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        검색결과 389

        224.
        2014.09 서비스 종료(열람 제한)
        Skeletal deformities are important factor of evaluation of fish value commercially. Deformities of opercular are commonly observed type of fish deformation. Although these malformations in fish can be caused by culture conditions, the environmental factors are unknown. This study examined the effect of water temperature on the opercular deformity of the red spotted grouper, Epinephelus akaara. Experimental fish (TL; 7.49±0.10 cm) were respectively divided into 3 groups that were reared at 20, 24, 28℃ for 6 weeks. All specimens were photographed from the left lateral view using a Canon EOS 70D. We placed 11 landmark points for visualization the shape differences of operculum in the whole body. In order to measure the reduction of opercular, we estimated total length (TL) and shortening of the distal part (distance between landmarks 10 and 11). After 6 weeks, both growth rate and incidence of opercular shortening were high in 24 and 28℃. At 28℃, the distance of distal part of operculum was the highest as 0.36 cm and exposure to the 24℃ induced the highest growth rate during this experiment. On the other hand, both growth rate and opercular deformity were low at the lower temperature (20℃). This study shows opercular malformation as well as the growth rate of E. akaara are influenced by the high water temperature.
        225.
        2014.09 서비스 종료(열람 제한)
        Reactive oxygen species (ROS) are produced in organisms as the natural products of oxidative metabolism by environmental stress and pathogen invasion. ROS, such as superoxide anion and hydrogen peroxide, can be toxic to cells and tissues to cause oxidative stress. Recent study revealed that olive flounder (Paralichthys olivaceus) superoxide dismutase (SOD) has been identified as a partial gene and strongly induced to benzoin[a]pyrene and it was deduced indicator of aquatic oxidative stress responses, but its transcriptional response against viral infection has not been investigated. In the present study, spatial and temporal expression profile was analyzed to investigate the function of Of-SOD in the anti-viral response. Of-SOD transcripts were ubiquitously detected in diverse tissues with variable levels using a real-time PCR. The expression of Of-SOD was significantly higher in the muscle, liver and brain, but extremely low in the stomach and spleen. Following VHSV challenge, the expression of Of-SOD increased within 3 hours and subsequently decreased to the original level at 2 days post-challenge in kidney. Although expression pattern and induction time are slight differences depending on the tissue, the transcript of Of-SOD was consistently increased in acute infection response, but expression is low in the chronic response. Collectively, Of-SOD expressions were inducible after VHSV infection and they were probably involved in the immune response against viral challenge. These results suggest that SODs may play important roles in the immune defense system of P. olivaceus and perhaps contribute to the protective effects against oxidative stress in this flounder.
        226.
        2014.09 서비스 종료(열람 제한)
        Molecular markers are useful for selecting to include superior character genetic like as strong immune system and rapid growth in fish. The marker is also very important part of breeding technology in Olive flounder (Paralichthys olivaceus). Single nucleotide polymorphisms (SNPs) marker is already in use widely for genomic research and breeding. But this SNPs marker hardly has been validated for screening functional genes in Olive flounder. We study identify single nucleotide polymorphisms (SNPs) on Expressed sequence tag (EST) database, develop usable SNP marker and apply to wild sample and cultured of olive flounder. As a result, Out of total 4.327 ESTs, 693contigs and 514 SNP from total contigs were detected while these substitutions include 297 transitions and 217 transversions. 144 developed markers were applied in 16 samples (wild 8, culture 8), Out of total marker, only 32 markers had detected polymorphic in sample. Polymorphism of 32 markers was observed in the variety genes region involved in immunity and protein synthesis. And the 32 marker were identified 21 transitions, 11 transversions, and indel was not detected in polymorphic SNPs. The analysis on heterozygosity by sample showed 0.34 in wild sample and 0.29 in cultured sample. In conclusion, we was identified SNP and Polymorphism by designed new marker, it supports that development marker is suitable for SNP detection and diversity analysis in Olive flounder. The outcome of this study can be basic data for researches for immunity gene and characteristic with SNP.
        227.
        2014.07 서비스 종료(열람 제한)
        Citrus canker caused by Xanthomonas citri pv. citri is one of economically important diseases in the citrus industry. The devastating bacterial disease results in unattractive quality and a significant reduction in fruit production. Citrus growers and industry in Korea has been struggling with the serious disease causing the prohibition of export market. Korea also became the top import market for oranges. The development of markers linked to citrus canker resistance is strongly needed. In this study, we investigated molecular markers between ‘Kiyomi’ (Citrus unshiu x C. sinensis), a resistant cultivar, and Natsudaidai (C. natsudaidai), a susceptible cultivar. To develop markers, we focused on structural variation (copy number variation, CNV, and presence/absence variation, PAV). It has been well documented that CNV and PAV of defense-related genes are associated with resistant cultivars. Using a read depth approach following next-generation sequencing, we performed genome-wide analysis of CNV and PAV in two varieties. As a result, 633 genes showing at least two times difference between the mapping reads from two varieties and 61 genes showing presence of the mapping reads in only either one of them were screened. Visual inspection using the Integrative Genomics Viewer (IGV) was performed and experimental validation is being investigated. Interestingly, one of PAV candidates showed polymorphism in ‘Kiyomi’ and ‘Natsudaidai’ as well as other resistant and susceptible cultivars. Our results suggest a necessity for the detection of structural variation and indicate that the candidates may be useful for molecular breeding for citrus canker resistance and understanding disease resistance mechanism.
        228.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        TCR subunits are members of membrane-bound receptors which allow the fast and efficient elimination of the specific fish pathogens have regulated function in adaptive immunity. Sequence structure of TCR subunits have been reported for various teleosts, but the information of each TCR subunit functional characterization through expression analysis in fish was unknown. In this study, we examined the gene expression of TCR subunits in the early developmental stages and observed transcript levels in various tissues from healthy adult olive flounder by RT-PCR. The mRNA expression of alpha subunit was already detected in the previous hatching step. But the transcripts of another TCR subunit were not observed during embryo development and increased after hatching and maintained until metamorphosis at the same level. It was found that all TCR subunits mRNAs are commonly expressed in the immune-related organ such as spleen, kidney and gill, also weak expressed in fin and eye. TCR alpha and beta subunit were expressed in brain, whereas gamma and delta were not expressed same tissue. The sequence alignment analysis shows that there are more than 80% sequence homology between TCR subunits. Because it has a high similarity of amino acid sequence to expect similar in function, but expression analysis show that will have may functional diversity due to different time and place of expression.
        229.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        The innate immune system is the only defense weapon that invertebrates have, and it is the fundamental defense mechanism for fish. The innate immune response is important in newly hatched flounders because it is closely involved in the initial feeding phase, which is why it is essential for survival during the juvenile period. The expression analysis of genes involved in the innate immune response in the olive flounder (Paralichthys olivaceus) in the days after hatching is incomplete. Therefore, we have begun to examine the expression patterns of genes specifically induced during the development of the innate immune system in newly hatched flounders. Microscopic observation showed that pronephron formation corresponded with the expression of perforin-encoding gene. These results suggest that perforin plays a vital role in the innate immunity of the kidney during developmental stages. Perforin expression was strong at the start of the development of the innate immune response, and continued throughout all the development stages. Our findings have important implications with respect to perforin’s biological role and the evolution of the first defense mechanisms in olive flounder. Further studies are required to elucidate the perforin-mediated innate immunity response and to decipher the functional role of perforin in developmental stages.
        230.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Fish larvae are immediately exposed to microbes from hatching to maturation of their lymphoid organs, therefore effective innate mechanisms is very important for survival in such an environment. The key component of innate immune system, C3 is central protein of all activation pathways of the complement system, leading to inflammatory reactions, such as opsonisation, chemotaxis, and cell lysis of pathogens. Although, innate mechanisms is essential for survival in the early stage of development, little is known about defence mechanisms. In this study, the alignment analysis showed that amino acid sequence of C3 from olive flounder liver EST homologous to other known C3 sequences with 73-99% identity. Also, we examined the tissue distribution of olive flounder C3 and analyzed expression pattern from the fertilized egg until 28 days post hatching. As a result, olive flounder C3 mRNA was expressed only in the liver and the mRNA level more increased as developmental proceed during the early stage. These results may suggest that olive flounder C3 plays an important function in the early immune response of olive flounder larvae.
        231.
        2013.11 서비스 종료(열람 제한)
        Hydrolysis of triacylglycerol(TAG) from fats and oils to glycerol and free fatty acid (FFA), also referred to as fat splitting, is an important reaction for the olechemical industry. Typically, hydrolysis is carried out at 100-260℃ and 100-7000 kPa using 0.4-0.15(w/w) initial water to oil ratio with or without catalysts. It is an endothermic reaction occurs in a stepwise manner where TAG is initially hydrolyzed to diacyglycerol (DAG) then to monoacylglycerol(MAG) and finally to glycerol. Water, in its subcritical state, can be used as both a solvent and reactant for the hydrolysis of triglycerides. subcritical water (150℃<T<370℃,0.4<p<22Mpa) can act as an acid or base catalyst. To investigate milder reaction conditions, in this study, waste cooking oil and fresh soybean oils will be hydrolyzed to free fatty acids with deionized water under SC CO2 medium in a batch reactor. Effects of the reaction temperature, time and solvent to feed ratio on FFA in the hydroysis at equilibrium will also observed for optimum conversion of oil. The reaction products will be analyzed by acid-base titration, GC FID and HPLC.
        232.
        2013.11 서비스 종료(열람 제한)
        Recently biodiesel has drawn much attraction as renewable enegy due to its environmental benefits and the fact that it is made from renewable resources. However, the production cost of biodiesel is one of the main hurdle to commercialize it. One of the way to reduce the biodiesel production cost is to use the waste cooking oil as feedstock. In the conventional transesterification process of waste cooking oils for biodiesel production, the presence of free fatty acids and water causes severe problems such as formation of soap and decreasing of catalyst yield. Much effort has been devoted to solve the above problems and one of the promising way is the supercritical methanol treatment which is performed at the methanol supercritical environment (>239.45℃, >8.10 Mpa)one of the serious problems of the application of SCM process for the biodiesel production is the tough operation condition(high pressure, high temperature. In this study, we have studied about the supercritical methanol treatment for the biodiesel production with the soybean waste cooking oil as a feedstock in the present of various heterogeneous solid catalysts such as mesoporous silica and acid-doped mesorpous silica. Biodiesel conversion was increased at more mild opreation condition to the previous studies by using the catalysts. The conversion was more enhanced by modifying the catalysts.
        234.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is one of the commercial important flatfish species in Korea. The ocular signal transduction pathway is important in newly hatched flounders because it is closely involved in the initial feeding phase thus essential for survival during the juvenile period. However, the study of gene expression during ocular development is incomplete in olive flounder. Therefore we examined the expression analysis of specifically induced genes during the development of the visual system in newly hatched flounders. We searched ocular development-involved gene in the database of expressed sequence tags (ESTs) from olive flounder eye and this gene similar to arrestin with a partial sequence homology. Microscopic observation of retinal formation corresponded with the time of expression of the arrestin gene in the developmental stage. These results suggest that arrestin plays a vital role in the visual signal transduction pathway of the retina during ocular development. The expression of arrestin was strong in the ocular system during the entirety of the development stages. Our findings regarding arrestin have important implications with respect to its biological role and evolution of G-protein coupled receptor (GPCR) signaling in olive flounder. Further studies are required on the GPCR-mediated signaling pathway and to decipher the functional role of arrestin.
        235.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder.
        236.
        2013.08 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is a most important aquaculture species in Korea. Like most marine fishes, olive flounders are stomachless at first feeding and aquired gastric function during the metamorphosis, so food was mainly digested by pancreatic enzyme from first feeding to premetamorphosis. However, comprehensive analysis of pancreatic and gastric digestive enzyme of olive flounder at early developmental period is still unclear. In the expression study of pancreatic and gastric digestive enzyme by real-time PCR at early developmental stage, pancreatic enzyme such as chymotrypsinogen 2, preproelastase 2 and 4, pancreatic protein somatomedin-B domain (PPSB) mRNA expression were initiated at first feeding and strongly expressed in the pancreas developmental stage, while gastric digestive enzyme signal was not at all detected during same period. Although, trypsinogens were secreted from pancreas and have similar amino acid sequence, trypsinogen 3 expression induction was detected both pancreas and stomach developmental stage, while trypsinogen 2 expression was significantly increased only post-metamorphosis period. Pepsinogen mRNA expression was only detected at metamorphosis according to stomach differentiation. Lipid digestive enzyme, lipase and intestine fatty acid binding protein 1 (I-FABP 1), were already reached a certain level at beginning of hatching and more increased during early developmental stage and then gradually decreased before metamorphosis. These results suggested that feed ingestion of olive flounder was exclusive charged by pancreatic digestive enyme, lipid digestive enzyme and trypsinogen 3 from first feeding and then fully swiched by gastric digestive enzyme and trypsinogen 2 from metamorphosis period.
        237.
        2013.08 서비스 종료(열람 제한)
        For the study of population genetic structure with mtDNA, it is essential to measure genetic diversity at each mtDNA regions. Also, to evaluate the variation according to the each region should follow as well as to see if there are differences. In this study, we delved into the variations and dendrogram among samples of seven mtDNA regions (NDⅡ, NDⅤ, NDⅣ, NDⅣL, NDⅥ, NDⅠ, 12SrRNA) from wild Pacific abalone, Haliotis discus hannai collected in Yeosu, Korea. The region with the highest genetic variation was NDⅣ region (Haplotype diversity = 1.0000, Nucleotide diversity = 0.010823) with two to five times higher variation than the others. Furthermore, the study to see if there is a difference between the regions of samples showed that similar aspects of dendrogram in NDⅡ and NDⅠ(divergence of 90% and 87%), which forms a group with hd4, 7, 8 and 10 at bootstrap support, based on 1000 replications. Also, pair-wise FST between clusters within the regions showed high values; 0.4061 (P=0.0000), 0.4805 (P=0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of NDⅣ with the highest variation in addition to the regions of NDⅡ and NDⅠ, which formed clusters with high bootstrap value, for study of population genetic structure in this species.
        238.
        2013.06 서비스 종료(열람 제한)
        Peritonitis is a common, major complication in continuous ambulatory peritoneal dialysis (CAPD) patients and tuberculous (TB) peritonitis has been reported to constitute 1-2% of all peritonitis cases. In CAPD patients, TB peritonitis is often diagnosed late and has a high mortality rate. In a recent recommendation made regarding the treatment of TB peritonitis, primary removal of a peritoneal dialysis catheter has been advised in addition to anti-TB drugs. Here, we describe two cases of TB peritonitis in CAPD patients successfully treated without peritoneal dialysis catheter removal.
        240.
        2012.07 서비스 종료(열람 제한)
        Phosphorus is one of the macronutrients essential for plant growth and development, as well as crop productivity. Many soils around the world are deficient in phosphate (Pi) that plants can utilize. To cope with the stress of Pi starvation, plants have evolved many adaptive strategies, such as changes of root architecture and enhanced Pi acquisition form soil. To understand molecular mechanism underlying Pi starvation stress signaling, we characterized the activation-tagged mutant showing altered responses to Pi deficiency compared to wild type Arabidopsis and named hsp3 (hypersensitive to Pi starvation3). hsp3 mutant exhibits enhanced phosphate transporter activity, resulting in higher Pi content than wild type. However, in root architectural change under Pi starvation, hsp3 shows hyposensitive responses than wild type, such as longer primary root elongation, lower lateral root density. Histochemical analysis using hsp3 mutant expressing auxin-responsive DR5::GUS reporter gene, indicated that auxin allocation from primary to lateral roots under Pi starvation is aborted in hsp3 mutant. Molecular genetic analysis of hsp3 mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’ end processing. Here, we propose that mRNA processing plays a crucial role in Pi homeostasis in Arabidopsis.