• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.108-116
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• 2003

To investigate bacteria with algal Iytic activities against Anabaena cylindrica when water blooming occurs and to study enzyme profiles of alga-Iytic bacteria, various bacterial strains were isolated from surface waters and sediments in eutrophic lakes or reservoirs in Korea. Abacterial strain AK-07 was characterized and identified as Acinetobacter johnsonii based on its16S rDNA base sequence. When AK-07 was co-cultivated with A. cylindrica, bacterial cells propagated to $8\;{\times}\;10^8$ cfu $ml^{-1}$ and Iyses algal cells. However, culture filtrates of AK-07 did not exhibit algal Iytic activities. That suggesting the enzymes on the surfaces of the bacterium might be effective algal Iytic agents to cause Iyses of cells. Acinetobacter johnsonii AK-07 exhibited high degradation activities against A. cylindrica, and formed alginase, caseinase, lipase, fucodian hydrolase, and laminarinase. Moreover, glycosidases for example ${\beta}$-galatosidase, ${\beta}$-glucosidase, ${\beta}$-glucosaminidase, and ${\beta}$-xylosidase, which hydrolyzed ${\beta}$-0-glycosidic bonds, were found in cell-free extracts of A. johnsonii AK-07. Other glycosidase such as ${\alpha}$-galctosidases, ${\alpha}$-N-Ac-galctosidases, ${\alpha}$-mannosidases, and ${\alpha}$- L-fuco-sidases, which cleavage ${\alpha}$-0-glycosidic bondsare not detected. In the results, enzyme systemsof A. johnsonii AK-07 were very complex to do-grade cell walls of cyanobacteria. The polysaccharides or peptidoglycans of A. cylindrica maybe hydrolyzed and metabolized to a range of easily utilizable monosaccharides or other low molecular weight organic substances by strain AK-07 of A. johnsonii.

• Journal of fish pathology
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• v.25 no.3
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• pp.151-158
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• 2012

Diseased eel (Anguilla bicolor) displayed severe hemorrhages in the gills, and congestion and swelling in the liver. During the epizootic, the water temperature was $28^{\circ}C$ and the morality rates were about 5%. No parasites were found on the gills and skin. Bacteria were not cultured from any internal organs using TSA or SS agar at $28^{\circ}C$ for 48 hrs. Histopathologically, the gills showed epithelial hyperplasia in the base of secondary gill lamellae and hemorrhages in the capillaries. Some cells in the proliferated interlamellar epithelia exhibited marginal hyperchromatosis. And severe vacuolated changes in the parenchymal cells and congestion in the central veins were observed in the liver. The specific amplicon (396 bp) was detected from gills and opercula of affected eel PCR using Anguillid herpesvirus-1 (AngHV-1) -specific primer sets HVAPOLVPSD (5-'GTG TCG GGC TTT GTG GTG C-3') and HVAPOLOOSN (5'-CAT GCC GGG AGT CTT TTT GAT-3'). Sequencing analysis of the amplicon demonstrated that this gene was 99% homologous to the AngHV-1 sequence deposited in GenBank. This is the first report of AngHV-1 outbreak in the farmed shortfin eels (A. bicolor) in Korea. When diseased fish were maintained for 10 days at water temperatures of $32^{\circ}C$ and $35^{\circ}C$, the cumulative mortalities were 100% and 10%, respectively. Even though the AngHV-1 genome in the gills from the eel kept at $35^{\circ}C$ was detected using PCR, the structure of gill filaments was similar with that of normal fish. Increasing the water temperature to $35^{\circ}C$ was an effective way to diminish the mortality of AngHV-1 affected eel.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.333-341
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• 2021

In this study, to select strains suitable as microbial agent from among rhizosphere microorganisms present in rhizosphere soil and roots, the mineral solubilization ability, antifungal activity against 10 types of plant pathogenic fungi, and plant growth-promoting activity of rhizosphere microorganisms were evaluated. As a result, DDP346 was selected because it has solubilization ability of phosphoric acid, calcium carbonate, silicon, and zinc; nitrogen fixing ability; production ability of siderophore, indole-3-acetic acid, and aminocyclopropane-1-carboxylate deaminase; and antifungal activity against seven types of plant pathogenic fungi. DDP346 showed a 99.9% homology with Acinetobacter pittii DSM 21653 (NR_117621.1); phylogenetic analysis also revealed a close relationship with Acinetobacter pittii based on the 16S rRNA base sequence. The growth conditions of DDP346 were identified as temperatures in the range of 10-40 ℃, pH in the range of 5-11, and salt concentrations in the range of 0-5%. In addition, a negative correlation coefficient (r² = -0.913, p <0.01) was shown between pH change and the solubilized phosphoric acid content of Acinetobacter sp. DDP346, and this is assumed to be due to the organic acid generated during culture. Consequently, through the evaluation of its mineral solubilization ability, antifungal activity against plant pathogenic fungi, and plant growth-promoting activity, the potential for the utilization of Acinetobacter sp. DDP346 as a multi-purpose microbial agent is presented.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.229-239
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• 2021

Thamnaconus modestus, distributed in the Northwest Pacific, has high economic value and is used in various seafood. In this study, the morphological and genetic characteristics of T. modestus and T. septentrionalis were compared and analyzed. We observed the external and internal morphology of T. modestus, sketched skeletal elements, and analyzed phylogenetic evolutionary relationships using the cytochrome c oxidase subunit I (COI) gene on mitochondrial DNA compared to T. septentrionalis. The T. modestus observed in this study had blackish-brown patterns irregularly scattered on the gray-brown body, and the fins were blue-green. Genetic analysis results based on the COI sequences of T. modestus showed seven types of base sequence variation; however, the homology was more than 98.8%. In addition, as a result of comparison of the COI nucleotide sequences and phylogenetic analysis in Tetraodontiformes, two T. septentrionalis sequences (JN813099, MW485059) were similar to T. modestus with 99% homology, and the other two T. septentrionalis sequences (EF607583, KP267619) were similar to those of species belonging to another genus Thamnaconus with 95% homology with T. modestus. It was not easy to classify the species based on morphological characteristics, and phylogenetic analysis between T. modestus and T. septentrionalis confirmed the difference in classification. These results provide the external and internal morphology of T. modestus and will be used as important information for the taxonomic study of T. modestus and T. septentrionalis.

• Genes and Genomics
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• v.40 no.12
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• pp.1351-1361
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• 2018

A new cold tolerant germplasm resource named glutinous rice 89-1 (Gr89-1, Oryza sativa L.) can overwinter using axillary buds, with these buds being ratooned the following year. The overwintering seedling rate (OSR) is an important factor for evaluating cold tolerance. Many quantitative trait loci (QTLs) controlling cold tolerance at different growth stages in rice have been identified, with some of these QTLs being successfully cloned. However, no QTLs conferring to the OSR trait have been located in the perennial O. sativa L. To identify QTLs associated with OSR and to evaluate cold tolerance. 286 $F_{12}$ recombinant inbred lines (RILs) derived from a cross between the cold tolerant variety Gr89-1 and cold sensitive variety Shuhui527 (SH527) were used. A total of 198 polymorphic simple sequence repeat (SSR) markers that were distributed uniformly on 12 chromosomes were used to construct the linkage map. The gene ontology (GO) annotation of the major QTL was performed through the rice genome annotation project system. Three main-effect QTLs (qOSR2, qOSR3, and qOSR8) were detected and mapped on chromosomes 2, 3, and 8, respectively. These QTLs were located in the interval of RM14208 (35,160,202 base pairs (bp))-RM208 (35,520,147 bp), RM218 (8,375,236 bp)-RM232 (9,755,778 bp), and RM5891 (24,626,930 bp)-RM23608 (25,355,519 bp), and explained 19.6%, 9.3%, and 11.8% of the phenotypic variations, respectively. The qOSR2 QTL displayed the largest effect, with a logarithm of odds score (LOD) of 5.5. A total of 47 candidate genes on the qOSR2 locus were associated with 219 GO terms. Among these candidate genes, 11 were related to cell membrane, 7 were associated with cold stress, and 3 were involved in response to stress and biotic stimulus. OsPIP1;3 was the only one candidate gene related to stress, biotic stimulus, cold stress, and encoding a cell membrane protein. After QTL mapping, a total of three main-effect QTLs-qOSR2, qOSR3, and qOSR8-were detected on chromosomes 2, 3, and 8, respectively. Among these, qOSR2 explained the highest phenotypic variance. All the QTLs elite traits come from the cold resistance parent Gr89-1. OsPIP1;3 might be a candidate gene of qOSR2.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.94-100
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• 2018

Bird electrocution on contact with electricity lines is well reported and is quite common in Mongolian open areas. We visited 15-kV electricity distribution pole lines in a Southern Mongolian semi-desert region three times in 2017, in April, July, and September, to assess their risks to birds. The carcasses of 45 electrocuted birds representing 12 species were identified from 250 poles (overall mortality rate of 1.12% every 10 km). The majority of these electrocuted birds were endangered Saker Falcon (n=11) and common Black Kite (n=11). The lacks of roosting or perching sites in our study sites (indeed other open areas in Mongolia) may resulted for such high rate bird electrocution. A 751-base pair (bp) cytochrome c oxidase I (COI) gene was amplified for DNA sequence-based identification of carcasses that were difficult to identify directly. Our findings revealed the high electrocution risk for birds in Mongolian open areas, especially for the birds of prey, with relatively low-efficiency electrocution mitigation approaches. The findings also indicate that there is a need for better understanding of the risk of bird electrocution, particularly in the open areas. This will contribute to the conservation of endangered species.

• Journal of Life Science
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• v.28 no.12
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• pp.1536-1544
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• 2018

Depression is a common, serious, and recurring mental disorder. The pathogenesis of depression involves many factors such as environmental factor, genetic factor and alteration of structure and function in neurobiological systems. Increasing evidence supports that epigenetic alteration may be associated with depression. The epigenetics is explained as the mechanisms by which environmental factor causes changes in chromatin structure and alters gene expression without changing DNA base sequence. DNA methylation and histone modification involving histone acetylation and methylation are the main epigenetic mechanisms. Animal studies have shown that stressful environment such as early life stress can leave persistent epigenetic marks in the genome, which alter gene expression and influence neural and behavioral function through adulthood. A potentially important gene in depression is brain-derived neurotrophic factor (BDNF). BDNF plays a central role in depression and antidepressant action. In studies of the rodent, exposure to stress at prenatal, postnatal, and adult stages alters BDNF expression through histone modification and DNA methylation of the BDNF gene which results in anxiety and depressive-like behavior. This review discusses recent advances in the study of the epigenetic mechanisms that contribute to depression, particularly histone modification and DNA methylation of the BDNF gene, that may help in the development of new targets for depression treatment.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.47-57
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• 2021

In the fishery industry, global aquaculture production has stagnated due to overfishing of aquatic products, restrictions between countries, and climate change. The aquaculture suggests the possibility of a blue revolution that can be expanded in a new way. The aquaculture industry now accounts for more than half of the fishery products from the sea as a raw material for seafood for human consumption. Various latest biological research methods are being applied for the development of a sustainable aquaculture industry. Genomics has made significant progress in recent years. Since the genome sequence of Atlantic cod was sequenced in 2011, the genomes of more species have been sequenced. The genome information is providing a more robust and productive knowledge base for the aquaculture industry, including breeding and breeding of superior traits, improving disease resistance quality, and optimizing aquaculture feed and feed methods. This review looked at the status of genome analysis technology and the current status of genome research of aquaculture species. The development of genome research technology and massive genomic information is important in solving the challenges of the aquaculture industry and will help sustainable fisheries and aquaculture.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.52-52
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• 2001

Many nucleoside diphosphate (NDP) kinases are ubiquitous enzymes responsible for the exchange of ${\gamma}$-phosphates between tri- and diphosphonucleosides. The catalytic Many nucleoside diphosphate (NDP) kinases are ubiquitous enzymes responsible for the exchange of ${\gamma}$-phosphates between tri- and diphosphonucleosides. The catalytic reaction follows a ping-pong mechanism in which the enzyme is transiently phosphorylated on a histidine residue conserved in all nucleoside diphosphate kinases. Beside their role in nucleotide synthesis, these enzymes present additional functions, possibly independent of catalysis, in processes such as differentiation, cell growth, tumor progression, metastasis and development. To clone murine nm23-M5, several expressed sequence tags (ESTs) of the GenBank data base, selected according to their homology to nm23-H5 cDNA, reconstituted a complete open reading frame (GenBank AF222750). To test whether murine NDPKs (1, 2, 3, 4, 5, and 6) can inhibit Bax-mediated toxicity in yeast, co-transformation was performed respectively. The yeast S.cerevisiae was transformed with a copy expression plasmid containing the histidine selection marker and expressing murine Bax under the control of a galactose-inducible promoter. Several clones were selected and found to be growth inhibited when Bax expression was induced with galactose. A representative clone was transformed again with a copy expression plasmid containing the tryptophane selection marker and expressing either murine Bcl-xL or NDPK under the control of a galactose-inducible promoter. Several subclones of the double-transformants were selected and characterized. The ability of Bcl-xL and NDPKs to suppress Bax-mediated toxicity was determined by growing yeast cells overnight in galactose media and spot-testing on galactose plates starting with an equal number of yeast cells as determined by taking the OD$_{600}$. Ten-fold serial dilutions were used in the spot-test. Plates were grown at 3$0^{\circ}C$ for 2-3 days. All murine NDPKs suppressed Bax dependent apoptosis. Futher study will be peformed whether Bax-toxicity inhibition was caused by NDP kinase activity or additional function.n.

• Journal of Life Science
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• v.18 no.8
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• pp.1090-1095
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• 2008

Marbling (intramuscular fat) is an important factor in determining meat quality in Korean beef market. A grain based finishing system for improving marbling leads to inefficient meat production due to an excessive fat production. Identification of intramuscular fat-specific gene might be achieved more targeted meat production through alternative genetic improvement program such as marker assisted selection (MAS). We carried out ddRT-PCR in 12 and 27 month old Hanwoo steers and detected 300 bp PCR product of the inducible cAMP early repressor (ICER) gene, showing highly gene expression in 27 months old. A 1.5 kb sequence was re-sequenced using primer designed base on the Hanwoo EST sequence. We then predicted the open reading frame (ORF) of ICER gene in ORF finder web program. Tissue distribution of ICER gene expression was analysed in eight Hanwoo tissue using realtime PCR analysis. The highest ICER gene expression showed in Small intestine followed by Longissimus dorsi. Interestingly, the ICER gene expressed 2.5 time higher in longissimus dorsi than in same muscle type, Rump. For gene expression analysis in high- and low marbled individuals, we selected 4 and 3 animal based on the muscle crude fat contents (high is 17-32%, low is 6-7% of crude fat contents). The ICER gene expression was analysed using ANOVA model. Marbling (muscle crude fat contents) was affected by ICER gene (P=0.012). Particularly, the ICER gene expression was 4 times higher in high group (n=4) than low group (n=3). Therefore, ICER gene might be a functional candidate gene related to marbling in Hanwoo.