• BMB Reports
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• 제34권1호
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• pp.59-65
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• 2001

In subtractive hybridization, target sequences in the tester are enriched by hybridizing with an excess amount of driver, followed by removing the tester hybridized with the driver. All of existing subtractive cloning methods are designed to remove the tester/driver hybrid. The removal of hybrid, however, is often unsatisfactory For various reasons. In this study we developed a subtractive enrichment protocol in which the tester/driver can be completely removed by selecting only the tester/tester after hybridization. In this protocol both the tester and driver DNAs are ligated with same linker DNAs and amplified by polymerase chain reaction (PCR). The tester DNA is then digested with two different enzymes and used in subsequent hybridization with an excess driver. After hybridization, the DNA is ligated with the adaptor that is only compatible with the tester/tester. Since only the tester/tester can have the new adaptor, no tester/driver can be amplified by PCR in this protocol. Unlike other methods, a 100% subtraction efficiency can be achieved even though the enzymatic treatments used in the enrichment procedure are incomplete. Furthermore, only the hybridized tester DNA can have the new adaptor and be amplified by PCR, resulting in 100% denaturation in effect. The efficacy of this novel method was verified with the model system in which a known amount of the target sequence is included.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
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• pp.49-49
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• 2001

• Journal of Plant Biology
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• 제39권3호
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• pp.189-195
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• 1996

The major cuticular components have been shown to be synthesized in the epidermis. Therefore, cloning of epidermis-specific genes could yield information to be used to isolate and characterize the enzymes involved in the cuticle biosynthesis. A subtractive cDNA library was prepared from Senecio odorus in which epidermis-specific cDNAs were enriched. Differential screening of the library using epidermal and non-epidermal probes revealed two cDNAs. One of them designated epi425 was identified, based on the sequence homology, as a member of a new class in the LTP gene family and the other clone designated epi23 as a gene encoding an aldehyde decarbonylase. Northern blot analyses showed that epi425 and epi23 cDNAs hybridized with a transcript of about 600 and 2, 100 nucleotides, respectively, from the epidermis but not from the non-epidermal tissues. Further characterization of these clones will provide more information on the mechanism of the cuticle biosynthesis.

• Journal of Plant Biotechnology
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• 제29권2호
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• pp.79-84
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• 2002

Suppression subtractive hybridization (SSH)를 통해 상처에 의해 발현이 유도되는 cDNA들을 분리하였고, 그 중 하나인 gmwi33은 $\beta$-amyrin synthase 유전자들과 높은 유사성을 보였다. gmwi33의 전장 cDNA인 GmAMS1은 2416 bp 길이에 739개 아미노산으로 구성된 긴 open reading frame(ORF)를 포함하고 있었다. GmAMS1 단백질은 감초의 $\beta$-amyrin synthase인 GgbAS와 89%, 완두의 OSCPSY와 86%의 유사성을 보였다. 암조건 하에 5일간 기른 콩나물에서, GmAMS1는 빛을 쪼여주었을 때 가장 강하게 발현되었고 methyl jasmonate 처리와 저온처리 시에도 발현이 유도된 반면, UV-B나 elicitor를 처리하였을 때는 발현이 유도되지 않았다. 이러한 GmAMS1의 발현양상은 사포닌의 활성산소 제거기능과 밀접한 연관이 있을 것으로 추측된다.

• The Plant Pathology Journal
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• 제26권4호
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• pp.380-385
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• 2010

Suppression subtractive hybridization was used to isolate wound-induced genes from soybean. One of the wound-induced genes, gmwi143 designated as GmCCR, showed high homology with genes encoding cinnamoyl-CoA reductase (CCR; EC 1.2.1.44). Deduced amino acid sequences encoded by GmCCR showed the highest identity (77%) with those of Acacia CCR. There are 2 CCR genes highly homologous to GmCCR in soybean genome based on Phytozome DB analysis. RNA expression of GmCCR was specifically induced by local and systemic wounding, drought, high salinity or by ultraviolet stress. Our study suggests that GmCCR may be involved in resistance mechanism during abiotic stresses in plants.

• 한국발생생물학회지:발생과생식
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• 제6권2호
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• pp.89-96
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• 2002

성장을 멈추고 있는 원시난포(primordial follicle)에서 난포발달이 개시되어 1차난포(primary follicle)로 발달하는 조절기전은 잘 알려져 있지 않다. 이 초기 난포발달 과정에 관여하는 유전자를 알아내기 위해 suppression subtractive hybridization(SSH)을 사용하였다. 생후 1일과 5일째의 생쥐 난소로부터 얻은 cDNA로 forward와 reverse subtraction을 수행하여 각각 day1과 day5-subtracted cDNA library를 얻었다. 이를 cloning한 결과, 357개 clone의 염기 서열을 BLAST와 RIKEN을 이용해 분석하여 27개의 clone은 novel gene으로 330개의 clone은 데이터 베이스와 일치함을 알았다. 이 중에 기능이 알려진 유전자는 day1에서는 42종, day5에서는 47종이 각각 차이 나게 발현하고 있는 것으로 나타났다. Day1-subtracted cDNA library에서는 GDF8, lats2, septin2, wee1등 4개 유전자를, day5-subtracted cDNA library에서는 HSP84, laminin2, MATER, MTi7, PTP 및 wrn등 6개 유전자를 선택하여 LCM-RT-PCR방법으로 실제로 원시난포와 1차난포에서 차이 나게 발현되고 있는 것을 확인하였다. 본 연구에서 얻은 유전자 발현 양상의 결과는 앞으로 생쥐뿐만 아니라 사람 난소에서 primordial-primary follicle transition에 관여하는 기전을 연구하는데 중요한 정보를 제공할 수 있을 것으로 사료된다.

• BMB Reports
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• 제37권5호
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• pp.527-532
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• 2004

A subtracted cDNA library specific to osmotic stress of Haloxylon ammodendron (Mey.) Bge seedlings was constructed by suppression subtractive hybridization (SSH) and T/A cloning. SSH was performed between two groups of H. ammodendron seedlings, one was cultivated in Hoagland (H) solution as a driver and the other group was treated with osmotic stress of the Hoagland solution by the addition of 400 mM mannitol (M), as a tester. The library consisted of about 400 recombinant clones, with the average size being of 500 bp, ranging from 300 bp to 1500 bp. Using a PCR-select differential screening kit, 100 recombinant clones were randomly chosen from the subtracted cDNA library and hybridized with forward,reverse subtracted and unsubtracted probes for two rounds. As a result, 21 positive clones specific to osmotic stress were obtained and some of them were verified by Northern blot analysis. The sequencing analysis of 6 positive clones and the following homology comparison to GenBank [blastx] non-redundant databases characterized that two sequences obtained in this experiment may contribute to novel drought-related genes.

• 한국발생생물학회지:발생과생식
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• 제7권2호
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• pp.119-126
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• 2003

본 연구실에서는 이전의 실험에서 suppression subtractive hybridization(SSH)을 통하여 생쥐의 생후 1일자 난소와 5일자 난소에서 차이 나게 발현하는 유전자들의 목록을 얻었고 그 중에서 MT transposon-like element, clone MTi7(MTi7)이 성장하는 난포에서 더 높게 발현한다는 것을 알아냈다(Park et al., 2002). In situ hybridization과 RNA interference를 이용한 연구결과, MTi7은 난자에서 특이 적으로 발현하는 유전자로 특히 난자성숙에 관여하는 것으로 관찰되었다(Park et at., 2003). 그러나 현재까지 MTi7의 염기서열은 생쥐에서만 알려져 있다. 따라서 본 연구는 두 부분으로 나누어서 첫째, MTi7이 다른 포유류에도 존재하는지 알아보기 위해 소,돼지, 흰쥐 그리고 사람 등 각기 다른 네 종의 난소 cDNA를 사용하여 새로운 MTi7을 분리하고자 하였으며, 둘째, 생쥐의 MTi7이 transposon의 특징을 갖고 있어 다른 유전자에 삽입되어 있는지를 알아보기 위해 inverse PCR을 시행하여 MTi7주변의 유전자가 있는지를 조사하였다. 네 종의 난소 cDNA를 사용하여 생쥐의 MTi7과 매우 유사한 염기서열을 갖고 있음을 알았다(87%∼98%). Inverse PCR 결과, 생쥐의 MTi7은 beta-carotene 15, 15'-monooxygenase(Bcdo) 유전자 혹은 serine protease inhibitor, Kunitz type I(Spint 1) 유전자에 삽입되어 있음을 알 수 있었다. 본 연구의 결과로 여러 포유류의 MTi7 sequence를 알아내고, 또한 생쥐의 MTi7이 삽입되어 있는 유전자를 알아냄으로써 머지 않은 장래에 난자형성 및 난포형성과정에 있어서 MTi7의 역할을 밝혀 낼 수 있을 것으로 기대된다.

• 식물조직배양학회지
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• 제27권4호
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• pp.259-268
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• 2000

Senescence is a sequence of biochemical and physiological events that lead to death of a cell, organ, or whole organism. Senescence is now clearly regarded as a genetically determined and evolutionarilly acquired developmental process comprising the final stage of development. However, in spite of the biological and practical importance, genetic mechanism of senescence has been very limited. Through forward and reverse genetic approaches, we are trying to reveal the molecular and genetic mechanism of senescence in plants, employing leaf organs of Arabidopsis as a model system. Using forward genetic approach, we have initially isolated several delayed senescence mutants either from T-DNA insertional lines or chemical-mutagenized lines. In the case of ore 4 and ore 9 mutants, the mutated genes were identified. The recent progress on characterization of mutants and identification of the mutated genes will be reported. We are also screening mutations from other various sources of mutant pools, such as activation tagging lines and promoter trap lines. Two dominant senescence-delayed mutants were isolated from the activation tagging pool. Cloning of the genes responsible for this phenotype is in progress. For reverse genetic approach, the genes that induced during leaf senescence were first isolated by differential screening method. We are currently using PCR-based suppression subtractive hybridization, designed to enrich a cDNA library for rare differentially expressed transcripts. Using this method, we have identified over 35 new sequences that are upregulated at leaf senescence stage. We are investigating the function of these novel genes by systemically generating antisense lines.

• The Plant Pathology Journal
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• 제21권1호
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• pp.47-54
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• 2005

Identification of host genes involved in disease progresses and/or defense responses is one of the most critical steps leading to the elucidation of disease resistance mechanisms in plants. Soybean mosaic virus (SMV) is one of the most prevalent pathogen of soybean (Glycine max). Although the soybeans are placed one of many important crops, relatively little is known about defense mechanism. In order to obtain host genes involved in SMV disease progress and host defense especially for virus resistance, two different cloning strategies (DD RT-PCR and Subtractive hybridization) were employed to identify pathogenesis- and defenserelated genes (PRs and DRs) from susceptible (Geumjeong 1) and resistant (Geumjeong 2) cultivars against SMV strain G7H. Using these approaches, we obtained 570 genes that expressed differentially during SMV infection processes. Based upon sequence analyses, differentially expressed host genes were classified into five groups, i.e. metabolism, genetic information processing, environmental information processing, cellular processes and unclassified group. A total of 11 differentially expressed genes including protein kinase, transcription factor, other potential signaling components and resistant-like gene involved in host defense response were selected to further characterize and determine expression profiles of each selected gene. Functional characterization of these genes will likely facilitate the elucidation of defense signal transduction and biological function in SMV-infected soybean plants.