• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.2
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• pp.139-145
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• 2009

We cloned and sequenced the open reading frame (ORF) cDNA encoding myostatin from the muscle of abalone (Haliotis discus hannai). The ORF cDNA of the abalone myostatin is 1134 bp and encoded 377 amino acid residues that were 60-96% homologous with the amino acids of other organism myostatins. In addition, the ORF contained a conserved proteolytic cleavage site (RXRR) and nine conserved cysteine residues in the C-terminus. Semi-quantitative RT-PCR revealed the presence of myostatin mRNA in various tissues. The strongest expression was observed in the mantle of female abalone, and the gills and heart of male abalone.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.227-230
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• 1991

A comparative study was conducted in total thirty six large while weaner pigs of about 15 kg body weight namely boars, barrows and gilts to evaluate best sex and economic slaughter weight with one standard ration. In 159 days study period feed consumption, growth, feed conversion ratio and carcass quality were judged in all sexes of pigs at 50, 70 and 90 kg body weight. It was noted that upto 70 kg body weight the growth in boars and gills 46.0 and 49.0 kg and feed conversion ratio 4.83 and 4.81 were superior and economical over the barrows, which were 45.5 kg and 4.95. Later on there were too many fluctuations in growth and feed conversion ratio in all sexes of pigs, which would be uneconomical. Carcass quality was also better in boars and gilts than barrows, No boar taint was noted in most of the boar carcasses. Hence it is concluded that boars and gilts can be raised upto the 70 kg body weight for economic pork production.

• Journal of fish pathology
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• v.28 no.3
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• pp.145-155
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• 2015

The pathogenecity of atypical Aeromonas salmonicida was studied in healthy Oreochromis niloticus. Inoculum at concentration of $1.5{\times}10^8CFU/ml$ and $3{\times}10^8CFU/ml$ was injected into healthy fish through intramuscular and intraperitoneal injections. Experimentally infected Oreochromis niloticus showed ulceration at the dorsal musculature and trunk region in addition to black coloration, congested gills, exophthalmia, and ocular hemorrhage. Congested liver and kidney were recorded in post-mortem examination. Mortality of the experimentally infected Oreochromis niloticus reached 100% after intramuscular injection at concentration of $3{\times}10^8CFU/ml$. Histopathological investigation of infected organs was also performed. There was a focal area of bundles of skeletal musculature showing hyalinization. In addition, hyperplasia, congestion, and fusion were noticed in the gill lamellae. There was also congestion in the blood vessels in the ocular chamber. Severe congestion was also noticed in the central vein of liver associated with focal aggregation of the melanin pigmented cells in the parenchyma. Degenerative changes were noticed in the epithelial cells lining of kidney tubules. Plant extracts carvacrol and its biological precursor cymene were found to be effective in treating experimentally infected Oreochromis niloticus at concentration of 100 or 200 ppm.

• Ocean and Polar Research
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• v.25 no.2
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• pp.147-154
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• 2003

To develop fast and sensitive biomarkers for metal exposures in Antarctic marine organisms we examined histological alterations of an Antarctic sentinel bivalve species Laternula elliptica following a short-term exposure to a sublethal-level of Cd. Distinct histological alterations of tissues and cells of the gills, kidneys, and digestive glands were observed after 8-to 16-hours of exposure to Cd while an increase of Cd concentrations in tissues was not detectable. Most alterations were highly localized in the epithelium of the three tissues; epithelia were found to be detached from the remaining tissue parts. In addition ultra-structural changes such as cytosolic vacuolization, dilation of nucleus and rER membranes were detected in all three tissues, which suggested that the clams are subject to sublethal stresses. Thus, histological and ultrastructural changes on localized tissue parts were rapid and sensitive, suggesting that they may serve biomarkers for Cd exposures. Linkages between the shown ulrastructural changes and higher biological organization level responses are to be established by longer-term exposure experiments.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1055-1059
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• 2013

The ectomycorrhizal fungus Tricholoma matsutake grows symbiotically with Pinus densiflora. Phenylalanine ammonia-lyase (E.C. 4.3.1.24) catalyzes the conversion of L-phenylalanine to trans-cinnamic acid. The role of fungal phenylalanine ammonia-lyase, however, has not been clear until now. In this study, the gene encoding phenylalanine ammonia-lyase (PAL), which was isolated from T. matsutake, was cloned and characterized. The PAL gene (tmpal) consists of 2,160 nucleotides, coding for a polypeptide containing 719 amino acid residues. The deduced amino acid sequence of tmpal from T. matsutake shows high identity (70%) with that from Laccaria bicolor. Comparative analysis of the PAL genes among T. matsutake and other species of the class Agaricomycetes showed that both active sites and binding sites were significantly conserved among these genes. The transcriptional analysis of the PAL gene revealed a differential gene expression pattern depending on the developmental stages (mycelium, primordium, stipe, pileus, and gills) of T. matsutake. These results suggest that the PAL gene in T. matsutake plays an important role in multiple physiological functions.

• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.19.1-19.7
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• 2016

A laboratory experiment was conducted to determine hexavalent chromium ($Cr^{6+}$) accumulation in the mullet and investigate $Cr^{6+}$ toxicity using a panel of biomarkers including metallothioneins (MTs), glutathione (GSH), glutathione S-transferase (GST), and superoxide dismutases (SODs) for 4 weeks. $Cr^{6+}$ bioaccumulation in all tissues, except muscle, was consistently time- and dose-dependent. The accumulation of $Cr^{6+}$ for 4-week exposures was in the following order: $kidney{\approx}liver$ > $intestine{\approx}gill$ > spleen > muscle. Compared with the control, $Cr^{6+}$ bioaccumulation was increased in ${\geq}200{\mu}g\;L^{-1}$ groups (P < 0.05). An independent relation was observed between accumulation factors (AFs) and exposure concentration. But AFs increased with exposure time. In the liver and gill, GST and SOD differed from the control at a high $Cr^{6+}$ concentration at 2 and 4 weeks (P < 0.05). This study indicated that the gills were as sensitive as the liver to $Cr^{6+}$ toxicity. However, the latter appeared to influence largely on the organism's adaptive response to $Cr^{6+}$, since $Cr^{6+}$ may elevate GSH and MT levels by enhancing the hepatic uptake of metal in the mullet.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.209-218
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• 2009

We examined physiological and histological responses related to the survival, oxygen consumption, excretion, and O/N ratio of the ark shell, Scapharca subcrenata, as a result of salinity changes. The 20-day $LS_{50}$ (median lethal salinity) at $15^{\circ}C$ was 13.87 practical salinity units (psu; confidence limits 10.30-18.74 psu), whereas the 14-day $LS_{50}$ at $25^{\circ}C$ was 12.59 psu (confidence limits 8.03-18.16 psu). In conditions of decreasing salinity, the osmolarity of individuals acclimated within 5 h above 26.4 psu but required more than 60 h below 13.2 psu. Oxygen consumption and ammonia excretion rates varied irregularly as salinity decreased. The O/N ratio was 19 and 27 at water temperatures of $15^{\circ}C$ and $25^{\circ}C$, respectively, but decreased to 1-10 as salinity declined. The effects of decreasing salinity were observed in the histological changes to each organ of S. subcrenata. As salinity decreased, cilia fell off, the epithelial layer underwent necrosis and vacuolation, the connective tissue layers of the mantle and visceral mass were destroyed, and hemocytes increased in the gills. The results of this study could prove important in investigating causes of mass mortality and managing shellfish aquaculture farms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.326-332
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• 2006

To investigate the effects of environmental salinity on the expression of the genes for growth hormone (GH) and prolactin (PRL) in the pituitary, and their receptors (GHR, PRLR) In the kidney, intestine, and gills in teleosts, we acclimated juvenile olive flounders (Paralichthys olivaceus) to different salinities (5, 15, 25, or 32 psu) for 3 days and examined their mRNA levels using the reverse transcription-polymerase chain reaction (RT-PCR). In the fish adapted to low salinity, the PRL mRNA levels in the pituitary were elevated dramatically, whereas the GH mRNA levels did not differ significantly. PRLR mRNA increased significantly in fish exposed to low salinity, whereas GHR mRNA levels did not differ. These results suggest that PRL is an important hormone for flounders that are acclimated to brackish water and it may control ion homeostasis with PRLR in the osmoregulatory organs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.725-730
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• 2015

We observed yellow catfish Pelteobagrus fulvidraco fingerlings cultured in land ponds in Korea swimming in a corkscrew spiral pattern while hanging head-up and tail-down at the water surface, before eventually dying. Externally, these fish displayed “hole in the head” disease, pale gills, and hemorrhages in the base of the pectoral and caudal fins; internally they had liver hemorrhages and kidney discoloration. The bacterium Edwardsiella ictaluri (YCK-01 and YCL-01) was identified in the kidneys and livers of diseased fish via phenotypic characteristics and PCR analysis using the ictaluri-specific primers IVS (an intervening sequence) and IRS (the inter-ribosomal spacer). Infectivity challenges by intraperitoneal and immersion routes showed that a representative bacterial strain (YCK) exhibited strong virulence to yellow catfish, with an LD₅₀ of 3.2×10⁴ CFU/fish and 2.5×10⁶ CFU/mL, respectively. This is the first report of E. ictaluri infection in yellow catfish from Korea.

• Journal of Microbiology and Biotechnology
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• v.21 no.5
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• pp.455-463
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• 2011

Metallothioneins are a class of small cysteine-rich proteins that have been associated with increased tolerance to metal and oxidative stresses in animals, plants, and fungi. We investigated a metallothionein-like (mt-like) gene shown previously to be upregulated in fruiting bodies of the fungus Agaricus bisporus in response to post-harvest storage. Analysis of an A. bisporus genomic DNA cosmid library identified two similar mt-like genes (met1 and met2) arranged as a bidirectional gene pair transcribed from the same promoter region. The promoter contained regulatory elements including 9 metal responsive elements and a CAAT box region 220 bp downstream of met1 that showed striking similarity to a feature in Coprinopsis cinerea mt-like gene promoters. Transcriptional analysis showed that both met genes are significantly and rapidly (within 3 hours) upregulated during post-harvest storage and expression is significantly greater in stipe and cap tissues compared with the gills. However, a strong directionality of the promoter was demonstrated, as transcript levels of met1 were at least two orders of magnitude greater than those of met2 in all samples tested.