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        검색결과 1,425

        681.
        2015.04 구독 인증기관·개인회원 무료
        The population of Myrmica ants, which is most abundant in high altitudinal areas in South Korea, is expected to decrease significantly due to climatic warming, whereas Aphaenogaster japonica population is expected to increase in these areas. The two ant groups are similar in shape, size, and ecology, indicating intensive competition in overlapping areas. To determine the competitions between the two groups, I investigated the ants at a high mountain (Mt. Gaebangsan) during two ant foraging seasons (2010 and 2011) using pitfall traps and bait traps along altitudinal gradients. Two Myrmica species (kotokui and kurokii) were present between 800 m to 1577 m, whereas A. japonica appeared up to 1200 m. Fights between ants were observed 22 times and fights between these two ant groups were most frequently found. Although a competitive hierarchy was not apparent, A. japonica appears to be dominant over Myrmica species in food competition when considering the more timid behavior of Myrmica species and my unpublished data. However, food discovery speed is greater in Myrmica species than in A. japonica, indicating a dominance-discovery tradeoff. The food discovery capability of A. japonica was greatly reduced at 1050 m elevation, which is around the elevational limit. This elevational suppression of food discovery capability was not found in Myrmica species.
        682.
        2015.04 구독 인증기관·개인회원 무료
        Indianmeal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is an important pest of stored grains products. As a natural enemy, an ectoparasitoid Bracon hebetor Say (Hymenoptera, Braconidae) has been used to control Lepidopteran pest insects. Venom from parasitoid female alters many physiological functions in host insects. However, mechanism of physiological response of host insects against envenomation and parasitization is not clear. Here we observed the effect of B. hebetor envenomation on the gene expression (shsp, hsp70, grp78 and hsp90) in P. interpunctella at different time intervals of post envenomation. Fifth instar day 5 larvae of P. interpunctella were used in experiment to observe the effect of envenomation. Our results showed that parasitoid envenomation affected the gene expression differently in host insect. This study will provide comprehensive insights on physiological and biochemical mechanism in host-parasitoid relationships.
        683.
        2015.04 구독 인증기관·개인회원 무료
        Transcriptome analysis was conducted for the identification of genes associated with insecticide resistance in Frankliniella occidentalis. Resistant strain (FO_RDAHC) exhibited 39.2- ~ 533-fold resistance to acrinathrin, spinosad, emmamectin benzoate and thiamethoxam compared with a susceptible FO_RDA strain. Average 7.6 million reads (± 5,068,895 reads) were obtained from the pyrosequencing and were assembled into the draft CDS database. Gene annotation was conducted by BLAST (UniProt), Pfam, FUNCAT and COG analysis. In the deferentially expressed gene (DEG) analysis, 838 genes were up-regulated and 815 genes were down-regulated over 2-fold ratio in FO_RDAHC strain. Highly up-regulated genes included genes encoding several cuticle-related proteins, cytochrome P450s, esterases and transporter genes. An autotransporter protein gene exhibited the highest up-regulation (596 fold) whereas a GMC oxido-reductase revealed the highest down-regulation (12 fold). Further study would be necessary to validate the actual transcript levels of DEGs and to investigate their functional roles in insecticide resistance.
        684.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Clostridium perfringens (C. perfringens) 와 Mycobacterium fortuitum (M. fortuitum)은 동물과 사람에서 심각한 질병과 관련이 있는 세균들로 알려져 있다. 본 연구에서는, povidoneiodine을 주성분으로 하는 소독제의 살균효과를 C. perfringes와 M. fortuitum을 대상으로 평가하였다. 소독제의 살균효과는 배지희석법을 이용하여, 대상 세균들을 4℃에서 소독제에 30분 동안 노출시킨 다음, 가장 낮은 소독제의 살균 희석배수를 결정하였다. 소독제는 경수와 유기물로 희석하였으며, 경수 조건에서, C. perfringes와 M. fortuitum에 대해 효과적인 소독제 희석배수는 각각 50과 80배이었다. 유기물 조건에서는, C. perfringes와 M. fortuitum에 대해 효과적인 소독제 희석배수는 모두 15배로 나타났다. 이상의 결과로부터, povidone-iodine을 주성분으로 하는 소독제는 C. perfringes와 M. fortuitum에 대해 살균효과를 갖는 것으로 확인되었으며, C. perfringes와 M. fortuitum에 의한 질병의 확산을 방지하기 위해 사용될 수 있을 것으로 사료된다.
        4,000원
        685.
        2015.03 구독 인증기관 무료, 개인회원 유료
        Osteocalcin (OC) is the most abundant noncollagenous protein of extracellular matrix in the bone. In an OC deficient mouse, bone formation rates are increased in cancellous and cortical bones. OC is known as a negative regulator of mineral apposition. OC is also expressed in the tooth of the rat, bovine, and human. However, little is known about OC during tooth development in Xenopus. The purpose of this study is to compare the expression of OC with mineralization in the developing tooth of Xenopus, by using von Kossa staining and in situ hybridization. At stage 56, the developmental stage of tooth germ corresponds to the cap stage, and an acellular zone was apparent between the dental papilla and the enamel organ. From stage 57, calcium deposition was revealed by von Kossa staining prior to OC expression, and the differentiated odontoblasts forming predentin were located at adjoining predentin. At stage 58, OC transcripts were detected in the differentiated odontoblasts. At stage 66, OC mRNA was expressed in the odontoblasts, which was aligned in a single layer at the periphery of the pulp. These findings suggest that OC may play a role in mineralization and odontogenesis of tooth development in Xenopus.
        4,000원
        686.
        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
        687.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed to evaluate the effect of bovine serum albumin (BSA) in a maturation medium on oocyte maturation and embryonic development in pigs. Immature pig oocytes were matured for 44 h in a medium supplemented with 0.4% (w/v) BSA, 0.1% (w/v) polyvinyl alcohol (PVA), or 10% (v/v) pig follicular fluid (PFF). After IVM, oocytes reached metaphase II stage were activated for parthenogenesis (PA) or used as cytoplasts for somatic cell nuclear transfer (SCNT). Nuclear maturation (89.5%, 90.7% and 91.3% for BSA, PVA and PFF, respectively) and intraoocyte glutathione contents (1.20, 1.16 and 1.00 pixels/oocyte for BSA, PVA and PFF, respectively) were not altered by the macromolecules added to maturation medium. IVM of oocytes in a medium containing BSA (21.4%) and PVA (20.7%) showed significantly lower blastocyst formation after PA than culture in medium with PFF (39.2%). After SCNT, oocytes matured in medium with BSA showed decreased embryonic development to the blastocyst stage (9.2%) compared to those matured in medium with PFF (28.9%), while 23.6% of SCNT oocytes matured in medium with PVA developed to the blastocyst stage. When the effect of BSA in a maturation medium during the first 22 h and the second 22 h of IVM in combination with PFF or PVA was examined, PVA-BSA showed a higher nuclear maturation (94.1%) than BSA-PFF (84.5%). However, there was no significant difference in the blastocyst formation among tested combinations (47.3, 52.2, 50.0, 44.4 and 49.0% for PFF-PFF, PFF-BSA, PVA-BSA, BSA-PVA and BSA-PFF, respectively). Our results demonstrate that BSA and PVA added to maturation medium can support oocyte maturation comparable to PFF-supplemented medium. However, maturation of oocytes in a BSA-containing medium decreases embryonic development after PA and SCNT when compared with the medium supplemented with PFF.
        4,000원
        688.
        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
        689.
        2014.11 구독 인증기관·개인회원 무료
        Dictyophora indusiata (Vent.) Desv., “Queen of the mushroom”, is a mushroom in family Phallaceae of Basidiomycota, which is commonly used as edible and medicinal mushroom in China and Korea. This study initiated to evaluate the anti-cholinesterase, skin anti-wrinkle and melanogenesis inhibitory of 80% methanol extract from fruiting body of D.indusiata. In the anti-cholinesterase experiment, acetyl-cholinesterase and butyryl-cholinesterase inhibitory activities were performed. The extract were inhibited acetyl-cholinesterase and butyryl-cholinesterase 44.09% and 49.14% at the concentration 1 mg/mL, respectively. The skin anti-wrinkle effect of the extract were determined by measuring anti-collagenase and anti-elastase activities. While melanogenesis inhibitory activities were performed by tyrosinase, DOPA inhibitory and melanin synthesis inhibitory activities. The tyrosinase inhibitory activity of the extract were from 37.60~68.96%, while DOPA inhibitory activity were from 15.43 ~ 29.58% at the concentration ranged from 0.125~2.0 mg/mL. In addition, cellular tyrosinase activity was tested with result of the enzyme activity reduced from 99.09% to 72.91% against 25~500 μg/mL of the extract. The methanol extract of D.indusiata was inhibited melanin synthesis activity 41.86% at the concentration 500 μg/mL. The collagenase inhibitory activity of the extract from D.indusiata were 34.87%, which was comparable with the positive control, EGCG ( 45.31%). While the extract showed good inhibition of elastase enzyme (46.64%). The experiment results suggested that fruiting body of Dictyophora indusiata could be used as natural anti-cholinesterase and skin care agents.
        690.
        2014.11 구독 인증기관·개인회원 무료
        Calocybe indica (Purkayastha, 1974), Milky mushroom, is a relatively new to the world of mushroom industry, which is belong to Lyophyllaceae of Basidiomycota, and commonly used as edible mushroom in India and Southern Asia country. This study was conducted to investigate the free radical scavenging, skin whitening and anti-collagenase activities of methanol extract from fruiting body of C.indica cultivated in Bangladesh. In addition, the polyphenol compounds of the extract were analyzed by HPLC. The mushroom extract showed good activity in lipid peroxidation which ranged from 29.35% to 55.39% at the concentration 0.125~2.0 mg/mL. The scavenging activity of the extract on 1,1-diphenyl-2-picrylhydrazy radicals were from 20.22~83.93% at the same tested concentration, which were comparable with the positive control BHT. The hydroxyl radical scavenging activity of the extract was 76.24~93.92%. The skin whitening effect of the mushroom extract was performed with UV light protecting, tyrosinase and DOPA inhibitory activities. The methanol extract absorbed UV-B wavelength with maximum level of 0.356 at 280 nm. The tyrosinase and DOPA inhibitory activities of the extract were ranged from 30.36 ~ 66.25% and 7.13 ~ 30.25% at the concentration 0.125~2.0 mg/mL, respectively. Furthermore, anti-collagenase activity were determined by measuring collagenase and elastase inhibitory activity. The collagenase and elastase inhibitory activity of the extract were 42.77% and 51.08% at the concentration 1.0 mg/mL, respectively. The experiment results suggested that fruiting body of Calocybe indica could be used as natural skin care and antioxidant agents.
        691.
        2014.11 구독 인증기관·개인회원 무료
        In the past two decades, European ash trees (Fraxinus spp.) have been severely damaged by ash dieback disease of which causal agent is a fungal species called Hymenoscyphus fraxineus (anamorphic stage Chalara fraxinea). Recent molecular phylogenetic and population genetic studies suggested that this fungus may have been introduced from Eastern Asia to Europe. In the course of fungal biodiversity survey in Korea, H. fraxineus-like apothecia were collected from fallen leaves, rachis and petioles of Korean ash and Manchurian ash trees. The morphological and ecological traits of these materials are provided, supplemented by ITS rDNA sequence comparison of H. fraxineus strains collected from Europe, China and Japan.
        696.
        2014.10 구독 인증기관·개인회원 무료
        The Riptortus pedestris-Burkholderia symbiotic system is a promising model for understanding molecular mechanism of symbiosis. In previous studies, the Burkholderia symbiont has been shown to play important biological roles in the growth and fitness of host R. pedestris. The Burkholderia symbiont, one of bacteria found in the soil, is the only bacterium that can colonize the symbiotic midgut region of R. pedestris. However, the molecular mechanism of host selectivity for the Burkholderia symbiont remains unknown. To determine where the selection occurs, we firstly compared initial infectivity of different mid-gut regions after oral infection of Escherichia coli and Burkholderia. Interestingly, E. coli were not detected in any regions of mid-gut, while Burkholderia could reach to the posterior region of mid-gut. Therefore, we hypothesized that host selectivity for the Burkholderia symbiont is occurred in the salivary gland. To address this hypothesis, we treated E. coli and Burkholderia with lysate of salivary gland and examined their survival by estimation of colony forming unit (CFU) on the plate. We found that E. coli, but not Burkholderia, was susceptible to the lysate of salivary gland. To determine molecular basis of the selective mechanism in the salivary gland, we analyzed antimicrobial proteins (AMPs) from lysate of salivary gland. we identified three AMPs, namely rip-trialysin1, rip-trialysin2 and lysozyme and further purified rip-trialysin1 and rip-trialysin2. When E. coli and Burkholderia were treated with rip-trialysin1 and rip-trialysin2, rip-trialysin1 exhibited little antimicrobial activity, but rip-trialysin2 exhibited antimicrobial activity. Furthermore, we found that E. coli was susceptible, but Burkholderia is resistant to commerciallypurchased egg white lysozyme. Our results suggest that R. pedestris salivary gland provides a chance of selection for the Burkholderia symbiont and lysozyme in salivary gland seems to play an important role for the selection of gut symbiont.
        697.
        2014.10 구독 인증기관·개인회원 무료
        Several Mites are currently the most serious threat to the world bee industry. The ectoparasitic honey bee mites was originally confined to the Asian honey bee(Apis cerana etc.). Varroa destructor and Tropilaelaps clareae has plagued European honey bees, Apis mellifera. Differences in mite tolerance are reported between two honey bee species A. mellifera and A. cerana. We were amplified antimicrobial peptide cDNA genes (Defencin, Abaecin, Royalisin, Apidaecin and Hymenoptaecin) by RT-PCR. We explored the transcriptional response to mite parasitism in A. mellifera 4th instars larvae which differ in susceptibility to V. destructor and T. clareae, comparing parasitized and non-parasitized 4th instars larvae (worker and Drone) from same hive. Differential gene expression of worker bees and Drone bees induced by mites (V. destructor and T. clareae) infection was investigated by northern blot. Mites (V. destructor and T. clareae) parasitism caused changes in the expression of genes related to sex distinction. Bees tolerant to mites (V. destructor and T. clareae) were mainly characterized by differences in the expression of genes regulating antimicrobial gene expression. It provides a first step toward better understanding molecular expression involved in this differential sex distinction host-parasite relationship. We were detected bee virus in A. mellifera, comparing parasitized and non-parasitized 4th instars larvae (worker and Drone). Therefore, this result was demonstrated that mites were another possible route of horizontal transmission, as several viruses were detected in mites and their hosts.
        698.
        2014.10 구독 인증기관·개인회원 무료
        South Korea has over 38 millions of managed honey bee (Apis cerana) colonies before 2009 years ago, which produce the highest quantity of honey in the Korea; however, almost colony (99%) were collapsed by Korean Sacbrood Virus (KSBV) in South Korea. Korean Sacbrood Virus (KSBV) is the pathogen of A. cerana Sacbrood disease, which poses a serious threat to honeybee A. cerana, and tends to cause bee colony and even the whole apiary collapse. Colony collapse of A. cerana was first reported on the Pyeong-Chang of the South Korea in 2009. Symptoms of KSBV include the rapid transmission of larval stage honeybees (A. cerana), many dead larvae found in the bottom of hive and comb. Honeybees (A. cerana) are a very important species because they provide a number of pollination services for various ecosystems in some provinces (ex. jeon-nam, jeon-buk province). They are also extremely important organisms within human society, both agriculturally and economically. The fact that a direct cause has been determined suggests that colony collapse is a complex problem with a combination of natural and anthropogenic factors. Possible instigators of colony collapse include: wax moth, viral and fungal diseases, increased population, decreased genetic diversity, climate changing and a variety of other factors. The interaction among these potential causes may be resulting in immunity loss for honeybees and the increased likelihood of collapse.
        699.
        2014.10 구독 인증기관·개인회원 무료
        Biological properties of antimicrobial peptides (AMPs) of hemimetabolous insect are poorly characterized in innate immunity field. To investigate the biochemical properties of hemimetabolous insect’s AMPs, we purified the pyrrhocoricin-like AMP from the hemolymph of Riptortus pedestris and then named as riptocin. We successfully determined the primary protein structure and its cDNA sequence. Interestingly, the determined cDNA revealed that riptocin precursor is composed of 12 repeating units of active riptocins, which implied that riptocin precursor might require to be processed to generate active riptocins by several unidentified processing enzymes. In order to characterize the bio-processing mechanisms of riptocin precursor, we generated the antibody against active riptocin. Using quantitative PCR and Western blot analyses, we showed that gene of riptocin was started to express from the fatbody after three hours post bacterial infection. To address our hypothesis that active riptocin is generated from riptocin precursor by several processing enzymes, we need to obtain the riptocin precursor. Currently, we are expressing the recombinant riptocin precursor using in vitro translation system. Meanwhile, we investigated whether naive hemolymph (naive HL), which may contain precursor riptocin, can generate active riptocin when riptocin precursor was co-incubation with bacteria-challenged hemolymph (active HL), which may contain all processing enzymes. Actually, when naive HL was incubated with active HL, antimicrobial activity was dramatically increased, suggesting that processing enzymes in active HL may induce processing of riptocin precursor to generate active riptocins.
        700.
        2014.10 구독 인증기관·개인회원 무료
        Riptortus pedestris possesses Burkholderia as gut symbiont in a symbiotic organ M4 midgut. To answer why Burkholderia symbionts are not eliminated by Riptortu s immune responses, we developed two hypotheses: (i) Burkholderia symbionts do not activate host innate immunity, or (ii) Burkholderia symbionts are resistant to th e host immune responses. For the first hypothesis, we compared the antimicrobial activities of the cultured Burkholderia-injected hemolymph and symbiotic Burkhol deria-injected hemolymphs. As a result, the symbiotic Burkholderia induced antim icrobial activity like the cultured Burkholderia, indicating the symbiotic cells are st ill immunogentic to host. However, when the activated hemolymph was treated to the Burkholderia cells, the symbiotic Burkholderia showed much higher susceptibi lity than the cultured Burkholderia. To understand molecular basis of these results, we purified antimicrobial peptides (AMPs) from Riptortus hemolymph. Similarly, the symbiotic Burkholderia exhibited the high susceptibility to the purified AMPs, riptocin and rip-defensin. To understand how symbiotic Burkholderia can survive in host in spite of their immuno-susceptibility, we examined the AMP expression i n the M4 midgut. Interestingly, the expression of AMPs is suppressed in the M4 mi dgut in comparison to that of the fat body. Finally, we proposed that the immuno-su sceptibility of Burkholderia symbiont helps them to retain in the symbiotic organ. Our in vivo data showing the rapid clearance of the symbiotic Burkholderia after inj ection to host Riptortus supports our proposal.