• Journal of Plant Biotechnology
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• 제36권3호
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• pp.294-300
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• 2009

Activation tagging that uses T-DNA vectors containing multimerized transcriptional enhancers from the cauliflower mosaic virus (CaMV) 35S gene is a powerful tool to determine gene function in plants. This approach has been successfully applied in screening various types of mutations and cloning the corresponding genes. We generated an activation tagged hairy root pool of ginseng (Panax ginseng C.A. Meyer) in an attempt to isolate genes involved in the biosynthetic pathway of ginsenoside (triterpene saponin), which is known as the major active ingredient of the root. Quantitative and qualitative variation of ginsenoside in activation tagged hairy root lines were profiled using LC/MS. Metabolic profiling data enabled selection of a specific hairy root line which accumulated ginsenoside at a higher level than other lines. The relative expression level of several genes of triterpene biosynthetic pathway in the selected hairy root line was determined by real time RT-PCR. Overall results suggest that the activation tagged ginseng hairy root system described in this study would be useful in isolating genes involved in a complex metabolic pathway from genetically intractable plant species by metabolic profiling.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.186-186
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• 2022

Phytophthora root and stem rot (PRSR) and wildfire disease (WFD) of soybean are frequently observed in the field of South Korea. The most environmentally friendly way to control PRSR and WFD is to use soybean varieties with resistance to Phytophthora sojae (P. sojae) and Pseudomonas amygdali pv. tabaci. Plant germplasm is an important gene pool for soybean breeding and improvement. In this study, hundreds of soybean accessions were evaluated for the two pathogens, and genome-wide association analyses were conducted using 104,955 SNPs to identify resistance loci for the two pathogens. Of 193 accessions, 46 genotypes showed resistance reaction, while 143 did susceptibility for PRSP. Twenty SNPs were significantly associated with resistance to P. sojae on chromosomes (Chr.) 3 and 4. Significant SNPs on Chr.3 were located within the known Rps gene region. A region on Chr. 4 is considered as a new candidate resistance loci. For evalation of resistance to WFD, 18, 31,74,36 and 34 genotypes were counted by a scale of 1-5, respectively. Five SNP markers on Chrs 9,11,12,17 and 18 were significantly associated with resistance to P. amygdali pv. tabaci. The identified SNPs and genomic regions will provide a useful information for further researches and breeding for resistance to P. sojae and P. amygdali pv. tabaci.

• 대한의생명과학회지
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• 제18권3호
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• pp.324-327
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• 2012

Acanthamoeba is a free-living amoeba that causes human infections, and recently the incidence of amoebic keratitis has increased among contact lens wearers. In order to investigate Acanthamoeba contamination of contact lens storage cases, a short survey was performed on 57 contact lens wearers, and Acanthamoeba was found in one contact lens storage case. To diagnose Acanthamoeba, the 18s small subunit ribosomal DNA (18s rDNA) gene was amplified by polymerase chain reaction (PCR), and subsequently, the isolate was identified as A. lugdunensis. This species was originally isolated from a freshwater pool in France, and was reported recently to be a cause of amoebic keratitis. This observation indicates the need for a large survey to investigate the extent of Acanthamoeba contamination, and suggests that contact lens wearers be aware of the importance of hygiene and of the implications of Acanthamoeba infection.

• 한국작물학회지
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• 제51권spc1호
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• pp.274-276
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• 2006

다량의 페놀류 2차 대사산물과 다당류가 포함된 녹두 종자의 RNA를 Tris-buffer와 guanidium thiocyanate 용액을 이용하여 손쉽고 간편하게 고순도의 RNA를 분리하는 방법을 확립하였으며, 우리의 분리 방법을 이용하여 추출한 RNA를 사용하여 RT-PCR과 유전자 클로닝 등의 분석시험에 이용할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.146-152
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• 2010

Streptomyces clavuligerus NRRL3585 produces a clinically important $\beta$-lactamase inhibitor, clavulanic acid (CA). In order to increase the production of CA, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene (gap) was deleted in S. clavuligerus NRRL3585 to overcome the limited glyceraldehyde-3-phosphate pool; the replicative and integrative expressions of ccaR (specific regulator of the CA biosynthetic operon) and claR (Lys-type transcriptional activator) genes were transformed together into a deletion mutant to improve clavulanic acid production. We constructed two recombinant plasmids to enhance the production of CA in the gap1 deletion mutant of S. clavuligerus NRRL3585: pHN11 was constructed for overexpression of ccaR-claR, whereas pHN12 was constructed for their chromosomal integration. Both pHN11 and pHN12 transformants enhanced the production of CA by 2.59-fold and 5.85-fold, respectively, compared with the gap1 deletion mutant. For further enhancement of CA, we fed the pHN11 and pHN12 transformants ornithine and glycerol. Compared with the gap1 deletion mutant, ornithine increased CA production by 3.24- and 6.51-fold in the pHN11 and pHN12 transformants, respectively, glycerol increased CA by 2.96- and 6.21-fold, respectively, and ornithine and glycerol together increased CA by 3.72- and 7.02-fold, respectively.

• Laboraroty Animal Research
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• 제34권4호
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• pp.311-316
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• 2018

Laboratory inbred mice are used widely and commonly in biomedical research, but inbred mice do not have a big enough gene pool for the research. In this study, genetic and morphometric analyses were performed to obtain data on the characteristics of a newly developing inbred strain (KWM/Hym) captured from Chuncheon, Korea. All of five Korean wild male mice have the zinc-finger Y (ZfY) gene. Also, all of 19 Korean wild mice used in this analysis have the AKV-type murine leukemia virus gene, indicating that Korean wild mice might be Mus musculus musculus. To identify the genetic polymorphism in KWM/Hym, SNP analysis was performed. In a comparison with 28 SNP markers, there was a considerable difference between KWM/Hym and several inbred strains. The homogeneity between KWM/Hym and the inbred strains was as follows: C57BL/6J (39.3%), BALB/c AJic (42.9%), and DBA/2J (50%). KWM/Hym is most similar to the PWK/PhJ inbred strain (96.4%) derived from wild mice (Czech Republic). To identify the morphometric characteristics of KWM/Hym, the external morphology was measured. The tail ratio of male and female was $79.60{\pm}3.09$ and $73.55{\pm}6.14%$, respectively. KWM/Hym has short and agouticolored hairs and its belly is white with golden hair. Taking these results together, KWM/Hym, a newly developing inbred mouse originated from wild mouse, might be use as new genetic resources to overcome the limitations of the current laboratory mice.

• 대한의생명과학회지
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• 제11권2호
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• pp.165-173
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• 2005

A potent demethylating agent, 5-Azacytidine (5-AzaC) has been widely used as in many studies on DNA methylation, regulation of gene expression, and cancer biology. The mechanisms of the demethylating activity were known to be formation of complex between DNA and DNA methyltransferase (MTase), which depletes cellular MTase activity. However, 5-AzaC can also induce hypermethylation of a transgene in a transgenic cell line, G12 cells and it was explained as a result of defense mechanisms to inactivate foreign gene(s) somehow. This finding evoked the question that whether the phenomenon of hypermethylation induced by 5-AzaC is limited to the transgene or it can be occurred in endogenous gene(s). In order to answer the question, mutagenicity test of 5-AzaC and molecular characterization of mutants obtained from the test were performed using an endogenous gene, thymidine kinase (tk) in Chinese hamster V79 cells. When V79 and V79-J3 subclone cells were treated with 1, 2.5 ,5, $10{\mu}M$ of 5-AzaC for 48 hours, their maximum mutant frequencies were revealed as $6\times10^{-3}\;at\;5{\mu}M$(350-fold induction over background) and $8\times10^{-3}\;at\;2.5{\mu}M$ (l,800-fold induction over background) respectively. Since the induction rates were too high to be induced by true mutations, many trifluorothymidine (TFT)-resistant $(TFT^R)$ cells were subjected to Northern blot analysis to check the presence of tk transcripts. Surprisingly, all clones tested possessed the transcripts in a similar level, that implicates the $TFT^R$ phenotype induced by 5-AzaC has not given rise to hypermethylation of the gene in spite of unusually high mutation frequency. In addition, it has shown that the TK activity in the pool of 5-AzaC-induced $TFT^R$ cells has about a half of that in spontaneously-induced $TFT^R$ cells or in non-selected parental V79-J3 cells. This result suggests that the mechanism(s) underlying the TFT-resistance between spontaneously occurred and 5-AzaC-induced cells may be different. These findings have shown that the $TFT^R$ phenotype induced by 5-AzaC has not given rise to hypermethylation of the tk gene, and 5-AzaC may be induced by one or combined pathways among many drug resistance mechanisms. The exact mechanisms for the 5-AzaC-induced $TFT^R$ phenotype remain to elucidate.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권12호
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• pp.1229-1237
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• 2005

분류 성능을 향상시키기 위해서 다수의 분류기들을 결합하는 연구가 활발히 진행되고 있다. 우수한 앙상블 분류기를 회득하기 위해서는 정확하고 다양한 개별 분류기를 구축해야 한다. 기존에는 Bagging이나 Boosting 등의 앙상블 학습 기법을 이용하거나 획득된 개별 분류기의 학습 데이타에 대한 다양성을 측정하였지만 유전 발현 데이타와 같이 학습 데이타가 적은 경우 한계가 있다. 본 논문에서는 유전자 프로그래밍으로부터 획득된 규칙의 구조적 다양성을 분석하여 결합하는 앙상블 기법을 제안한다. 유전자 프로그래밍으로 해석 가능한 분류 규칙을 생성하고 그들 사이의 다양성을 측정한 뒤, 이들 중 다양한 규칙의 집합을 결합하여 분류를 수행한다. 유전 발현 데이타로부터 림프종 암, 폐 암, 난소 암 등을 분류하는 문제를 대상으로 실험하여 제안하는 방법의 유용성을 검증하였다. 앙상블 시 분류 규칙 사이의 다양성을 분석하여 결합한 결과, 다양성을 고려하지 않을 때보다 높은 분류 성능을 획득하였고, 개별 분류 규칙들 사이의 다양성에 따라서 정분류율이 증가하는 것도 확인하였다.

• 식물분류학회지
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• 제47권1호
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• pp.11-22
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• 2017

Prangos fedtschenkoi (Regel et Schmalh.) Korovin (Apiaceae) is an endemic species for mountainous Middle Asia, which is both a rare and useful plant. Organic extractions from this species are being used in pharmaceutics and cosmetology. In recent years, P. fedtschenkoi distribution area has considerably decreased, presumably, resulting from human activities such as agriculture, construction works, overgrazing and collection from wild for pharmaceutic purposes. Six populations were found in Uzbekistan and their genetic divergence and differentiation were studied with 10 inter-simple sequence repeat (ISSR) markers, selected out of 101. Totally 166 amplified ISSR fragments (loci) were revealed, of which 164 were polymorphic. Relatively moderate level of polymorphism was found at population level with polymorphic bands ranging from 27.71% to 47.59%. Mean P = 39.05%, $N_a=1.40$, $N_e=1.25$, S.I. = 0.21, and $H_e=0.14$ were revealed for all loci across six populations. AMOVA showed higher variation among populations (62%) than within them (38%). The Bayesian model determined 5 clusters, or genetic groups. The posteriori distribution of the Theta II estimator detected full model identifying high inbreeding, intensified by low gene flow (Nm = 0.3954). Mantel test confined population 6 as distinct cluster corresponding to geographic remoteness (R = 0.5137, $p{\leq}0.005$). Results were used as the bases for developing conserve measures to restore populations.

• 정보처리학회논문지B
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• 제12B권4호
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• pp.429-436
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• 2005

본 논문에서는 유전자 알고리즘의 일반적인 문제점인 과도한 저장공간의 소모와 탐색의 비효율성을 줄이기 위해 PBIL을 이용한 단순한 스테레오 정합 기법을 제안한다. PBIL은 확률벡터에 기반해서 통계적 탐색과 경쟁학습을 이용하는 변종 유전자 알고리즘이며 확률벡터의 사용으로 인해 직렬 및 병렬 유전자 알고리즘군에 비해 단순한 구조를 가진다. 본 논문에서는 이 PBIL을 스테레오 정합 환경에 맞게 변형 및 단순화시켜 정합 알고리즘을 개발한다. 높은 적응성을 갖는 염색체는 생존 확률 또한 높다는 진화 법칙을 보존하면서 유전자 풀, 염색체 교차 및 유전자 돌연변이를 제거할 수 있으며 그 결과 저장공간을 줄이고 정합 규칙을 간소화하여 계산 비용을 감소시킬 수 있다. 추가적으로 다해상도 정합 기법처럼 넓은 영역의 변이 일관성을 획득하기 위해 변이 연속성에 대한 이웃들의 거리를 제어하는 방식을 추가하여 고정된 작은 정합창을 사용하면서 안정된 결과를 얻을 수 있게 한다. 마지막으로 단순한 시스템에 적용될 수 있게 하기 위해서 확률벡터를 사용하지 않는 제안한 알고리즘의 소형 대안 기법을 제시한다.