• 제목/요약/키워드: mutant frequency

검색결과 114건 처리시간 0.028초

유전자수준에서 돌연변이 유발기전을 밝히는 Transgenic Mutagenesis Assay (Transgenic Mutagenesis Assay to Elucidaate the Mechanism of Mutation at Gene Level)

  • 류재천;윤지윤;조경혜;장일무
    • 한국환경성돌연변이발암원학회지
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    • 제18권1호
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    • pp.15-21
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    • 1998
  • Transgenic animal and cell line models which are recently developed and used in toxicology fields combined with molecular biological technique, are powerful tools to study the mechanism of mutation in vivo and in vitro, respectively. Transgenic models, which have exogenous DNA incorporated into their genome, carry recoverable shuttle vector containing reporter genes to assess endogenous effects or alteration in specific genes related to disease processes. The lac I and lac Z gnee most widely used as a mutational target in transgenic systems. The assay is performed by treatment with putative mutagenic agents, isolation of genomic DNA from cells or tissues, exposure the isolated DNA to in vitro packaging extract, plating and sequencing. The results from these processes provide not only mutant frequency as quantitative evaluation but also mutational spectrum as qualitative evaluation of various agents. Therefore we introduce and review the principle, detailed procedure and application of transgenic mutagenesis assay system in toxicology fields especially in mutagenesis and carcinogenesis.

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분리 핵을 이용한 Trichoderma koningii의 형질전환 (Transformation of Trichoderma koningii Using Isolated Nuclei)

  • 민경림;박희문;하영칠;정재훈
    • 한국미생물·생명공학회지
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    • 제18권6호
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    • pp.560-565
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    • 1990
  • Trichocderma koningii의 영양요구성 돌연변이주인 CUT 121로부터 얻은 원형질체를 야생형인 ATCC 26113의 핵과 혼합하여 PEG 용액을 처리한 결과, 독립 영양형의 형질전환체가 30 이상의 빈도로 생성되었다. 이 독립영양형 군체로부터 얻은 분리체 중의 하나는 xylanase의 활성이 야생형보다 3배 가량 증진되었으며, 다른 세포의 다당류 분해효소는 야생형과 유사한 수준을 나타내었다. 분리체의 DNA 함량, 인위적인 불리양상 및 동위효소 양상 등을 조사 분석한 결과, 독립영양형의 형질전환체는 실험에 사용된 형질전환체로 판명되었다. 이상의 결과로 Trichoderma속 균류의 균주개량법으로, 핵전이법이 통상의 원형질체 융합법보다 효율적인 것으로 판명되었다.

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팽나무버섯 Leu 2 gene(${\beta}-isopropylmalate$ dehydrogenase)의 사철 느타리버섯 형질전환 (Transformation of the ${\beta}-Isopropylmalate$ Dehydrogenase Gene of Flammulina velutipes into Pleurotus florida)

  • 변명옥;유영복;고승주;유창현;차동열;박용환
    • 한국균학회지
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    • 제17권1호
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    • pp.27-30
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    • 1989
  • 팽나무버섯 ${\beta}-isopropylmalate$ dehydrogenase의 유전자가 PBR322에 크로닝된 백터를 이용하여 사철느타리버섯 Leucine 영양요구성 균주를 형질전환 시켰다. 형질전환율은 저조하였으나 형질전환된 균총은 버섯 최소배지에서 다소 느리지만 생육할 수 있었다. 형질전환은 Southern hybridization과 형질 전환된 사철 느타리버섯 염색체 DNA를 다시 대장균에 형질전환시켜 확인하였다.

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일일초에서의 기능획득 돌연변이 모상근의 대량생산 (Mass Production of Gain-of-Function Mutants of Hairy Roots in Catharanthus roseus)

  • 고석민;정화지;이효연
    • 한국자원식물학회지
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    • 제24권5호
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    • pp.514-520
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    • 2011
  • 본 연구는 아그로박테리움을 이용한 기능획득 일일초 모상근의 대량생산을 위한 조건 확립에 대한 것이다. 본 연구에서는, 효율적인 형질전환 일일초 모상근 생산에 있어서의 최적의 일일초 품종의 선발과 최적의 일일초 조직을 결정하였으며, 또한 다양한 배지에 있어서의 모상근 유도를 조사하였다. 최종적으로 약 2,500개의 독립적인 형질전환 일일초 모상근 line을 생산하였으며, 또한 이들을 이용하여, 대사체 연구를 위한 효율적 관리 시스템을 구축하였다. 이들 모상근 line은 일일초 인돌알칼로이드 생합성 관련 유전자의 발굴 및 기능해석에 유용하게 쓰일 것이다.

Chronic Granulomatous Disease on Jeju Island, Korea

  • Cho, Moonjae;Shin, Kyung-Sue
    • Journal of Genetic Medicine
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    • 제10권1호
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    • pp.1-6
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    • 2013
  • Chronic granulomatous disease (CGD) is a rare inherited disorder of a defective NADPH oxidase enzyme, resulting in very low or no production of superoxide and subsequent reactive oxygen species. Consequently, patients with CGD are highly susceptible to severe bacterial and fungal infections. CGD is a genetically heterogeneous disease caused by defects in any one of the genes encoding the NADPH oxidase components. CGD generally affects about 3-4 per 1,000,000 individuals; thus, it is surprising that the prevalence of CGD on Jeju Island is 34.3 per 1,000,000 individuals. At present, 20 patients with CGD from 14 unrelated families on Jeju Island have been identified; nine males and 11 females. All patients with CGD tested on Jeju Island had an identical and homozygous mutation (c.7C>T in CYBA, p.Q3X in $p22^{phox}$). Therefore, all patients were autosomal recessive form of CGD. This strongly suggests that the unique and identical mutation in CYBA may be inherited from a common proband. Using mutation-specific primers to detect the mutated allele in CYBA, the frequency of subjects carrying a mutated allele was 1.3% of enrolled subjects from Seogwipo City. Further studies are necessary to elucidate how frequently this mutant allele occurs in the population on Jeju Island. Additionally, it is important to construct a national registry system to understand the pathophysiology of CGD and develop a strategy for long-term therapy.

수종의 Aspergillus 속 균 사이의 핵전이에 의한 종간잡종 형성 (Construction of Interspecific Hybrids detween Aspergillus spp. by Nuclear transfer)

  • 노형선;이정애;이영하;김진미;정재훈;맹필재
    • 미생물학회지
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    • 제29권1호
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    • pp.8-15
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    • 1991
  • Interspecific hybrids between the ASpergillus spp., A. awamori, A. usamii and A. oryzae, were obtained by nuclear transfer technique. Nuclei isolated from an auxotrophic mutant strain were transferred into the protoplasts of a recipient strain of different species. The frequency of interspecific hybrid formation by nuclear transfer was $2*10^{-5}$ $-7*10^{-4}$ In contrast, no interspecific hybrid was isolated by protoplast fusion. Among the hybrids tested, 10 strains showed increased activity of some or all components of cellulases, xylanases and amylase up to more than two times. Isozyme pattern of the hybrids were analyzed by polyacrylamide gel electrophoresis and isoelectric focusing followed by activity staining, which showed that some of the hybrids have isozyme patterns unidentical to either of the two parents. By measuring the DNA contents and the sizes ofthe conidia, the karyotypes of the hybrids were estimated to be aneuploid near to haploid, diploid or triploid. It was concluded that the unclear transfer technique is much more efficient in the formation of interspecific hybrids than protoplast fusion and is very useful for the improvement of Aspergillus strains.

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상동성 유전자재조합을 이용한 단백질분해효소 비생산 바실러스균주의 구축 (Construction of Pretense-defective Mutant of Bacillus subtilis by Homologous DNA Recombination)

  • Lee, Jin-Tae;An, Bong-Jeun
    • 한국식품저장유통학회지
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    • 제7권4호
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    • pp.414-417
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    • 2000
  • 단백질분해효소를 생산하지 않는 균주 B. subtilis MT-2의 염색체 DNA를 추출한 다음, B. subtilis AC819 균주에 상동성 유전자재조합을 이용하여 competent cell 형질전환을 시켰다. 얻어진 형질전환체를 B. subtilis HL-1이라고 명명하였으며, 그 표현형은 histidine 요구성, streptomycin 내성, tetracyclin 내성을 나타내면서 단백질 분해효소를 생산하지 않았다. 플라스미드 pUB110 을 이용한 B. subtilis HL-1의 protoplst 형질전환율은 B. subtilis MT-2의 형질전환율보다 높았다. 따라서 새로운 B. subtilis HL-1균주는 단백질분해효소의 형질전환과 내열성 protease 유전자클로닝에서 숙주로 사용하는데 유용하다.

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Killer 효모의 원형질체 형성 및 융합조건 (Conditions for protoplast formation and fusion of the killer yeast)

  • 정기택;방광웅;송형익;김재근;정용진
    • 미생물학회지
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    • 제27권4호
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    • pp.422-429
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    • 1989
  • Auxotrophic mutant were isolated from wild types by the treatment with NTG as a mutagen, and the conditions of protoplast formation for them were established. The protoplasts of killer yeast Saccharomyces cerevisiae K52 were formed to the level of above 70% when cells grown for 20 hr in PM medium were treated with 200 unit/ml Lyticase 50,000 at $30^{\circ}C$ for 60 min after pretreatment of 50 mM 2-mercaptoethanol in 10mM potassium phosphate buffer (pH 7.5) containing EDTA and 0.6 M sorbitol for 15 min. Also, the protoplast of the recipient S. cerevisiae S 29 were formed to the level of above 85% as it was cultured to the log phase of 24 hr in PM medium under the same conditions. The fusion frequency between the protoplast of killer yeast S. cerevisiae K 52 and the protoplast of recipient S. cerevisiae S 29 was reached to $8.2\times 10^{-6}$ when the hypertonic regeneration medium embeded with the fused protoplasts after mixing the parental protoplasts to 10$^{8}$ cells/ml in SP buffer containing 20 mM $CaCl_{2}$ and 30% PEG 6,000 for 15 min at $30^{\circ}C$ were incubated.

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Genetic Distances Among Rice Mutant Genotypes Assessed by AFLP and Aluminum Tolerance-Related Traits

  • Malone, Emilia;Kopp, Mauricio Marini;Malone, Gaspar;Branco, Juliana Severo Castelo;Carvalho, Fernando Iraja Felix;Oliveira, Antonio Costa de
    • Journal of Crop Science and Biotechnology
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    • 제10권2호
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    • pp.106-111
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    • 2007
  • Increasing genetic variability with mutagenic agents has been broadly employed in plant breeding because it has the potential to alter one or more desirable traits. In this study, a molecular analysis assessed by Amplified Fragment Length Polymorphisms(AFLPs) and a morphological analysis based on seedlings subjected to aluminum stress were compared. Also, an analysis of allelic frequencies was performed to observe unique alleles present in the pool. Genetic distances ranging from 0.448 to 0.953 were observed, suggesting that mutation inducing was effective in generating variability. The genetic distances based on morphological data ranged from 0(genotypes 22 and 23) to 30.38(genotypes 15 and 29). In the analysis of allelic frequency, 13 genotypes presented unique alleles, suggesting that mutation inducing was also targeting unique sites. Mutants with good performance under aluminum stress(9, 15, 18 and 27) did not form the same clusters when morphological and molecular analyses were compared, suggesting that different genomic regions may be responsible for their better performance.

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Pneumococcal Δpep27 Immunization Attenuates TLRs and NLRP3 Expression and Relieves Murine Ovalbumin-Induced Allergic Rhinitis

  • Yu, Jae Ik;Kim, Ji-Hoon;Nam, Ki-El;Lee, Wonsik;Rhee, Dong-Kwon
    • Journal of Microbiology and Biotechnology
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    • 제32권6호
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    • pp.709-717
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    • 2022
  • Allergic rhinitis (AR), one of the most common inflammatory diseases, is caused by immunoglobulin E (IgE)-mediated reactions against inhaled allergens. AR involves mucosal inflammation driven by type 2 helper T (Th2) cells. Previously, it was shown that the Streptococcus pneumoniae pep27 mutant (Δpep27) could prevent and treat allergic asthma by reducing Th2 responses. However, the underlying mechanism of Δpep27 immunization in AR remains undetermined. Here, we investigated the role of Δpep27 immunization in the development and progression of AR and elucidated potential mechanisms. In an ovalbumin (OVA)-induced AR mice model, Δpep27 alleviated allergic symptoms (frequency of sneezing and rubbing) and reduced TLR2 and TLR4 expression, Th2 cytokines, and eosinophil infiltration in the nasal mucosa. Mechanistically, Δpep27 reduced the activation of the NLRP3 inflammasome in the nasal mucosa by down-regulating the Toll-like receptor signaling pathway. In conclusion, Δpep27 seems to alleviate TLR signaling and NLRP3 inflammasome activation to subsequently prevent AR.