• Journal of Life Science
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• v.17 no.2 s.82
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• pp.235-240
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• 2007

AvrRpt2 protein triggers hypersensitive response (HR) and strong disease resistance when it is translocated from a bacterial pathogen Pseudomonas sp. to host plant cells containing a cognate RPS2 resistance protein through Type III Secretion System (TTSS). However, AvrRpt2 protein can function as the effector that suppresses a basal defense and enhances the disease symptom when functional RPS2 resistance protein is absent in the infected plant cells. Using Affymetrix Arabidopsis DNA chip, we found that many genes were specifically regulated by AvrRpt2 protein in the rps2 Arabidopsis mutant. Here, we showed that expression of AtERF11 that is known as a member of B1a subcluster of AP2/ERF transcription factor family was down regulated specifically by AvrRpt2. To determine its function in plant resistance, we also generated the Arabidopsis thaliana transgenic plants constitutively overexpressing AtERF11 under CaMV 355 promoter, which conferred an enhanced resistance against a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Thus, these results collectively suggest that AtERF11 plays a role as a positive regulator for disease resistance against biotrophic bacterial pathogen in plant.

• Journal of Radiation Protection and Research
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• v.22 no.1
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• pp.15-21
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• 1997

In vitro somatic mutation induced by ${\gamma}$-radiation and pentachlorophenol(PCP) which is representative of chemical pollutant was measured at the hypoxanthine-guanine phosphoribosyl transferase(hprt) locus in human T- lymphocytes by a cell cloning assay. Mutant cells were selected by their ability to form a clone in the presence of purine analogue 6-thioguanine. The mutant frequencies by ${\gamma}$-irradiation to a dose of 1.0 Gy, 2.0 Gy and 3.0 Gy were 40%, 400% and 750% higher than those in controls. Significant changes were not observed in mutant frequencies in the 0.2 Gy and 0.5 Gy irradiated groups. When the doses of PCP were 15 ppm, 25 ppm and 50 ppm, the mutant frequencies increased by 30%, 90% and 520%, respectively. No changes were observed in the 10 ppm treated group. Similar types of dose-response relationship were shown in the two different mutagens. Reverse transcriptase/polymerase chain reaction technique(RT/PCR) was needed for the mutation spectrum to discriminate combined exposure to radiation and chemicals.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.334-340
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• 1998

This research was conducted to identify plant regulatory regions by gene tagging method. A promoterless GUS coding sequence was introduced to Populus nigra ${\times}$ P. maximowiczii via Agrobacterium strains(LBA4404/EHA101), and putative transgenic poplars were selected by culturing on medium containing G418($60mg/{\ell}$) and by GUS assay. Among them one positive plant was to amplify the native sequences flanking to the introduced GUS gene in plant genome by inverse PCR method and from this 730 by DNA product was obtained. After subcloning and sequencing, it has 88% homology to the Eucalyptus gunnii CAD(cinnamyl alcohol dehydrogenase) gene. The GUS gene fused with the putative promoter reinserted into poplar leaves by particle bombardment method to test the funtional promoter activity. Upon staining with X-gluc, many blue spots appeared on the leaf segments bombarded by the chimeric gene 2-3 days, thus the isolated DNA fragment contain some possible coding region as well as a putative regulatory sequences of poplar CAD gene.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.110-116
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• 1998

The secY gene of Streptomyces lividans TK24 was cloned by the PCR method with synthetic oligonucleotide primers designed on the basis of the conserved regions of Ll5-secY-adk operon from E. coli, B. subtilis, and M luteus. The deduced amino acid sequences of the SecY are highly homologous to those of other known SecY. It has 46%, 43%, 57%, 44%, 42%,56%, 90% similarity to Escherichia coli, Bacillus subtilis, Micrococcus luteus, Bacillus licheniformis Staphylococcus carnosus, Brevibacterium flavum, Streptomyces scabies, respectively and almost the same with Streptomyces coelicolor, The gene organization of Ll5- SecY-Adk is also similar to those of other bacteria. SecY and Adk are very likely translationally coupled that is overlapping stop codon of SecY and start codon of Adk with one base pair, which is common structure among high GC content strains of gram positive bacteria.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.109-113
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• 1998

In this study we tried to transform an antimicrobial peptide gene (Shiva) under the promoter of tomato phenylalanine ammonia-lyase (tPAL5) into tobacco and potato plants. Antimicrobial peptide gene was isolated originally from giant silk moth (Hyalophora cecropia) and modified ie nucleotide sequence to increase antimicrobial activity. Transgenic tobacco plants were regenerated and their seeds were tested on the media containing kanamycin (500 mg/L). The results of PCR amplification and genomic Southern blot hybridization confirmed the integration of construct (tPAL5 promoter-Shiva-NOS-GUS-NOS) into chromosome. We observed that one of the transgenic tobacco plants showed chromosome rearrangement when integrated. In case of potato transformation, the efficiency of regeneration was maximized at the medium containing Zeatin 2mg/L, NAA 0.01mg/L, GA$_3$ 0.1mg/L. We also observed the high expression of GUS (${\beta}$-glucuronidase) enzyme which was located next to the terminator sequence of nopaline synthase gene (NOS) in the vascular tissue of stem, leaves of transgenic potatoes. This result suggested that a short sequence of Shiva gene (120 bp) and NOS terminator sequence might be served as a leader sequence of transcript when translated.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.166-174
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• 2003

Microcystin produced by cyanobacteria in surface waters, such as eutrophic lake and river, is a kind of serious environmental problems due to its toxicity to human and wild animals. Microcystin is synthesized nonribosomally by the large modular multi-functional enzyme complex known as microcystin synthetase encoded by the mcy gene cluster. Amplification of mcy genes by PCR from cultures and environmental samples is a simple and efficient method to detect the toxigenic Microcystis. In order to evaluate primers designed to detect toxic microcystin-producing strains, 17 cyanobacterial strains and 20 environmental samples were examined by PCR with 7 pairs of primers. Some microcystin-producing cyanobacteria were not detected with FAA-RAA, TOX4F-TOX4R and FP-RP primers. The fragment of unexpected size was amplified with NSZW2-NSZW1 primers in Microcystis strains isolated from the lakes in Korea. TOX1P-TOX1F primers failed in amplification of toxin-producing strains. Only MSF-MSR and TOX2P- TOX2F primers amplified the fragments of mcy genes from 11 strains of microcystin-producing Microcystis. The water samples taken from 20 lakes in Korea were analyzed by PCR using each of the primers. In all the water samples, cyanobacteria capable of producing microcystin were detected by the PCR with TOX2P-TOX2F primers. These results indicate that TOX2P-TOX2F primers are better than the other primers for detection of microcystin-producing Microcystis strains in Korea. The nucleotide sequences of mcy gene in Microcystis aeruginosa NIER10010 suggest genetic diversity of Korean isolates.

• KSBB Journal
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• v.18 no.3
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• pp.190-196
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• 2003

An analytical system detecting DNA particularly utilizing a concept of membrane strip chromatography initially applied to home-version tests for, such as, pregnancy and ovulation has been developed. We have chosen S. typhimurium as model analyte among food-contaminating microorganisms that occurred in high frequencies, and invA gene, as a detection target, specific to Salmonella species. This gene was able to be amplified by PCR under optimal conditions employing newly designed primers in our laboratory. The PCR product was specifically measured via hybridization between the analyte and a DNA probe, which was a totally different feature from the conventional gel electrophoresis detecting the products based only on the molecular size. It is notable thar the DNA probe sequence was specially designed such that no separation of excess primers present after PCR was required. This was immobilized on a nitrocellulose (NC) membrane via streptavidin-biotin linkage minimizing a steric effect when the hybridization with the amplified DNA took place. The analyrical system detected the microorganism in a concentration of minimum $10^3$ cfu/mL (i.e., 10 cells per system), estimated from the standard curve, 20 to 40 minutes after adding the sample. This sneitivity was approximately 10 times higher than that of gel electrophoresis as an analytical tool conventionally used. Furthermore, the assay was able to be run at room temperature, which would ofter an extra advantage to users.

• 대한위암학회:학술대회논문집
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• 2002.04a
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• pp.9-17
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• 2002

위의 parietal cell 혹은 대식세포와 유사한 세포 내부에서 H. pylori가 발견된다는 보고가 있기는 하나 일반적으로 H. pylori는 Shigella와 같은 침습성 세균은 아닌 것으로 알려져 있다. 그럼에도 불구하고 H. pylori에 감염된 위점막에는 많은 수의 호중구를 위시한 염증세포의 침윤이 관찰되는데 H. pylori가 위상피세포에 부착 할 경우 위상피세포를 자극하여 interleukin-8을 위시한 cytokine 을 발현케하고 이에 의하여 호중구 등의 염증세포가 몰려들게 된다. 한편 고유층에 몰려든 호중구에서는 다시 interleukin-8을 위시한 일련의 호중구 활성화 chemokine을 분비하여 염증반응을 증폭해 나갈 것이다. 호중구에서 발현되는 myeloperoxidase나 활성 산소 등도 위점막의 조직 손상에 기여할 것이다. 위상피세포를 덮고 있는 점액층은 위상피세포를 보호한다고 알려져 있으나 H. pylori 감염의 경우 점액층에 의하여 H. pylori의 운동성이 증가하고 이것이 위상피세포로부터의 cytokine 발현을 자극하여 염증반응을 증폭하는데 관여할 가능성도 있다. H. pylori는 위상피세포에 대하여 apoptosis를 유도함과 동시에 고유층에 몰려든 호중구에 대하여는 apoptosis를 억제케하여 궁극적으로 염증반응을 증폭 및 지속시켜 나가는 쪽으로 작용한다. 한편 H. pylori는 위상피세포로부터 COX-2의 발현을 증가시키는데 이는 위상피세포의 apoptosis를 억제하는 방향으로 작용한다. 이외에 H. pylori의 urease에 의하여 발생한 암모니아나 H. pylori 자신이 분비하는 세포독소가 세포 손상을 유발할 가능성도 있다. 상술한 여러 독성 인자들 중 어느 하나가 단독으로 작용하기보다는 여러 인자가 같이 동시에 또는 시차를 두고 작용할 가능성이 많다고 생각된다.(\gamma-FeOOH)$, 침철광$(\alpha-FeOOH)$, 적금광$(\beta-FeOOH)$, 그리고 자철광$(Fe_3O_4)$이다. 인위적 부식에서는 전부 인철광의 부식물이 생성되었고 자연적 부식에서는 모두 침철광의 부식물이 생성되었다. 특히 철제 표면에 자연적으로 생성된 공식 녹을 XRD 분석한 결과 적금광으로 동정되었다. 이런 모든 시편들을 각 탈염방법에 따라 탈염처리한 후 XRD와 SEM-EDS으로 분석한 결과 인철광과 침철광은 어떠한 변화도 보이지 않았고, 다만 적금광으로 동정된 시편만이 잔존하지 않았다. 철기 제작별 $Cl^-$ 이온 추출량과 탈염효과에 대한 비교 실험은 이온 크로마토그래피 분석 결과와 마찬가지로 단조 철제유물이 주조 철제보다 $Cl^-$ 이온을 많이 가지고 있었으며, 탈염 처리 후에는 $Cl^-$ 이온은 전혀 발견되지 않았다. 이상의 결과 $K_2CO_3$와 Sodium 용액은 탈염처리에서 가장 적합한 탈염처리 용액으로 알수가 있었으며 특히 어떠한 탈염 용액으로 유물을 처리한다 해도 철제유물에 생성된 부식물은 제거되지 않는다는 것을 알게 되었다. 따라서 보존처리자는 유물 표면의 부식 상태만을 보고 처리하기 보다는 철기제작물로 고려하여 처리하는 것이 필요하다. 또한 금속에 부식을 야기시키는 $Cl^-$ 이온과 부식물을 완전하게 제거하여 탈염처리를 하는 것이 유물 부식을 최대한 지연시킬 수 있는 것이라 생각된다.TEX>$88\%$)였다.(P=0.063). 결론: 본 연구에서는 MTHFR C/T & T/T 유전자 다형성이 위암의 발생과 그 위치에 대해 관련이 있는 것으로 여겨지고, 흡연력, 음주력과는 관련이 없는 것으로 여겨진다.험이

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.114-114
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• 2002

포유동물에서 뇌와 부신에서 합성.분비되는 카테콜아민(Catecholamine, CA)계 신경전달물질인 dopamine(DA), norepinephrine(NE), epinephrine(E)은 체내 각종 생리현상의 조절에 필수적이며, 생식과 관련지어서는 시상하부-뇌하수체 간 GnRH-gonadotropin 호르몬 축의 활성을 조절하는 기능 외에도 번식과 관련된 여러 행동양식을 조절함이 잘 알려져 있다. 본 연구는 CA 생합성 효소들인 tyrosine hydroxylase(TH), dopamine beta-hydroxylase(DBH), phenylethanolamine-N-methyltransferase(PNMT)의 유전자 발현에 미치는 sex steroid의 영향을 조사하였다. 성숙한 암컷 횐쥐(SD strain)의 난소를 제거하고 1주 경과 후 vehicle(sesame oil; OVX+Oil 실험군) 또는 estradiol 17$\beta$(235ug/m1; OVX+E$_2$실험군)이 든 silastic capsule(길이 14mm; 내경 1.55mm; 외경 3.125mm)을 48 시간 동안 처리한 뒤 희생시켰다. 적출된 조직으로부터 RNA를 추출한 후 semi-quantitative RT-PCR을 시행하였다. (i) TH의 발현 정도는 OVX+Oil 군에서는 시상하부) substantia nigra(SNc)) 부신 순으로, OVX+E$_2$군에서는 SN글 부신) 시상하부 순으로 나타났다. TH 발현에 미치는 estradiol의 효과로 SNc과 부신에서는 유의한 증가를 보인데 비해 시상하부에서는 유의한 감소를 관찰하였다. (ii) DBH 발현 정도는 OVX+Oil군에서는 SNc> 부신> 시상 하부 순으로, OVX+E$_2$군에서는 부신＞ SNc＞ 시상하부 순이었다. DBH 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 감소하는 경향을 보였다. (iii) PNMT의 발현의 경우 SNc와 시상하부에서는 기보고된 바와 같이 alternative splicing에 의해 110bp 차이의 크고 작은 두 형태의 cDNA(PNMTI & PNMTs)가 증폭되었으나 부신에서는 작은 cDNA 만이 관찰되었다. PNMTs의 발현 정도는 OVX+Oil군과 OVX+E$_2$군에서 공히 부신＞ 시상하부＞ SNc 순이었고, PNMTI의 발현은 SNc가 시상하부 보다 다소 높은 경향이었으나 유의성은 없었다. PNMTs 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 증가하는 경향을 보였다. 본 연구에서는 CA 생합성 효소들의 유전자 발현의 조절에 미치는 estrogen 의 영향이 세포 기원이 neural crest cell인 부신 수질은 물론 뇌의 상이한 지역간에서도 조직특이적임을 관찰하였다. 이러한 결과는 각 조직에서의 estrogen 수용체 유형의 차이 혹은 작용 모드와 각 효소 유전자 발현 사이에 중요한 상관관계가 있음을 시사한다.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.149-154
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• 2007

In the present study, we performed the PCR assay using TOX2P/TOX2M primer targeting a specific region within mcyB gene to identify potential microcystin-producing cyanobacteria. TOX2P/TOX2M primer set was effective in amplifying mcy gene in the field samples containing Microcystis spp. of 1,000 cells per mL. Moreover, the results from the PCR assay agreed with those of the ELISA analysis. Consequently, this study demonstrated that TOX2P/TOX2M primer set can be used as a genetic probe for the early detection of cyanobacterial toxigenicity in Korean water bodies.