and cry1D. We modified the plasmid capture system (PCS) to clone plasmid from Bt 1-3 through in vitro transposition. Fifty-three clones were acquired and their sizes were approximately 10 kb. Based on the sequence analysis, they were classified according to similarities with four known Bt plasmids, pGI3, pBMB175, pGI1 and pGI2, respectively. One of pGI3-like clones, named as pBt1-3, was fully sequenced and its 20 putative open reading frames (ORFs), Rep-protein, double-strand origin of replication (dso), single-strand origin of replication (sso), have been identified. The structure of pBt1-3 showed high similarity with pGI3 which is one of rolling-circle replication (RCR) group VI family.
        435.
        2010.05 구독 인증기관·개인회원 무료
        Baculovirus chitinase gene (ChiA) is a late gene and is essential for liquefying host insect at the late stage of infection for its hydrolyzing chitin function. In previous report, baculovirus ChiA can offer many interseting new opportunities for pest control. Recently, a putative chitinase gene (ChiA) was identified in the Spodopter litura nucleopolyhedorvirus (SlMNPV-K1) genome. The open reading frame (ORF) contains 1,692 nucelotides (nt) and encodes a protein of 563 amino acids (aa) with a predicted molecular weight of 62.62 kDa. To conform the insecticidal activity of ChiA from SlMNPV-K1, we constructed a baculovirus transfer vector, pBac-SlChiA, and this transfer vector was co-transfected with the bApGOZA DNA into sf9 cell to generate corresponding recombinant viru which designed Ap-SlChiA. Western blot analysis indicate that SlMNPV-K1 ChiA was successfully expressed. We found the chitinase activity of recombinant virus was enhanced 53% than wide type AcMNPV by chitinase assay, and the recombinant virus showed higher evidently insecticidal activity against 3rd instar larvae of Spodotera exigua than wide type AcMNPV (4.5 time). These results suggested that the chitinase gene from SlMNPV-K1 could be successfully applied to improve pathogenicity of bauclovirus
        436.
        2010.05 구독 인증기관·개인회원 무료
        Autographa californica nucleopolyhedrovirus (AcMNPV) has a large doublestrand DNA genome of approximately 134 kbp and comprises 156 open reading frames (ORFs). To elucidate DNA replication cascade of AcMNPV, we developed a novel baculovirus genome that can be maintained in Escherichia coli as a plasmid and can infect susceptible lepidopteran insect cells. This genome, named bAc-MK, contains a mini-F replicon and a kanamycin resistance marker. Using a convenient Tn7 transposon-based system, pPCS-S, which contains an ampicillin resistance gene, 56 single ORF-truncated mutants were generated by random insertion into bAc-MK genome. These single ORF-truncated mutants were independently transfected into Sf9 cells to verify viral replication. Interestingly, both lef-1 and p48 knockout mutants showed normal viral replication in infected cells, which are reported to essential for viral replication. These results suggest that these single ORF-truncated mutants are useful for elucidation of viral replication cascade.
        437.
        2010.05 구독 인증기관·개인회원 무료
        Through an application of plasmid capture system (PCS) to Bacillus thuringiensis plasmid DNAs, we acquired 21 polymorphic clones of putative genomic DNA of bacteriophage. The genome size of phage 1-3 (PhBT1-3) was determined to be 46,517 base pairs (bp) with 35.43% G + C content and 83% coding region. Sixty-five putative open reading frames (ORFs) with more than 50 codons were found in the new phage genome. In accordance with this genome finding, the phage particles and its DNA were confirmed from the supernatant of B. thuringiensis 1-3. Morphological characterization and infectivity assay demonstrated that PhBT1-3 belongs to the family Siphoviridae and it showed infectivity to three B. thuringiensis type strains, galleriae, entomocidus, and morrisoni. Based on these results, we screened the existence of phages in B. thuringiensis type strains by PCR with terminase small subunit-specific primers. Ten of 67 type strains showed PCR products and the similarity of those putative amino acids was more than 70%. Furthermore, we verified the existence of various shaped phages from the supernatants of 10 B. thuringiensis type cultures. In conclusion, we characterized a putative genome of phage, PhBT1-3 from B. thuringiensis 1-3, and confirmed the distribution of phages in the group of 67 B. thuringiensis type strains.
        438.
        2010.05 구독 인증기관·개인회원 무료
        A new Bacillus thuringiensis isolate 19-22 (Bt 19-22) exhibited high anti-fungal activity against barley powdery mildew (Blumeria graminis f. sp. hordei). The cry gene content of Bt 19-22 comprised cry1Aa, cry1Ab, cry1Ac and cry1D which have high insecticidal activity against lepidopteran larvae. We tried to confer a dipteran insecticidal activity to Bt 19-22 for constructing a recombinant strain which has multiple functions, anti-fungal and dual insecticidal activity. The insecticidal cry11Aa gene of B. thuringiensis was constructed under cry1Ac promoter in an E. coli-B. thuringiensis shuttle vector (pPro11A). The plasmid, pPro11A was introduced into Bt 19-22 isolate by electroporation and four transformants which had different cry gene contents were identified by PCR with cry11Aa and cry1-type specific primers. Among them, a Bt 19-22 transformant (11A/19-22 No. 7) expressed Cry11A protein (approximately 70 kDa) successfully without change of its inherent characteristics such as Cry protein expression and antifungal activity. The insecticidal activity of 11A/19-22 No. 7 was checked against Plutella xylostella and Culex pipiens. These results suggests that the recombinant strain shows dual insecticidal activity against lepidopteran and dipteran larvae as well as antifungal activity.
        439.
        2010.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The precipitation polymerization of acrylonitrile (AN) was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at 50~65℃ using α,α'-azobisisobutyronitrile (AIBN) as an initiator. The increased molecular weight polyacrylonitrile (PAN) was prepared with increasing the H2O/DMSO ratio from 10/90 to 80/20. The viscosity average molecular weight of H2O/DMSO solvent was 4.4 times larger than that of H2O/DMF solvent, and precipitation polymerization was accelerlated due to the far decreased chain transfer effect of DMSO. Based on the experimental results, the increased PAN molecular weight was regarded as the summation of two mechanisms: i) particle-particle aggregation and ii) particle-radical attachment. The theoretical equation derived from the mechanisms was well coincided with the experimental results showing the linear relationship between the viscosity average molecular weight and the H2O/DMSO ratio.
        4,000원
        440.
        2009.12 구독 인증기관 무료, 개인회원 유료
        The most famous ethnic minorities in northeast China are manchu ,korean,and mongolian. Besides Xibo, daur, ewenki, olunchun, and hezhen nationalities are only living in northeast China.This paper is a comparison analysis of Ondol in Folk Housing of Several Peoples in Northeast China from the morphological characteristics and residential culture. Ultimately enable readers to realize heating tools in the cold region in northern China, and the relationship between peoples’daily life in northern China and Ondol.
        4,000원