• 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.

• Fisheries and Aquatic Sciences
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• v.20 no.12
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• pp.31.1-31.11
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• 2017

Background: Liver-expressed antimicrobial peptide-2 (LEAP-2) is an important component of innate immune system in teleosts. In order to understand isoform-specific involvement and regulation of LEAP-2 genes in mud loach (Misgurnus mizolepis, Cypriniformes), a commercially important food fish, this study was aimed to characterize gene structure and expression characteristics of two paralog LEAP-2 isoforms. Results: Mud loach LEAP-2 isoforms (LEAP-2A and LEAP-2B) showed conserved features in the core structure of mature peptides characterized by four Cys residues to form two disulfide bonds. The two paralog isoforms represented a tripartite genomic organization, known as a common structure of vertebrate LEAP-2 genes. Bioinformatic analysis predicted various transcription factor binding motifs in the 5'-flanking regions of mud loach LEAP-2 genes with regard to development and immune response. Mud loach LEAP-2A and LEAP-2B isoforms exhibited different tissue expression patterns and were developmentally regulated. Both isoforms are rapidly modulated toward upregulation during bacterial challenge in an isoform and/or tissue-dependent fashion. Conclusion: Both LEAP-2 isoforms play protective roles not only in embryonic and larval development but also in early immune response to bacterial invasion in mud loach. The regulation pattern of the two isoform genes under basal and stimulated conditions would be isoform-specific, suggestive of a certain degree of functional divergence between isoforms in innate immune system in this species.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.5-5
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• 2006

• Journal of fish pathology
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• v.24 no.3
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• pp.269-278
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• 2011

Gene expression of two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) paralogs was examined during Edwardsiella tarda challenge and heavy metal exposures in mud loach (Misgurnus mizolepis; Cypriniformes) kidney and spleen. Transcription of the two mud loach GAPDH paralogs (mlGAPDH-1 and mlGAPDH-2) was significantly modulated by these stimulatory challenges in an isoform-dependent manner. Based on the real-time RT-PCR analysis, the mlGAPDH-2 transcripts were more preferentially induced by E. tarda challenge, whereas the mlGAPDH-1 transcripts were proven to show more inducibility in response to heavy metal exposure using Cd, Cu, Mn and Zn at $5{\mu}M$. Their isoform-specific response patterns were closely in accordance with the TF binding profiles in promoter and intron-1 of the two mlGAPDH isoforms, in which the mlGAPDH-2 has more binding sites for immune-related transcription factors than mlGAPDH-1 while the mlGAPDH-1 possesses exclusively metal responsive elements in its intron. Collectively, the mlGAPDHs are potentially involved in cellular pathways independent of glycolysis and the two GAPDH paralogs might undergo functional diversification or subfunctionalization at least at the transcription level.

• Journal of Environmental Impact Assessment
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• v.20 no.5
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• pp.757-764
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• 2011

This study is performed to clarify the fish fauna and fish habitat of downstream of Singok submerged weir within Han River estuary during April ~ December 2009. It was studied at the nine sites of Han River estuary area. The three of them were located in the mainstream of Han River and six of them were located in three wetlands which as Sannam, Janghang and Dolbangguji. Total fish fauna was identified as 9 order 15 family and 38 species (2,230 individuals). It was divided as 8 order 11 family 28 species from three sites in the mainstream of Han River and as 5 order 8 family 19 species in waterways at mud flats of three wetlands. It was made up the fish fauna as 3 order 4 family 12 species during the survey period at the waterways in the rice paddies. Hemibarbus labeo was dominant species in the whole research sites and waterways at mud flats. Carassius auratus was dominant species in the waterways between rice paddies and Chelon haematocheilus was dominant species in mainstream of Han River estuary.

• Fisheries and Aquatic Sciences
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• v.20 no.9
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• pp.23.1-23.9
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• 2017

Two distinct cDNAs encoding aquaporins (mmAQPs 1a and 3a) were isolated and characterized from mud loach Misgurnus mizolepis. The identified mud loach AQP cDNAs encode for polypeptides of 260 and 302 amino acids. Topology predictions confirmed six putative membrane-spanning domains connected by five loops and the N- and C-terminal domains being cytoplasmic. The mud loach AQPs 1a and 3a showed broad distribution in multiple tissues including immune-responsive tissues as well as osmoregulatory tissues. Hence, the diversity of AQP distribution and expression possibly indicated its differential functions in the regulation of fluid movement in response to environmental stimuli. The transcription of mmAQP genes was differentially modulated by immune challenges. In particular, the mmAQP3a expression level in the liver was more responsive to immune challenges than that of mmAQP1a. Taken together, fish stimulation or infection resulted in significant modulation of mud loach AQP genes, suggesting potential functional roles of these proteins in piscine pathophysiological process.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.31-36
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• 1977

The monthly distribution of marine bacteria in the coastal waters of Chung-Mu was investigated from April, 1976 to March, 1977. The aim of this study was to obtain basic data for the prevention of food poisoning and for the efficient aquaculture of the area. Samples of sea water, mud, fish and shell fish were taken every month. The results are as follows: 1. One thousand four hundred and twenty-six strains were isolated from 732 samples of sea water, mud, fish and shell fish. They were 450 strains of Pseudomonas fluorescens, 422 strains of Achromobacter liquefacience, 72 strains of Vibrio parahaemolyticus, 234 strain of Vibrio alginolyticus, and 248 strains of Proteus vulgaris. 2. V. parahaemolyticus occupied $9.84\%$ of the total samples and $52\%$ of them were found in the sea water and mud. 3. The muds sampled districtly beneath the aquaculture raft contained much gas. They seemed to originate from the deposition of excretion of shell fish. The fatness of the shell fish was low where the gas was abundant. 4. It was .found that the shell fish with low fatness contained much Vibrio sp. 5. Regional distribution shows that marine bacteria were abundant in the order of station 10, 9, 8, 11, 1. The area around station 9 was polluted by reclamation of the area, and station 8 showed the influence of the excrement treat tank located nearly.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.116-122
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• 2017

Basic dyes such as malachite green and methylene blue have been used as disinfectants to control water fungal infections since the 1930s. However, after succeeding reports of carcinogenicity and bioaccumulation of the dye, their use was forbidden in lieu of public health. This study undertook to evaluate the therapeutic effect of sulfur solution processed by effective microorganisms (EM-PSS) against Saprolegnia parasitica infection, and its safety in fish. In vitro antifungal evaluation of EM-PSS inhibited the growth of S. parasitica mycelia at concentrations of 50 ppm or higher. The acute toxicity test of EM-PSS to the mud fish (Misgurnus mizolepis) measured a no effect concentration (NOEC) at 100 ppm, the lowest effect concentration (LOEC) at 125 ppm, and the half-lethal concentration ($LC_{50}$) at 125 ppm in juvenile and 250 ppm in the immature stage. In addition, the ecotoxicity test of EM-PSS using Daphnia magna inhibited swimming of D. magna at concentrations of 100 ppm or less. Lastly, the EM-PSS prevented infection of S. parasitica to mud fish, at concentrations of 50 ppm. Furthermore, at 100 ppm concentration, the EM-PSS showed no acute toxicity on mud fish, nor any eco-toxic effects on D. magnano. Therefore, we conclude that carcinogenic disinfectants such as malachite green and methylene blue could be replaced by EM-PSS to remove S. parasitica in mud fish farming, and might be a potential eco-friendly disinfectant in aquaculture.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.314.2-314
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• 1998

No Abstract, See Full Text

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.65-77
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• 2006

Gene transcripts potentially responsive to the heat stress were surveyed by cDNA microarray analysis in mud loach (Misgurnus mizolepis). Transcriptional profiles of hepatic tissue in the fish exposed to either $23^{\circ}C$ or $32^{\circ}C$ for 4 weeks were compared each other by 3 replicated hybridization assays using 1,124 unigene clones selected from mud loach liver expressed sequence tags (ESTs). A total of 93 clones showed the substantially increased mRNA levels (>2-fold) in $32^{\circ}C$-exposed group when compared in $23^{\circ}C$control group. It includes various enzymes and proteins involved in energy pathway, protease/protein metabolisms, immune/antioxidant functions, cytoskeleton/cell structure, transport and/or signal transduction. Maximum level of increase was up to 15-fold relative to $23^{\circ}C$ treatment. Heat exposure also resulted in the significant decrease (less than 50% relative to $23^{\circ}C$-exposed fish) of the transcriptional activities in 85 genes. Besides the above categories, yolk protein (vitellogenin) and ribosomal proteins were notably down regulated in the fish exposed to heat stress. A number of novel gene transcripts were also detected in both up-regulated and down-regulated groups.