• 수산해양기술연구
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• 제59권4호
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• pp.387-398
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• 2023

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

• Animal cells and systems
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• 제6권4호
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• pp.323-326
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• 2002

One hundred and three random complementary DNA clones representing rainbow trout intestine were par1i811y sequenced as an approach to analyze the transcribed sequences of its genome. Of the sequences generated, 60.0% of the ESTs were represented by 40 known genes. Thirty-five clones of unknown gene products potentially represented 34 novel genes. The most Bbundantly represented messages were the 28S ribosomal protein (6.5%) and beta actin (5.8%). The genes involved in ribosome formation (18%) accounted for the major gene expression. Development of EST panels representing the genes expressed in a particular tissue will be useful in determining the role of these genes in normal function and in response to developmental, hormonal, environmental and physiological changes.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.559-560
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• 2001

The objective of the present study was to analyze genetic variation and characteristics in rainbow trout(Oncorhynchus mykiss) using amplified fragment length polymorphism(AFLP) method as molecular genetic technique, to evaluate the usefulness of AFLP as genetic markers, and to compared the efficiency of agarose and polyacrylamide sequencing gels. The amplified products were performed by agarose and sequencing gel electrophoresis to detect AFLP band patterns, respectively. Using 9 primer combinations, total of 141 AFLP bands were produced, 108 bands(82.4％) of which were polymorphic in agarose gels. In sequencing gels, total of 288 bands were generated, and 220 bands (76.4％) were polymorphic. The level of bandsharing(BS) ranged from 0.18 to 0.32 for the 9 primer combinations tested, with a mean of 0.24. Consequently, AFLP markers of these rainbow trout could be used as genetic information such as species identification, genetic relationship or analysis of genome structure, and selection aids for genetic improvement of economically importment traits in fish species.

• 한국어병학회지
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• 제36권2호
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• pp.415-422
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• 2023

In veterinary medicine for mammals, studies are being conducted to confirm the effects of antioxidants using pathological toxicity model studies, and are also used to confirm the effect of mitigating liver or kidney toxicity of specific substances. It was considered necessary to study such a toxicity model for domestic farmed fish, so thioacetamide (TAA), a toxic substance that causes tissue damage by mitochondrial dysfunction, was injected into rainbow trout (Oncorhynchus mykiss), a major farmed freshwater fish species in Korea. The experiment was conducted with 40 rainbow trout (Oncorhynchus mykiss) weighting 53 ± 0.6 g divided into two groups. Thioacetamide(TAA) 300mg/kg of body weight was intraperitoneally injected into rainbow trout and samples were taken 1, 3, 5, 7 days after peritoneal injection. As a result, in serum biochemical analysis, AST levels related to liver function decreased 3 and 5 days after intraperitoneal injection and increased after 7 days, and ALT levels also increased after 7 days. In addition, creatinine related to renal malfunction increased 3 and 5 days after TAA injection. In histopathological analysis, pericholangitis and local lymphocyte infiltration were observed in the liver from 1 day after intraperitoneal injection of TAA, and hepatic parenchymal cell necrosis was also observed from 3 days after intraperitoneal injection. Hyaline droplet in renal tubular epithelial cell was observed from 1 day after TAA injection, and acute tubular damage such as tubular epithelial cell necrosis appeared from 3 days after TAA injection. Accordingly, it is thought that it will be able to contribute to studies that require a toxicity model.

• 한국수산과학회지
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• 제56권1호
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• pp.79-88
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• 2023

A 12-week feeding trial was conducted to evaluate the effect of different stocking densities on the growth, body composition, stress, antioxidant status, and immune responses of juvenile rainbow trout Oncorhynchus mykiss. Juvenile rainbow trout (32.2±0.5 g) were randomly placed in eight experimental tanks, each containing 2,000 L of water, at stocking densities of 150, 300, 600, and 1,200 individual/m³. The trout were assigned to four treatments (2.4, 4.8, 9.7, and 19.4 kg/m³) in duplicates. Following after the feeding trial, the fish cultured in the less dense group showed significantly higher growth and survival (P<0.05). In terms of proximate composition, the whole body crude protein and lipid contents were lower in the denser group (19.4 kg/m³). Regarding the antioxidant and immune responses, the fish reared in the relatively denser group exhibited lower lysozyme, immunoglobulin M, and superoxide dismutase levels. The stress indicators, glucose and cortisol, were significantly lower in the less dense group (2.4 kg/m³), while the denser group (19.4 km/m³) exhibited higher AST and ALP levels(P<0.05). The results showed that denser stocking has a crowding stress effect and negatively impacts growth and immune responses.

• 한국어병학회지
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• 제16권2호
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• pp.81-90
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• 2003

High mortality with signs similar to viral haemorrhagic septicemia (VHS) such as severe haemorrhages in the skin, muscle and air bladder occurred in the farmed adult rainbow trout, Oncorhynchus mykiss, in Ku-mi and Je-chun area in Korea. The isolates were neutralized by an antiserum against IHNV but not by antisera against VHSV. Electron micrograph of an ultrathin section showed large numbers of bullet-shaped virus particles. The newly isolated rhabdovirus was composed of five structural proteins. In the western blot analysis Ihe anti-DiNV serum strongly reacted with G. N and MI protein. The cumulative mortalities of RTK infected rainbow trout (10-12cm.9-12g) with $10^{3.5}\;and\;10^{1.5}TCID_{50}/m{\ell}$ were 80% and 30%. respectiveIy_ RTJ infected fish showed 50% mortality by infection with $10^{3.5}TCID_{50}/m{\ell}$. Control group and IHNVChAb exhibited no mortality. From these results, the viruses were identified lHNV although diseased fish showed similar sign. with VHS and caused high mortality in large-sized fish.

• 한국동물학회지
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• 제36권1호
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• pp.77-83
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• 1993

난모세포성숙기 (peripheral germinal vesicle stage)의 무지개송어(Oncorhynchus mykiss)를 대상으로 방사성 표지 전구체(3H-pregnenolone, 3H-l7$\alpha$-hydroxyprogesterone 그리고 3H-androstenedione)를 이용하여 유 nitro에서 관찰한 협막세포층의 스테로이드 주 대사 경로는 다음과 같으며, pregnenolone -) 17a-hydroxypregnenolone$\longrightarrow$ 17u-hydroxyprogesterone $\longrightarrow$ androstenedione $\longrightarrow$ testosterone 이는 $\Delta$5-스테로이드 경로의 존재가능성을 지적하고 있다.

• Fisheries and Aquatic Sciences
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• 제6권3호
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• pp.130-134
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• 2003

Proinflammatory effects of bacterial lipopolysaccharide (LPS) have been assessed by analysing the induction of two inflammatory genes, $interleukin-1\beta$ $(IL-1\beta)$ and cyclooxygenase-2 (COX-2), in rainbow trout (Oncorhynchus mykiss) macrophage cells. Production of a metabolite of arachidonic acid by COX-2, prostaglandin $E_2\;(PGE_2)$, was also analysed in macrophage cells after LPS stimulation. Northern blot analysis revealed that LPS $(5{\mu}g/mL)$ significantly upregulated $IL-1\beta$ (54 times) and COX-2 (40.7 times) gene expression in macrophage cells after 4 h stimulation. According to RT-PCR (Reverse Transcription Polymerase Chain Reaction) analysis, $IL-1\beta$ gene induction in LPS stimulated macrophage cells was started within 1h and significantly increased thereafter until 4h. Meanwhile, COX-2 gene induction by LPS was delayed in comparison with $IL-1\beta$ gene induction as a faint band was observed after 4h stimulation in head kidney macrophage cells. LPS also significantly increased $PGE_2$ production in head kidney leucocytes, presumably via activating COX-2 expression that metabolites arachidonic acid to $PGE_2$. In conclusion, it was demonstrated that LPS could induce two main inflammatory and immune related genes, $IL-1\beta$ and COX-2, and increase $PGE_2$ production in trout head kidney macrophage cells, representing a strong inflammatory activity.

• 한국양식학회지
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• 제9권2호
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• pp.133-140
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• 1996

경제성이 높은 어종인 무지개송어와 은연어를 대상으로 두 종간의 장점을 갖춘 신품종을 개발하기 위하여 종간 잡종 및 잡종 3배체를 유도하였다. 그 결과, 잡종의 부화율은 $51.7\%$로 여타 대조군에 비해 낮았으나 잡종 3배체의 부화율은 $77.6\%$로 무지개송어 3배체와 유사한 부화율을 보였다. 또한 부화 2개월후의 생존율은 잡종인 경우 $1.7\%$로 매우 낮았으나 잡종 3배체는 $54.5\%$로 무지개송어 3배체의 $56.6\%$ 생존율과 유사하였다. 잡종의 세포 및 핵의 평균 크기는 양친으로 사용된 두 종의 중간을 보였으며 잡종 3배체의 세포 및 핵의 크기는 잡종에 비해 크게 나타났다. 잡종의 염색체수는 60개로 나타나 n=30의 염색체수를 가진 무지개송어 난자와 n= 30의 염색체수를 가진 은연어 정자와 교배된 개체만이 생존력을 갖는 것으로 나타났다. 잡종 3배체의 경우 그의 염색 체수는 $90\~93$개로 Robertsonian형의 전좌에 의한 염색체 다형현상을 보여주었다.

• 한국수산과학회지
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• 제44권3호
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• pp.225-231
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• 2011

Prolactin (PRL) plays an important role in freshwater (FW) osmoregulation by preventing the loss of ions and the uptake of water in fish. Growth hormone (GH) promotes acclimation to seawater (SW) in several teleosts. We acclimated rainbow trout Oncorhynchus mykiss weighting $68.2{\pm}16.6$, $138.3{\pm}24$, and $287.5{\pm}42.1$ g in separate experiments to SW under slow-acclimation (SSW) or acute-acclimation (ASW) conditions, and then examined the PRL and GH mRNA levels using the real-time quantitative polymerase chain reaction. The PRL mRNA levels in all three experimental groups decreased significantly with both the SSW and ASW treatments, as compared to a control group kept in FW for 30 days. The GH mRNA levels increased with ASW in the largest fish, whereas the levels in the other groups did not change significantly. The mortality rate of the largest fish was lower than for the other groups, whereas the growth rate among the three experimental groups did not differ significantly. The growth rate of the ASW group was highest for the smallest fish. These results suggest that SW acclimation is associated with the gene expression levels of PRL and GH in relatively large rainbow trout. In addition, the fish mortality and growth rate on FW-SW transfer seem to be related to body weight, and the SW acclimation method may be applied to the hatcheries industry.