• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.903-908
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• 2001

The gene aeg-46.5, which is expressed under anaerobic condition, has putative triple -10 regions and four transcription start sites. The mRNA transcription level and its start point change depending on the aerobic/anaerobic growth condition. RNA polymerase and its regulatory proteins must choose which of three -10 region to use. The putative triple 10 region was mutated to make only one of them function with consensus -10 region sequence (TATAAT) and the other two as non-functional region. The results show that the second and third -10 regions are used for the aerobic/anaerobic expression. The third -10 region is responsible for the high aerobic to anaerobic switch ratio. This suggests that only the last two of the putative triple -10 region have functions on aeg-46.5 gene expression switch control. The phenotype of the mutated promoter was tested in the wild type cell and narL - cell. The results indicate that the control by NarL is independent from the selection of -10 region. The expression patterns on multi-copy plasmids and on single-copy chromosome were compared. These results show that the aerobic/anaerobic switch control of aeg-46.5 is through the choice of -10 region. The mechanism of choosing different -10 region remains to be seen.

• 한국균학회지
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• 제17권3호
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• pp.119-123
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• 1989

주름버섯목(目) 느타리버섯과 민주름버섯목(目) 잔나비걸상버섯과의 이목간(異目間) 원형질체(原形質體)를 polyethylene glycol로 유도하여 융합주(融合株) heterokaryon을 선발하였다. 버섯최소배지에서 극히 균사생장이 느렸으며 버섯완전배지에서 3번 계대배양되면서 다소 생장이 빨라졌다. 융합주 36균주의 75%는 양친의 균사가 혼합된 균총형태였으며 16.7%는 새로운 형태, 8.3%는 느타리버섯 형태이었다. 이들 중 양친의 균총(菌叢)이 혼합된 형태는 3번 계대배양 후 모두 느타리버섯 형태로 변하였다. 균사(菌絲)에는 클램프연결체가 없었고 원기(原基)도 형성하지 않았다. 융합주(融合株)를 전기영동법으로 esterase, malate dehydrogenase, peroxidase의 동위효소(同位酵素) 분석(分析)으로 비교하였는데 잔나비걸상버섯 효소는 뚜렷하지 않았으나 새로운 밴드의 형성으로 보아 두 양친 genome간의 상호작용이 존재하였다.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.62-72
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• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• Interdisciplinary Bio Central
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• 제3권1호
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• pp.3.1-3.16
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• 2011

Investigation of the genetic functions in complex biological systems is a challenging step in recent year. Hence, several valuable and interesting research projects have been developed with novel ideas to find out the unknown functions of genes or proteins. To validate the applicability of their novel ideas, various approaches are built up. To date, the most promising and commonly used approach for discovering the target proteins from biological system using small molecule is well known a forward chemical genetics which is considered to be more convenient than the classical genetics. Although, the forward chemical genetics consists of the three basic components, the target identification is the most challenging step to chemical biology researchers. Hence, the diverse target identification methods have been developed and adopted to disclose the small molecule bound protein. Herein, in this review, we briefly described the first two parts chemical toolbox and screening, and then the target identifications in forward chemical genetics are thoroughly described along with the illustrative real example case study. In the tabular form, the different biological active small molecules which are the successful examples of target identifications are accounted in this research review.

• The Plant Pathology Journal
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• 제25권4호
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• pp.322-327
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• 2009

A total of 23 isolates of Botrytis cinerea causing the grey mold were collected from infected ginseng in several fields of Korea. The sensitivity to carbendazim and the mixture of carbendazim plus diethofencarb was determined through a mycelial inhibition test on PDA amended with or without fungicides. B. cinerea isolates were classified as 3 phenotypes, which were the first phenotype resistant to both of carbendazim and the mixture ($Car^RMix^R$), the second one resistant to carbendazim and sensitive to the mixture ($Car^RMix^S$), and the last one sensitive to both of them ($Car^RMix^S$). Carbendazim resistance correlated with a single mutation $\beta$-tubulin gene of B. cinerea amplified with primer pair tubkjhL and tubkjhR causing a change of glutamate to alanine at amino acid position 198. Furthermore, the substitution of valine for glutamate led the resistance to carbendazim and the mixture at the same position of amino acid. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis using the restriction endonuclease, Tsp451 and BstUI allowed differentiation of the PCR fragment of $\beta$-tubulin gene of $Car^SMix^S$ isolates from that of $Car^RMix^R$ and $Car^RMix^S$ isolates. This method will aid in a fast detection of resistance of carbendazim and the mixture of carbendazim plus diethofencarb in B. cinerea in ginseng field.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.14-14
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• 2017

The discipline of plant breeding is experiencing a renaissance impacting crop improvement as a result of new technologies, however fundamental questions remain for predicting the phenotype and how the environment and genetics shape it. Inexpensive DNA sequencing, genotyping, new statistical methods, high throughput phenotyping and gene-editing are revolutionizing breeding methods and strategies for improving both quantitative and qualitative traits. Genomic selection (GS) models use genome-wide markers to predict performance for both phenotyped and non-phenotyped individuals. Aerial and ground imaging systems generate data on correlated traits such as canopy temperature and normalized difference vegetative index that can be combined with genotypes in multivariate models to further increase prediction accuracy and reduce the cost of advanced trials with limited replication in time and space. Design of a GS training population is crucial to the accuracy of prediction models and can be affected by many factors including population structure and composition. Prediction models can incorporate performance over multiple environments and assess GxE effects to identify a highly predictive subset of environments. We have developed a methodology for analyzing unbalanced datasets using genome-wide marker effects to group environments and identify outlier environments. Environmental covariates can be identified using a crop model and used in a GS model to predict GxE in unobserved environments and to predict performance in climate change scenarios. These new tools and knowledge challenge the plant breeder to ask the right questions and choose the tools that are appropriate for their crop and target traits. Contemporary plant breeding requires teams of people with expertise in genetics, phenotyping and statistics to improve efficiency and increase prediction accuracy in terms of genotypes, experimental design and environment sampling.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.831-837
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• 2001

Pediocin K1, a bacteriocin produced by Pediococcus sp. K1 isolated from Korean traditional fermented flatfish, inhibited certain strains of Lactobacillus, Streptococcus, and Listeria monocytogenes. Pediocin K1 was found to be stable at $90^{\circ}C$ for 30 min. Among the organisms tested, Listeria monocytogenes was the most sensitive to pediocin K1 and was completely killed when the initial inoculum size of L.monocytogenes cells was equal to or less than $10^3 CFU/ml$. The degree of inibition of Listeria monocytogenes by pediocin K1 increased 10-fold on the addition of citric acid ($0.2\%$) to the medium, thereby showing the synergistic effect of citric acid. Listeria monocytogenes cells resistant to pediocin K1 appeared at a frequency of about $10^-4$/cells. Once developed after exposure to pediocin K1, the resistant phenotype still persisted in the absence of pediocin K1 in successive cultures. This infers that resistance may be attributable to genetic change(s) in the resistant cells.

• Mycobiology
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• 제29권1호
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• pp.19-26
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• 2001

Defense mechanisms against anthracnose disease caused by Colletotrichum orbiculare on the leaf surface of cucumber plants after pre-treatment with plant growth promoting rhizobacteria(PGPR), amino salicylic acid(ASA) or C. orbiculare were compared using a fluorescence microscope. Induced systemic resistance was mediated by the pre-inoculation in the root system with PGPR strain Bacillus amylolquefaciens EXTN-1 that showed direct antifungal activity to C. gloeosporioides and C. orbiculare. Also, systemic acquired resistance was triggered by the pre-treatments on the bottom leaves with amino salicylic acid or conidial suspension of C. orbiculare. The protection values on the leaves expressing SAR were higher compared to those expressing ISR. After pre-inoculation with PGPR strains no change of the plants was found in phenotype, while necrosis or hypersensitive reaction(HR) was observed on the leaves of plants pre-treated with ASA or the pathogen. After challenge inoculation, inhibition of fungal growth was observed on the leaves expressing both ISR and SAR. HR was frequently observed at the penetration sites of both resistance-expressing leaves. Appressorium formation was dramatically reduced on the leaves of plants pre-treated with ASA, whereas EXTN-1 did not suppress the appressorium formation. ASA also more strongly inhibited the conidial germination than EXTN-1. Conversely, EXTN-1 significantly increased the frequency of callose formation at the penetration sites, but ASA did not. The defense mechanisms induced by C. orbiculare were similar to those by ASA. Based on these results it is suggested that resistance mechanisms on the leaf surface was different between on the cucumber leaves expressing ISR and SAR, resulting in the different protection values.

• 한국식품영양과학회지
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• 제27권1호
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• pp.141-148
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• 1998

This study describes the effects of 1,25-dihydroxyvitamin D3[1,25(OH)2D3, calcitriol] analog, 1,25(OH)2-16ene-23yne-D3 on proliferatin and differentiatin of the human histiocytic lymphoma cell line U937. This paper also describes the effects of 1,25(OH)2-16ene-23yne-D3 on ${\gamma}$-interferon(IFN-${\gamma}$) synthesis by phytohemagglutinin-activated peripheral blood lymphocytes(PBLs). In the present investigation, 1,25(OH2)-16ene-23yne-D3 was compared to the natural metablite of vitamin D3, 1,25(OH)2D3. 1,25(OH)2-16ene-23yne-D3 was more potent than 1,25(OH)2D3 for inhibition of proliferation and induction of differentiation of U937 cells, Its effects on inhibition of proliferation was about 30-fold more potent than 1,25(OH)2D3. On induction of differentiation as measured by nonspecific esterase (NSE) activity and morphologic change, this analog morphologically and functionally differentiated U937 cells to monocyte-macrophage phenotype showing a decrease of N/C ration in Giemsa staining and the increase of adherence ability of surface. After 3 days in culture, a more significant supression of IFN-${\gamma}$ synthesis analog on supression of IFN-${\gamma}$ synthesis was a dose-dependent manner, with peak activity at 10-7M. The strong direct effects of 1,25(OH)2-16ene-23yne-D3 on cell proliferation and cell differentiation, make this compound an interesting candidate for clinical studies for several types of malignancies, and the effects on supression of IFN-${\gamma}$ synthesis provide the further evidence for a role of 1,25(OH)2-16ene-23yne-D3 in immunoregulation.

• 한국어류학회지
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• 제20권1호
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• pp.1-6
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• 2008

제브라피쉬 배아로부터 확보한 세포주로부터 외부형태와 세포 크기에 따라 3종류의 동형세포주를 확립하였다. 활발하게 증식하는 안정된 세포주 및 이들로부터 확립된 동형세포주의 세포특성은 변하지 않고 지속적으로 유지되었으며, 안정된 세포주로부터 총 18개의 콜로니를 확보하여 배양한 다음 3종류의 동형세포주를 선별하여 세포 특성을 분석하였다. 대부분의 동형세포주는 약 80% 정도 정상적인 염색체(2N=50)를 가지고 있었으며 FACs 분석과 일치하였다. 배아로부터 확립된 동형세포주에 항체테스트 결과, vimentin에서 양성을 보이는 결과로 볼 때 확립된 세포주는 분화된 섬유세포임이 확인되었다. 이러한 결과는, 확립된 동형세포주를 이용한 유전자조작과 어류복제에의 활용도를 높일 수 있음을 시사한다.