• 제목/요약/키워드: RecA

검색결과 284건 처리시간 0.025초

Gene Targeting in Mouse Embryos Mediated by recA and Modified Single-Stranded Oligonucleotides

  • Kang, Jee-Hyun;Won, Ji-Young;Heo, Soon-Young;Hosup Shim
    • 한국동물번식학회:학술대회논문집
    • /
    • 한국동물번식학회 2004년도 춘계학술발표대회
    • /
    • pp.193-193
    • /
    • 2004
  • Gene targeting is an in situ manipulation of endogenous gene with precise manner by the introduction of exogenous DNA. The process of gene targeting involves a homologous recombination reaction between the targeted genomic sequence and an exogenous targeting vector. In elucidating the function of many genes, gene targeting has become the most important method of choice. (omitted)

  • PDF

Assessing Alternative Renewable Energy Policies in Korea's Electricity Market

  • KIM, HYUNSEOK
    • KDI Journal of Economic Policy
    • /
    • 제41권4호
    • /
    • pp.67-99
    • /
    • 2019
  • This paper, focusing on the renewable portfolio standard (RPS), evaluates alternative renewable energy policies. We propose a tractable equilibrium model which provides a structural representation of Korea's electricity market, including its energy settlement system and renewable energy certificate (REC) transactions. Arbitrage conditions are used to define the core value of REC prices to identify relevant competitive equilibrium conditions. The model considers R&D investments and learning effects that may affect the development of renewable energy technologies. The model is parameterized to represent the baseline scenario under the currently scheduled RPS reinforcement for a 20% share of renewable generation, and then simulated for alternative scenarios. The result shows that the reinforcement of the RPS leads to higher welfare compared to weakening it as well as repealing it, though there remains room to enhance welfare. It turns out that subsidies are welfare-inferior to the RPS due to financial burdens and that reducing nuclear power generation from the baseline yields lower welfare by worsening environmental externalities.

A Study on Gamma ray effects on Stress Response and Cellular Toxicity using Bacterial Cells

  • 민지호;이현주;이창우;구만복
    • 한국생물공학회:학술대회논문집
    • /
    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
    • /
    • pp.187-190
    • /
    • 2000
  • 본 연구는 5가지의 발광성 미생물을 이용하여 유해 방사선으로 알려져 있는 ${\gamma}-rays$가 여러가지 cellular stresses 중, 특히 유전자 손상과 생물막 손상을 유발하였는데, 이들의 손상 정도가 총 방사선량과 상관관계가 있음을 발생하는 bioluminescence 로써 확인하였다. 뿐만 아니라, 선량률의 변화를 통하여 방사선으로 인한 유전자 손상 및 일반적인 독성 효과가 큰 영향을 받는 것을 확인하였는데, 선량률 증가에 따라 이들 손상정도가 증가하는 것으로 보아 선량률이 genetic 및 radioprotecion에 심각한 영향을 미치는 것을 확인하였다.

  • PDF

비틀림 비정형을 가지는 학교건물의 편심율에 따른 좌굴방지가새형 이력댐퍼의 제진성능분석 (Analysis of Damping Performance of Hysteretic Dampers of Buckling restrained Braced Type According to eccentricity of school buildings with Torsional irregularities)

  • 김유성;이준호;김기철
    • 한국공간구조학회논문집
    • /
    • 제23권2호
    • /
    • pp.37-44
    • /
    • 2023
  • In the case of a school building, even though it is a regular structure in terms of plan shape, if the masonry infill wall acts as a lateral load resisting element, it can be determined as a torsionally irregular building. As a result, the strength and ductility of the structure are reduced, which may cause additional earthquake damage to the structure. Therefore, in this study, a structure similar to a school building with torsional irregularity was selected as an example structure and the damping performance of the PC-BRB was analyzed by adjusting the eccentricity according to the amount of masonry infilled wall. As a result of nonlinear dynamic analysis after seismic reinforcement, the torsional irregularity of each floor was reduced compared to before reinforcement, and the beams and column members of the collapse level satisfied the performance level due to the reduction of shear force and the reinforcement of stiffness. The energy dissipation of PC-BRB was similar in the REC-10 ~ REC-20 analytical models with an eccentricity of 20% or less. REC-25 with an eccentricity of 25% was the largest, and it is judged that it is effective to combine and apply PC-BRB when it has an eccentricity of 25% or more to control the torsional behavior.

Molecular Characterization of Burkholderia Strains Isolated from Rice Cultivars (Oryza sativa L.) for Species Identification and Phylogenetic Grouping

  • Madhaiyan, Munusamy;Poonguzhali, Selvaraj;Kwon, Soon-Wo;Song, Myung-Hee;Sa, Tong-Min
    • Journal of Microbiology and Biotechnology
    • /
    • 제18권6호
    • /
    • pp.1005-1010
    • /
    • 2008
  • The genus Burkholderia consists of extremely versatile bacteria that occupy diverse niches and are commonly encountered in the rhizosphere of crop plants. In this study, we characterized three plant growth promoting strains assigned as Burkholderia sp. using biochemical and molecular characterization. The Burkholderia spp. strains CBMB40, CBPB-HIM, and CBPB-HOD were characterized using biochemical tests, BIOLOG carbon substrate utilization, fatty acid methyl ester analysis, analysis of recA gene sequences, and DNA-DNA hybridization. The results from these studies indicated that the strains CBMB40, CBPB-HIM, and CBPB-HOD can be assigned under Burkholderia vietnamiensis, Burkholderia ubonensis, and Burkholderia pyrrocinia, respectively.

Antimutagenic Effects of Juices from Edible Korean Wild Herbs

  • Ham, Seung-Shi;Oh, Deog-Hwan;Hong, Jeong-Kee;Lee, Jae-Hoon
    • Preventive Nutrition and Food Science
    • /
    • 제2권2호
    • /
    • pp.155-161
    • /
    • 1997
  • The mutagenic and antimutagenic activities of juices from 20 common edible wild herbs found in Korea were investigated using the spore-rec assay and Ames test. The juices of Hemerocallis fulva and Capsella bursapastoris exhibited a little induction or inhibition of mutagenesis in the presence of selected metal ions, but juices of most edible wild herbs did not affect on the mutagenesis in the spore-rec assay. In the other hand, all of the juices strongly inhibited the mutagenesis induced by benzo[a]pyrene, 2-amino-fluorene, and 3-amino-1,4-dimethyl-5H-pyridol tested on Salmonella typhimurium TA98 or TA100 in the presence of S-9 mix. The antimutagenic effects increased as the concentration of the mutagens increase. The results suggest that concentration of samples or types of various mutagen interact to affect the antimutagenic potential of the juices in the TA98 and TA100 strain.

  • PDF

α-Kleisin subunit of cohesin preserves the genome integrity of embryonic stem cells

  • Seobin Yoon;Eui-Hwan Choi;Seo Jung Park;Keun Pil Kim
    • BMB Reports
    • /
    • 제56권2호
    • /
    • pp.108-113
    • /
    • 2023
  • Cohesin is a ring-shaped protein complex that comprises the SMC1, SMC3, and α-kleisin proteins, STAG1/2/3 subunits, and auxiliary factors. Cohesin participates in chromatin remodeling, chromosome segregation, DNA replication, and gene expression regulation during the cell cycle. Mitosis-specific α-kleisin factor RAD21 and meiosis-specific α-kleisin factor REC8 are expressed in embryonic stem cells (ESCs) to maintain pluripotency. Here, we demonstrated that RAD21 and REC8 were involved in maintaining genomic stability and modulating chromatin modification in murine ESCs. When the kleisin subunits were depleted, DNA repair genes were downregulated, thereby reducing cell viability and causing replication protein A (RPA) accumulation. This finding suggested that the repair of exposed single-stranded DNA was inefficient. Furthermore, the depletion of kleisin subunits induced DNA hypermethylation by upregulating DNA methylation proteins. Thus, we proposed that the cohesin complex plays two distinct roles in chromatin remodeling and genomic integrity to ensure the maintenance of pluripotency in ESCs.

돌연변이와 DNA 손상회복에 미치는 muc 유전자의 기능 (Function of muc Gene on Mutagenesis and DNA Repair)

  • 전홍기;이상률;백형석
    • 미생물학회지
    • /
    • 제28권3호
    • /
    • pp.192-198
    • /
    • 1990
  • 플라스미드 pKM101과 이의 돌연변이제 pSLA의 mutator 유전자를 subcloning하여 재조합 플라스미드 pJB200과 pJB210을 선별하였고, umuC36- uvrA6-(TK 610) 균주에 도입하여 UV와 MMS에 대해서 보호효과와 돌연변이율에 미치는 영향을 조사하였다. 재조합된 플라스마드는 UV와 MMS에 대해서 nonmutability인 umu- 균주에서 완전히 돌연변이율을 회복시켰고 보호효과를 크게 증가시켰다. 이 사실은 muc 유전자가 cloning된 재조합 플라스미드가 돌연변이원의 처리에 의해 효과적인 발현을 하며, muc 유전자 만으로도 pKM101의 기능을 나타낸다는 것을 확인하였고, pSLA의 muc 유전자가 그 효과에 었어서 높은 영향을 미쳤다. 또한 pKM101의 muc gene을 포함한 pJB210 은 recA - (JC2926) 균주에서 돌연변이 유발능에 영향을 미치지 못한 것은 muc 유전자가 recA 유전자에 의존함을 알 수 있었다.

  • PDF

주요 솔잎 추출물의 돌연변이 억제효과 (Inhibitory Effect of Main Pine Needle Extracts on the Chemically Induced Mutagenicity)

  • 김은정;정성원;최근표;함승시;강하영
    • 한국식품과학회지
    • /
    • 제30권2호
    • /
    • pp.450-455
    • /
    • 1998
  • 한국에 널리 분포하고 있는 곰솔, 리기다, 잣나무, 적송의 에탄올추출물과 각 용매 분획물을 이용하여, in vitro assay로서 spore rec-assay와 Salmonella typhimurium reversion assay법으로 시료자체 변이원성 유무와 4가지 양성변이원 물질(MNNG, 4NQO, Trp-P-1 및 B(a)p)에 대한 돌연변이 억제효과를 고찰하였다. 곰솔, 리기다, 잣나무, 적송의 에탄올 추출물은 spore rec-assay와 S. typhimurium를 이용한 mutagenicity assay에서 변이원성을 나타내지 않았다. 돌연변이 억제 시험에서는 4가지 시료 모두 농도 증가에 따른 억제율을 나타내었고 또 각각의 시료들의 분획물 중 잣나무와 소나무의 에테르 분획물들이 간접변이원인 Trp-P-1의 변이원성에 대하여 다른 분획물에 비하여 높은 억제율을 보여주었다.

  • PDF

산채류(山菜類) 가열즙(加熱汁)의 돌연변이 억제 작용에 관(關)한 연구(硏究) (Desmutagenic Activity of Heated Mountain Herb Juices)

  • 함승시
    • Applied Biological Chemistry
    • /
    • 제31권1호
    • /
    • pp.38-45
    • /
    • 1988
  • 10종류(種類)의 산채류가열즙(山菜類加熱汁)에 대한 돌연변이원성(突然變異原性)을 Spore rec-assay, Ames test 그리고 DNA 절단실험(切斷實驗)으로 검토(檢討)하였으며 가열즙(加熱汁)의 조제(調製)는 $100^{\circ}C$에서 20분간 가열하여 가열즙(加熱汁)을 얻었다. Spore rec-assay 결과 10종류(種類)의 시료(試料)모두 변이원성(變異原性)은 없었으며 금속이온의 영향에서 소리쟁이가열즙은 $Pb^{2+}$, 곰취와 참나물가열즙의 경우는 $Zn^{2+}$의 존재하에서 변이원성을 나타내었다. Ames 시험과 DNA 절단시험에서도 시료모두 변이원성은 없었으며 DNA 절단(切斷)시험에서는 곰취, 머위, 잔대, 개미취가열즙의 경우는 25mM $Cu^{2+}$ 공존하에서 절단활성(切斷活性)이 촉진되었다. 그러나 두릅, 원추리, 잔대, 참나물 그리고 참취가열즙(加熱汁)은 $Fe^{2+}$의 공존시 DNA 절단활성(切斷活性)을 억제(抑制)시키는 결과(結果)를 얻었다. Benzo${\alpha}$pyrene에 대한 돌연변이(突然變異) 억제작용(抑制作用)에서는 시료(試料) 모두 농도증가(濃度增加)에 따라 강(强)한 변이원(變異原) 억제작용(抑制作用)을 나타내었다.

  • PDF