• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.83-89
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• 2012

Flavobacterium johnsoniae was isolated from farmed rainbow trout Oncorhynchus mykiss in Korea, and its biochemical and molecular characterization was determined. Yellow-pigmented bacterial colonies were isolated from 18 of 64 fish samples (28.1%) on trypticase soy agar plates, and their biochemical profiles were characterized by API 20E and API 20NE test kits. F. johnsoniae was identified by biochemical phenotyping of factors including rapid gliding motility, Gram-negative condition, oxidase- and catalase-positive status, Congo red absorption, nitrate reduction, ${\beta}$-galactosidase production, acid production from glucose, and gelatin and casein hydrolysis. PCR and subsequent sequencing of 16S rRNA confirmed that the yellow-pigmented colonies were most similar to F. johnsoniae. The alignment analysis of 16S rRNA sequences also showed that all 18 rainbow trout isolates had highly similar homologies (97-99% identity). One isolate was selected and named FjRt09. This isolate showed 98% homology with previously reported F. johnsoniae isolates, and in phylogenetic analysis was more closely grouped with F. johnsoniae than with F. psychrophilum, F. columnare, or F. branchiophilum. This is the first report on the occurrence and biochemical characterization of F. johnsoniae isolated from rainbow trout in Korea.

• 한국양식학회지
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• 제10권1호
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• pp.49-54
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• 1997

무지개송어, 산천어, 무지개송어와 산천어간의 잡종 3배체를 대상으로 성비조사와 형태학적 계측형질을 측정하였다. 무지개송어, 산천어의 암.수 성비는 공히 유사한 비율로 나타난 반면, 잡종과 잡종 3배체에서는 수컷이 암컷에 비해 높게 나타났다(p<0.01). 잡종 3배체는 두고/두장, 등지느러미 기부장/체장 및 가슴지느러미 길이/체장의 계측형질에서는 친어로 사용된 무지개송어와 산천어의 중간을 나타낸 반면 상악장/두장의 계측형질에서는 무지개송어 쪽을 다소 닮게 나타났다. 이러한 결과들은 잡종 3배체에서 3배체화에 따른 사용된 친어들에 대비된 성비 그리고 계측형질에서의 특징을 나타내었다.

• Fisheries and Aquatic Sciences
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• 제26권7호
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• pp.447-454
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• 2023

Fast somatic growth is important considerations for successful and competitive aquaculture industry. In rainbow trout reared in South Korea, triploid induction was used to suppress negative influence of reproductive maturation to body growth. However, the effects of triploidy are visible in both mature fish and developing juvenile fish. Thus, it is also important to explicate the effect of triploid induction on growth during the early-life stages of rainbow trout-alevins and fry. Rainbow trout fertilized eggs were subjected to triploid induction and polyploidy was checked by flow cytometry. Diploid and triploid alevins and fry were reared separately in tanks with constant flow of freshwater through flow-through water system and growth measurements were done from zero days after hatching (DAH 0) until DAH 134. The egg-yolk morphometrics of alevins-yolk length, yolk height, yolk volume and yolk weight-were statistically similar (p > 0.05) in both genotypes from DAH 0 to DAH 22. The total length, body height, and body weight of alevins and fry were statistically better (p > 0.05) in both genotypes until DAH 92 but thereafter, triploid had a significantly better growth performance (p < 0.05) over diploid fish until the completion of study at DAH 134. With that, triploid induction did not influence alevin yolk regions and body growth and fry somatic growth until around 3 months after hatching, but considerable growth enhancement was subsequently apparent.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.174-178
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• 1996

The content of anserine, taurine, and L-histidine was measured by HPNC in the muscle of mature(670~690g) and juvenile(80~120g) rainbow trout fatmed in Chungsun, Korea. The concentration of anserine and taurine was higher in mature rainbow trout than in juvenile, but that of L-histidine was lower in mature than in juvenile. When measured with the chemiluminescence(CL) assay, anserine and taurine showed very powerful antioxidative activity above physiological concentration rainbow trout. Taurine still showed antioxidative activity below physiological concentration, while anserine showed prooxidative activity below that. L-Histidine was prooxidative dose-dependently. In TBA method, while taurine showed very week antioxidative effect, anserine appeared very powerful antioxidant and L-histidine prooxidant at physiological concentration. There was no synergism between anserine and taurine and anserine inhibited prooxidative effect of L-histidine.

• 한국식품영양학회지
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• 제6권2호
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• pp.73-80
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• 1993

In order to examine food components of coho salmon and rainbow-trout, We analyzed the composition of protein, amino acids and total lipids. The coho salmon muscle contained about 19.3% of protein with the composition of 29.9% in sarcoplasmic protein, 56.3oA in myofibrillar protein 12.5% alkali soluble protein and 2.6% in stroma. Those of rainbow-trout contained 34.1%, 56.4%, 8.3% and 2.9%, respectively. The sarcoplasmic and myofibrillar protein were composed of 13 subunits in coho salmon, and 16 and 15 subunits in rainbow-trout. Judging from the contents of essential amino acids, both muscle proteins were complete proteins. The most remarkable feature of free amino acids was that a large amount of dipeptide anserine was present with fairly lower levels of 1 methyl histidine, taurine, histidine, alanine and glycine in both muscle extracts. The total fatty acids of coho salmon was composed of 31.49% polyenes, 43.79% monoenes and 24.73% saturates. The composition of total fatty acid of coho salmon muscle was not different from that of rainbow-trout muscle.

• Journal of Microbiology
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• 제33권4호
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• pp.273-277
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• 1995

Although trout farming is well established in Korea, very little information is available on the composition of intestinal microflora in rainbow trout (Salmo gairdnerii). In 1994, from October through November, we investigated the composition and succession of intestinal bacteria. As fish grew, total viable counts increased dramatically until 45 days after fertilization when anaerobes started to appear on the media. After this time, they increased steadily. Ten aerobic generic were identified and Gram negative bacteria constituted 85% of total isolates. Among these, Pseudomonas, Eikenella, and Alcaligenes were the three major genera. Six anaerobic genera were isolated and identified. The ratio of anaerobes to aerobes was about 1 : 1 in adult trout and the composition of genera was changed under different conditions.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.293-295
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• 1998

• 생명과학회지
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• 제20권12호
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• pp.1902-1905
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• 2010

본 연구는 무지개송어 양식 산업의 생산성 향상을 위한 일환으로 염색체공학 기법을 이용하여 전 암컷 무지개 송어의 대량생산을 유도 하였다. 자성발생 2배체를 유도한 후 17 alpha-methyltestosteron으로 성전환을 성공적으로 유도하였다. 성전환된 수컷에서는 일반 암컷 모양을 띤 생식소가 형성 되었으나, 수정관의 발달은 보이지 않는 전형적인 성전환 개체의 특징을 나타내었다. 성전환된 자성발생 2배체 가짜수컷을 이용하여 정상 암컷과 단순교배로 발안율 55.7%, 부화율 52.9%의 전 암컷 집단 97,850 마리를 얻을 수 있었고, 4개월 사육 후 치어기(6~7 cm)때의 생식소 확인 결과 100% 암컷임이 확인되었다.

• 한국발생생물학회지:발생과생식
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• 제14권4호
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• pp.261-268
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• 2010

As in the O. mykiss electrophoretic profiles of RNA, the signals of each RNA sample from 9 individual tissues such as liver, muscle, brain, heart, pituitary gland, kidney, intestine, spleen and gill similar to positive control were obtained. The tissue distributions of the complimentary DNA (cDNA) of O. mykiss four genes were analyzed using quantitative real-time PCR with primer sets for tissue expression analysis. In this rainbow trout species, author obtained bands of various sizes, ranged from 700 bp to 1,400 bp. A dissociation curve was made at the end of each run to make sure that there was no non-specific amplification. Supplementarily, the Ct of each DNA was compared. The Ct values of vinculin with rainbow trout tissues were determined in a manner similar to those for agouti-related protein (AgRP) and melanocortin receptors (MC4R I and MC4R II). Further, obtained Cts for standard curve of each DNA were affected by specific product (vinculin, AgRP and MC4R II genes). After several experiments with four individual genes of rainbow trout, author estimated a variation ratio of the mean Ct value of the DNA extracted using the comparative CTt method was 37.27, and the standard deviation was 5.33. The correlation coefficient between the Ct values and the concentration of cDNA was -0.98, -0.99, -0.91 and -0.86, respectively (vinculin, AgRP, MC4R I and MC4R II genes). Since this correlation showed high linearity, the straight line obtained was used as a standard for the O. mykiss tissues reared in aquarium. A PCR efficiency of 100% is ideally achieved when the slopes are close to the theoretical value of -3.31. According to quantification method, the results of quantification are strongly affected by the DNA fragmentation. The size of most DNA fragments obtained from various tissues of rainbow trout used in the experiment was approximately 100 bp. According to the four slopes, an efficiency of nearly 100% was estimated for four genes detection methods. Additionally, further analysis with more individuals and primers will be required to fully establish optimization in rainbow trout.

• 한국양식학회지
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• 제20권3호
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• pp.154-159
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• 2007

Manchurian trout (Brachymystax lenok) is an endangered fish species in East Asia including the Korean peninsula. To establish a method for artificial propagation and to improve our understanding of the reproduction in the species, we have produced recombinant gonadotropins, follicle-stimulating hormone (r-mtFSH) and luteinizing hormone (r-mtLH), which may play central roles in reproductive activities. In the present study, the biological activities of the recombinant hormones were analyzed by gonadosomatic index (GSI), ovarian follicle diameter, and sex steroid levels in mature rainbow trout (Oncorhynchus mykiss). In the 6th day post-injection, FSH-injected fish were slightly decreased in the GSI value, although there were no significant differences among those of control, r-mtFSH, and r-mtLH treatments. Injection of the r-mtFSH increased follicle diameters significantly as compared with those of control- and r-mtLH-injected fish. The plasma steroid levels showed wide differences in the groups at 1, 3, or 6th day post-injection. Despite the variable steroid levels, three individuals receiving either r-mtFSH or r-mtLH showed a great increase in a maturation-inducing steroid, $17{\alpha},20{beta}$-dihydroxy-4-pregnen-3-one, at 3 and 6 days. Taken together, these results suggest that biological efficacies of the recombinant FSH and LH should be further studied in the Manchurian trout.