• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.48-48
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• 2003

본 실험은 spermatogonia 단계에 발현하는 유전자를 찾기 위하여 suppression subtractive hybridization를 수행하였다. 기존에 mouse에서는 spermatogonia 특이적인 유전자들이 밝혀져 있기 때문에 pig에 특이적인 유전자를 찾기 위하여 pig 250days testis와 pig 60days testis를 재료로 하여 실험하였다. SSH를 통하여 254days testis에 특이적으로 발현되는 후보유전자를 7개 찾았고 25days testis와 60days testis 의 Northern blot을 통하여 25days에 과발현하고 60days에 발현의 양이 대폭 줄어드는 spermatogonia 유전자로 생각되는 후보유전자 2개를 선택하여 pig tissue northern blot, genomic DNA southern blot, RT-PCR 그리고 In-situ hybridization을 수행하였다. Tissue northern blot과 RT-PCR을 통하여 후보자 1번은 간과 폐, 난소, 정소에서 발현하고, 후보유전자 15번은 난소와 정소에서만 특이적으로 발현함을 알았다. DNA sequence analysis와 NCBI Blast search를 통하여 후보자 1번은 다른 종에서 밝혀진 유전자였고 후보유전자 15번은 어느 종에서도 밝혀지지 않은 새로운 유전자였다. Degenerated primer를 통하여 후보자 1번의 pig full sequence를 밝히고 NCBI에 등록하였다. 그리고 In-situ hybridization을 통하여 후보유전자득이 20일째 testis의 Leydic cell에서 많이 발현되고 adult testis에서는 발현이 감소하는 결과를 얻었다. 이것으로 보아 위의 두 후보유전자는 spermatogonia에 직접 관련된 유전자이기 보다는 spermatogonia의 발달에 영향을 주는 leydic cell 특이발현을 가진 유전자로 사료되어진다.

• Molecules and Cells
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• v.20 no.2
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• pp.247-255
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• 2005

Three different catalase cDNA clones (CaCat1, CaCat2, and CaCat3) were isolated from hot pepper (Capsicum annuum L.), and their expression patterns were analyzed at the levels of mRNA and enzyme activity. Northern hybridization showed that the three catalase genes were differentially expressed in various organs, and that expression of CaCat1 and CaCat2 was regulated differently by the circadian rhythm. In situ hybridization revealed different spatial distributions of CaCat1 and CaCat2 transcripts in leaf and stem. In response to wounding and paraquat treatment, CaCat1 mRNA increased at 4-12 h in both paraquat-treated and systemic leaves. In contrast, wounding had no significant effect on expression of the catalase genes. The increase of catalase activity in the paraquat-treated and systemic leaves paralleled that of CaCat1 mRNA, but did not match that of CaCat1 mRNA in paraquat-treated stems. Our results suggest that CaCat1 may play a role in responses to environmental stresses.

• Journal of Plant Biology
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• v.38 no.2
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• pp.203-209
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• 1995

Tobacco (Nicotiana tahacum L. cv. Wisconsin 38) leaf discs were cocultivated with Agrohacterium carrying a leghemoglobin (Lb) cDNA from Canavalia lineata. Seven plants were regenerated from the transformed leaf discs on MS media supplemented with 0.5 mg/L BAP, 0.1 mg/L ${\alpha}-NAA$, 200 mg/L kanamycin and 500 mg/L carbenicillin. Southern hybridization and PCR of genomic DNA from transgenic plants showed that the Lb cDNA was stably integrated into the genome of the tobacco. Total RNA from the transgenic tobacco showed northern hybridization signal at 1,000 nt and PCR of the first strand cDNA synthesized from the total RNA amplified 0.5 kb Lb cDNA. Furthermore, western hybridization using a polyclonal antibody against soybean Lb showed a 15.8 kD LB-like band on SDS-PAGE of proteins from the transformed tobacco. These results demonstrated that the Lb cDNA of C. lineata was not only incorporated into the genome of tobacco, but also transcribed into mRNA and translated into Lb protein in the transformed tabacco.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.43-50
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• 2005

Purpose : A number of genes and their products are Induced early or late following exposure of cells to ionizing radiation. These radiation-Induced genes have various effects on irradiated cells and tissues. Suppression subtractive hybridization (SSH) based on PCR was used to Identify the differentially expressed genes by radiation in cervix carcinoma cells. Materials and Methods : Total RNA and poly $(A)^+$ mRNA were Isolated from Irradiated and non-irradiated HeLa cells. Forward- and reverse-subtracted cDNA libraries were constructed using SSH. Eighty-eight clones of each were used to randomly select differentially expressed genes using reverse Northern blotting (dot blot analysis). Northern blotting was used to verify the screened genes. Results : Of the 17t clones, 10 genes in the forward-subtracted library and 9 genes In the reverse-subtracted library were identified as differentially expressed radiation-induced genes by PCR-select differential screening. Three clones from the forward-subtracted library were confirmed by Northern blotting, and showed increased expression in a dose-dependent manner, including a telomerase catalytic subunit and sodium channel-like protein gene, and an ESTs (expressed sequence tags) gene. Conclusion : We Identified differentially expressed radiation-induced genes with low-abundance genes with SSH, but further characterization of theses genes are necessary to clarify the biological functions of them.

• Molecules and Cells
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• v.23 no.1
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• pp.100-107
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• 2007

The moss Physcomitrella patens has two life cycles, filamentous protonema and leafy gametophore. A modified from of suppression subtractive hybridization (SSH), mirror orientation selection (MOS), was applied to screen genes differentially expressed in the P. patens protonema. Using reverse Northern blot analysis, differentially expressed clones were identified. The identified genes were involved mainly in metal binding and detoxification. One of these genes was an AP2 (APETALA2) domain-containing protein (PpACP1), which was highly up-regulated in the protonema. Alignment with other AP2/EREBPs (Ethylene Responsive Element Binding Proteins) revealed significant sequence homology of the deduced amino acid sequence in the AP2/EREBP DNA binding domain. Northern analysis under various stress conditions showed that PpACP1 was induced by ethephon, cadmium, copper, ABA, IAA, and cold. In addition, it was highly expressed in suspension-cultured protonema. We suggest that PpACP1 is involved in responses to metals, and that suspension culture enhance the expression of genes responding to metals.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.440-446
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• 2006

To investigate flowering related genes in winter-type oilseed rape (Brassica napus L. cv. Tammi), differentially expressed genes were isolated from leaves of the plant after low temperature treatment which is requirements for floral induction. As a result of suppression subtractive hybridization (SSH), 288 clones were randomly selected from SSH library. Using reverse Northern blot analysis, 150 of 288 clones were identified to be differentially expressed. Out of these 150 clones, 45 clones showed very high identities with the known genes. Four clones showed very high identities over 90% with metallothionein-like gene that is related to flowering-induced genes. Of these 4 clones, the cDNA clone, rfs-13, revealed high identity with meotallothionein-like protein in Arabidopsis thaliana (98%) and Brassica compestris (89%). Furthermore, gene expressed in immature flower stages was confirmed by Northern blot analysis.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.137-141
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• 2002

The SNF2/SW12 family comprises proteins from a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. This study was shown the characterization of hrp2+ gene which was isolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of hrp2+ gene showed striking evolutionary conservation among the SNF2 family of proteins. The transcript of hrp2+ gene was found to be a 4.7 kb as identified by Northern hybridization. In addition, to determine the transcription initiation site of hrp2+ gene, primer extension analysis was performed. This result showed the band of 64 bp. The transcriptional start point was mapped to a position of 47 base pair from the first ATG codon of translational initiation codon. In order to investigate the inducibility of hrp2+ gene, transcript levels were examined after treating the cells to various DNA damaging agents. The transcripts of hrp2+ were induced by UV-irradiation. But the transcripts were not induced by treatment of 0.25% Methylmethane sulfonate (MMS). These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of this gene.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.192-196
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• 2005

The SNF2/SW12 family comprises proteins from a variety of species with in vivo functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. This study was shown the characterization of hrp2+ gene which was isolated by PCR amplification using the conserved domain of SNF2 motifs. Sequence analysis of hrp2+ gene showed striking evolutionary conservation among the SNF2 family of proteins. The transcript of hrp2+ gene was found to be a 4.7 kb as identified by Northern hybridization. To investigate the inducibility of hrp2+ gene, transcript levels were examined after treating the cells to various DNA damaging agents. The transcripts of hrp2+ were induced by UV-irradiation. But the transcripts were not induced by treatment of $ 0.25\%$ Methylmethane sulfonate (MMS). These results implied that the effects of damaging agents are complex and different regulatory pathways exist for the induction of this gene. Hrp2 protein was purified near homogeneity by combination of affinity chromatography. We tested the purified Hrp2 protein for the helicase activity in an oligonucleotide release assay. However we were unable to detect any helicase activity associated with the Hrp2 protein, indicating that the helicase motifs in Hrp2 are merely indicators of a broader DNA-dependent ATPase activity.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.91-99
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• 2014

The objective of this study is to identify cold-tolerance genes in Brassica rapa. In order to acheive this goal, we analyzed a KBGP-24K oligo chip data [BrEMD (B. rapa EST and Microarray Database)] using B. rapa ssp. pekinensis inbred line 'Chiifu' under cold stress condition ($4^{\circ}C$). Among 23,929 unigenes of B. rapa, 417 genes (1.7%) were primarily identified as cold responsive genes that were expressed over 5-fold higher than those of wild type control, and then a gene which has unknown function and has full length sequence was selected. It was named BrCSR (B. rapa Cold Stress Resistance). BrCSR was transformed using expression vector pSL101 to confirm whether BrCSR can enhance cold tolerance in tobacco plants. $T_1$ transgenic tobacco plants expressing BrCSR were selected by PCR and Southern hybridization analyses, and the function of BrCSR was characterized by expression level analysis and phenotype observation under cold stress condition. The expression level of BrCSR in transgenic tobacco plants increased up to about two folds in quantitative real-time RT-PCR assay and this was very similar to Northern blot hybridization analysis. Analysis of phenotypic characteristics clearly elucidated that transgenic tobaccos expressing BrCSR were more cold tolerant than wild type control under $4^{\circ}C$ treatment. Based on these results, we conclude that the over-expression of BrCSR might be closely related to the enhancement of cold tolerance.

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.114-117
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• 2003

In molecular biology, it is necessary to develop an easy and rapid method to identify a specific DNA sequence. Though Southern and Northern blot techniques have been used widely for the analysis of gene structure and function, those methods are inconvenient in the points that we need to control incubation temperature, time, and other parameters to get the final result. In this study, we report a new method for the rapid analysis of specific DNA sequence with the modification of an immunochromatographic method. The lateral flow DNA analysis strip is composed of a sample pad, a nitrocellulose membrane for the separation and propagation of analytes, and an absorption pad for the generation of capillary action. Capture DNA was immobilized on the membrane by UV cross-linking and target DNA was labeled with Cy-5 for signaling. The samples containing target DNA were applied onto the sample pad, incubated for 15 min for separation, and scanned with a GSI fluorescence scanner. Though the hybridization reaction occurs in a short time without any washing steps, there appears to be little cross hybridization between the different sequences. The result showed a possibility that the new method can be used for the rapid identification of specific DNA sequence among the samples.