• Journal of Life Science
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• v.6 no.4
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• pp.286-292
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• 1996

Angiogenesis is a fundamental process by which new blood vessels are formed. It is essential in embryo development, and wound healing. Furthermore, malignant tumor growth and metastasis are also angiogenesis-dependent. In the catilage tissue, normal angiogenesis process is suppressed. In fact, it was reported that angiogenesis-inhibitory substances were isolated from the extracts of cow and shark catilage tissue. In order to isolate genes involved in the regulation of angiogenesis from a catilage fish, we constructed a shark cDNA library from Scylliohinus torazame. We then screened the library using hyman tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) gene as a probe. Among the 4 X 10$^{4}$ plaques screened, we isolated 2 positive clones (T-1, T-2). Restriction enzyme analysis revealed that the T-1 clone contains 0.8 kb cDNA insert, and the T-2 clone contains 1.2 kb and 2.2 kb inserts, respectively. Further DNA sequence analysis shows that the DNA sequence of the T-1 clone is 53% homologous to that of the human TIMP-1 gene.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.4
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• pp.266-274
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• 2000

Understanding of microbial community structure in soil-root system is necessary to use beneficial soil and rhizosphere microbes for improvement of crop production and biocontrol. The knowledge of behavior and function of microbes in soil-root system plays a key role for the application of beneficial inocula. Because the majority of the intact bacteria in soil are unable to grow on nutrient media, both culturable and nonculturable bacteria have to be studied together. In our study, culture-independent survey of bacterial community in the soil-root system of red pepper fields was conducted by the sequence analysis of three universal clone libraries of genes which code for small-subunit rRNA (rDNA). Universal small subunit rRNA primers were used to amplify DNA extracted from each sample and PCR products were cloned into pGEM-T. Out of 27 clones sequenced, 25 clones were from domain bacteria. Two of the rDNA sequences were derived from eukaryotic organelles. Within the domain bacteria, several kingdoms were represented : the Proteobacteria (16 clones). Cytophyga-Flexibacter-Bacteroides group (2 clones). the high G+C content gram-positive group(1 clone) and 4 unknown clones.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.247-253
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• 1994

This study was carried out to isolate and characterize $A{\alpha}$ mating locus controlling fruiting body formation directly in the Basidiomycete Schzophyllum commune growing in the North America. Total numbers of genomic library of S. commune UVM1-34 was about $2{\times}10^4$ cells. About 90% library was appeared to have about 35 kb inserted genome DNA in cosmid pTC20 vector. 6 clones were proved to have positive signal to probes within Z and Y region in colony and southern hybridization. In the mating activity test, all the 6 positive clones were appeared to have $A{\alpha}3$ mating activity although they had two different restriction patterns. pSC13 containing 5.7 Kb PstI-fragment of UVM 1-34 $A{\alpha}3$ allele showed about 50% clamp cell formation indicating mating activity when cotransformation was done together with cosmid pTC20.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.142-144
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• 1996

To clone the gene coding for steroid $\Delta^1$-dehydrogenase of Arthrobacter simplex, its genomic library was constructed with a , $\lambda$gt11 expression vector and immunoscreened with antiserum against the enzyme. One positive clone was found to carry a 1.6-kb EcoR I restriction endonuclease fragment of A. simplex DNA. The restriction map of the 1.6-kb EcoR I fragment was determined after cloning of the DNA into pBS vector.

• Journal of Plant Biology
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• v.38 no.2
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• pp.137-141
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• 1995

We isolated a cDNA clone, BLSC1, encoding 5' exon of ATP synthase CF0 subunit I from broccoli. BLSC1 is 285 nucleotides long which consists of a 5' noncoding region of 34 nucleotides, a 5' exon of 145 nucleotides and an intron of 106 nucleotides. The 5' exon codes for 48 amino acids which reveals mostly hydrophobic. The amino acid sequence deduced from BLSC1 shares 83%, 83% and 91% identities with the genes coding for atpF from wheat, rice and spinach, respectively. Genomic Southern blot analysis for BLSC1 showed a typically strong signal for a gene located in the chloroplast genome. Northern blot analysis identified three major classes of transcripts showing strong positive signals in the leaves, but only trace amounts of the transcripts were identified in the other organs like stems, flowr buds and roots.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.89-96
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• 2000

For large DNA fragment transformation in dicots and monocots, BIBAC2 vector system was applied to Arabidopsis thaliana and Oryza sativa L. cv. Jinmi as a model plant, respectively. For Arabidopsis, the Th1 gene in T23L3 BAC clone whose size is about 90 kb was used as the target gene source for transformation. Because T23L3 BAC clone was originally constructed in pBelloBAC11, the target gene was reconstructed into BIBAC2. As the results of reconstruction, 476 colonies were survived in selection medium containing 40 mg/L kanamycin. In colony hybridization analysis, 24 out of 476 colonies exhibited positive signals. In the pulsed-field gel electrophoresis analysis, 11 out of 24 positive clones exhibited the band at the location of 90 kb. In Southern hybridization, positive signal band at the location of 90 kb was observed in all 11 transformants. Using these verified clones, Agrobacterium-mediated transformation was applied to Arabidopsis thaliana th1-201 mutant for genetic complementation test. Twelve thousands T$_1$ seeds were harvested, and antibiotic selection test is being analyzed to verify whether these seeds were transformed. for rice, COR356 that contains 150 kb human genomic DNA in a BIBAC2 vector was used as the target gene. As the results of transformation, 151 out of 210 co-cultivated calli were survived in selection medium containing 5 mg/L hygromycin, and 45 out of 151 survived calli were regenerated into plants. Transformation efficiency was 21.6%. Progeny test using 71 seeds is being analyzed now. These results provide the potential that large DNA fragments can be transferred into both dicots and monocot by Agrobacterium-mediate d transformation system.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.161-165
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• 1997

The R-mb locus of maize is one of several genes that encode tissue-specific transcriptional regulator for the anthocyanin biosynthesis in plant parts and the aleurone layer in seeds. We found that the seed pigment frequencies gradually decreased at selfed progenies of the R-mb genetic stocks. In order to analyze the genomic structure of R-mb locus components, genomic Southern blot was performed by using R specific probe, pR-nj:1. Two bands were detected at the size of about 3.9 and 7.75kb. Five R-mb positive clones (mb-II, III, V,Ⅵ, and Ⅶ) were obtained by screening of maize genomic λFIXII library using R specific probe pR-nj:1. We constructed the restriction map of clone mb-II (7.75Kb positive) and mb-Ⅵ (3.9Kb positive), and have compared these with other R locus genes. From genetic and molecular analysis, it is suggested that R-mb complex consists two copy of R elements, and each element shows the paramutagenic and gene silencing effects by the fashion of cis-inactivation.

• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.83-86
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• 2003

Major advances in positive-sense RNA virus research have been facilitated by the development of reverse genetics systems. These systems consist of an infectious cDNA clone that encompasses the genome of the virus in question. This clone is then used as a template for the subsequent synthesis of infectious RNA for the generation of synthetic viruses. However, the construction of infectious cDNA for the Japanese encephalitis virus (JEV) has been repeatedly thwarted by the instability of its cDNA. As JEV is an important human pathogen that causes permanent neuropsychiatric sequelae and even fatal disease, a reliable reverse genetics system for this virus is highly desirable. The availability of this tool would greatly and the development of effective vaccines as well as facilitate studies into the basic biology of the virus, including the molecular mechanisms of viral replication, neurovirulence, and pathogenesis. We have successfully constructed a genetically stable infectious JEV cDNA containing full-length viral RNA genome. Synthetic RNA transcripts generated in vitro from the cDNA were highly infectious upon transfection into susceptible cells, and the cDNA remained stable after it had been propagated in E. coli for 180 generations. Using this infectious JEV cDNA, we have successfully expressed a variety of reporter genes from the full-length genomic and various subgenomic RNAs in vitro transcribed from functional JEV cDNAS. In summary, we have developed a reverse genetics system for JEV that will greatly facilitate the research on this virus in a variety of different fields. It will also be useful as a heterologous gene expression vector and aid the development of a vaccine against JEV.

• Journal of the Korea Furniture Society
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• v.19 no.4
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• pp.273-282
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• 2008

Increasing demand for timber and the depletion of natural forest have encouraged utilization of many non-popular species. The understanding of wood properties and behavior is important to evaluate the potential of these species to produce high quality end products. This study determines the anatomical and physical properties of Hevea species viz Hevea pauciflora, Hevea guianensis, Hevea spruceana, Hevea benthamiana and Hevea brasiliensis. Each sample tree was cut into three different portions along the height (bottom- B, middle- M and upper -T parts) and two radial samples (outer- O and inner- I parts). H. brasiliensis clone RRIM 912 exhibited the longest fibre with $1214{\mu}m$, followed by H. benthamiana (HB, $1200{\mu}m$), H. pauciflora (HP, $1189{\mu}m$), H. spruceana (HS, $1158{\mu}m$) and H. guianensis (HG, $1145{\mu}m$). Fibre length has a positive correlation with specific gravity. The largest fibre diameter ($24.9{\mu}m$) and lumen diameter ($12.5{\mu}m$) were recorded in H. guianensis. The highest moisture content was obtained from H. spruceana (64.34%) compared to the lowest with 60.01% (Clone RRIM912). The higher moisture content is normally associated with lower strength. Overall, the properties of clone RRIM 912 is found to be comparatively better because of higher strength due to longer fibre length, thicker cell walls and higher specific gravity than the other Hevea species. Therefore, this species can be used as a general utility timber.

• Journal of Plant Biotechnology
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• v.7 no.1
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• pp.45-50
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• 2005

To clone blue and white flower color specific genes, mRNA differential display was carried out with two different Commelina species, C. communis Linne for blue color and C. coreana Leveille for. leucantha Nakai for white color. Fifty two and 100 cDNA clones specific for blue or white flower color, respectively, were ranging from 200 to 700 bp in size. From the reverse northern blot analysis, 12 and 7 positive clones were selected for blue and white flower, respectively. These clones appear to be novel cDNAs for these Commelina plants, but not color specific. This finding was supported by the northern blot analysis. However, two clones, B18 and B19, derived from blue flowered Commelina were highly expressed than in the white Commelina species, implying that further study will be valuable. The results indicated that both mRNA display experiment and dot blot analysis may not sensitive enough to clone color-determining gene from the plant, leading to explore more advanced method, like high-density colony array study (HDCA).