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        검색결과 1,593

        861.
        2009.05 구독 인증기관·개인회원 무료
        Sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is a serious pest of many economically important crops. The insect has developed resistance to chemical insecticides. Therefore, the development of microbial agent is necessary. Among the several entomopathogenic fungi, Lecanicillium lecanii Btab01 which has high insecticidal activity was carried out this experiments. To develop mass culture, we subcultured L. lecanii Btab01 on PDA, TSA, SDA+Y, RA and GSA media at 25℃ incubator to select the optimal solid culture medium. Hyphal growth was measured every 3 or 4 days. L. lecanii Btab01 grew fastest in RA, followed GSA, SDA+Y, PDA and TSA. L. lecanii Btab01 was cultured on PDB, TSB, SDB+Y, RB, GSB media at 25℃, 180rpm shaking incubator to select the optimal liquid medium. Spore germination was measured by spread plate method every 12 or 24 hours. Spore germination appeared 7.8×108 CFU/ml after 4 days in RB, followed GSB (5.5×108 CFU/ml), SDB+Y (2.7×108 CFU/ml), TSB (1.7×108 CFU/ml) and PDB (0.6×108 CFU/ml).
        862.
        2009.05 구독 인증기관·개인회원 무료
        Reactive oxygen species (ROS) is toxic to living organisms, because its high reactivity causes oxidative damage to proteins, nucleic acids, and lipids. Superoxide dismutase (SOD) is an enzyme facilitating the removal of superoxide anions from living organisms. This study focused on the cloning of MnSOD cDNA from Hyphantria cunea and its induction upon bacterial infection and various stresses. The open reading frame of MnSOD is composed of 645 bp, encoding 215 amino acid residues. The theoretical molecular mass and pI of putative MnSOD was evaluated to be 24276 Da and 9.14, respectively. The MnSOD from H. cunea is highly similar to human MnSOD (59.5%) as well as Bombyx mori MnSOD (76.2%). MnSOD showed no big induction upon bacterial infection and stresses, compared to that of Cu/ZnSOD.
        863.
        2009.05 구독 인증기관·개인회원 무료
        Apolipophorin-Ⅲ (apoLp-Ⅲ) is a hemolymph protein whose function is to facilitate lipid transport in an aqueous medium in insect. Recently, apolipophorin-Ⅲ in Galleria mellonella and Hyphantria cunea was shown to play an unexpected role in insect immune activation. We show here a novel possible function/role of apoLp-Ⅲ in insects. To investigate the genes which have a relationship with apoLp-Ⅲ in fall webworm larvae, we reduction of endogenous Hc apoLp-Ⅲ mRNA levels in larvae via RNA interference (RNAi). The RNAi-mediated Hc apoLp-Ⅲ reduction resulted in the reduction of antioxidants, like MnSOD, catalase, and glutathione S transferase as well as immune proteins. In particular, expression of MnSOD commonly decreased in fat body, midgut, and hemocytes following the knockdown of Hc apoLp-Ⅲ, which induced an elevated level of superoxide anion in H. cunea larvae. The observed effect of Hc apoLp-Ⅲ RNAi suggests that Hc apoLp-Ⅲ is related to the action/expression of antioxidants.
        864.
        2009.05 구독 인증기관·개인회원 무료
        Innate immunity responses are triggered by the immune challenge and therefore involve signaling processes. The cellular response is initiated by hemocytes and mainly involves phagocytosis and encapsulation of intruders by these cells. To address whether Hc-STAT is activated upon bacterial challenge, we examined the subcellular location of STAT protein in hemocyte by immunostaining. A new insect member of the STAT family of transcription factors (Hc-STAT) has been cloned from the lepidopteran, Hyphantria cunea. The domain involved in DNA interaction and the SH2 domain are well conserved. The gene is transcribed at a low level during all stages of development, and the protein is present in hemocytes, fat body, midgut, epidermis, and Malphigian tuble (Mt). Especially, hemocytes and Mt showed transcriptional activation of Hc-STAT upon Gram (-) bacteria and fungal challenge. Gram (-) bacteria and fungal challenge specifically results in nuclear translocation of Hc-STAT protein and induction of DNA-binding activity that recognizes a STAT target site in H. cunea hemocyte. In vitro treatment with pervanadate translocates Hc-STAT to the nucleus in hemocyte cells. Here we report the first evidence for the involvement hemocyte JAK/STAT pathway upon microbial infection in lepidopteran insect.
        865.
        2009.05 구독 인증기관·개인회원 무료
        Eumenis autonoe belonging to a lepidopteran family Nymphalidae (superfamily Papilionoidea) is an endangered species in Korea. Historically, the species was distributed in Europe and Asian region including a wide region in Korean peninsula. However, in Korean peninsula, the species is found only in two isolate dregions: South in a remote island Jeju, where altitude is higher than1, 400 meter on Halla Mt. and North in far northern Korean peninsula around Mt. Bekdu. In this study, we report the complete mitochondrial genome of the endangered E. autonoe collected from Mt. Halla. The 15,489-bp long E. autonoe genome has a typical gene content found in animal mitochondrial genomes and contains the gene arrangement identical to all other sequenced lepidopteran insects, which differs from the most common type found in insects, as the result of the movement of tRNAMet to a position 5’-upstream of tRNAIle. As seen in many other lepidopteran insects, no typical ATN codon for COI gene is available. Thus, we tentatively designated the CGA (arginine) found at the beginning of the COI gene, as has been suggested for lepidopteran COI starter. The intergenic spacer sequence located between tRNASer (UCN) and ND1 of E. autonoe mitogenome also contains the ATACTAA motif which is conserved in all sequenced lepidopteran species. The 678-bp long A+T-rich region, which is longest in sequenced lepidopteran insects contains ten identical tandem repeats composed of 27 bp plus one 13-bp long identical incomplete final repeat. Such repeat sequence is rare in the lepidopteran mitogenomes known so far. The E. autonoe A+T-rich region also contains a poly-T stretch located at the end of the region as 19 bp and also contains the downstream conserved motif ATAGA that were previously suggested to serve as a structural signal for minor-strand mtDNA replication. Phylogenetic analysis using the concatenated 13 amino acid sequences of PCGs among available six lepidopteran superfamilies (Tortricoidea, Pyraloidea, Papilionoidea, Bombycoidea, Geometroidea, and Noctuoidea) rooted with three dipteran species with BI and ML analyses supported the following topology: ((((Bombycoidea + Geometroidea +Noctuoidea) + Papilionoidea) + Pyraloidea) + Tortricoidea). Within Papilionoidea, a closer relationship between Lycaenidae and Pieridae, excluding Nymphalidae was observed. Further fruitful information will be available after more analysis is done.
        866.
        2009.05 구독 인증기관·개인회원 무료
        The complete nucleotide sequences of the mitochondrial genome (mitogenome) from the white-spotted flower chafer, Protaetia brevitarsis (Coleoptera: Cetoniidae) was determined. The 20,319-bp long circular genome is the longest among the completely sequenced arthropods. This extraordinary length of the genome stemmed from 5,654-bp long A+T-rich region composed of twenty-eight 117-bp tandem repeats, seven 82-bp tandem repeats, and each two 19-bp and 38-bp tandem repeats. The P. brevitarsis contains a typical gene complement, order, and arrangement identical to most common type found in insects. The P. brevitarsis COI gene does not have typical ATN codon. Thus, we also designated it as AAC (asparagine), which is found in the start context of all sequenced Polyphaga within Coleoptera. All tRNAs showed stable canonical clover-leaf structure of other mt tRNAs, except for tRNASer (AGN), DHU arm of which could not form stable stem-loop structure. The 5bp-long motif sequence (TAGTA) that has been suggested to be the possible binding site for the transcription termination peptide for the major-strand also was found betweent RNASer (UCN) and ND1, as have been detected in all sequenced coleopteran insects.
        867.
        2009.05 구독 인증기관·개인회원 무료
        The bumblebee, Bombus ardens, is a valuable natural resource, and is most notably utilized for greenhouse pollination. In order to gain a greater understanding of the population genetic structure and the genetic diversity of this species, we sequenced a portion of the mitochondrial COI gene corresponding to the “DNA Barcode” region (658 bp) from 160 individuals collected over 15 Korean localities. Uncorrected pairwise distances among the eight haplotypes suggested low intraspecific genetic diversity, with a maximum sequence divergence of 0.3%. Such a low level of intraspecific genetic diversity was further reflected in local populations, particularly to islet populations, such as those of Youngheungdo, Jakyakdo, and Ulleugdo, which had zero genetic diversity. Geographically, one haplotype (BARBA01) was widespread and dominant, with a frequency of 90.6% (145 among 160 individuals). Other haplotypes were restricted to one to three localities and had low frequency. Overall, a very high rate of per generation female migration ratio (Nm= 4.6 to infinite) and a very low level of genetic fixation (FST= 0 to 0.099) were detected between pairs of localities, suggesting that the B. ardens population sonthe Korean peninsula are panmictic, which is consistent with our understanding of their dispersal capability.
        870.
        2008.12 구독 인증기관 무료, 개인회원 유료
        It has been reported that the antimicrobial susceptibility patterns of viridans streptococci vary according to geographical region. Although several studies on the antibiotic resistance of viridans streptococci in foreign countries have been reported, little is known about the distribution of resistance among viridans streptococci in Korea. In this study, 88 isolates of viridans streptococci from Korean students' dental plaque were identified as 12 different species. The susceptibility of these isolates to 8 antibiotics was investigated. The in vitro antibiotic activity of penicillin G, ampicillin, vancomycin, streptomycin, gentamicin, erythromycin, amoxicillin, and tetracycline was measured by the broth microdilution method. The range of the minimum inhibitory concentrations (MIC), MIC50, MIC90, and the percentage of the susceptible isolates were determined. Streptococcus mutans and Streptococcus salivarius were susceptible to the 8 antibiotics. Isolates with resistance to vancomycin, streptomycin, and amoxicillin were not found. The overall resistance rates of the 88 isolates to penicillin G, ampicillin, gentamicin, erythromycin, and tetracycline were 12.5%, 62.5%, 62.5%, 26.1%, and 26.1%, respectively.
        4,000원
        872.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Inositol 1,4,5-trisphosphate (IP₃) plays an important role in the release of Cα²+ from intracellular stores into the cytoplasm in a variety of cell types. IP₃ translocation dynamics have been studied in response to many types of cell signals. However, the dynamics of cytosolic IP₃ in salivary acinar cells are unclear. A green fluorescent protein (GFP)-tagged pleckstrin homology domain (PHD) was constructed and introduced into a phospholipase C δ1 (PLC δ1) transgenic mouse, and then the salivary acinar cells were isolated. GFP-PHD was heterogeneously localized at the plasma membrane and intracellular organelles in submandibular gland and parotid gland cells. Application of trypsin, a G protein-coupled receptor activator, to the two types of cells caused an increase in GFP fluorescence in the cell cytoplasm. The observed time course of trypsin-evoked IP₃movement in acinar cells was independent of cell polarity, and the fluorescent label showed an immediate increase throughout the cells. These results suggest that GFP-PHD in many tissues of transgenic mice, including non-cultured primary cells, can be used as a model for examination of IP₃intracellular dynamics.
        4,000원
        874.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The early diagnosis of bovine pregnancy is an essential component of successful reproductive planning on farms, because lack of bovine pregnancy over the long term results in reproductive failure and low milk yield‐the latter of which is a special concern on dairy farms. This study was designed to identify early pregnancy‐specific whey proteins in bovine, by comparing milk samples collected from cattle during pregnancy (Days 30 and 50) and from non‐pregnant cattle. In this study, differentially expressed proteins in five pregnant and five non‐pregnant Holstein dairy cattle were investigated and compared, using proteomics analysis. The first dimension was applied to a pH 3.0~10.0 strip, by loading a 2‐mg milk protein sample. After the second‐dimension separation was performed, the gels were stained with colloidal Coomassie brilliant blue. The stained gels were scanned and the images were analyzed, to detect variations in protein spots between non‐pregnant and pregnant cattle milk protein spots, using ImageMaster; this was followed by analysis with MALDI TOF‐MS. Analysis of the 2‐DE gel image resulted in a total of approximately 500~600 protein spots, of which 12 spots were differentially expressed, six spots were up‐regulated, and four spots were downregulated; two spots were identified as pregnancy‐specific proteins. These proteins were identified as lactoferrin, NADH dehydrogenase subunit 2, albumin, serum albumin precursor and transferrin. Our results via 2‐D PAGE analysis revealed composite profiles of several milk proteins related to early bovine pregnancy, implying the possible use of these milk proteins in the early detection of bovine pregnancy.
        4,000원
        875.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro‐matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM‐199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1 kV/cm for 30 μs in 0.3 M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium‐3 (PZM‐3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM‐3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine‐porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat‐porcine and porcine‐bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.
        4,000원
        876.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells retain the capacity for self‐renewal, are pluripotent and differentiate into the three embryonic germ layer cells. The regulatory transcription factors Oct4, Nanog and Sox2 play an important role in maintaining the pluripotency of human ES cells. The aim of this research was to identify unknown genes upregulated in human ES cells along with Oct4, Nanog, and Sox2. This study characterizes an unknown gene, named chromosome 1 open reading frame 31 (C1orf31) mapping to chromosome 1q42.2. The product of C1orf31 is the hypothetical protein LOC388753 having a cytochrome c oxidase subunit VIb (COX6b) motif. In order to compare expression levels of C1orf‐ 31 in human ES cells, human embryoid body cells, vascular angiogenic progenitor cells (VAPCs), cord‐blood endothelial progenitor cells (CB‐EPCs) and somatic cell lines, we performed RT‐PCR analysis. Interestingly, C1orf31 was highly expressed in human ES cells, cancer cell lines and SV40‐immortalized cells. It has a similar expression pattern to the Oct4 gene in human ES cells and cancer cells. Also, the expression level of C1orf31 was shown to be upregulated in the S phase and early G2 phase of synchronized HeLa cells, leading us to purpose that it may be involved in the S/G2 transition process. For these reasons, we assume that C1orf31 may play a role in on differentiation of human ES cells and carcinogenesis.
        4,000원