• YAKHAK HOEJI
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• v.31 no.2
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• pp.116-125
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• 1987

It is still difficult and time consuming to obtain cDNA sequences that contain the entire nucleotide sequence of the corresponding mRNA. A rapid and high efficient cloning method to obtain full-length cDNA segments is thus developed. The cloning procedure described here consists of the construction of oligo(dT)-tailed vector primer using pWR34 plasmid, polyadenylation of mRNA-cDNA heteroduplex using terminal deoxytransferase, and replacement of MRNA strand with DNA by RNase H and DNA polymerase I. The restriction endonuclease analysis shows that the size of inserted-cDNA is in the range of 1.5~4.0 kb long suggesting that most of cloned cDNA are full-length or nearly full-length cDNA. The plasmid-DNA recombinants obtained were 4$\times$$10^5$~$10^{6}$ per $\mu\textrm{g}$ of rat liver poly (A$^+$)mRNA, which is 4 to 10 fold higher cloning efficiency in comparison to the presently used methods for full-length cDNA cloning. The results indicate that the described cloning system is much simpler, less time consuming, and very efficient cloning method to construct a cDNA library.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.442-448
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• 2003

Melanin concentrating hormone (MCH) regulating color change of fish skin was identified from brain cDNA library of Olive flounder (Paralichthys olivaceus) during the analysis of Expressed Sequence Tags (ESTs). Olive flounder MCH gene consisted of 598 nucleotides encoding 150 amino acids. Olive flounder MCH protein revealed to contain signal peptide of 19 amino acid residues, pro-MCH of 131 amino acids being processed to biologically active and mature form of hormone with 25 amino acid residues at the carboxyl terminus. A comparative structural analysis revealed that Olive flounder MCH precursor had low sequence identity with other fish species and mammalian counterparts, while the amino acid sequences of mature hormone had a relatively high identity and more conserved. RT-PCR analysis revealed that olive flounder MCH precersor gene was expressed spectically only in the brain and not in other tissues.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.450-455
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• 1996

The genomic DNA was prepared from trout liver which was treated with 3-methycholanthrene, and cloned into lambda EMBL3 at BamHl site. The genomic library was constructed via infections of these recombinant phages into E. coli K802, and screened by the most $5^I$-portion of trout CYP1A1 cDNA. After the screening of $10^9$ clones of the amplified library, 12 positive clones were isolated, and subjected to further screenings. The results of southern blot hybridization of genomic DNA prepared from the positive clone showed the presence of a single gene of CYP1A1, and 3.5 Kb PstI fragment that hybridizes with the most $5^I$-region DNA of CYP1A1 cDNA. The restriction map of PstI fragment was determined by the restriction digestion with various enzymes. The nucleotide sequence of the upstream genomic DNA of CYPIAI was determined by DNA sequencing of exonuclease III unidirectionally deleted PstI fragment DNA using $[^{35}/S]$dATP. This paper presented the upstream genomic DNA of CYP1A1 contained a part of coding region which was about 351 base pairs (from ATG to PstI site at 3563).

• Horticultural Science & Technology
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• v.29 no.2
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• pp.116-122
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• 2011

In this study, we report the generation and analysis of 1,392 expressed sequence tags (ESTs) from Korean Stewartia (Stewartia koreana Nakai). A cDNA library was generated from the young leaf tissue and a total of 1,392 cDNA were partially sequenced. EST and unigene sequence quality were determined by computational filtering, manual review, and BLAST analyses. Finally, 1,301 ESTs were acquired after the removal of the vector sequence and filtering over a minimum length 100 nucleotides. A total of 893 unigene, consisting of 150 contigs and 743 singletons, was identified after assembling. Also, we identified 95 new microsatellite-containing sequences from the unigenes and classified the structure according to their repeat unit. According to homology search with BLASTX against the NCBI database, 65% of ESTs were homologous with known function and 11.6% of ESTs were matched with putative or unknown function. The remaining 23.2% of ESTs showed no significant similarity to any protein sequences found in the public database. Annotation based searches against multiple databases including wine grape and populus sequences helped to identify putative functions of ESTs and unigenes. Gene ontology (GO) classification showed that the most abundant GO terms were transport, nucleotide binding, plastid, in terms biological process, molecular function and cellular component, respectively. The sequence data will be used to characterize potential roles of new genes in Stewartia and provided for the useful tools as a genetic resource.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.113-117
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• 1997

Simple sequence repeats (SSR) are widely dispersed throughout eukaryotic genomes, highly polymorphic, and easily typed using polymerase chain reaction (PCR). The objective of this study was to determine the polymorphism of different Chlamydomonas reinhartdtii strains and to determine the mode of inheritance of the SSR locus in Chlamydomonas. A genomic DNA library of C. reinhardtii was constructed and screened with a radiolabeled $(AC)_{11}$ probe for the selection of (CA/GT)n repeat clone. Selected clone was seqeuenced, and PCR primer set flanking (CA/GT)n sequence was constructed. PCR was used to specifically amplify the SSR locus from multiple isolates of C. reinhardtii. The locus was polymorphic in some of the C. reinhardtii isolates. However, the locus was amplified only 4 of 6 isolates of C. reinhardtii, not in other 2 isolates of C. reinhardtii, suggesting that this locus is not extensively conserved. A simple Mendelian inheritance pattern was found, which showed 2:2 segregation in the tetrads resulting from a cross between C. reinhardtii and C. smithii. Our results suggest that this simple sequence repeat DNA polymorphism will be useful for identity testing, population studies, linkage analysis, and genome mapping in Chlamydomonas.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1607-1615
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• 2007

We investigated the applicability of the TEM-l ${\beta}$-lactamase fragment complementation (BFC) system to develop a strategy for the screening of protein-protein interactions in bacteria. A BFC system containing a human Fas-associated death domain (hFADD) and human Fas death domain (hFasDD) was generated. The hFADD-hFasDD interaction was verified by cell survivability in ampicillin-containing medium and the colorimetric change of nitrocefin. It was also confirmed by His pull-down assay using cell lysates obtained in selection steps. A coiled-coil helix coiled-coil domain-containing protein 5 (CHCH5) was identified as an interacting protein of human uracil DNA glycosylase (hUNG) from the bacterial BFC cDNA library strategy. The interaction between hUNG and CHCH5 was further confirmed with immunoprecipitation using a mammalian expression system. CHCH5 enhanced the DNA glycosylase activity of hUNG to remove uracil from DNA duplexes containing a U/G mismatch pair. These results suggest that the bacterial BFC cDNA library strategy can be effectively used to identify interacting protein pairs.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.283-292
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• 2006

Expressed sequence tag (EST) analysis was conducted using a complementary DNA (cDNA) library made from the kidney mRNA of olive flounder (Paralichthys olivaceus). In the survey of 390 ESTs chosen from the kidney cDNA library, 250 ESTs showed significant homology to previously described genes while 140 ESTs were unidentified or novel. Comparative analysis of the 250 identified ESTs showed that 14 (5.6%) clones were representing 11 unique genes identified as homologous to the previously reported olive flounder ESTs, 198 (79.2%) clones representing 160 unique genes were identified as orthologs of known genes from other organisms, and orthologs were established for 38 (15.2%) clones representing 37 genes of known sequences with unknown functions. We also identified several kinds of immune associated proteins, indicating EST as a powerful method for identifying immunerelated genes of fish as well as identifying novel genes. Further studies using cDNA microarrays are needed to identify the differentially expressed transcripts after disease infection.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.96-104
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• 1997

A silkworm Bombyx mori genomic DNA library was constructed from polyphagous J111 strain and unpolyphagous $C_3$ strain to develop the genomic study by DNA makers. Genomic DNAs of two strains were digested with restriction enzyme EcoRI and ligated into pUC18. The ligated plasmids were transferred into E. coli host strain DH5$\alpha$. When the genomic DNAs were hybridized with insert DNAs from transformant, could be categorized from hybridization patterns to three groups as high repetitive sequence, moderately repetitive sequence, and low-copy number sequences. A total of 219 clones containing single or low-copy number sequence inserts were examined for any polymorphisms between two strains of J111 and $C_3$. Forty six clones showed RFLPs and 10 of these clones were used as a probe of analysis of $F_2$ population derived from crossing between J111 and $C_3$ strain. The genetic inheritance tested with each clones will be important tools to construct the genetic map of the silkworm, Bombyx mori.

• BMB Reports
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• v.29 no.2
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• pp.137-141
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• 1996

A partial cDNA encoding a Korean radish isoperoxidase was obtained from a cDNA library prepared from 9 day old radish root. In order to obtain Korean radish isoperoxidase cDNA, 5' RACE (rapid amplification cDNA end) PCR was performed and a cDNA (prxK1) encoding a complete structural protein was obtained by RT (reverse transcription)-PCR. Sequence analysis revealed that the length of the cDNA was 945 base pairs, and that of the mRNA transcript was ca. 1.6 kb. The deduced amino acid of the protein were composed of 315 amino acid residues and the protein was 92% homologous to turnip peroxidase, and 46% to 50% homologous to other known peroxidases. The 945 bp cDNA encoding Korean radish isoperoxidase was overexpressed in Escherichia coli up to approximately 9% of total cellular protein. The recombinant fusion protein exhibited 43 kDa on SDS-PAGE analysis and the activity level of the recombinant nonglycosylated protein was two fold higher in IPTG induced cell extracts than that of uninduced ones.

• Journal of Life Science
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• v.7 no.3
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• pp.167-171
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• 1997

As an initial effort to elucidate RNA: protein binding in a way to regulate translation initiation and phosphorylation, a cDNA encoding a double-stranded RNA binding factor (RBFII)was isolated from Hela ZAPII cDNA library by affinity screening using [$\alpha$$^{-32}$P] UMP-labeled HIV Rev-responsive element(RRE) RNA. The nucleotide sequence of RBF (or TRBP) cDNA except the 5’end. At the 5’end, This common ORF was fused in-frame to N-terminal residues of Lac-Z through a unique 138 nt sequence encoding 46residues in the case of RBFII and a 63 nt sequence encoding 21 residuces in the case of RBFI. The context of ATG appearing first in the sequences suggests that both these cDNA inserts are incomplete at the 5’end.