• 제목/요약/키워드: Mutation Rate

검색결과 351건 처리시간 0.027초

저선량율의 감마선 조사에 의한 자주 달개비의 체세포 돌연변이 출현에 관한 연구 (Mutation Frequency of Tradescantia (BNL Clone 4430) Stamen Hairs Exposed to Low Dose of Gamma Ray in the KAERI ${\gamma}$-Field)

  • Shin Han Kwon;Young Il Lee;Kyu Hoi Chung;Jeung Haing Oh
    • Nuclear Engineering and Technology
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    • 제13권3호
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    • pp.161-167
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    • 1981
  • 자주달개비(Tradescantia) BNL clone 4430을 본 연구소 감마농장(${\gamma}$-field)에 거리별로 배치하고 ${\gamma}$-선을 3.6mR/day~182R/day의 선량율로 완조사시켜, 이 식물의 수술털에 나타나는 분홍색 체세포돌연변이를 대상으로 돌연변이의 출현율을 조사하는 한편 화기에 미치는 형태변화를 조사하였다. 분홍색 체세포돌연변이율은 22.2R/day의 선량율에서 수술털 1,000개당 85.81$\pm$6.45개로 가장 높았고, 이보다 높은 선량율에서는 오히려 변이율이 감소하여 포화선량효과를 초래하였다. 또한 3.6mR/day의 낮은 선량율체서도 이 체세포돌연변이율이 자연돌연변이율보다 증가하였음을 볼 수 있었으며 비교적 낮은 선량율 조사에서는 꽃, 수술, 수술털등의 형태적 변화가 없이 돌연 변이율만의 증가를 볼수가 있어 감마농장내에서 과수나 화목등 영년식물에 저선량의 완조사를 통해 체세포돌연변이의 유기가 가능할것으로 보이며, 한편 이 식물의 특성을 이용하여 저위 방사선에 의한 유전적변화를 탐지하는데에도 적절한 수단이 될 것 같다.

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Mutation spectrum of NF1 gene in Korean unrelated patients with neurofibromatosis 1: Six novel pathogenic variants

  • Sung Hee Han;Eun Joo Kang;Mina Yang;Suekyeung Kim;Sang Gon Lee;Eun Hee Lee
    • Journal of Genetic Medicine
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    • 제21권1호
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    • pp.22-30
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    • 2024
  • Purpose: Neurofibromatosis 1 (NF1) is one of the most common autosomal dominant diseases caused by heterozygous mutation in the NF1 gene. Mutation detection is complex owing to the large size of the NF1 gene, the presence of a high number of partial pseudogenes, and the great variety of mutations. We aimed to study the mutation spectrum of NF1 gene in Korean patients with NF1. Materials and Methods: We have analyzed total 69 unrelated patients who were clinically diagnosed with NF1. PCR and sequencing of the NF1 gene was performed in all unrelated index patients. Additionally, multiplex ligation-dependent probe amplification (MLPA) test of the NF1 and SPRED1 gene analysis (sequencing and MLPA test) were performed in patients with negative results from NF1 gene sequencing analysis. Results: Fifty-five different variants were identified in 60 individuals, including six novel variants. The mutations included 36 single base substitutions (15 missense and 21 nonsense), eight splicing mutations, 13 small insertion or deletions, and three gross deletions. Most pathogenic variants were unique. The mutations were evenly distributed across exon one through 58 of NF1, and no mutational hot spots were found. When fulfilling the National Institutes of Health criterion for the clinical diagnosis of NF1, the detection rate was 84.1%. Cafe-au-lait macules were observed in all patients with NF1 mutations. There is no clear relationship between specific mutations and clinical features. Conclusion: This study revealed a wide spectrum and genetic basis of patients with NF1 in Korea. Our results aim to contribute genetic management and counseling.

Folding Mechanism of WT* Ubiquitin Variant Studied by Stopped-flow Fluorescence Spectroscopy

  • Park, Soon-Ho
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2877-2883
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    • 2010
  • The folding kinetics of $WT^*$ ubiquitin variant with valine to alanine mutation at sequence position 26 (HubWA) was studied by stopped-flow fluorescence spectroscopy. While unfolding kinetics showed a single exponential phase, refolding reaction showed three exponential phases. The semi-logarithmic plot of urea concentration vs. rate constant for the first phase showed v-shape pattern while the second phase showed v-shape with roll-over effect at low urea concentration. The rate constant and the amplitude of the third phase were constant throughout the urea concentrations, suggesting that this phase represents parallel process due to the configurational isomerization. Interestingly, the first and second phases appeared to be coupled since the amplitude of the second phase increased at the expense of the amplitude of the first phase in increasing urea concentrations. This observation together with the roll-over effect in the second folding phase indicates the presence of intermediate state during the folding reaction of HubWA. Quantitative analysis of Hub-WA folding kinetics indicated that this intermediate state is on the folding pathway. Folding kinetics measurement of a mutant HubWA with hydrophobic core residue mutation, Val to Ala at residue position 17, suggested that the intermediate state has significant amount of native interactions, supporting the interpretation that the intermediate is on the folding pathway. It is considered that HubWA is a useful model protein to study the contribution of residues to protein folding process using folding kinetics measurements in conjunction with protein engineering.

Morphological Identification and Phylogenetic Analysis of Laelapin Mite Species (Acari: Mesostigmata: Laelapidae) from China

  • Yang, Huijuan;Yang, Zhihua;Dong, Wenge
    • Parasites, Hosts and Diseases
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    • 제60권4호
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    • pp.273-279
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    • 2022
  • Laelapinae mites are involved in transmission of microbial diseases between wildlife and humans, with an impact on public health. In this study, 5 mite members in the subfamily Laelapinae (laelapin mites; LM) were morphologically identified by light microscopy, and the phylogenetic relationship of LM was analyzed in combination with the sequence information of part of the LM cytochrome oxidase subunit I (cox1) gene. The morphological identification revealed that 5 mites belonged to the genera Laelaps and Haemolaelaps, respectively. Sequence analysis showed that the ratio of nonsynonymous mutation rate to synonymous mutation rate of LM was less than 1, indicating that the LM cox1 gene had undergone purifying selection. Phylogenetic analysis showed that the Laelapinae is a monophyletic group. The genera Haemolaelaps and Hyperlaelaps did not separated into distinct clades but clustered together with species of the genus Laelaps. Our morphological and molecular analyses to describe the phylogenetic relationships among different genera and species of Laelapinae provide a reference for the improvement and revision of the LM taxonomy system.

결핵균 Adenylate Kinase 돌연변이 유전자와 Human Muscle-type Adenylate Kinase 합성 유전자를 형질전환한 BCG의 성장속도 변화 유무 조사 (Investigation of the Growth Rate Change in Recombinant BCG which was cloned Mycobacterium tuberculosis Adenylate Kinase Mutation Gene or Human Muscle-type Adenylate Kinase Synthetic Gene)

  • 이승헌;김효준;박영길;배길한
    • Tuberculosis and Respiratory Diseases
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    • 제60권2호
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    • pp.187-193
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    • 2006
  • 배 경 : 결핵균의 성장 속도가 늦은 이유가 mammalian cell이나 대장균에 비해 결핵균 AK의 매우 낮은 활성도에 의한 것이라는 추측으로부터 AK1과 유사한 촉매능을 나타내는 AKmt 돌연변이 유전자와 human muscle-type AK 합성 유전자(AK1)를 각각 Mycobacterium/E.coli 발현벡터에 재조합(pMVAKmtDM, pEMAK1)하여 성장 속도가 매우 느린 BCG에 형질전환함으로써 이들 단백질들의 촉매능에 의한 성장 속도 변화가 일어나는지를 확인하고자 하였다. 방 법 : Human AK1의 촉매 활성도와 유사하도록 결핵균 AK (AKmt)유전자의 ATPbd와 LID domain을 돌연변이하여 제조한 유전자(AKmtDM)와 human muscle-type adenylate kinase 합성 유전자(AK1)를 Mycobacterium/E.coli 발현벡터에 클로닝하여 재조합 BCG를 제조하였고, 이들 재조합 BCG와 BCG Pasteur $1173P_2$ (wild-type)를 7H9 액체배지에 접종하여 2-3 일 간격으로 $A_{600}$ 값을 측정하였다. 결 과 : 재조합 BCG의 성장 속도는 Wild-type BCG의 성장 속도에 비해 변화가 없었다. 결 론 : 결핵균 adenylate kinase의 정확한 기능은 알 수 없으나, adenylate kinase의 촉매 활성도의 증가는 BCG의 성장 속도에는 영향을 주지 않는 것으로 판단된다.

무선통신 네트워크에서 동적채널할당을 위한 진화프로그램의 개발 (Development of Evolution Program for Dynamic Channel Assignment in Wireless Telecommunication Network)

  • 김성수;한광진;이종현
    • 산업공학
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    • 제14권3호
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    • pp.227-235
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    • 2001
  • There is a rapidly growing demand for wireless telecommunication. However, the number of usable channel is very limited. Therefore, the problem of channel assignment becomes more and more important to use channels as efficiently as possible. The objective of this paper is to develop an evolution program (EP) to find an efficient dynamic channel assignment method for minimum interference among the channels within reasonable time. The series of specific channel number is used as a representation of chromosome. The only changed chromosomes by crossover and mutation are evaluated in each generation to save computation time and memory for the progress of improved EP. We can easily differentiate the fitness value of each chromosome using proposed evaluation function. We also control the weighting factor of the mutation rate and the used number of elitist chromosomes for the speed of convergence to the optimal solution.

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The Regulation of Alpha-Amylase Synthesis in Bacillus subtilis

  • Won, Mi-Sun
    • Journal of Microbiology and Biotechnology
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    • 제1권4호
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    • pp.256-260
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    • 1991
  • In B. subtilis, $\alpha$-amylase synthesis is regulated by amyR located directly on the upstream of amyE. Three different amyR alleles have been reported, amyR1, amyR2 and amyR3. Strains bearing the gra-10 mutation which confers derepression for catabolite repression has GlongrightarrowA transition mutation at +5 of amyR1. S1 nuclease mapping demonstrated that transcription initiated at 8 bases downstream from the -10 region of putative E$\sigma^{A}$ promoter P1 in amyR1 and gra-10. In amyR2, the major transcription initiatd at the same place and the minor, 10 bases downstream from -10 of P2. The transcript from P2 contributed approximately 15-20% of total amyE mRNA. S1 nuclease protection experiment indicated that amyE mRNA levels corresponded to the rate of synthesis assumed by specific activities of $\alpha$-amylase in culture supernatants, suggesting that $\alpha$-amylase synthesis is regulated at the level of transcription.n.

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진화 시스템을 위한 유전자 알고리즘 프로세서의 구현 (Implementation of an Adaptive Genetic Algorithm Processor for Evolvable Hardware)

  • 정석우;김현식;김동순;정덕진
    • 대한전기학회논문지:시스템및제어부문D
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    • 제53권4호
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    • pp.265-276
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    • 2004
  • Genetic Algorithm(GA), that is shown stable performance to find an optimal solution, has been used as a method of solving large-scaled optimization problems with complex constraints in various applications. Since it takes so much time to execute a long computation process for iterative evolution and adaptation. In this paper, a hardware-based adaptive GA was proposed to reduce the serious computation time of the evolutionary process and to improve the accuracy of convergence to optimal solution. The proposed GA, based on steady-state model among continuos generation model, performs an adaptive mutation process with consideration of the evolution flow and the population diversity. The drawback of the GA, premature convergence, was solved by the proposed adaptation. The Performance improvement of convergence accuracy for some kinds of problem and condition reached to 5-100% with equivalent convergence speed to high-speed algorithm. The proposed adaptive GAP(Genetic Algorithm Processor) was implemented on FPGA device Xilinx XCV2000E of EHW board for face recognition.

구속조건의 효율적인 처리를 위한 유전자 알고리즘의 개발 (Development of Genetic Algorithms for Efficient Constraints Handling)

  • 조영석;최동훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.725-730
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    • 2000
  • Genetic algorithms based on the theory of natural selection, have been applied to many different fields, and have proven to be relatively robust means to search for global optimum and handle discontinuous or even discrete data. Genetic algorithms are widely used for unconstrained optimization problems. However, their application to constrained optimization problems remains unsettled. The most prevalent technique for coping with infeasible solutions is to penalize a population member for constraint violation. But, the weighting of a penalty for a particular problem constraint is usually determined in the heuristic way. Therefore this paper proposes, the effective technique for handling constraints, the ranking penalty method and hybrid genetic algorithms. And this paper proposes dynamic mutation tate to maintain the diversity in population. The effectiveness of the proposed algorithm is tested on several test problems and results are discussed.

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유전알고리즘을 이용한 영상의 적응형 전처리 필터 구현에 관한 연구 (A study on Adaptive Image Preprocessing Filter using Genetic Algorithm)

  • 구지훈;이승영;이종호;이필규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2693-2695
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    • 2001
  • In this paper, we present an adaptive image filter using genetic algorithm. The filter is robust to the characteristic variance of image and noise, by evolving the parameter and combination of image preprocessors properly. And we have adopted adaptive mutation strategy, which use different mutation rate for specific region of chromosome. The filter is implemented on FPGA board and controlled by host PC.

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