• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.447-453
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• 1989

In order to study the transfer of antibiotics resistance genes of the genetically cloned bacteria in water environments, DK1 strain, which is resistant to kanamycin (Km), chloramphenicol (Cm), streptomycin (Sm), and sulfadiazine (Su), was selected from the Gram-negative bacterial isolates from wastewater. One of 4 plasmids harboured in the DK1 strain was found to possess Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ gene and be about 68 kb in size, and it was designated as pDK101. The plasmid of pDK101 was also found to have 16, 32, and 6 restriction sites for EcoRI. .PstI, and SalI, respectively. From the digestion fragments of pDK101 plasmid and pKT230 used as a vector by EcoRI restriction endonuclease, pDT309 and pDT529 were constructed as chimeric plasmids which possess Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ gene and are 30.9 and 52.9 kb in size, respectively. When the chimeric plasmids were trasformed into E. coli C600 or E. coli HB101, transformants of DKC601, DKC602, DKH102, and DKH103 were obtained as cloned bacterial cells. The Km$^{${\gamma}$}$Cm$^{${\gamma}$}$ genes were well expressed in those cloned cells and the chimeric plasmids were clearly detected in the cloned cells of DKC601 and DKH103.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.88-94
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• 1997

The mitochondrial DNA (mtDNA) restriction fragment length polymorphi는 (RFLPs) of five populations were analyzed to delineate the stocks of Penaeus chinensis (Osbeck) in the Yellow Sea. Comparison of P. chinensis with P. japonicus to clarify the nucleotide divergence between two species was also carried out. Based on the fragment patterns, three composite haplotypes were analyzed in P. chinensis mtDNA as four naplotypes were in P. japonicus. Most individuals of each P. chinensis population are shared by one dominant haplotype. Another two haplotypes haying variations at the C/a I and hull sites were also distributed evenly in the Korean and Chinese populations. It is suggested that the gene exchange occurring between populations in the Yellow Sea is frequent. Average length of the mtDNA molecule was estimated to be about 16.44 kb in P. chinensis and 16.31 kb in P. japonicus, Sequence divergence (p) of mtDNA between two species estimated by using Upholt's (1977) fomula was $13.7\%$.

• Food Science of Animal Resources
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• v.22 no.4
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• pp.301-309
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• 2002

This study was carried out to develop the breed-specific DNA markers for breed identification of Korean native goat meat using amplified fragment length polymorphism (AFLP)-PCR techniques. The genomic DNAs of Korean native goat, imported black goat and four dairy goat breeds(Saanen, Alpine, Nubian and Toggenburg) were extracted from muscle tissues or blood. Genomic DNA was digested with a particular combination of two restriction enzymes with 4 base(Mse I and Taq I) and 6 base(EcoR I and Hind III) recognition sites, ligated to restriction specific adapters and amplified using the selective primer combinations. In AFLP profiles of polyacrylamide gels, the number of scorable bands produced per primer combination varied from 36 to 74, with an average of 55.5. A total of 555 bands were produced, 149(26.8%) bands of which were polymorphic. Among the ten primer combinations, two bands with 2.01 and 1.26 kb in M13/H13 primer and one band with 1.65 kb in E35/H14 primer were found to be breed-specific AFLP markers in Korean native goat when DNA bands were compared among the goat breeds. In the E35/H14 primer combination, 2.19, 2.03, 0.96 and 0.87 kb bands detected in imported black goat, 2.13 kb band in Saanen breed and 2.08 kb band in Nubian breed were observed as breed-specific bands showing differences between goat breeds, respectively. The E35/H14 primer combination produced four DNA bands distinguished between Korean native goat and Saanen breed. The is study suggested that the breed specific AFLP bands could be used as DNA markers for the identification of Korean native goat meat from imported black goat and dairy goat meats.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.260-269
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• 2005

Taxonomic studies on morphological, principal component analysis (PCA), palynological, RAPD and PCR-RELP analysis were conducted to intraspecific relationships of Rubus oldhami. Three types of Rubus oldhami based on the flower characters such as petal length and number were used in this study. Among the 14 morphological characters, perianth length, calyx lobe length, apical leaflet shape and leaflet length were used to distinguish for each type. The pollen characters such as shape, aperture number, surface sculpture were showed very similar among three types. Eight primers out of 20 arbitrary primers were screened for three types, and were revealed 33 ($60\%$) polymorphic bands. The phonogram by RAPD data showed incongruent with morphological analysis. Even though ten restriction endonucleases produced 20 restriction sites, polymorphic bands were not observed. Based on the results, three types of Rubus oldhami divided well by morphological characters, but pollen and DNA data were not supported. Therefore, type 1 and 2 which different from type 3 by flower characters considered as a temporary hybrid or ecotype because of their similar habitats.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.29-34
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• 2005

This study was conducted to estimate the effects of genotype for chicken major histocompatibility complex (MHC) B-LB genes on economic traits. To detect polymorphism, 400 bp fragments of MHC B-LB genes were obtained and sequenced. After digestions using restriction enzyme Hea III, two restriction enzyme sites were observed. There were two mutations at position 427 and 651 those were decided as Type I and Type II, respectively. Using RFLP analyses, type I were genotyped to TT, TC and CC, and type II to MM, Mm and mm. The relatively higher TC genotype frequencies (0.8) of Type I and Mm genotype frequencies (0.88) of Type II were observed in Korean native chickens. The effects of the genotype on 150 days body weight trait were investigated by the associations of CC and Mm genotypes (P<0.05) in Korean native chickens. This result suggests that a significant association exists between the SNP and 150 days body weight.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.31-49
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• 2012

Satae cheon, a tributary of the Suip cheon in Yanggu, Gangwon province, is an international river extended to North Korea. Most of drainage basin area of the river was the fierce battle field during the Korean War(1950-1953) and hard to access as it located between the MDL(Military Demarcation Line) and the CCZ(Civilian Control Zone: about 10km south from MDL). By the restriction of access to the sites, most of natural landscape have been well conserved except limited use for military activities. Even the landfoms in that area were not studied, except the government's heritage reports. Satae Cheon's channel follows the Imdang fault line(N-S) to Satae-ri and flow to west to the Dutayeon area. The river meanders along geological structure or weak line at the Dutayeon area. The meandering channel was shorten by the meander cut which linked the thalweg line of meander loop ant the meander neck. As a result of this cut, the river cliff formed by the Satae cheon became the part of newly formed channel bed and the S-forms are formed. After the channel route stabilized, channel incised the rock with large potholes and undulating walls were formed. The channel width changes from 1m to 10m with restriction of the undulating walls, so this part can be regarded as inner channel or inner gorge. From the point of planar forms it also can be slot-type canyon.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.202-215
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• 2019

This study was conducted to investigate the spawning preference of the Acheilognathinae fishes in relation to the shell size of host mussels after identifying the species of eggs and fries in the host mussel using our recently developed RFLP (Restriction Fragment Length Polymorphism) molecular marker at four sites [Hongcheon Naechoncheon (HN) and Deokchicheon (HD) from the North Han River basin and Jeongseon Goljicheon (JG) and Joyanggang (JJ) from the South Han River] in South Korea during May in each year between 2015 and 2018. The Acheilognathinae fish observed in the studied sites included one species (Acheilognathus signifer) in HN and JG, three species (Rhodeus uyekii, A. signifer, and Acheilognathus yamatsutae) in HD, and two species (A. signifer and Acheilognathus yamatsutae) in JJ, and we collected 982 host mussels (Unio douglasiae sinuolatus) that inhabited in all four sites. Using the RFLP molecular marker, we confirmed 46 eggs and fry of the Acheilognathinae fish (454 A. signifer, 43 Acheilognathus yamatsutae, and 149 Acheilognathus yamatsutae) in Unio douglasiae sinuolatus (N=163; 16.6%). We compare the average shell length, shell height, and shell width of mussels with [presence] eggs/fry and mussels without [absence] eggs/fry to examine the spawning preference according to the size of host mussels in each site. The results show that the shell length (1.98 mm), shell height (0.85 mm), and shell width (0.73 mm) of mussels with the eggs/fry were significantly larger (Mann-Whitney U test, P=0.002; difference=1.98 mm) than those of mussel without eggs/fry in HD where three species cohabitated. Although the shell length, shell height, and shell width of mussels with the eggs/fry were larger also in the other three sites, the difference was not statistically significant. In addition, we analyzed the mean number of spawned eggs and fry of each species and found $9.31{\pm}5.94$ R. uyekii, $2.86{\pm}2.45$ A.signifer, and $2.50{\pm}1.32$ A. yamatsutae. R. uyekii spawned 6.45-6.81 more eggs than A.signifer and A. yamatsutae on average per mussel, and it was statistically significant (Kruskal-Wallis test, P < 0.001). These findings indicate that the three species of Acheilognathinae fish tend to prefer larger mussels as their spawning hosts, and this tendency increases when the number of cohabitating bitterling fish species increases. Moreover, A.signifer and A. yamatsutae spawned a smaller number of eggs evenly in more host mussels while R. uyekii spawned many eggs on relatively fewer mussels. We found mussels (N=4) having the eggs/fry of two coexisting species, A. signifier and A. yamatsutae in HD and JJ where more than two bitterling fish species occurred. It suggests the interspecific competition taking place between the Acheilognathinae fishes for utilizing the same resource of mussels for spawning when two or more species cohabitate. This study is expected help to understand better the spawning patterns and reproductive ecology of the Acheilognathinae fishes, which will provide insightful information for advancing our understanding of their ecological relationships - mutualism or host-parasitism - with host mussels.

• Journal of Life Science
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• v.19 no.6
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• pp.809-817
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• 2009

The phenotypes associated with a gene function are often the best clue to its role in the plant. Transgenic plants ectopically expressing or suppressing a gene can provide useful information related to the gene function. In this study, we constructed three vectors - pFGL571, pFGL846 and pFGL847 - for the Agrobacterium-mediated ectopic expression of plant genes using pPZP211 and modified CaMV 35S, UBQ3 or UBQ10 promoters. The three vectors have several merits such as small size, high copy in bacteria, enough restriction enzyme sites in multi cloning sites and nucleotide sequence information. Analysis of transgenic plants containing GUS or sGFP reporter genes under the control of modified CaMV 35S, UBQ3 or UBQI0 promoter revealed that all of the three promoters showed high activities during most developmental stages after germination and in floral organs. Furthermore, we generated a RNAi module vector, pFGL727, to suppress plant gene expressions and confirmed that pFGL727 is useful for the suppression of a gene expression using rice transgenic plants. Taken together, our new vectors would be very useful for the ectopic expression or the suppression of plant genes.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.5-15
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• 2011

Conventional designs of landfill covers use geosynthetics such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature or humidity in landfill sites cause the development of cracks or structural damage inside the final cover. This study examined the application of a Self Recovering Sustainable Liner (SRSL) as an alternative landfill final cover material. SRSL consists of double layers, which have chemicals, can generate precipitates filling the pores of the layers by chemical reaction. The interface material forms an impermeable layer and in case of internal cracks, the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing flexible wall permeameter tests to prove that the hydraulic conductivity is lower than the regulations and unconfined compression tests to judge whether the strength satisfies the restriction for the landfill final cover. Furthermore, the environmental impacts on the permeability and strength were evaluated. The experimental results show that the SRSL has lower hydraulic conductivity and higher strength than the regulations and is little influenced by climatic changes such as wet/dry or freeze/thaw process.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.175-182
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• 2007

Two fruit moths of the oriental fruit moth, Grapholita molesta (Busck), and the peach fruit moth, Carposina sasakii (Matsumura), infest apples in Korea by internally feeding behavior. C. sasakii is a quarantine insect pest from some other countries importing Korean apples. G. molesta is not a quarantine insect pest, but can be incorrectly identified as C. sasakii especially when it is found inside apple fruits at its larval stages because it is not easy to identify the two species by morphological characters alone. This incomplete identification results in massive economical loss by fruits needlessly destroyed or turned away at border inspection stations of the importing nations. This difficulty can be overcome by molecular DNA markers. Several polymorphic regions of mitochondrial DNA of both species were sequenced and used for developing specific striction sites and polymerase chain reaction (PCR) primers. Based on these sequences, three diagnostic PCR-restriction fragment length polymorphism (RFLP) sites were detected and validated for their practical uses. Also, species-specific PCR primers were devised to develop diagnostic PCR method for identifying the internal feeders.