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        검색결과 160

        83.
        2015.10 구독 인증기관·개인회원 무료
        Mosquitoes are vectors of many human diseases such as Japanese encephalitis, vivax malaria, west nile fever, dengue fever and yellow fever. However, factors affecting the abundance and distribution of mosquitoes are not well-understood. Moreover, the global climate change makes it even more difficult to address and predict the population dynamics of mosquitoes. Therefore, it is important to monitor this medically-important pest throughout landscapes over a long period of time. This study was conducted as a part of the nation-wide surveillance program to monitor insect vectors. In 2015, mosquitoes were collected using black light traps and BG-Sentinel traps in Gyeonggi-do at every two weeks from April to September. Three types of potential mosquito habitats were selected for surveillance: urban area (Suwon), cattle shed (Yongin) and wild bird refuge (Gwangju). Among the three habitats, female mosquitoes were first caught on April 4 by BG-Sentinel trap in the urban area. The highest density of female mosquitoes in the traps was recorded in July in the urban area (134 ± 84 per trap); the highest density was observed in June in the cattle shed (2473 ± 1319) and wild bird refuge (21 ± 15) (mean ± SE). The dominant mosquito species were Culex pipens pallens (91%), Aedes vexans nipponii (79%) and Anopheles sinensis (33%) in the urban area, cattle shed and wild bird refuge, respectively. The results of this study indicate that female mosquitoes were most abundant in the cattle shed habitat type. It is also noteworthy that the dominant mosquito species varied among the habitat types surveyed. This nation-wide monitoring program for medical pests will provide fundamental basis to develop effective management strategy under the global climate change environment.
        84.
        2015.10 구독 인증기관·개인회원 무료
        Leptotrombidium pallidum is the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. To understand the molecular mechanism of L. pallidum, we sequenced the whole genome using Illumina sequencing technology. Totally four genomic libraries with different insert sizes ranging from 280 bp to 8 kb were used to generate 45.1 Gb of genome in the combination of paired-end and mate-pairs sequencing reads. Quality filtering and correction of paired-end reads for very small and/or bad-quality sequences yielded 26.9 Gb of high-quality sequences, which are used to estimate the genome size as 175 Mbusing kmer methods and assembled into a 193.7 Mb genomic sequence scaffolds with N50 length of 92,945 bp. Furthermore, 94% of CEGMA completeness score were obtained from genome scaffold assembly. To facilitate gene annotation, we used a combination of de novo and homology based tools to predict gene models in the chigger mite genome. A combination of evidence-based and de novo approaches predicted 15,842 high-confidence protein-coding genes with an average transcript length of 1,511 bp and 2.4 exons per gene which corresponds to about 12.4% total gene length. Bacterial endosymbiosis are very common in mite species and can range from mutualistic to pathogenic associations. Henceforth, the endosymbionts in L. pallidum were predicted using the NCBI microbial draft genomes and mitochondrial genome. Besides, this L. pallidum draft genome can be used as a significant reference for comparative genomic studies across mite species.
        85.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A large-scale neutral hydrogen (H i) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with MHi ~ 1:67 X 109M⊙, unique in size in the Local Universe. It is still under debate where this Hi ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and Hi gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam u*, g', r' and i'-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.
        3,000원
        87.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cloning efficiency is extremely low despite successful somatic cell nuclear transfer (SCNT) method producing cloned animals in several mammals. In general, faulty epigenetic modifications underlying the incomplete reprogramming of donor cell nuclei after SCNT mainly results in low cloning efficiency. The nuclear reprogramming process involves epigenetic modifications, such as DNA demethylation and histone acetylation, which may be an important factor in enhancing the cloning efficiency. Recently, the histone deacetylase inhibitors (HDACi), such as trichosatin A (TSA) and m-carboxycinnamic acid bishydroxamide (CBHA), to increase histone acetylation have been used to improve the developmental competence of SCNT embryos. Therefore, we compared the effects of TSA with CBHA on the in vitro developmental competence and pluripotency-related gene expression (Oct4, Nanog and Sox2) in porcine cloned blastocysts and histone acetylation pattern (H3K9ac). The porcine cloned embryos were treated with a 50nM concentration of TSA and 100μM concentration of CBHA during the in vitro early culture (10h) after cell fusion and then were assessed to cleavage rate, development to the blastocyst stage and pluripotency-related gene expression in NT blastocyst also, level of histone acetylation in zygote, 2cell, 4cell stage. As results, Although NT, TSA and CBHA treated NT embryos were not different between all groups for cleavage rates, the developmental competence to the blastocyst stage was significantly increased in CBHA treated embryos (22.7%) compared to that of normal NT and TSA treated NT embryos (8.1% and 15.4%)(p<0.05). In addition, all of pluripotent transcription factors (Oct4, Nanog and Sox2) were expressed in the CBHA treated NT embryos, however, Sox2 and Oct4 were expressed in TSA treated NT embryos and expression pattern of CBHA treated NT embryos is particularly similar to that of IVF embryos. Also, CBHA treated NT embryos were increased in level of histone acetylation (H3K9ac) at the zygote, 2-cell, 4-cell stage compared to those of NT and TSA treated NT embryos. In conclusion, the treatment of CBHA as a histone deacetylase inhibitor significantly increased the developmental competence of porcine NT embryos and pluripotency-related gene expressions(Oct4, Nanog and Sox2) in NT blastocysts and level of histone acetylation (H3K9ac).
        5,200원
        88.
        2014.12 구독 인증기관 무료, 개인회원 유료
        Differentiated nuclei can experimentally be returned to an undifferentiated embryonic status after nuclear transfer (NT) to unfertilized metaphase II (MII) oocytes. Nuclear reprogramming is triggered immediately after somatic cell nucleus transfer (SCNT) into recipient cytoplasm and this period is regarded as a key stage for optimizing reprogramming. In a recent study (Dai et al., 2010), use of m-carboxycinnamic acid bishydroxamide (CBHA) as a histone deacetylase inhibitor during the in vitro early culture of murine cloned embryos modifies the acetylation status of somatic nuclei and increases the developmental competence of SCNT embryos. Thus, we examined the effects of CBHA treatment on the in vitro preimplantation development of porcine SCNT embryos and on the acetylated status of histone H3K9 on cloned embryos at the zygote stage. We performed the three groups SCNT: SCNT (NT), CBHA treatment at the porcine fetus fibroblast cells (PFFs) used as donor cells prior to SCNT (CBHA-C) and CBHA treatment at the porcine SCNT embryos during the in vitro early culture after oocyte activation (CBHA-Z). The PFFs were treated with a 15 μM of CBHA (8 h) for the early culture and the porcine cloned embryos were treated with a 100 μM concentration of CBHA during the in vitro early culture (10 h). Cleavage rates and development to the blastocyst stage were assessed. No significant difference was observed the cleavage rate among the groups (82.6%, 76.4% and 82.2%, respectively). However, the development competence to the blastocyst stage was significantly increased in CBHA-Z embryos (22.7%) as compared to SCNT and CBHA-C embryos (8.6% and 4.1%)(p<0.05). Total cell numbers and viable cell numbers at the blastocyst stage of porcine SCNT embryos were increased in CBHA-Z embryos as compared to those in CBHA-C embryos (p<0.05). Signal level of histone acetylation (H3K9ac) at the zygote stage of SCNT was increased in CBHA-Z embryos as compared to SCNT and CBHA-C embryos. The results of the present study suggested that treatment with CBHA during the in vitro early culture (10 h) had significantly increased the developmental competence and histone acetylation level at the zygote stage.
        4,300원
        89.
        2014.10 구독 인증기관·개인회원 무료
        Leptotrombidium pallidum is the major vector mite for Orientia tsutsugamushi, the causative agent of scrub typhus, in Asian countries, including Korea. The genome size of L. pallidum was previously estimated to be 191 ± 7 Mb (Kim et al., 2014). Genomic DNA (gDNA) was extracted from a single female from a 9-generation inbred L. pallidum colony and used for whole genome amplification (WGA). The resulting amplified gDNA was used for the construction of paired-end and mate-pair libraries and sequenced using Illumina platforms (HiSeq2000 and MiSeq). An unamplified gDNA sample extracted from 20 female mites was also used for sequencing in parallel. More than 45Gb sequence reads from both paired-end and mate-pair libraries of the WGA gDNA were trimmed and then de novo assembled using the CLC Asembly Cell v.4.0 for contig assembly and SSPACE for scaffolding. The assembly generated approximately 6,545 scaffolds with N50 value of 92,945 and total size of ~193Mb, which was in a good agreement with our previous estimation. Repeat analysis showed that about 30% of genome (~58Mb) was masked as repeats, most of which were unclassified novel elements. For gene predictions, generated were the PASA models based on genomic alignments of RNA-seq reads from 4 different chigger mite samples (i.e. male, female, larva, and protonymph) and the GeneWise models based on genomic alignments of protein sequences from 4 closely related species with chigger mite. Independently, ab initio gene predictions were performed with AUGUSTUS and FgeneSH with custom trained matrices optimized for L. pallidum and GENEID with pre-trained matrix for Acyrthopsiphon pisum. By combining all together, 15,842 genes were predicted finally. Manual curation is in progress for various groups of genes, including chemosensory receptor genes, immune-related genes, acaricide target genes, etc.
        90.
        2014.07 구독 인증기관·개인회원 무료
        Driven by the consumer demand for companies to be socially responsible, companies are increasingly relating their brands to causes and charities in order to accomplish nonprofit objectives and corporate sustainability. In a social marketing campaign, the consumers’ choice of the cause can influence their reactions through the processes of choice. Allowing the consumers to choose the cause may also reinforce their personal role in the donation process, which may result in a better outcome. Further, advertisers are paying increasing attention to the launch of social marketing campaigns via social media, since social media has recently become an essential part of daily life and therefore an imperative venue through which companies connect with consumers. Focusing on the rapidly evolving social media landscape, this study primarily clarifies (1) how choice influences consumers’ perceived interactivity with a social marketing campaign in the social media context, and (2) consumer involvement, as consumers’ individual differences can enhance or limit the effects of a social marketing campaign with choice. Using field experiments, this study investigates the relationships between the consumers’ choice, perceived interactivity, attitude, and purchase intention, and considers the moderating effects of involvement on those relationships. This study’s contributions are that it illuminates (1) the effects of choice on the perceived interactivity of social marketing campaigns in social media contexts, (2) the role of involvement in social marketing campaigns as a moderator, and (3) attitude and purchase intention as outcomes that can facilitate the construction of a theoretical model for social marketing campaigns with choice in the social media context and offer possible implications for advertising practitioners.
        91.
        2014.04 구독 인증기관·개인회원 무료
        The Riptortus (stinkbug) has a specialized symbiotic organ, M4 midgut, to harboring symbiont Burkholderia. M4 midgut is located in abdomen and surrounded with insect hemolymph. Recently our group demonstrated that symbiotic Burkholderia showed different physiology after adapting in M4 gut compare with in vitro cultured Burkholderia. And population of symbiotic Burkholderia in the M4 midgut is regulated by special organ. However, the molecular mechanism to prevent spreading and migrating symbiont bacteria to other host tissues from symbiotic organ is not clear. Therefore, we assumed that symbiont Burkholderia are susceptible to host humoral immunity after established infection in M4 midgut to prevent spreading and migrating into the other host tissues through Riptortus hemolymph. To prove this assuming, we tested the susceptibility and survival rate of symbiont Burkholderia in hemolymph of Riptortus in vitro and in vivo. We also examined the susceptibility of symbiont Burkholderia using purified antimicrobial peptides (AMP), pyrrhocoricin-like, thanatin-like and defensin-like AMPs. Finally, we tested inducing ability for AMPs by systemic infection of symbiotic Burkholderia. Gene expression of purified AMPs was not different after systemic infection of both symbiont and in vitro cultured Burkholderia. Surprisingly, in vitro cultured Burkholderia resisted on bacteria injected hemolymph and purified AMPs but symbiont Burkholderia were highly susceptible in bacteria injected hemolymph and purified AMP. These results suggest that symbiont Burkholderia can't survive in the hemolymph after escaping symbiotic organ. Moreover, humoral immunity of host Riptortus is important to prevent spreading and migrating symbiont Burkholderia into the other host tissue or organ from symbiotic organ.
        92.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        차 (Tea)는 네팔을 포함한 남아시아의 주요 농산물 수출품목 중에 하나이다. 네팔의 차 생산은 150년 전에 시작되었지만, 상업적인 생산 규모는 발전 가능성이 있음에도 불구하고초창기 모습 그대로이다. 차 생산에서 우위를 차지하고 있는인도, 스리랑카, 방글라데시와 같이 네팔은 좋은 품질의 차를생산할 수 있는 큰 잠재력을 가지고 있다. 그리고 현재 차 산업의 선도자로 남아시아 국가의 잠재력을 강화하기 위해 남아시아지역협력연합 (South Asian Association for the RegionalCooperation, SAARC)은 각 회원국의 National Tea board가차 산업을 육성할 수 있도록 지원하기 위하여 차 위원회를 설립할 예정이다. 이러한 남아시아지역협력연합의 차 위원회 설립에 맞추어 본 연구는 남아시아 차 산업에서 부각되고 있는네팔의 차 생산과 소비, 그리고 수출 경향을 다른 남아시아국가와 비교하여 분석하였다. 남아시아는 전세계 차 생산량의약 1/3를 생산하고 있으며, 대표적인 차 생산국가는 인도, 스리랑카, 방글라데시, 네팔이다. 남아시아 중에서 네팔은 연간약 1만8천톤의 차를 생산하고 있으며, 최근 20여년간(1994~2012) 차 생산량이 약 100배(196톤→18,309톤) 가까이 급증하고 있다. 네팔의 차 산업은 수출증대를 통해 외화획득과 경제발전에 기여할 뿐만 아니라 차 생산과 가공산업에참여하는 농가와 농촌여성의 고용창출 측면에서 매우 중요한역할을 담당하고 있다.
        4,000원
        93.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Muscle satellite cell (SC) is responsible for postnatal muscle growth, repair, and regeneration. Satellite cell is an im-portant source of multi-potent stem cell process and differentiation into adipogenic, myogenic, and osteoblastogenic. The objective of this study was to identify alter of transcriptome during differentiation in porcine satellite cell and to elevated transcriptome at different stages of postnatal development to gain insight into the differences in differ-entiated PSC. We used RNA-seq technique to investigate the transcriptomes during differentiation in pig muscle. Sequence reads were obtained from Illumina HiSeq2000. Differentially expressed genes (DEG) were detected by EdgeR. Gene ontology (GO) terms are powerful tool for unification among representation genes or products. In study of GO biological terms, functional annotation clustering involved in cell cycle, apoptosis, extracellular matrix, phosphoryla- tion, proteolysis, and cell signaling in differences stage. Taken together, these results would be contributed to a better understanding of muscle biology and processes underlying differentiation. Our results suggest that the source of DEGs could be better understanding of the mechanism of muscle differentiation and transdifferentiation.
        4,500원
        94.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Satellite cells were derived from muscular tissue in postnatal pig. Satellite cell is an important to growth and development in animal tissues or organs. However, the progress underlying induced differentiation is not clear. The aim of this study was to evaluate the morphologic and the transcriptome changes in porcine satellite cell (PSC) treated with insulin, rosiglitazone, or dexamethasone respectively. PSC was obtained from postnatal muscle tissue. In study 1, for study the effect of insulin and FBS on the differentiated satellite cells, cells were cultured at absence or presence of insulin treated with FBS. Total RNA was extracted for determining the expression levels of myo-genic PAX3, PAX7, Myf5, MyoD, and myogenin genes by real-time PCR. Myogenic genes decreased expression levels of mRNA in treated with insulin. In study 2, in order to clarify the relationship between rosiglitazone and lipid in differentiated satellite cells, we further examined the effect of FBS on lipid accumulation in the presence or absence of the rosiglitazone and lipid. Significant differences were observed between rosiglitazone and lipid by FBS. The mRNA of FABP4 and PPARγ increased in rosiglitazone treatment. In study 3, we examined the effect of dexame-thasone on osteogenic differentiation in PSC. The mRNA was increased osteoblasotgenic ALP and ON genes treated with dexamethasone in 2% FBS. Dexamethasone induces osteoblastogenesis in differentiated PSC. Taken together, in differentiated PSCs, FABP4 and PPARγ increased to rosiglitazone. Whereas, no differences to FBS and lipid. These results were not comparable with previous reports. Our results suggest that adipogenic, myogenic, and osteoblasto-genic could be isolated from porcine skeletal muscle, and identify culture conditions which optimize proliferation and differentiation formation of PSC.
        4,000원
        95.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Muscular satellite cell (SC), which is stem cell of postnatal pig, is an important for study of differentiation into adipogenesis, myogenesis, and osteoblastogenesis. In this study, we isolated and examined from pig muscle tissue to determine capacity in proliferate, differentiate, and expression of various genes. Porcine satellite cells (PSC) were isolated from semimembranosus (SM) muscles of 90∼100 days old pigs according to standard conditions. The cell proliferation increased in multi-potent cell by Masson’s, oil red O, and Alizarin red staining respectively. We per-formed the expression levels of differentiation related genes using real-time PCR. We found that the differentiation into adipocyte increased expression levels of both fatty acid binding protein 4 (FABP4) and peroxisome proliferator- acti-vated receptor gamma (PPARγ) genes (p<0.01). Myocyte increased the expression levels of the myosin heavy chain (MHC), myogenic factor 5 (Myf5), myogenic regulatory factor (MyoD), and Myogenic factor 4 (myogenin) (p<0.01). Osteo-blast increased the expression levels of alkaline phosphatase (ALP) (p<0.01). Finally, porcine satellite cells were indu-ced to differentiate towards adipogenic, myogenic, and osteoblastogenic lineages. Our results suggest that muscle satellite cell in porcine may influence cell fate. Understanding the progression of PSC may lead to improved strat-egies for augmenting meat quality.
        4,000원
        96.
        2013.10 구독 인증기관·개인회원 무료
        Most traditional genome sequencing projects involving infectious viruses include culturing and purification of the virus. This can present difficulties as an analysis of multiple populations from multiple locations may be required to acquire sufficient amount of high-quality DNA for sequence analysis. The electrophoretic method provides a strategy whereby the genomic DNA sequences of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) were analyzed by purifying it from host DNA by pulsed-field gel electrophoresis, thus simplifying sampling and labor time. The genomic DNA of infected P. rapae was embedded in agarose plugs, digested with a restriction nuclease and methylase, and pulsed-field gel electrophoresis (PFGE) was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the separated viral DNA. The double-stranded circular genome of PiraGV-K encodes 120 open reading frames (ORFs), covering 92% of the sequenced genome. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF11), involved in the liquefaction of the host, were found in the genome. The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the pulsed field electrophoretic method. The method appears to be applicable to the analysis of genomes of large viruses. The chitinase, identified by PiraGV-K genome sequence, was functionally characterized by quantitative PCR, Western blot analysis, immunohistochemistry and transmission electron microscopy.
        97.
        2012.06 구독 인증기관·개인회원 무료
        Since embryonic stem cells (ESCs) were first established from explant cultures of in vivo day 3.5 mouse embryos, the establishment of ESCs from species such as primates and rat has been developed. However, this success relies on the development of culture medium suitable for human and rat cells, which has different requirements from the murine ESC. In general, the establishment of ESC from pig and cow is of great interest both the agricultural perspective and for biomedical application. Large animal models, particularly pig, are likely to provide models of human genetic diseases and transplantation research where rodent models are inappropriate. However, establishment of ESCs establishment from pigs has remained an elusive goal. In the present study, we focused on signaling transduction regulation in pig epiblast stem cells (pEpiSCs). Pig epiblasts were isolated from early tubular stage embryos collected in vivo day 10.5~12 after insemination. Epiblasts were separated from trophoblast and underlying primitive endoderm using 21G needles and fine forceps. Epiblasts were cultured on mitomycin C (10 μl/ml) treated mouse embryonic feeder cells in Dulbecco’s modified Eagle’s medium (DMEM) containing 1% minimal essential medium (MEM) nonessential amino acids, 1% penicillin/ streptomycin, 1% glutamine, 0.007% β-mercaptoethanol, 5 ng/ml bFGF and 1 ng/ml LIF. After plating rapid differentiation of isolated epiblasts to extraembryonic cell types was visualized in most cultures but stem cells were enclosed by these differentiated cells. We have established seven pig epiblast stem cells lines (pEpiSC1-7) from Days 10.5–12 pig embryos. pEpiSC expressed the pluripotent markers including OCT4, NANOG, SOX2 and NODAL at 3-5 passage. In addition, the modification of culture condition by the inclusion of particular protein kinase inhibitor such as Akt inhibitor, PD0325091(PD), delyed rapid differentiation of pEpiSCs. These results showed that stemness of pEpiSCs can be maintained by regulation of signaling pathway. * This work was partly supported by a grant from the NPR (2011-0013703) and the Next-Generation BioGreen 21 Program (No. PJ008209), Rural Development Administration, Republic of Korea.
        100.
        2011.10 구독 인증기관·개인회원 무료
        Somatic cell nuclear transfer (SCNT) and induced pluripotent stem cell (iPS) experiments have generally demonstrated that a differentiated cell directly converts into a undifferentiated or pluripotent state. In SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor cell nuclei to the recipient cytoplasm of matured oocytes. Although nuclear reprogramming of cells by the ex-ovo methods is not always consistent or efficient, it has been suggested that a combination of nuclear reprogramming technique may improve the efficiency or frequency of normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from GV stage sturgeon's oocytes prior to their use as nuclear donors for SCNT will improve subsequent development. We reported a reversible permeabilization protocol with digitonin to deliver sturgeon oocyte exteact (SOE) to porcine fetal fibroblast cell nuclei ex ovo. Porcine fibroblasts were permeabilized by 4 μg/ml of digitonin for 2 min at 4℃ and then incubated in SOE for 7h at 15 18℃ followed by resealing of cell membrane. As results, no difference was observed in the number of fused couplets or the number of fused couplets that cleaved between the extract treated or control group. However, there was a significantly decrease in the percentage of fused couplets that developed to the blastocyst stage in the SOE treated group (p<0.05). Histone acetylation status was determined using an antibody to acetylation at lysine 9 on histone 3 (H3K9Ac). The intensity of H3K9Ac staining in 1-cell stage NT embryos was significantly increased when treated with the SOE (p<0.05), similar to that in 1-cell stage IVF embryos. In addition, porcine NT embryos reconstructed by using donor cell exposed to SOE prior to cell fusion significantly decreased developmental competence to the blastocyst stage but increased pluripotent gene expressions (Sox2, Nanog and Oct3/4) when compared with those in normal NT embryos (p<0.05).
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