• 한국미생물·생명공학회지
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• 제32권4호
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• pp.297-306
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• 2004

열 충격단백질(Heat shock protein : HSP)은 온도 스트레스에 대하여 세포 내에서 발현되는 단백질이다. HSP의 중요 분류군의 하나가 HSP90 family 이다. 여러 종류의 포유동물과 조류에서 HSP 유전자 특성에 대한 연구가 많이 진행되었다. 본 연구에서는 넙치(Paralichthys olivaceus)로부터 제조한 넙치 뇌 cDNA 유전자 은행을 이용하여 넙치 HSP90 cDNA 유전자를 분리하여 구성 염기서열의 특성을 밝혀 내었다. 염기서열의 분석결과 넙치의 hsp90$\beta$ 유전자는 2,791 개의 뉴클레오타이드로 구성되어 있고, 726개의 아미노산 잔기가 암호화되어 있었다. 넙치 hsp90$\beta$ 유전자는 European sea bass와 96.6% zebrafish와 92.9%, Atlantic salmon와 92.0%, 그리고 사람과는 89.5%의 염기서열 상동성을 지니고 있었다. 또한 HSP90 아미노산 서열을 바탕으로 척추동물 종들과의 진화계통수를 구축하였다. 넙치 hsp90$\beta$ 유전자의 mRNA의 분포 정도를 RT-PCR를 이용하여 조사하였다. hsp90$\beta$ 유전자는 조사한 모든 조직(뇌, 간, 신장, 근육, 비장)에서 높은 수준으로 발현이 되고 있었다. 또한, 넙치 hsp90$\beta$ 단백질을 대량발현하기 위하여 대장균에서 발현을 유도하였다.

• Fisheries and Aquatic Sciences
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• 제19권4호
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• pp.18.1-18.10
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• 2016

In this study, to clarify the function of $PoPLC-{\beta}1$, in response to stress challenge, we examined the $PoPLC-{\beta}1$ expression pattern in response to external stress (pathogen-associated molecular pathogen challenge and environmental challenge including temperature and salinity). $PoPLC-{\beta}1$ expression analysis of tissue from olive flounder showed that the messenger RNA (mRNA) was predominantly expressed in the brain, heart, eye, liver, spleen, and stomach. We also tested the mRNA expression of the $PoPLC-{\beta}1$ in the spleen and kidney of olive flounder by RT-PCR and real-time PCR following stimulation with lipopolysaccharide (LPS), concanavalin A (ConA), or polyinosinic:polycytidylic acid (PolyI:C) and compared with the inflammatory cytokines IL-1b and IL-6 in the stimulated flounder tissues. Each of the spleen and kidney and mRNA transcripts of $PoPLC-{\beta}1$ were increased 30- and 10-fold than normal tissue at 1-6 h post injection (HPI) with PolyI:C when the expression of $PoPLC-{\beta}1$ transcript was similar to LPS and ConA. We also tested the expression of $PoPLC-{\beta}1$ in response to temperature and salinity stress. The expression of $PoPLC-{\beta}1$ also was affected by temperature and salinity stress. Our results provide clear evidence that the olive flounder $PLC-{\beta}1$ signal pathways may play a critical role in immune function at the cellular level and in inflammation reactions. In addition, $PLC-{\beta}1$ appears to act as an oxidative-stress suppressor to prevent cell damage in fish.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.167-171
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• 1999

This study was designed to develop biomarkers of coastal pollution using biochemical indices of flounder (Paralichthys olivaceus) by changes in lactate dehydrogenase (LDH) activity in the serum and cholinesterase activities in brain membranes. For this purpose acetylcholiesterase (AChE) activity, butyrylcholinesterase (BChE) activity, LDH/AChE ratio and LDH/BChE ratio of cultured flounders at 5 different sites on the southern coast of Korea were compared to those of wild flounders caught in the Pohang, eastern coast of Korea as a control group. Relatively high LDH activities were measured in the serum of flounders cultured on the southern coast of Korea (0.101-0.145 unit) than those in the Pohang control group (0.093 unit). AChE activities were significantly low $(about\;10-20\%)$ in brain membranes of cultured flounders compared to those in the Pohang control group. The ratios of LDH/AChE and LDH/BChE were consistently higher $(136-178\%,\; 155-214\%)$ in cultured flounders than those of Pohang control group. Thus, we propose that the ratios of LDH/AChE and LDH/BChE in flounders could be applicable for the diagnosis of marine pollution.

• 한국어병학회지
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• 제16권1호
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• pp.13-21
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• 2003

The infection characteristics with scuticociliates at on-land rearing farms and hatcheries of flounder, Paralithys olivaceus was investigated during the year of 2001 by juvenile infection routes. When culture tanks for living food organisms such as chlorella, rotifer, and Artemia were searched, scuticocilates were detected both in live and dead rotifer, and at the dregs of culture tank bottoms at almost hatcheries. When rotifer infected with scuticocilates fed on fish larvae, lots of scuticocilate were inhabited at the bottom of fry rearing tanks. After feeding on scuticocilates-infected rotifer on fish larvae, first infection was detected at 10 days after bottom dwelling or 40 days old after hatching. By histopathological examination we confirmed the infection route of eyeball or brain contamination was that the ciliate worms digged through mouth and front part of the dosal fin cuticle, transferred into eyeball along the epithelium and muscle tissue, and reached finally into brain by the muscle and nerve tissue. The infection of internal organs was clarified into two routes. The first route was started from the infection at ventral and anal fin rays by the worms, and reached at the anus and rectum through the epithelium and muscle tissue. The second route was initiated from the infection at urinary organ and reached into the rectum epithelium cells, inner wall of intestine, abdominal cavity, pancreas, kidney, and pancreas. At seed production farms where fish larvae fed on scuticocilate-free rotifer, the worms were not detected not only at the food organisms culture tanks and juvenile rearing tanks but also larval flounder less than 7cm in total length.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.263-271
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• 2010

G protein-coupled receptors (GPCR) constitute the largest superfamily of cell membrane receptors, mediating diverse signal-transduction pathways. The melanocortin 4 receptor (MC4R) has been of interest for its physiological role and size, one of the smallest among the GPCRs, which makes it a good model system for the structural study of GPCRs. To study the molecular structure and tissue-specific expression of MC4R in olive flounder (Paralichthys olivaceus), the full-length MC4R gene was obtained using PCR amplification of genomic DNA as well as cDNA synthesis. Sequence analysis of the gene indicates that 978 bp of the MC4R gene encodes 325 amino acids without introns. Sequence alignment with the MC4Rs from other fish shows the highest degree of identity (96%) between Paralichthys olivaceous and Verasper moseri, followed by Takifugu rubripes and Tetraodon nigroviridis (89%). RNA was isolated from various tissues to examine the tissue distribution of MC4R by using RT-PCR. The results showed major expression of MC4R in the liver, brain, and eye, which is consistent with the expression pattern in other fish belonging to the order Pleuronectiformes.

• 한국수산과학회지
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• 제30권4호
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• pp.608-613
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• 1997

해양오염의 진단을 위한 생화학적 오염지표 설정의 기초연구의 일환으로서, 오염이 심각한 서해 (또는 황해)산 넙치(Paralichthys olivaceus)에 이어 서해산 도다리 (Pleuronichthys cornutus)의 혈액 및 뇌중의 활성산소종 및 그들의 제거효소의 활성을 동해안의 포항의 자연산 도다리를 대조군으로 하여 분석 평가하였다. 이들 넙치의 혈청중의 단백질의 함량은 해역이나 서식환경에 따라 뚜렷한 차이를 발견할 수 없었지만, 서해안 자연산 도다리의 뇌 및 근육중의 단백질의 함량은 동해안의 포항산 도다리 대비 뇌는 $15\~45\%$, 근육은 $35\~45\%$나 현저히 감소되고 있었다. 서해안의 자연산 도다리의 혈청중의 과산화지질 (MDA)의 함량은 포항의 자연산 도다리의 대조군 대비 $30\~70\%$나 현저히 높았다. 서해안의 자연산 도다리의 혈청중의 히드록시 라디칼의 생성이 동해안 포항의 자연산 도다리의 혈청중의 히드록시 라디칼의 생성 대비 $15\~90\%$ 정도나 유의적으로 높았다. 서해안의 자연산 도다리의 혈청중의 SOD의 활성은 동해안 포항의 자연산 도다리의 혈청중의 SOD의 활성 대비 $20\~40\%$나 SOD의 활성이 유의적으로 낮았을뿐만 아니라 서해안의 자연산 도다리의 뇌중의 GSHPx의 활성도 동해안 포항의 자연산 도다리의 뇌중의 GSHPx의 활성 $10\~60\%$정도나 유의적으로 낮았다. 이러한 사실도 도다리의 SOD의 활성과 마찬가지로 해양오염에 의해 활성산소의 제거효소로서 생체의 방어효소가 그 만큼 활성이 저하되고 있다는 사실을 입증하고 있다. 이상의 실험결과에서 볼 때 뇌나 근육중의 단백질 함량의 감소, 혈청중의 SOD 및 뇌중의 GSHPx 활성의 저하, 그리고 혈청중의 과산화지질의 함량이 서해안의 도다리가 동해안의 대조군 대비 유의적인 변화를 나타낸다는 사실은 생화학적 오염지표로서의 가능성을 검토할 가치가 있다고 판단된다.

• 한국양식학회지
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• 제12권3호
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• pp.175-183
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• 1999

We have shown previously that the sequence of olive flounder (Paralichthys olivaceus) hsp70-related cDAN has a high similarity with those of cognate hsc70 of other species (Kim et al., 1999; J. Aquaculture, 12:91-100). In order to investigate whether this gene encodes the congate hsc70, we examined the expression of this gene in normal and heat-shocked conditions. By in vitro translation, this gene encoded a 70 kD protein which was constitutively experessed and was not induced by heat shock. This translated protein was recognized by anti-hsp/hsc70 antibody. Tests of heat-inducibility showed that this gene was constitutively expressed in normal conditions and its expression was not increased after heat shock. The expression levels of this gene were high in stomach, gill, intestine, kidney and brain, moderate in liver, and comparatively low in overy and heart. Furthermore, Northern blot analysis of transcript expression showed that the corresponding mRNA were detected throughout embryonic development in the absence of any heat shock. These results provided evidence that olive flounder hsp70-related cDNA encoded to cognate member of hsp70 family, hsc70.

• 한국해양생명과학회지
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• 제7권1호
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• pp.1-9
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• 2022

This investigation aimed to assess the appetite response changes of olive flounder to starving and re-feeding conditions. Three different feeding groups (2 weeks feeding, fed; 2 weeks starving, starved; and 1 week starving and 1 week feeding, re-fed) were established to examine the changes in appetite-related genes for each group. The weight gain of the fish was highest for the fed group and lowest for the starving group. Based on the daily feed intake (DFI) and cumulative feed intake (CFI), overall food intake was found to increase in the re-fed group more than in the fed group from week 1 to week 2 of the experiment. Hypocretin neuropeptide precursor (HCRT) and galanin receptor 1 (GAL-R1) mRNA expression in the brain of olive flounder were decreased in the starved group. Corticotropin-releasing hormone (CRH) was decreased in all experimental groups, except for the fed group. However, overall leptin concentrations in the plasma did not change across groups. Considering the differences between this study and previous studies on starving and feeding, various factors (except the production and expression mechanisms of appetite-related factors in response to starving) are likely acting on the appetite responses of the fish. In this study, a 1-week re-feeding period induced substantial effects on appetite response when compared to a 2-week feeding period. These findings show that even if re-feeding is performed after starving, the unbalance caused by the re-feeding can affect various physiological changes in fish by feed intake efficiency.

• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.325-337
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• 2014

To assess the functional structure of prepro-melanin-concentrating hormone (pMCH), we isolated and cloned pMCH (of-pMCH) mRNA from the brain of the olive flounder, Paralichthys olivaceus, and compared its amino acid sequence with those from other animals. In addition, to examine whether activation of the brain of-pMCH gene is influenced by background color, density, and feeding, we compared pMCH mRNA activities against different background colors (bright and dark) and at different densities (100% PCA and 200% PCA). To examine whether the pMCH gene is related with malpigmentation of blind-side skin and appetite, we compared pMCH gene expression between ordinary and hypermelanic flounders, and between feeding and fasting flounders. The of-pMCH cDNA was 405 bp in the open reading frame [ORF] and encoded a protein of 135 amino acids; MCH was 51 bp in length and encoded a protein of 17 amino acids. An obvious single band of the expected size was obtained from the brain and pituitary by RT-PCR. In addition, of-pMCH gene activity was significantly higher in the bright background only at low density (< 100% PCA) making the ocular skin of fish whitening, and in ordinary fish. However, the gene activity was significantly decreased in dark background, at high density (>200% PCA), and in hypermelano fish. These results suggest that skin whitening camouflage of the flounder is induced by high MCH gene activity, and the density disturbs the function of background color in the physiological color change. Moreover, our data suggest that a low level of MCH gene activity may be related to malpigmentation of the blind-side skin. In feeding, although pMCH gene activity was significantly increased by feeding in the white background, the pMCH gene activity in the dark background was not influenced by feeding, indicating that the MCH gene activity increased by feeding can be offset by dark background color, or is unaffected by appetite. In conclusion, this study showed that MCH gene expression is related to ocular-skin whitening camouflage and blind-skin hypermelanosis, and is influenced by background color and density.

• 한국발생생물학회지:발생과생식
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• 제25권4호
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• pp.235-244
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• 2021

Interferon Regulatory Factor 3 (IRF3) is a member of interferon-regulated transcription factor family and is known to play an important role in the innate immune response against viral infections. In this study, the expression of IRF3 in different tissues, developmental stages, and stocking densities of olive flounder was investigated. The expression of IRF3 was observed to gradually increase in early-stage juvenile fish. The highest expression was observed in later-stage juvenile fish when immune tissues were formed. High IRF3 expression was observed in the muscles and the brain tissues. The expression of IRF3 was observed in fish at different stocking densities after viral hemorrhagic septicemia virus (VHSV) infection. It yielded an interesting expression pattern in the muscles and the brain tissues of fish stocked at low density. These observations can be used as basic data for the study of the expression of immune response-related genes against viruses based on stocking density and immune systems in other fish species.