• Fisheries and Aquatic Sciences
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• v.4 no.1
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• pp.39-46
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• 2001

To examine the effect of copy number-dependent transgenic genotype on the expression of foreign gene, stable hemizygous and homozygous transgenic breeding line was established using artificial parthenogenesis. For this purpose, induced diploid gynogenetic transgenesis was optimized in mud loach (Misgurnus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to $4,050\;ergs/mm^2$ The UV-irradiated sperm were inseminated into eggs from recessive color strain (yellow) or heterozygous transgenic mud loach containing CAT gene. Cold shock at $2^{\circ}C$ for 60 min, 5 min post fertilization successfully restored the diploidy of eggs inseminated with UV-irradiated sperm. Restoration to diploidy was confirmed by flow cytometry and gynogenetic status was verified by examining maternal exclusive inheritance of multi-locus DNA fingerprints, body color and transgenic marker. Putative isogenic transgenic fish clearly showed homozygous status at trans gene locus based on Southern blot hybridization and progeny testing. Further, such homozygous gynogenetic diploids revealed the increased levels of transgene expression, when compared to those of heterozygous (hemizygous) transgenic fish.

• Journal of fish pathology
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• v.37 no.1
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• pp.17-23
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• 2024

Spring viremia of carp virus (SVCV) poses a significant threat to numerous cyprinid fish species, particularly the common carp (Cyprinus carpio), often resulting in substantial mortalities. This study explores the potential use of a chimeric recombinant snakehead rhabdovirus carrying the SVCV G gene (rSHRV-Gsvcv) as a live vaccine against SVCV infection. Through virulence testing in zebrafish at different temperatures (15 ℃ and 20 ℃), no mortality was observed in groups infected with either rSHRV-wild or chimeric rSHRV-Gsvcv at both temperatures, whereas 100% mortality occurred in fish infected with wild-type SVCV. Subsequently, as no mortality was observed by rSHRV-Gsvcv, three independent experiments were conducted to determine the possible usage of chimeric rSHRV-Gsvcv as a vaccine candidate against SVCV infection. Fish were immunized with either rSHRV-Gsvcv or rSHRV-wild, and their survival rates against the SVCV challenge were compared with a control group injected with buffer alone at four weeks post-immunization. The results showed that chimeric rSHRV-Gsvcv induced significantly higher fish survival rates compared to rSHRV-wild and the control groups. These findings suggest that genetically engineered chimeric rSHRV-Gsvcv holds the potential for a prophylactic measure to protect fish against SVCV infection.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.306-315
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• 2019

The estuary of the Han River constantly suffers from pollutants and pathogenic microorganisms which could cause serious damage to aquatic organisms living there. Despite of this potential risk, it is hard to find any reliable scientific reports on the status of reportable disease infection to the organisms living in this area. In this study, cyprinid fish and crustaceans in Jeonryu-ri, a region of the Han River estuary, were investigated for the infection by representative reportable communicable diseases(SVC, spring viraemia of carp; KHVD, koi herpesvirus disease; EUS, epizootic ulcerative syndrome; WSD, white spot disease) and parasites. Peripheral fish and primary freshwater fish were observed in Jeonryu-ri with cyprinid caught most frequently. Crustaceans were mostly marine species. No positive bands to any of the reportable diseases were produced in any of the fish and crustacean examined in this study by PCR. No trace of Clonorchis sinensis, a liver fluke potential threat to human health, was detected in any of fish samples. However, many fish were infected by metacecaria of other flukes, and other various parasites such as nematode, cestode, copepod, monosite and acanthocephalan. These results suggest that important aquatic organisms in the Han River estuary is not seriously polluted yet. However, it is important to keep monitoring the diseases since the water quality in this region is constantly changing, and devastating influence of infectious diseases is unpredictable. Further, it is required to expand monitoring area toward upstream and increase the number of fish for examination.

• Development and Reproduction
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• v.24 no.4
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• pp.277-285
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• 2020

The disease-causing koi herpes virus (KHV), also known as cyprinid herpesvirus-3 (CyHV3), causes mass mortality of koi and carp. Koi (Cyprinus carpio) is a host for KHV, one of 12 virus species in the Alloherpesviridae family. We examined the effects of KHV disease koi (KK), and on koi×red common carp (KR) and red common carp×koi (RK) cross, using a virus challenge test. The infected fish had clinical signs that included gill necrosis and skin lesions. The RK and KR were highly more resistant (cumulative mortality: RK; 6% and KR; 8%) to KHV infection than KK fish (cumulative mortality: 28%). KHV DNA was confirmed in the tissues of all dead fish in groups by use of polymerase chain reaction (PCR), and the presence of the KHV protein in kidney was confirmed by immunohistochemistry. Histological analysis showed severe gill lesions and fusion of the lamellae in KK fish, but less severe damage in RK fish. In immunohistochemistry analysis, the KHV protein localized in the cytoplasm of infected kidney cells of KK, but the cross groups had lower levels of KHV antigen. Our data indicate that the cross groups had increased resistance to KHV disease.

• Development and Reproduction
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• v.21 no.4
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• pp.361-370
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• 2017

Koi herpesvirus (KHV), also known as Cyprinid herpes virus 3 (Cyprinid 3) is lethal disease in common carp and koi (Cyprinus carpio). Two different groups (KK and RK) were infected KHV by intraperitoneal injection. Fish for gene expression analysis were sampled at 0 h, 12 h, 24 h, 48 h and 72 h post infection (p.i). The results showed that two immune related gene, Interferons (INFs) ${\alpha}{\beta}$ and Interleukin (IL)-12 p35 induced a high response in RK. The IL-12 p35 cytokine and Toll-like receptor (TLR) 9 were significantly high expressed on 48 h post infection (p.i) in RK as compared to the KK. The histopatological examination reveals focal necrosis in liver and infiltrate of lymphocytes in spleen of KK as compared to the RK. In immunohistochemistry analysis, the KHV protein high expressed in the infected kidney cell and slenocyte of KK. Therefore, the expression of IL-12 p35, IFN ${\alpha}{\beta}$ and TLR 9 may provide a potentially genes related with KHV resistance in Koi and red common carp ${\times}$ koi.

• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.47-52
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• 1990

Anew species of cyprinid fish Acheilognathus koreensis is described from specimens collected in several rivers of southern part of Korea. In general aspect it is similar to A. liηzbata but differs form this by having large snout length, narrow interorbital width and characters of early developmental stage. The new species is distinguished from A. signifer by color parttern of dorsal and anal fin ray in male, and egg form and ovipositor length in female.

• Animal Systematics, Evolution and Diversity
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• v.7 no.2
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• pp.189-194
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• 1991

A new speices of cyprinid fish, Acheilognathus somjinensis is described based on the specimens collected in the Somjin River, Sinpyong-myon, Imsil -gun , Chollabuk-do province of Korea. In general morphology it is similar to A. koreensis. however, the new speices differs from the latter in having longer ovipositor of female in spawing season and showing pear-shaped eggs. In hybridization experiments, it was found that A.somjinensis is repoductively isolated from A.koreensis.

• Journal of Marine Life Science
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• v.7 no.1
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• pp.10-14
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• 2022

Monitoring infectious diseases for fishery species takes a key role in preventing disease emergence and spreading of cultured fishery species. This research has examined a total of 1,115 fishes of four species (leather carp, fancy carp, stone moroko, carassius auratus) at 23 farm in Jeollanamdo and Jeollabukdo in 2021 for pathogen infection. As a result of disease screening for three legally designated diseases (SVC, Spring viraemia of carp, EUS, Epizootic ulcerative syndrome, and KHVD, Koi herpesvirus disease), no infectious diseases were detected in all examined samples; cyprinid fish studied in Jeolla province would provide important information for declaring a disease-free nation or disease-free region.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.289-296
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• 2005

The fish fauna and community structure at 20 stations in streams of the Mt. Biseul were investigated from June 2003 to May 2004. During the study period, 29 species, 25 genera belonging to 9 families were collected. Cyprinid fish occupied 48.3% (14 species) and cobitid fish had 13.8% (4 species). Six species (22.2%) were korean endemic and two species of Micropterus salmoides and Lepomis macrochirus were exotic. It was found that the population density of carnivorous fish (Opsariichthys uncirostris amurensis) increased in the lower-reach of small streams in the Mt. Biseul area since it had been introduced from the other native rivers in the middle 1990s. As the result of analyzing fish community in the surveyed area, the species diversity ranged from 0.553 to 1.023. The findings showed that the Geumpo, Chacheon and Hyeonpung streams had higher species diversity indicies of 0.936 ${\sim}$ 1.023 than the Sincheon and Gisegok streams with 0.553 ${\sim}$ 0.727.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.152-157
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• 2002

The fauna of freshwater fish and the structure of fish community were investigated from March to October in 2001 at six stations in the middle reach of the Seomjin River, Gokseong-gun. The collected fishes (1,786 individuals) were identified into 30 species of 22 genera belonging to S families. Of them, cyprinid fish occupied 26 species, only one species (Rhinogobius brunneus) was secondary freshwater fish. Dominant species was Zacco platypus (dominance index: 24.2%) and subdominant species was Pungtungia herzi (10.7%). The endemic species of Korea were 11 species including Rhodeus uyekii (36.7%) about the ichthyofauna. In estimation of water quality by diversity indices, the general conditions of water quality of all survey times and all stations were relatively fine $(\beta$-mesosaprobic, diversity index: 2.70). But four survey sites except St. 2 and St. 3 showed severe water pollution with one or move times in total survey periods.