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Seo J.S.,South Korean National Fisheries Research and Development Institute | Jeon E.J.,South Korean National Fisheries Research and Development Institute | Kim M.S.,Pukyong National University | Woo S.H.,Pukyong National University | And 7 more authors.
Korean Journal of Parasitology | Year: 2012

Intestinal giant-cystic disease (IGCD) of the Israel carp (Cyprinus carpio nudus) has been recognized as one of the most serious diseases afflicting inland farmed fish in the Republic of Korea, and Thelohanellus kitauei has been identified as the causative agent of the disease. Until now, studies concerning IGCD caused by T. kitauei in the Israel carp have been limited to morphological and histopathological examinations. However, these types of diagnostic examinations are relatively time-consuming, and the infection frequently cannot be detected in its early stages. In this study, we cloned the full-length 18S rRNA gene of T. kitauei isolated from diseased Israel carps, and carried out molecular identification by comparing the sequence with those of other myxosporeans. Moreover, conventional PCR and real-time quantitative PCR (qPCR) using oligonucleotide primers for the amplification of 18S rRNA gene fragment were established for further use as methods for rapid diagnosis of IGCD. Our results demonstrated that both the conventional PCR and real-time quantitative PCR systems applied herein are effective for rapid detection of T. kitauei spores in fish tissues and environmental water. © 2012, Korean Society for Parasitology.

PubMed | Korea University, University of Ulsan, Mudanjiang Medical University, Daegu Haany University and 2 more.
Type: Journal Article | Journal: International immunopharmacology | Year: 2015

Clematis mandshurica Ruprecht root has been used in Asia as a traditional anti-inflammatory, analgesic, and antitumor agent. Its main active component is hederagenin, a naturally occurring triterpene, and in this study, we examined the anti-inflammatory effects of hederagenin in lipopolysaccharide-stimulated RAW 264.7 cells using an enzyme-linked immunosorbent assay, Western blot, and RT-PCR. In addition, its effects on acute inflammation in vivo were observed using a carrageenan-induced mouse hind paw edema assay. Furthermore, the changes on the histopathology and histomorphometry of hind paw skins were examined using carrageenan-treated mice. Treatment with hederagenin (10, 30 and 100M) resulted in inhibited levels of protein expression of lipopolysaccharide-stimulated iNOS, COX-2, and NF-B as well as production of NO, PGE2, TNF-, IL-1, and IL-6 induced by lipopolysaccharide. Consistent with these results, hederagenin also dose-dependently reduced the lipopolysaccharide-induced mRNA levels of iNOS and COX-2, and of the above-mentioned cytokines. Interestingly, results of the carrageenan-induced mouse hind paw edema assay showed an anti-edema effect of hederagenin. Furthermore, hederagenin (30mg/kg) inhibited the carrageenan-induced increases in skin thicknesses, infiltrated inflammatory cells, and mast cell degranulation. These results suggest that hederagenin may possess anti-inflammatory activities.

Kim J.Y.,Gyeongnam Development Institute | Jeong H.C.,University of Suwon | Kim H.,Southwest Research Institute | Kang S.,NFRDI
Fisheries Research | Year: 2015

Japanese anchovies, Engraulis japonicus, have exhibited substantial fluctuations in production in Korean waters. Anchovy drag net and drift gillnet fisheries are the major types of fishery that target different sizes of anchovies during different fishing seasons. We analyzed the monthly catch per unit effort (CPUE) for 1987-2012 using exponential smoothing methods, seasonal autoregressive integrated moving average (SARIMA), autoregressive neural network (ANN), and autoregressive recurrent neural network (ARNN) models to forecast the abundance of anchovies based on the fishing conditions. For the drag net fisheries, SARIMA provided better statistical insight than the other models, but the ARNN model was best for future forecasting (r2=0.819, PI=0.733). Additive Winters' exponential smoothing (AWES) was the most effective of the three smoothing methods, but its validation was poor compared with SARIMA and the other neural network models. AWES, SARIMA, ANN and ARNN were less suitable for the drift gillnet fisheries. A comparison of the CPUE of drift gillnet fisheries to that of drag net fisheries showed that the data had been contaminated by factors such as periods when anchovy fishing was prohibited or a fishery had been abandoned due to economic reasons, rather than biological factors. Nevertheless, ARNN proved to be an effective and accurate model in the training phase, and its forecasts showed a comparatively strong statistical performance (r2=0.797, PI=0.662) in the context of short-to-medium-length time periods. Additionally, whereas SARIMA performed worse than ANN or ARNN, its forecasting capability was comparatively satisfactory (r2=0.713, PI=0.584). Finally, SARIMA has the advantage of providing statistical descriptions of the catches. © 2014 Elsevier B.V.

We compiled and analyzed past time-series data to evaluate changes in oceanographic conditions and marine ecosystems near the Ieodo ocean research station (IORS) in the East China Sea (N 31°15′-33°45′, E 124°15′-127°45′) in relation to longterm changes in climate and global warming. The environment data we used was a depth-specific time-series of temperature and salinity for the water columns at 175 fixed stations along 22 oceanographic lines in Korean waters, based on bimonthly measurements since 1961 taken by the National Fisheries Research & Development Institute. As an indicator for the ecosystem status of the waters off Ieodo, we analyzed species composition in biomass of fishes caught by Korean fishing vessels in the waters near the IORS (1984-2010) and summarized the data in relation to the environmental changes using canonical correspondence analysis (CCA). To detect step changes in the time-series of environmental factors, we applied a sequential t-test analysis of regime shift. Correspondence analysis detected a major shift in fish assemblage structure between 1990 and 1993: the dominant species was filefish during 1981-1992, but chub mackerel during 1992-2007. This shift in fish assemblage structure seemed to be related to the well-established 1989 regime shift in the North Pacific, which was confirmed again with respect to temperature in the Yellow Sea and the Korea Strait (but not in the waters off the IORS). In overall from 1984 to 2010, salinity was more important than water temperature in CCA, implying that the fluctuation of the Tsushima warm current is a most important force driving the long-term changes in fish assemblage structure in the waters off the IORS. Further multidisciplinary researches are required to identify oceanographic and biological processes that link climate-driven physical changes to fish recruitment and habitat range fluctuations. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Netherlands.

PubMed | Gwangju Institute of Science and Technology, South Korean National Fisheries Research and Development Institute and NFRDI
Type: Journal Article | Journal: Marine pollution bulletin | Year: 2015

To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, (13)C and (15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment.

Kang H.J.,Pukyong National University | Zhang C.I.,Pukyong National University | Lee E.J.,NFRDI | Seo Y.I.,NFRDI
Ocean Science Journal | Year: 2015

Hairtail (Trichiurus lepturus) has been traditionally harvested by multi-gear types in the Yellow Sea and the East China Sea, except for the East Sea (Sea of Japan) in Korean waters. Six different fishery types such as offshore stownet fishery, offshore longline fishery, large pair-trawl fishery, large purse seine fishery, large otter trawl fishery and offshore angling fishery target to harvest the hairtail stock accounting for about 90% of the total annual catch. We attempted to develop an ecosystem-based fisheries assessment approach, which determines the optimal allocation of catch quotas and fishing efforts for major fisheries. We conducted standardization of fishing effort for six types of hairtail fisheries using a general linear model (GLM), and then estimated maximum sustainable yield (MSY) and maximum economic yield (MEY). Estimated MSY and MEY for the hairtail stock were estimated as 100,151 mt and 97,485 mt, respectively. In addition, we carried out an ecosystem-based risk analysis to obtain species risk index (SRI), which was applied to adjusting the optimal proportion of fishing effort for six hairtail fisheries as a penalty or an incentive. As a result, fishing effort ratios were adjusted by SRI for the six fisheries types. Also, the total allowable catch (TAC) was estimated as 97,485 mt and the maximum net profit at TAC by the hairtail fisheries was estimated as 778 billion won (USD 765 million). © 2015, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

Kang J.-H.,Biotechnology Research Division | Kim Y.-K.,Biotechnology Research Division | Park J.-Y.,Biotechnology Research Division | An C.-M.,Biotechnology Research Division | Jun J.-C.,NFRDI
Molecular Biology Reports | Year: 2012

Of the more than 300 octopus species, Octopus minor is one of the most popular and economically important species in Eastern Asia, including Korea, along with O. vulgaris, O. ocellatus, and O. aegina. We developed 19 microsatellite markers from Octopus minor and eight polymorphic markers were developed to analyze the genetic diversity and relationships among four octopus populations from Korea and three from China. The number of alleles per locus varied from 10 to 49, and allelic richness per locus ranged from 2 to 16.4 across all populations. The average allele number among the populations was 11.1, with a minimum of 8.3 and a maximum of 13.6. The mean allelic richness was 8.7 in all populations. The Hardy-Weinberg equilibrium (HWE) test revealed significant deviation in 19 of the 56 single-locus sites, and null alleles were presumed in five of eight loci. The pairwise F ST values between populations from Korea and China differed significantly in all pairwise comparisons. The genetic distances between the China and Korea samples ranged from 0.161 to 0.454. The genetic distances among the populations from Korea ranged from 0.033 to 0.090, with an average of 0.062; those among populations from China ranged from 0.191 to 0.316, with an average of 0.254. The populations from Korea and China formed clearly separated into clusters via an unweighted pair group method with arithmetic mean dendrogram. Furthermore, a population from muddy flats on the western coast of the Korean Peninsula and one from a rocky area on Jeju Island formed clearly separated subclusters. An assignment test based on the allele distribution discriminated between the Korean and Chinese origins with 96.9 % accuracy. © 2012 Springer Science+Business Media B.V.

Kang J.-H.,Biotechnology Research Division | Kim Y.-K.,Biotechnology Research Division | Kim M.-J.,Biotechnology Research Division | Park J.-Y.,Biotechnology Research Division | And 4 more authors.
International Journal of Biological Sciences | Year: 2011

The Far Eastern sea cucumber, Stichopus japonicus, is a favored food in Eastern Asia, including Korea, Japan, and China. Aquaculture production of this species has increased because of recent declines in natural stocks and government-operated stock release programs are on-going. Therefore, the analyses of genetic structure in wild and hatchery populations are necessary to maintain the genetic diversity of this valuable marine resource. In addition, given that sea cucumber color affects market price, with the rare, possibly reproductively isolated, red type being the most valuable, an understanding of the genetic structure and diversity in color variation of green and red types is necessary. We analyzed the genetic structure of wild and hatchery-produced green type S. japonicus from Korea and China, and wild red type from Korea using 9 microsatellite makers. The number of alleles per locus ranged from 11 to 29 across all populations. The mean allele numbers of the green types from Korea (10.6) and China (10.1) were similar, but differed slightly from that of the red type (9.1). Pairwise mul-tilocus FST and genetic distance estimations showed no significant differences between the green types from Korea and China, whereas the differences between the green and red types were significant. This was clearly illustrated by a UPGMA dendrogram, in which the two close subclusters of green types were completely separated from the red type. In addition, the allele frequencies of the green and red types were significantly different. Assignment tests correctly assigned 100% (quality index 99.97%) of individuals to their original color types and demon-strated the feasibility of microsatellite analysis for discrimination between color types. © Ivyspring International Publisher.

Han C.-H.,NFRDI | Chae J.,Korea Environmental Research Center for Hydrosphere | Jin J.,NFRDI | Yoon W.,NFRDI
Ocean Science Journal | Year: 2012

We examined the respiration rate of Aurelia aurita medusae at 20 °C and 28 °C to evaluate minimum metabolic demands of medusae population in Sihwa Lake, Korea during summer. While weight specific respiration rates of medusae were constant and irrespective to the wet weight (8-220 g), they significantly varied in respect to temperatures (p<0.001, 0.11±0.03 mg C g -1 of medusa d -1 at 20°C and 0.28±0.11 mg C g -1 of medusa d -1 at 28 °C in average, where Q 10 value was 2.62). The respiration rate of medusae was defined as a function of temperature (T, °C) and body weight (W, g) according to the equation, R=0.13×2.62 (T-20)/10W 0.93. Population minimum food requirement (PMFR) was estimated from the respiration rate as 15.06 and 4.86 mg C m -3 d -1 in June and July, respectively. During this period, increase in bell diameter and wet weight was not significant (p=1 in the both), suggesting that the estimated PMFR closely represented the actual food consumption in the field. From July to August, medusae grew significantly at 0.052 d-1, thus the amount of food ingested by medusae population in situ was likely to exceed the PMFR (1.27 mg C m -3 d -1) during the period. In conclusion, the medusae population of higher density during June and July had limited amount of food, while those of lower in July and August ingested enough food for growth. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Netherlands.

Kang J.-H.,Biotechnology Research Division | Yu K.H.,Biotechnology Research Division | Park J.-Y.,Biotechnology Research Division | An C.-M.,Biotechnology Research Division | And 2 more authors.
Journal of Genetics and Genomics | Year: 2011

Color variation is a well-known feature of sea cucumbers (Apostichopus japonicus), which are classified into three groups based on their colors of red, green and black. It is also one of the most important traits related to how they taste, and it thereby affects their market price. Attempts were made to identify single-nucleotide polymorphisms (SNPs) and to analyze differences associated with SNP genotypes between green and red color variants using HSP70 as the target gene. The HSP70 gene, which is found universally in organisms from bacteria to humans, is one of the most evolutionarily conserved genes and the most widely studied biomarker of stress response. DNA fragments of 1074 bp covering a partial sequence of the sea cucumber HSP70 gene, were amplified from both red and green variants, and subsequently analyzed for the presence of SNPs. Twenty-seven polymorphic sites in total, including heterozygous sites, were observed. Of these, six sites were found to be significantly different SNP genotypes between green and red variants. Furthermore, PCR with an internal primer designed to include an allele-specific SNP at the 3' end (site 443) showed differentiation between the two variants, 100% and 4.2% amplification in green and red variants, respectively. The validated SNPs may serve as informative genetic markers that can be used to distinguish variants at the early developmental stage, prior to color differentiation. © 2011, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China.

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