• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.4
• /
• pp.307-313
• /
• 2010

Stanniocalcin 1 (STC1) is a glycoprotein hormone that is important in the maintenance of calcium and phosphate homeostasis in both fish and mammals. STC1 and its paralog STC2 are expressed in multiple tissues in fishes, although the physiological roles of piscine STCs are still unclear compared with those of mammals. In this study, we cloned olive flounder STC1 (ofSTC1) and ofSTC2 cDNAs into pET28a vector and used E. coli Rosetta (DE3) as the host strain for protein expression. Expression experiments were carried out using isopropyl-$\beta$-D-thiogalactoside (IPTG) and nickel affinity chromatography. We could identify the recombinant proteins as single 29.5 kDa (ofSTC1) and 33.2 kDa (ofSTC2) bands in the insoluble fraction on sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE). These results indicate that ofSTC1 and ofSTC2 were expressed as insoluble proteins in E. coli. Furthermore, the injection of ofSTC1 protein into juvenile tilapia resulted in a decrease of the serum calcium level. These results suggest that the purified fish STC1 and STC2 proteins may be used to elucidate the physiological role of STCs in fishes.

• Ocean and Polar Research
• /
• v.29 no.4
• /
• pp.311-316
• /
• 2007

Ocean noise may be used for monitoring wind speed and rainfall rate on the sea surface, as well as for tracking whales' migration routes. In particular, low-frequency ocean noise has recently been of concern with relation to the behavior of marine mammals. Low-frequency ocean noise has been increasing over the past few decades due to increase of ship traffic and offshore oil industry activities. Mechanical noise such as flow noise and cable strumming noise may be induced if low-frequency ocean noise is measured by cabled traditional hydrophone in high current areas. To successfully measure low-frequency ocean noise in a shallow water environment with strong current, we developed a self-recording hydrophone. This paper describes the main configurations of the self-recording hydrophone and presents some results on measured data.

• Journal of Marine Life Science
• /
• v.2 no.1
• /
• pp.7-11
• /
• 2017

Sulfated polysaccharides are known to be immune-stimulators in mammals and can be used as food additives to enhance immunity. In this study, the immune-stimulating activity of water-soluble anionic macromolecules F₂ fractionation isolated from Codium fragile using ion-exchange chromatography was tested in olive flounder, Paralichythys olivaceus, in vitro and in vivo. The gene expression of interleukin (IL)-1β was adopted to check the immune-affection. As a result, in vitro study revealed that the expression of IL-1β was significantly upregulated in head kidney cells by 1 and 5 ㎍/ml of polysaccharides 4 h and by 5 ㎍/ml of polysaccharides at 24 h. In vivo, IL-1β gene expression in head kidney was significantly upregulated by 20 and 100 ㎍ of the polysaccharides at day 1 post-i.p. injection, while downregulated at day 3 but not significant. Meanwhile, in peritoneal cells, it was upregulated by 20 ㎍ of the polysaccharides at day 1 but the upregulation was sustained until day 3 though it was not significant. These results indicate that the sulfated polysaccharides from C. fragile are an immune-stimulator and might be potential feed additives for olive flounder.

• Korean Journal of Environment and Ecology
• /
• v.31 no.1
• /
• pp.30-41
• /
• 2017

Mammals in Korea have been studied in various fields such as animal science, veterinary medicine, laboratory animal science, ecology, and genetics. As the importance of biodiversity has been emphasized recently, conservation and management of mammals have attracted much public attention. However, in spite of such an increase in scientific research and public interest, it is still difficult to find a report or summary to grasp the trend of mammalian research in Korea. The purpose of this study is to provide the basic data for future plans of the detailed research area and the related policies by grasping the research trends of mammals in Korea. Using text-ming and co-word analysis, we analyzed 392 mammalian research papers published in Korean national journals as of 2015. Our results showed that the number of mammalian research papers published in Korea has gradually increased and that the research target species have also become increasingly diverse. The major research areas identified through text-mining and co-word analysis are (1) evolution/phylogenetics/genetics, (2) environmental science/ecology, (3) embryology/reproductive biology/cell biology, (4) veterinary medicine related to parasites, (5) parasitology related to rodents, (6) bacteriology/virology, (7) anatomy/cell biology/laboratory animal science, (8) veterinary science related to morphology and anatomy, (9) animal science, (10) marine mammalogy, and (11) Chiroptera (bat) research. Environmental science/ecology has been the most active field among the 11 research areas in recent times, and the proportion of research has increased sharply compared to the past. Environmental science/ecology is the core of biodiversity conservation, and as the importance of biodiversity has been emphasized in recent years, researchers' interest in mammal ecology appears to have increased. We expect that the results of this study will be useful for future research plan and related policies on mammals in Korea.

• Journal of fish pathology
• /
• v.33 no.1
• /
• pp.35-43
• /
• 2020

Hypoxia is a serious problem in the marine ecosystem causing a decline in aquatic resources. MicroRNAs (miRNAs) regulate the expression of genes through binding to the corresponding sequences of their target mRNAs. Especially, miRNAs in the cytoplasm can be secreted into body fluids, which called circulating miRNAs, and the availability of circulating miRNAs as biomarkers for hypoxia has been demonstrated in mammals. However, there has been no report on the hypoxia-mediated changes in the circulating miRNAs in fish. miR-210 is known as the representative hypoxia-responsive circulating miRNA in mammals. To know whether fish miR-210 also respond to hypoxia, we analyzed the change of circulating miR-210 quantity in the serum of olive flounder (Paralichthys olivaceus) in response to hypoxia. The expression of hypoxia related genes, hypoxia inducible factor 1α (HIF-1α) and the heat shock protein 90α (HSP90α) was also analyzed. Similar to the reports from mammals, miR-210-5p and miR-210-3p were significantly increased in the serum of olive flounder in response to hypoxia, suggesting that circulating miR-210 levels in the serum can be used as a noninvasive prognostic biomarker for fish suffered hypoxia. The target genes of miR-210 were related to various biological processes, which explains the major regulatory role of miR-210 in response to hypoxia. The expression of HIF-1α and HSP90α in the tissues was also up-regulated by hypoxia. Considering the critical role of HIF-1α in miR-210 expression and HSP90 in miRNAs function, the present up-regulation of HIF-1α and HSP90α might be related to the increase of circulatory miR-210, and the interaction mechanism among HIF-1α, HSP90α, and hypoxia-responsive microRNAs in fish should be further studied.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.1
• /
• pp.70-76
• /
• 2013

Some fish live in aquatic environments with low or temporally changing $O_2$ availability. Variation in dissolved oxygen (DO) levels requires behavioral, physiological, and biochemical adaptations to ensure the uptake of sufficient $O_2$. Several species are relatively well adapted to tolerate low $O_2$ partial pressures (hypoxia). The medaka (Oryzias dancena ) is an important model organism for biomedical research that shows remarkable tolerance to hypoxia. We investigated the regulation and role of hypoxia-inducible factor-1 (HIF-$1{\alpha}$) as a general hypoxia-response gene and stanniocalcin-2 (STC2), which is one of the genes regulated by HIF-$1{\alpha}$ in mammals under hypoxia. We subjected adult male medaka to the following three acute hypoxia regimes: 1, 24, and 72 h at DO = $1.8{\pm}0.5$ ppm. The changes in STC2 and HIF-$1{\alpha}$ mRNA were monitored using quantitative real-time reverse-transcription PCR. We found strong upregulation of HIF-$1{\alpha}$ mRNA in the livers of fish exposed to hypoxia. Hypoxia rapidly upregulated STC-2 mRNA expression in muscle, but not in the brain, gills, liver, or intestine. Therefore, unlike in mammals, hypoxia might regulate O. dancena STC-2 expression in an HIF-$1{\alpha}$-independent manner.

• Journal of Yeungnam Medical Science
• /
• v.28 no.2
• /
• pp.105-115
• /
• 2011

Mercury is a toxic, persistent pollutant that bioaccumulates and biomagnifies through food webs. People are exposed to methyhnercruy mainly through their diet, especially through the consumption of freshwater and marine fish and of other animals that consume fish (e.g., marine mammals). All humans are exposed to low levels of mercury. Dietary patterns can increase exposure to a fish-eating population where the fish and seafood are contaminated with mercury. The primary toxicity targets of mercury and mercury compounds are the nervous system, kidneys, and cardiovascular system. It is generally accepted that developing organ systems are most sensitive to the toxic effects of mercury. The fetal-brain mercury levels appear to be significantly higher than the maternal-blood mercury levels, and the developing central nervous system of the fetus is currently regarded as the main system of concern as it demonstrates the greatest sensitivity. The subpopulation that may be at greater risk for mercury toxicity are those exposed to higher levels of methylmercury due to carnivorous fish, including sharks.

• BMB Reports
• /
• v.47 no.11
• /
• pp.643-648
• /
• 2014

Stanniocalcin (STC), a glycoprotein hormone originally discovered in fish, has been implicated in calcium and phosphate homeostasis. While fishes and mammals possess two STC homologs (STC1 and STC2), the physiological roles of STC2 are largely unknown compared with those of STC1. In this study, we identified Ran-binding protein M (RanBPM) as a novel binding partner of STC2 using yeast two-hybrid screening. The interaction between STC2 and RanBPM was confirmed in mammalian cells by immunoprecipitation. STC2 enhanced the RanBPM-mediated transactivation of liganded androgen receptor (AR), but not thyroid receptor ${\beta}$, glucocorticoid receptor, or estrogen receptor ${\beta}$. We also found that AR interacted with RanBPM in both the absence and presence of testosterone (T). Furthermore, we discovered that STC2 recruits RanBPM/AR complex in T-dependent manner. Taken together, our findings suggest that STC2 is a novel RanBPM-interacting protein that promotes AR transactivation.

• The Journal of Fisheries Business Administration
• /
• v.22 no.2
• /
• pp.53-74
• /
• 1991

Interest on ocean environment has increased with the development of industrialized activities. Public marine resorces are defined broadly to include fish stocks, beaches, marine waters, recreational fishing, biota, waterfowls, shorebirds, seabirds and marine mammals But, it is not easy to analyze compensation for injury to publicly owned marine resources because the claimants do not exist clearly and the economic methodology of damage on public goods is not developed fully. This paper introduces basic idea of welfare economic theory and environmental legislation to the research question : How the economics and law can be applied to the case of damage on publicly owned marine resource. The paper discusses the concepts of willingness to pay (WTP) and willingness to accept (WTA). It is accepted generally that WTA is correct concept of welfare change in the case of damaged public goods. Four methods (compensating variation, equivalent variation, compensating surplus, equivalent surplus of measuring welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes caused by environmental damage. Vartia (1983) showed CV could be measured from the ordinary demand function using the differential equations. This paper also provides an overview of the emerging U.S. and Korea legal system for compensation for natural resource damages, with particular emphasis on U.S. legal system under Comprehensive Environmen-tal Response Compensation and Liability Act (CERCLA). These regulations are to include two different types of standardized procedures for assessing natural resources injury : Type A or simplified assessment techniques for small releases ; and Type B protocols that would include detailed and extensive assessment methodologies for major releases. Type A procedures are specified by Natural Resources Damage Assessment Model for Coastal and Marine Environment (NRDAM/CME) of the U.S. CERCLA provides a legal 'legitimization for the use of economic-based nonmarket valuation in the courts and have introduced appropriate and accurate nonmarket valuation methods based on willingness to-pay for damage assessment. By briefly reviewing economic theory and environmental legislation, we hope to help provide a better understanding of the compensation process and the economics of publicly owned marine resources in the U.S. and to integrate the economics and law of natural resources valuation into a single comprehensive package in Korea.

• Journal of fish pathology
• /
• v.22 no.2
• /
• pp.137-146
• /
• 2009

The black rockfish Sebastes schlegelii neutrophil cytosolic factor components p47 phox (phagocyte oxidase) cDNA was cloned. The sequence of the cDNA showed that rockfish p47 phox cDNA consisted of 1,952 bp contained open reading frame encoding predicted polypeptide of 420 amino acids. Additionally analysis of the p47 phox amino acid sequence showed two potential SH3 domains. The functional domains are highly conserved in many animals, though the sequence of the components of the black rockfish showed low homology with that of mammals. The deduced amino acid sequence of the black rockfish p47 phox was similar to those of the carp (60.4%), zebrafish (59,2%), rainbow trout (68.5%), xenopus (55.2%), mouse (54.2%), rabbit (54.5%), rat (53.7%), and chicken (50.9%). The expression of the rockfish p47 phox molecule was induced in peripheral blood leukocytes (PBLs) from 1 to 12 h following LPS stimulation, with a peak at 6 h after the stimulation, and which increased at 1, 3, and 12 h after treated with Poly I:C compared with the control. The rockfish p47 phox gene was expressed in various tissues of healthy fish. The level of p47 phox expression was high in the PBLs, kidney and spleen.