• BMB Reports
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• v.40 no.4
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• pp.459-466
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• 2007

The cDNA sequence of the Japanese flounder (Paralychthys olivaceus) IgD has been previously reported (GenBank accession no. AB052658) and this was followed by the detection of IgD mRNA expression in some flounder organ tissues. However, it has not been determined whether the flounder IgD gene is virtually expressed into IgD protein. To characterize the flounder immunoglobulins utilized in elucidating the mechanism, evolution and diversity of the flounder immune system, antibodies specific to IgD and IgM were necessary. In the present study, partial flounder recombinant IgD (rIgD), IgM (rIgM) and the conserved regions of IgD and IgM (rCIg) were produced by cloning the cDNA sequence using isotype specific primers which were designed to produce unique fragments of IgD and IgM specific amino acid sequences. The production of recombinant Igs was ascertained by SDS-gel electrophoresis and immunoblot analysis using anti-T7$\cdot}$Taq antibody. The produced recombinant Igs were purified using affinity columns, and used as immunogens. Antibodies specific to the isotype of flounder Igs were generated by immunizing rabbits with rfIgs and the antibodies produced were identified by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Specificities of the generated antibodies were evaluated by testing cross-reactivity between recombinant IgM and IgD. By ELISA, rabbit antibodies against the rfIgD fragment (anti-rfIgD) failed to recognize any kind of flounder serum Igs, whereas respective antibodies against rfCIg (anti-rfCIg) and rfIgM fragments (anti-rfIgM) reacted with serum Igs. Likewise, in immunoblot assays, though anti-rfIgD did not, both anti-rfCIg and anti-rfIgM bound with the ~85 kd flounder IgM heavy chain. By flow cytometry analysis, anti-rfCIg, anti-rfIgD and anti-rfIgM reacted with 6%, 3% and 6.5% of cells, respectively, suggesting that flounder IgD is not secreted in serum but expressed on flounder B-like cell surfaces as in mammals. Antibodies produced against recombinant flounder Igs could be used to develop sandwich assay systems for detecting flounder Igs and for further investigating the flounder immune system.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.6
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• pp.823-828
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• 1998

The objective of this study is to investigate cryoprotective effects of corn starch enzyme hydrolysates of nonsweet and low-calories on denaturation of frozen fish protein. The cryoprotective effects of were examined in Alaska pollack actomyosin solution by changes in SDS-PAGE pattern, solubility, and $Ca^{2+}$-ATPase activity. When samples stored for 0 and 30 days were compared on SDS-PAGE patterns, severe changes in all bands were shown on the control sample regardless of storage temperature, especially in myosin heavy chain (MHC). Not much difference no appeared the electrophoretic pattern in case of the samples containing sucrose at any storage temperature during 30 days of storage. The cryoprotective effect of the hydrolysates were markedly dependant on storage temperature and no MHC band was found in the samples stored at $-5^{\circ}C$. The SDS-PAGE patterns of sample stored at $-20^{\circ}C$, however, completely maintained after 30 days or storage. When the samples were stored at $-5^{\circ}C$, the solubility of the sample containing sucrose was retained at $90\%$ after 30 days of storage, whereas dramatically decreased in other samples. The samples including sucrose, D.E. 10, 15, and 20 revealed $90\%$ in solubility when stored at $-20^{\circ}C$. The tendency of remaining $Ca^{2+}$-ATPase activity was almost shown the same as that of solubility.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.84-90
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• 2001

This study was performed to know the effect of depolymerized alginate obtained by hydrolysis of alginate through a heating process at $121^{\circ}C$ on intestinal environment, Rats were fed with diets containing $1\%$, $5\%$, and $10\%$ of each depolymerized alginate (HAG-10, HAG-50, HAG-100 and alginate) for 35 days, The changes of weight, moisture content, pH and volatile basic nitrogen (VBN) of fecal, and a short chain fatty acids (SCFA) were checked in the rats. The fecal weight and moisture content were the highest in rats fed with alginate diets (p<0.01), followed by HAG-100, HAG-50 and HAG-10 in order. The $5\%$ of HAG-50 diets induced a significant increase in contents of protein and lipid of feces, resulting in the decrease of apparent digestibility of protein and lipid (p<0.01). The pH and VBN content in feces of the rats decreased in $5\%$ and $10\%$ of HAG-50 diets, but $10\%$ of HAG-100 diets; $5\%$ and $10\%$ of alginate diets brought about an increase of fecal pH and VBN (p<0.01), The amount of n-butyric acid in feces was increased while propionic and acetic acid contents decreased significantly (p<0.01) in diets containing $5\%$ and $10\%$ HAG-50. However, the feces of rat fed diet containing $5\%$ and $10\%$ alginate showed a tendency to being opposite in results than that of HAG-50.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.103-108
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• 2001

Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.516-522
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• 1998

An Actinomycetes strain, MSA-1, containing antimicrobial component was isolated from the black sponge, Halichondzia okadai, and was identified to a genus level by morphological and chemotaxonornic methods. The gray colored spores were oval type with smooth surface and formed flexibilis spore chains. The cell wall of this strain was type I containing D-aminopimellic acid (D-DAP) and no specific sugar was detected. Phospholipid of the cell membrane was PII type including phophoethanolamine and the major fatty acids of total lipid were branched anteiso-15 : 0, iso-16 : 0, 16 : 0 and iso-17 ; 0. From these results and other characteristics described in the Bergey's Manual, this strain was identificated as a Streptomyces sp. Meanwhile, 10mg of pale yellow colored antimicreobial component was isolated by HPLC method from the cultured Streptomyces sp. (70g of cryophillized mycellis). By crystallographyc analysis, HIRESMS and NMR assignment, the antimicrobial component produced from the strain MSA-1 was elucidated as the staurosporine (indolo[2,3-a]carbazole alkaloid).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.423-434
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• 2016

The importance of severe nuclear accidents and probabilistic safety assessment (PSA) were brought to international attention with the occurrence of severe nuclear accidents caused by the extreme natural disaster at Fukushima Daiichi nuclear power plant in Japan. In Korea, studies on level 3 PSA had made little progress until recently. The code systems of level 3 PSA, MACCS2 (MELCORE Accident Consequence Code System 2, US), COSYMA (COde SYstem from MAria, EU) and OSCAAR (Off-Site Consequence Analysis code for Atmospheric Releases in reactor accidents, JAPAN), were reviewed in this study, and the disadvantages and limitations of MACCS2 were also analyzed. Experts from Korea and abroad pointed out that the limitations of MACCS2 include the following: MACCS2 cannot simulate multi-unit accidents/release from spent fuel pools, and its atmospheric dispersion is based on a simple Gaussian plume model. Some of these limitations have been improved in the updated versions of MACCS2. The absence of a marine and aquatic dispersion model and the limited simulating range of food-chain and economic models are also important aspects that need to be improved. This paper is expected to be utilized as basic research material for developing a Korean code system for assessing off-site consequences of severe nuclear accidents.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.73-83
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• 2013

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a "good condition" by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species ($P_{TS}$) and sensitive species ($P_{SS}$) to water quality showed that the proportions of $P_{TS}$ had positive linear functions with nutrients, and that the $P_{SS}$ had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.43-50
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• 2015

In this study, single PCR and multiplex PCR tests were examined for identification of four types of squid species (giant squid, cuttlefish, octopus, beka squid) purchased from fish market as well as aquatic processed products in Busan. To design the specific primers against each species, the nucleotide sequences of the mitochondrial 16s rRNA gene of Architeuthis dux, Todarodes pacificus, Enteroctopus dofleini, Enteroctopus megalocyathus, Uroteuthis chinensis, Uroteuthis duvauceli, Uroteuthis edulis groups were analyzed for the identification of each species registered in the GeneBank (www.ncbi.nlm.nih.gov) and have been used for comparative analysis. In order to obtain the size variation of amplified fragments on multiplex PCR, we designed KOJ-F, OJ-F, OCT-F, HAN-F, ALLR primers for each species. The optimal PCR conditions and primers were selected for four types of squid species to determine target base sequences in its PCR products. In the case of single PCR, giant squid was only amplified by KOJ-F/ALLR primer; cuttlefish was only amplified by OJ-F/ALLR primer; octopus was only amplified by OCT-F/ALLR primer; and beka squid was only amplified by HAN-F/ALLR primer. For multiplex PCR, the mixture of four kinds of genomic DNA (giant squid, cuttlefish, octopus, beka squid) been prepared as a template and used together with the mixture of KOJ-F/OJ-F/OCT-F/HAN-F/ALLR primers in the reaction. By the multiplex PCR, it is confirmed that four samples are correspond to multiple simultaneous amplicon. Finally, we validated the established methods of multiplex PCR in the aquatic processed products. Although the mitochondrial 16s rRNA primers used in this study was useful as a marker for detection of each species among them, the study indicated that the established multiplex PCR method can be more useful tool for monitoring the processed products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.141-148
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• 2019

This study examined the effect of insulin-like growth factor (IGF)-I expression in the liver and muscle on the growth of Paralichthys olivaceus fed diets low in fish meal. A feeding experiment was conducted at Jeju National University, Jeju Island, Korea. Groups of P. olivaceus (total initial weight: 200 g) were maintained for 20 weeks on one of five experimental diets containing different proportions of fish meal. Diets containing 0%, 20%, 30%, 40%, and 50% fish meal were labeled FM0, FM20, FM30, FM40, and FM50, respectively. Fish growth was observed every 4 weeks during the feeding experiment, and plasma and liver and muscle tissues were sampled. Plasma IGF-I levels were analyzed using an ELISA kit. The mechanism of IGF-I receptor signaling was examined using immunoblotting and reverse transcription-polymerase chain reaction. The greatest total weight increase was observed in the FM30 group. In parallel, plasma levels of IGF-I and IGF-binding protein were highest in the FM30 group, and mRNA and protein expression were also significantly higher in this group. The first step in the IGF-I signaling pathway, tyrosine-phosphorylation checking, occurred smoothly until 20 weeks. These results suggest that a dietary ratio of 30% fish meal best promotes growth in this species. The IGF-I signaling pathway in the liver and muscle is associated with growth in P. olivaceus.