Treatment with a Small Molecule Mutant IDH1 Inhibitor Suppresses Tumorigenic Activity and Decreases Production of the Oncometabolite 2-Hydroxyglutarate in Human Chondrosarcoma Cells

Science.gov (United States)

Li, Luyuan; Paz, Ana C.; Wilky, Breelyn A.; Johnson, Britt; Galoian, Karina; Rosenberg, Andrew; Hu, Guozhi; Tinoco, Gabriel; Bodamer, Olaf; Trent, Jonathan C.

2015-01-01

Chondrosarcomas are malignant bone tumors that produce cartilaginous matrix. Mutations in isocitrate dehydrogenase enzymes (IDH1/2) were recently described in several cancers including chondrosarcomas. The IDH1 inhibitor AGI-5198 abrogates the ability of mutant IDH1 to produce the oncometabolite D-2 hydroxyglutarate (D-2HG) in gliomas. We sought to determine if treatment with AGI-5198 would similarly inhibit tumorigenic activity and D-2HG production in IDH1-mutant human chondrosarcoma cells. Two human chondrosarcoma cell lines, JJ012 and HT1080 with endogenous IDH1 mutations and a human chondrocyte cell line C28 with wild type IDH1 were employed in our study. Mutation analysis of IDH was performed by PCR-based DNA sequencing, and D-2HG was detected using tandem mass spectrometry. We confirmed that JJ012 and HT1080 harbor IDH1 R132G and R132C mutation, respectively, while C28 has no mutation. D-2HG was detectable in cell pellets and media of JJ012 and HT1080 cells, as well as plasma and urine from an IDH-mutant chondrosarcoma patient, which decreased after tumor resection. AGI-5198 treatment decreased D-2HG levels in JJ012 and HT1080 cells in a dose-dependent manner, and dramatically inhibited colony formation and migration, interrupted cell cycling, and induced apoptosis. In conclusion, our study demonstrates anti-tumor activity of a mutant IDH1 inhibitor in human chondrosarcoma cell lines, and suggests that D-2HG is a potential biomarker for IDH mutations in chondrosarcoma cells. Thus, clinical trials of mutant IDH inhibitors are warranted for patients with IDH-mutant chondrosarcomas. PMID:26368816

Treatment with a Small Molecule Mutant IDH1 Inhibitor Suppresses Tumorigenic Activity and Decreases Production of the Oncometabolite 2-Hydroxyglutarate in Human Chondrosarcoma Cells.

Directory of Open Access Journals (Sweden)

Luyuan Li

Full Text Available Chondrosarcomas are malignant bone tumors that produce cartilaginous matrix. Mutations in isocitrate dehydrogenase enzymes (IDH1/2 were recently described in several cancers including chondrosarcomas. The IDH1 inhibitor AGI-5198 abrogates the ability of mutant IDH1 to produce the oncometabolite D-2 hydroxyglutarate (D-2HG in gliomas. We sought to determine if treatment with AGI-5198 would similarly inhibit tumorigenic activity and D-2HG production in IDH1-mutant human chondrosarcoma cells. Two human chondrosarcoma cell lines, JJ012 and HT1080 with endogenous IDH1 mutations and a human chondrocyte cell line C28 with wild type IDH1 were employed in our study. Mutation analysis of IDH was performed by PCR-based DNA sequencing, and D-2HG was detected using tandem mass spectrometry. We confirmed that JJ012 and HT1080 harbor IDH1 R132G and R132C mutation, respectively, while C28 has no mutation. D-2HG was detectable in cell pellets and media of JJ012 and HT1080 cells, as well as plasma and urine from an IDH-mutant chondrosarcoma patient, which decreased after tumor resection. AGI-5198 treatment decreased D-2HG levels in JJ012 and HT1080 cells in a dose-dependent manner, and dramatically inhibited colony formation and migration, interrupted cell cycling, and induced apoptosis. In conclusion, our study demonstrates anti-tumor activity of a mutant IDH1 inhibitor in human chondrosarcoma cell lines, and suggests that D-2HG is a potential biomarker for IDH mutations in chondrosarcoma cells. Thus, clinical trials of mutant IDH inhibitors are warranted for patients with IDH-mutant chondrosarcomas.

Induced mutants of Streptococcus lactis by gamma irradiation and its effect on milk acidity

International Nuclear Information System (INIS)

Daowd, A.H.; Sabbour, M.M.; Newigy, N.A.; Wahab, G.A.M.

1988-01-01

Streptococus lactis was exposed to different doses of gamma-irradiation (10, 50, 100 and 150 Kr). The results of acidity production in sterilized milk inoculated by isolates from radiation treatments and control could be summarized in the following: 1. The mean acidity produced by S. lactis isolates after irradiation at 10 Kr increased to be 0.66% than that of control isolates (0.62%). The acidity produced by the isolates of the 50 Kr treatment showed more increment to reach the peak (0.7%). Thereafter, acidity production decreased by isolates of the 100 Kr (0.53%) and 150 Kr (0.51%) treatments. Heme, the 50 Kr treatment could be considered activation dose to S. lactis starter for acid production. 2. Two mutants were selected. Acidity production by mutant I (from 10 Kr treatment) was 0.95%, and that of mutant II (from 50 Kr treatment) was 1.0%, while acid production by the parent S. lactis culture was 0.62%. Concerning the stability of the isolates, it was found that acid production by mutant I and mutant II slightly decreased by time. The mutants were re-irradiated after 37 and 60 days at doses 10, 25 and 50 Kr. Acid production in milk by isolates of the radiation treatments was determined. The following results were obtained: -The re-irradiation of the mutants decreased the ability of the isolates for acid production than that of parent mutants. -The re-irradiation of the mutants after 60 days yielded isolates which showed more reduction in acid produced than of isolates obtained from re-irridation of the mutants after 37-days. -The higher the dose of the re-irradiation of the mutants, the lower the mean of acid production by isolates of the treatment

Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

KAUST Repository

Abdel-Azeim, Safwat; Oliva, Romina M.; Chermak, Edrisse; De Cristofaro, Raimondo; Cavallo, Luigi

2014-01-01

Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

Molecular dynamics characterization of five pathogenic factor X mutants associated with decreased catalytic activity

KAUST Repository

Abdel-Azeim, Safwat

2014-11-11

Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. Herein, we have analyzed a pool of pathogenic mutations, located in the FXa catalytic domain and directly associated with defects in enzyme catalytic activity. Using chymotrypsinogen numbering, they correspond to D102N, T135M, V160A, G184S, and G197D. Molecular dynamics simulations were performed for 1.68 μs on the wild-type and mutated forms of FXa. Overall, our analysis shows that four of the five mutants considered, D102N, T135M, V160A, and G184S, have rigidities higher than those of the wild type, in terms of both overall protein motion and, specifically, subpocket S4 flexibility, while S1 is rather insensitive to the mutation. This acquired rigidity can clearly impact the substrate recognition of the mutants.

Bending patterns of chlamydomonas flagella: III. A radial spoke head deficient mutant and a central pair deficient mutant.

Science.gov (United States)

Brokaw, C J; Luck, D J

1985-01-01

Flash photomicrography at frequencies up to 300 Hz and computer-assisted image analysis have been used to obtain parameters describing the flagellar bending patterns of mutants of Chlamydomonas reinhardtii. All strains contained the uni1 mutation, to facilitate photography. The radial spoke head deficient mutant pf17, and the central pair deficient mutant, pf15, in combination with suppressor mutations that restore motility without restoring the ultrastructural or biochemical deficiencies, both generate forward mode bending patterns with increased shear amplitude and decreased asymmetry relative to the "wild-type" uni1 flagella described previously. In the reverse beating mode, the suppressed pf17 mutants generate reverse bending patterns with large shear amplitudes. Reverse beating of the suppressed pf15 mutants is rare. There is a reciprocal relationship between increased shear amplitude and decreased beat frequency, so that the velocity of sliding between flagellar microtubules is not increased by an increase in shear amplitude. The suppressor mutations alone cause decreased frequency and sliding velocity in both forward and reverse mode beating, with little change in shear amplitude or symmetry.

Nature of mutants induced by ionizing radiation in cultured hamster cells. III. Molecular characterization of HPRT-deficient mutants induced by. gamma. -rays or. cap alpha. -particles showing that the majority have deletions of all or part of the hprt gene

Energy Technology Data Exchange (ETDEWEB)

Thacker, J

1986-05-01

DNA from 58 independent HPRT-deficient mutants of V79 hamster cells induced by ionizing radiation was analysed by Southern blot hybridization to a full-length hamster hprt cDNA. About half of the ..gamma..-ray-induced mutants (20/43) were apparently total gene deletions, because they lacked all functional hprt gene sequences hybridizing to the cDNA probe. Another 10 mutants showed various partial deletions and/or rearrangements of the hprt gene. The remaining 13 mutants showed no detectable change in comparison to the structure of the normal gene, which correlated well with previous characterization of these mutants indicating that most carry point mutations in the hprt gene. Thus, 70% or more of radiation-induced HPRT-deficient mutants arise through large genetic changes, especially deletions of all or part of the hprt gene. 16 references, 4 figures, 1 table.

Mutant in tobacco anther culture induced by 60Co γ-rays

International Nuclear Information System (INIS)

Tong Daoru; Jia Xinghua

1991-01-01

The tobacco anthers at uninucleate eccentric stage were irradiated by 60 Co γ-rays for the purpose of inducing desirable mutants. The results showed that the induction frequency of plantlets increased following 1kR of 60 Co γ-rays treatment. However, the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60 Co γ-ray radiation which was considered as a semilethal exposure. The plantlet numbers induced per anther were extremely low following 6kR of 60 Co γ-ray radiation. A white flower mutant appeared in the induced progenies. The tobacco leaf quality of this mutant were significantly improved as compared with its parental line. The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line

Generation and characterization of pigment mutants of ...

African Journals Online (AJOL)

Compared to the wild CC-124, these mutants are characterized by a decrease in chlorophyll a & b content and an increase in carotenoids. The lowest decrease in chlorophyll a was 3 to 4 folds, while the highest increase in carotenoids was 2 to 4 folds. The result of bio-test, using the resulting pigment mutant of C. reinhardtii ...

Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 1. Chlorophyll Mutations in Allelic tw Mutants and Their Revertants

International Nuclear Information System (INIS)

Vaitkuniene, V.

1995-01-01

Genotypical environment is an essential factor determining the mutability of mutants of the same type. Decreased chlorophyll mutant frequency was a common characteristic of all tested tw type (tw, tw 1 , tw 2 ) mutants induced in barley c. 'Auksiniai II'. The mutability of all the tested revertants was close to that of the initial c. 'Auksiniai II'. (author). 9 refs., 2 tabs

Isolation of baker's yeast mutants with proline accumulation that showed enhanced tolerance to baking-associated stresses.

Science.gov (United States)

Tsolmonbaatar, Ariunzaya; Hashida, Keisuke; Sugimoto, Yukiko; Watanabe, Daisuke; Furukawa, Shuhei; Takagi, Hiroshi

2016-12-05

During bread-making processes, yeast cells are exposed to baking-associated stresses such as freeze-thaw, air-drying, and high-sucrose concentrations. Previously, we reported that self-cloning diploid baker's yeast strains that accumulate proline retained higher-level fermentation abilities in both frozen and sweet doughs than the wild-type strain. Although self-cloning yeasts do not have to be treated as genetically modified yeasts, the conventional methods for breeding baker's yeasts are more acceptable to consumers than the use of self-cloning yeasts. In this study, we isolated mutants resistant to the proline analogue azetidine-2-carboxylate (AZC) derived from diploid baker's yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular proline, and among them, 5 mutants showed higher cell viability than that observed in the parent wild-type strain under freezing or high-sucrose stress conditions. Two of them carried novel mutations in the PRO1 gene encoding the Pro247Ser or Glu415Lys variant of γ-glutamyl kinase (GK), which is a key enzyme in proline biosynthesis in S. cerevisiae. Interestingly, we found that these mutations resulted in AZC resistance of yeast cells and desensitization to proline feedback inhibition of GK, leading to intracellular proline accumulation. Moreover, baker's yeast cells expressing the PRO1 P247S and PRO1 E415K gene were more tolerant to freezing stress than cells expressing the wild-type PRO1 gene. The approach described here could be a practical method for the breeding of proline-accumulating baker's yeasts with higher tolerance to baking-associated stresses. Copyright © 2016 Elsevier B.V. All rights reserved.

Selection of Mycoplasma hominis PG21 deletion mutants by cultivation in the presence of monoclonal antibody 552

DEFF Research Database (Denmark)

Jensen, L T; Ladefoged, S; Birkelund, S

1995-01-01

characterized. The mutants showed deletions of a various number of repeats. The deletions were accompanied by a decrease in size of the proteins. With increasing size of deletions, agglutination and growth inhibition by MAb 552 became less pronounced. Spontaneous aggregation of the mutant M. hominis cells...

Functional Loss of Bmsei Causes Thermosensitive Epilepsy in Contractile Mutant Silkworm, Bombyx mori

Science.gov (United States)

Nie, Hongyi; Cheng, Tingcai; Huang, Xiaofeng; Zhou, Mengting; Zhang, Yinxia; Dai, Fangyin; Mita, Kazuei; Xia, Qingyou; Liu, Chun

2015-07-01

The thermoprotective mechanisms of insects remain largely unknown. We reported the Bombyx mori contractile (cot) behavioral mutant with thermo-sensitive seizures phenotype. At elevated temperatures, the cot mutant exhibit seizures associated with strong contractions, rolling, vomiting, and a temporary lack of movement. We narrowed a region containing cot to ~268 kb by positional cloning and identified the mutant gene as Bmsei which encoded a potassium channel protein. Bmsei was present in both the cell membrane and cytoplasm in wild-type ganglia but faint in cot. Furthermore, Bmsei was markedly decreased upon high temperature treatment in cot mutant. With the RNAi method and injecting potassium channel blockers, the wild type silkworm was induced the cot phenotype. These results demonstrated that Bmsei was responsible for the cot mutant phenotype and played an important role in thermoprotection in silkworm. Meanwhile, comparative proteomic approach was used to investigate the proteomic differences. The results showed that the protein of Hsp-1 and Tn1 were significantly decreased and increased on protein level in cot mutant after thermo-stimulus, respectively. Our data provide insights into the mechanism of thermoprotection in insect. As cot phenotype closely resembles human epilepsy, cot might be a potential model for the mechanism of epilepsy in future.

The mTOR kinase inhibitor Everolimus decreases S6 kinase phosphorylation but fails to reduce mutant huntingtin levels in brain and is not neuroprotective in the R6/2 mouse model of Huntington's disease

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Frentzel Stefan

2010-06-01

Full Text Available Abstract Background Huntington's disease (HD is a progressive neurodegenerative disorder caused by a CAG repeat expansion within the huntingtin gene. Mutant huntingtin protein misfolds and accumulates within neurons where it mediates its toxic effects. Promoting mutant huntingtin clearance by activating macroautophagy is one approach for treating Huntington's disease (HD. In this study, we evaluated the mTOR kinase inhibitor and macroautophagy promoting drug everolimus in the R6/2 mouse model of HD. Results Everolimus decreased phosphorylation of the mTOR target protein S6 kinase indicating brain penetration. However, everolimus did not activate brain macroautophagy as measured by LC3B Western blot analysis. Everolimus protected against early declines in motor performance; however, we found no evidence for neuroprotection as determined by brain pathology. In muscle but not brain, everolimus significantly decreased soluble mutant huntingtin levels. Conclusions Our data suggests that beneficial behavioral effects of everolimus in R6/2 mice result primarily from effects on muscle. Even though everolimus significantly modulated its target brain S6 kinase, this did not decrease mutant huntingtin levels or provide neuroprotection.

Phenotypic, genetic and molecular characterization of a maize low phytic acid mutant (lpa241)

DEFF Research Database (Denmark)

Pilu, R.; Panzeri, D.; Gavazzi, G.

2003-01-01

-nutritional factor for animals, and isolation of maize low phytic acid (lpa) mutants provides a novel approach to study its biochemical pathway and to tackle the nutritional problems associated with it. Following chemical mutagenesis of pollen, we have isolated a viable recessive mutant named lpa 241 showing about...... 90% reduction of phytic acid and about a tenfold increase in seed-free phosphate content. Although germination rate was decreased by about 30% compared to wild-type, developement of mutant plants was apparentely unaffected. The results of the genetic, biochemical and molecular characterization...

Estimation of genetic variability, mutagenic effectiveness and efficiency in M2 flower mutant lines of Capsicum annuum L. treated with caffeine and their analysis through RAPD

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Rumana Aslam

2017-07-01

Full Text Available In the present investigation healthy and certified seeds of Capsicum annuum were treated with five concentrations of caffeine i.e. 0.10%, 0.25%, 0.50%, 0.75% and 1.0%. Germination percentage, plants survival and pollen fertility were decreased with the increase of caffeine concentrations. Similarly root length and shoot length were decreased as the concentrations increased in M1 generation. Different mutants were isolated in M1 generation. In M2 generation, various flower mutants with changes in number of sepals, petals, anther size colour i.e. Trimerous, tetramerous, pentamerous with fused petals, hexamerous etc were segregated. Heptamerous and anther change was not observed in lower concentration viz. 0.1%. All these mutants showed significant changes in morphological characters and good breeding values at lower and intermediate concentrations. Mutagenic effectiveness and efficiency was observed on the basis of M2 flower mutant frequency. It was generally decreased with the increase of mutagen concentrations. Cytological aberrations in mutants showed the decreasing trend at meiotic final stages. These mutants were further analysed through RAPD method and on the basis of appearance of polymorphic DNA bands, they distinguished these flower mutants genotypically. Among 93 bands 44 bands were polymorphic which showed great genetic variation produced by caffeine. As an outcome of that the above caffeine concentrations are good for the induction of genetic variability in Capsicum genotype.

Che-1 gene silencing induces osteosarcoma cell apoptosis by inhibiting mutant p53 expression

Energy Technology Data Exchange (ETDEWEB)

Liu, Ming; Wang, Dan, E-mail: danwangwdd@163.com; Li, Ning

2016-04-22

The transcriptional cofactor Che-1 is an RNA polymerase II (Pol II) which is involved in tumorigenesis, such as breast cancer and multiple myeloma. Che-1 can also regulate mutant p53 expression, which plays roles in many types of cancer. In this study, we aimed to investigate the effects and specific mechanism of Che-1 in the regulation of osteosarcoma (OS) cell growth. We found that Che-1 is highly expressed in several kinds of OS cells compared with osteoblast hFOB1.19 cells. MTT and flow cytometry assays showed that Che-1 depletion by siRNA markedly suppressed MG-63 and U2OS cell proliferation and promoted apoptosis. The chromatin immunoprecipitation (ChIP) assay verified the presence of Che-1 on the p53 promoter in MG-63 and U2OS cells carrying mutant p53. Further studies showed that Che-1 depletion inhibited mutant p53 expression. Notably, our study showed that the loss of Che-1 inhibits proliferation and promotes apoptosis in MG-63 cells by decreasing the level of mutant p53. Therefore, these findings open the possibility that silencing of Che-1 will have therapeutic benefit in OS. - Highlights: • Che-1 is highly expressed in several kinds of OS cells. • Che-1 depletion suppressed MG-63 and U2OS cell growth. • Che-1 is existed in the p53 promoter in MG-63 and U2OS cells. • Che-1 depletion inhibited mutant p53 expression. • Che-1 depletion inhibits cell growth by decreasing the level of mutant p53.

X-ray-induced mutants resistant to 8-azaguanine

International Nuclear Information System (INIS)

Carver, J.H.; Dewey, W.C.; Hopwood, L.E.

1976-01-01

Asynchronous Chinese hamster ovary cells were irradiated and colony survival in Alpha MEM medium with dialyzed serum was determined with or without 15 μg/ml 8-Azaguanine (AG). Data indicated that a reproducible assay for the system was dependent upon controlling cell density at least two days prior to induction as well as throughout the expression period. Generally, spontaneous and radiation-induced mutant frequencies decreased when cell densities exceeded a critical density of 3-6 x 10 4 cells/cm 2 . Infrequently, the critical density was exceeded by a factor of two with no observed decrease, possibly correlated with a longer cell doubling time. Drug depletion artifacts can occur because of drug degradation, or because wild-type cells utilize the drug or produce conditions which reduce uptake of the drug. Thus, as the effective drug concentration is lowered, the observed mutant frequency increases because a spectrum of mutants resistant to only low concentrations can now survive. In fact, refeeding with AG at intervals during the incubation period lowered spontaneous and radiation-induced frequencies approx. 5-fold. Therefore, to standardize conditions, cells were trypsinized at the end of the expression time and replated at a constant cell number for mutant selection by AG. Over two generations of growth during the expression period were required for optimal manifestation of induced mutants, and when densities were kept below 4 x 10 4 cells/cm 2 at all times, observed mutant frequencies did not change significantly over a period between 80 and 140 h post-induction (over 4 generations for irradiated cells and over 6 generations for controls). Previous reports of observed mutant frequencies decreasing beyond three generations may be due to cell interaction prior to mutant selection

Evaluation of Chemical Changes in Some Soybean Mutants Induced by Gamma Irradiation

International Nuclear Information System (INIS)

Abd-Elkalik, K.; Mekkawy, S.H.; El-Demerdash, H.M.

2010-01-01

The Egyptian soybean cultivar Giza-22 was used to induce genetic variability by using gamma rays at dose levels of 100, 150 and 200 Gy. Sixteen mutants (including parental cultivar) were evaluated in M3 generation for their agronomic traits and chemical analysis was done in seeds of M3 generation. Four mutants A21 (150 Gy), A22, A23 and A24 (200 Gy) showed superiority in their agronomic traits compared with parental cultivar. The results of chemical analysis of seeds of M3 generation showed that, oil and energy contents were unaffected by irradiation treatments while protein contents were significantly increased at doses 150 and 200 Gy. Phenolic and tannin contents in seeds of M3 generation showed no significant changes in their percentages due to irradiation treatments. Gamma irradiation significantly increased in linoleic acid content in most of the mutants compared with the control (Giza-22), whereas, there were decreases in linolenic acid content. Investigation of amino acid composition of mutants of M3 generation revealed significant increases in the essential amino acids in most mutants induced by gamma irradiation at 150 and 200 Gy. It could be suggested that the use of gamma irradiation can induce an improvement of the oil and protein composition in soybean

Mutants of Escherichia coli K-12 with enhanced resistance to ionizing radiation. 4. Peculiarities of recombination in Gamsup(r) mutants

International Nuclear Information System (INIS)

Bresler, S.E.; Kalinin, V.L.; Laneeva, N.I.

1984-01-01

Radioresistant mutant Gam sup(r) 444 differs from a wild type and from Gam sup(r) 445 mutant in decreased frequency of long episome heritage ORF 1 (pur E + -tsx + -proC + -lac + ) and F 14 (ilv + -argE + ), containing hot points of RecRecF - depending recombination and in increased frequency of chromosome mobilization and integrative suppression of temperature sensitive dna A46 mutation by sexual factor F. In this respect Gam sup(r) 444 mutant resembles rec BC sbs B mutant with RecF - recombination type

Metabolic and molecular analyses of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor.

Science.gov (United States)

Primetta, Anja K; Karppinen, Katja; Riihinen, Kaisu R; Jaakola, Laura

2015-09-01

MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid biosynthetic genes and the accumulation of flavonoids in white mutant and blue-colored wild-type bog bilberry (V. uliginosum) fruits were measured at different stages of berry development. In contrast to high contents of anthocyanins in ripe blue-colored berries, only traces were detected by HPLC-ESI-MS in ripe white mutant berries. However, similar profile and high levels of flavonol glycosides and proanthocyanidins were quantified in both ripe white and ripe wild-type berries. Analysis with qRT-PCR showed strong down-regulation of structural genes chalcone synthase (VuCHS), dihydroflavonol 4-reductase (VuDFR) and anthocyanidin synthase (VuANS) as well as MYBPA1-type transcription factor VuMYBPA1 in white berries during ripening compared to wild-type berries. The profiles of transcript accumulation of chalcone isomerase (VuCHI), anthocyanidin reductase (VuANR), leucoanthocyanidin reductase (VuLAR) and flavonoid 3'5' hydroxylase (VuF3'5'H) were more similar between the white and the wild-type berries during fruit development, while expression of UDP-glucose: flavonoid 3-O-glucosyltransferase (VuUFGT) showed similar trend but fourfold lower level in white mutant. VuMYBPA1, the R2R3 MYB family member, is a homologue of VmMYB2 of V. myrtillus and VcMYBPA1 of V. corymbosum and belongs to MYBPA1-type MYB family which members are shown in some species to be related with proanthocyanidin biosynthesis in fruits. Our results combined with earlier data of the role of VmMYB2 in white mutant berries of V. myrtillus suggest that the regulation of anthocyanin biosynthesis in Vaccinium species could differ

Arabidopsis AtDjA3 null mutant shows increased sensitivity to abscisic acid, salt, and osmotic stress in germination and postgermination stages

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Silvia eSalas-Muñoz

2016-02-01

Full Text Available DnaJ proteins are essential co-chaperones involved in abiotic and biotic stress responses. Arabidopsis AtDjA3 gene encodes a molecular co-chaperone of 420 amino acids, which belongs to the J-protein family. In this study, we report the functional characterization of the AtDjA3 gene using the Arabidopsis knockout line designated j3 and the 35S::AtDjA3 overexpression lines. Loss of AtDjA3 function was associated with small seed production. In fact, j3 mutant seeds showed a reduction of 24% in seed weight compared to Col-0 seeds. Expression analysis showed that the AtDjA3 gene was modulated in response to NaCl, glucose, and abscisic acid. The j3 line had increased sensitivity to NaCl and glucose treatments in the germination and cotyledon development in comparison to parental Col-0. Furthermore, the j3 mutant line exhibited higher abscisic acid sensitivity in comparison to parental Col-0 and 35S::AtDjA3 overexpression lines. In addition, we examined the expression of ABI3 gene, which is a central regulator in ABA signalling, in j3 mutant and 35S::AtDjA3 overexpression lines. Under 5 μM ABA treatment at 24 h, j3 mutant seedlings displayed higher ABI3 expression, whereas in 35S::AtDjA3 overexpression lines, ABI3 gene expression was repressed. Taken together, these results demonstrate that the AtDjA3 gene is involved in seed development and abiotic stress tolerance.

Repair-defective mutants of Alteromonas espejiana, the host for bacteriophage PM2

International Nuclear Information System (INIS)

Zerler, B.R.; Wallace, S.S.

1984-01-01

The in vivo repair processes of Alteromonas espejiana, the host for bacteriophage PM2, were characterized, and UV- and methyl methanesulfonate (MMS)-sensitive mutants were isolated. Wild-type A. espejiana cells were capable of photoreactivation, excision, recombination, and inducible repair. There was no detecttable pyrimidine dimer-DNA N-glycosylase activity, and pyrimidine dimer removal appeared to occur by a pathway analogous to the Escherichia coli Uvr pathway. The UV- and MMS-sensitive mutants of A. espejiana included three groups, each containing at least one mutation involved with excision, recombination, or inducible repair. One group that was UV sensitive but not sensitive to MMS or X rays showed a decreased ability to excise pyrimidine dimers. Mutants in this group were also sensitive to psoralen plus near-UV light and were phenotypically analogous to the E. coli uvr mutants. A second group was UV and MMS sensitive but not sensitive to X rays and appeared to contain mutations in a gene(s) involved in recombination repair. These recombination-deficient mutants differed from the E. coli rec mutants, which are MMS and X-ray sensitive. The third group of A. espejiana mutants was sensitive to UV, MMS, and X rays. These mutants were recombination deficient, lacked inducible repair, and were phenotypically similar to E. coli recA mutants

Assessment of Lupin Induced Mutants for Quality Traits and Susceptibility to Callosbruchus chinensis and Heliothis armigera insects

International Nuclear Information System (INIS)

Ragab, A.I.; Boshra, S.A.; Mehany, A.L.; Darwish, A.A.; Kharrab, M.M.

2008-01-01

This study was conducted to assess 23 induced mutants and two parental varieties Giza1 and Giza2 in the three generations (M3, M4, and M5) for seed quality traits, and susceptibility to two insects i.e C. chinnensis and H.armigera. The obtained results exhibited highly significant decrease for alkaloid content of mutants 20 and 23 as compared with the two local varieties. Most of mutants and Giza 2 showed marked increase for protein content as compared with Giza1, however, the increase did not reach the level of significance for the most mutants as compared with Giza2 in the three generations. Except of M4 generation. marked resistance for infestations with C.chinensis and H.armigera was obtained for mutants 1, 5 and 11 in the three generations. However, for total infestation with the two insects, resistance was obtained in mutants 4 and 10. Except of mutant lines 1, 5 and 11, all mutants showed higher loss percentage than that of the local varieties

Adhesion defective BHK cell mutant has cell surface heparan sulfate proteoglycan of altered properties

DEFF Research Database (Denmark)

Couchman, J R; Austria, R; Woods, A

1988-01-01

In the light of accumulating data that implicate cell surface heparan sulfate proteoglycans (HSPGs) with a role in cell interactions with extracellular matrix molecules such as fibronectin, we have compared the properties of these molecules in wild-type BHK cells and an adhesion-defective ricin......-resistant mutant (RicR14). Our results showed that the mutant, unlike BHK cells, cannot form focal adhesions when adherent to planar substrates in the presence of serum. Furthermore, while both cell lines possess similar amounts of cell surface HSPG with hydrophobic properties, that of RicR14 cells had decreased...... sulfation, reduced affinity for fibronectin and decreased half-life on the cell surface when compared to the normal counterpart. Our conclusions based on this data are that these altered properties may, in part, account for the adhesion defect in the ricin-resistant mutant. Whether this results from...

Gamma rays induced bold seeded high yielding mutant in chickpea

International Nuclear Information System (INIS)

Wani, A.A.; Anis, M.

2001-01-01

In pulses especially in chickpea (Cicer arietinum L.), genetic variability has been exhausted due to natural selection and hence conventional breeding methods are not very fruitful. Mutation techniques are the best methods to enlarge the genetically conditioned variability of a species within a short time and have played a significant role in the development of many crop varieties. Investigations on the effects of ionizing radiations and chemical mutagens in induction of macro-mutations have received much attention owing to their utmost importance in plant breeding. The present study reports a bold seeded mutant in chickpea, the most dominating pulse crop on the Indian subcontinent. Fresh seeds of chickpea variety 'Pusa-212' were procured from IARI, New Delhi and treated with different doses/concentrations of gamma rays ( 60 Co source at NBRI, Lucknow) and ethyl methanesulphonate (EMS), individually as well as in combination, to raise the M1 generation. Seeds of M 1 plants were sown to raise M2 plant progenies. A bold seeded mutant was isolated from 400 Gy gamma ray treatments. The mutant was confirmed as true bred, all the mutant seeds gave rise to morphologically similar plants in M 3 , which were quite distinct from the control. The bold seeded mutant showed 'gigas' characteristics and vigorous growth. The plant remained initially straight but later on attained a trailing habit due to heavy secondary branching. The leaves, petioles, flowers, pods and seeds were almost double that of the parent variety, in size. The flowering occurred 10 days later than the parent and maturity was also delayed accordingly. Observations were recorded on various quantitative traits. Plant height and number of primary branches showed a significant improvement over the parent. It is interesting to note that the number of pods and number of seeds per pod significantly decreased. However, the hundred seed weight (31.73±0.59g) in the mutant plants was more than double in the parent

Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma.

Science.gov (United States)

Kundu, Anup K; Iyer, Swathi V; Chandra, Sruti; Adhikari, Amit S; Iwakuma, Tomoo; Mandal, Tarun K

2017-01-01

The tumor suppressor p53 plays a crucial role in the development of osteosarcoma. The primary objective of this study is to develop and optimize lipid based nanoparticle formulations that can carry siRNA and effectively silence mutant p53 in 318-1, a murine osteosarcoma cell line. The nanoparticles were composed of a mixture of two lipids (cholesterol and DOTAP) and either PLGA or PLGA-PEG and prepared by using an EmulsiFlex-B3 high pressure homogenizer. A series of studies that include using different nanoparticles, different amount of siRNAs, cell numbers, incubation time, transfection media volume, and storage temperature was performed to optimize the gene silencing efficiency. Replacement of lipids by PLGA or PLGA-PEG decreased the particle size and overall cytotoxicity. Among all lipid-polymer nanoformulations, nanoparticles with 10% PLGA showed highest mutant p53 knockdown efficiency while maintaining higher cell viability when a nanoparticle to siRNA ratio equal to 6.8:0.66 and 75 nM siRNA was used. With long term storage the mutant p53 knockdown efficiency decreased to a greater extent. This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.

Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma.

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Anup K Kundu

Full Text Available The tumor suppressor p53 plays a crucial role in the development of osteosarcoma. The primary objective of this study is to develop and optimize lipid based nanoparticle formulations that can carry siRNA and effectively silence mutant p53 in 318-1, a murine osteosarcoma cell line.The nanoparticles were composed of a mixture of two lipids (cholesterol and DOTAP and either PLGA or PLGA-PEG and prepared by using an EmulsiFlex-B3 high pressure homogenizer. A series of studies that include using different nanoparticles, different amount of siRNAs, cell numbers, incubation time, transfection media volume, and storage temperature was performed to optimize the gene silencing efficiency.Replacement of lipids by PLGA or PLGA-PEG decreased the particle size and overall cytotoxicity. Among all lipid-polymer nanoformulations, nanoparticles with 10% PLGA showed highest mutant p53 knockdown efficiency while maintaining higher cell viability when a nanoparticle to siRNA ratio equal to 6.8:0.66 and 75 nM siRNA was used. With long term storage the mutant p53 knockdown efficiency decreased to a greater extent.This study warrants a future evaluation of this formulation for gene silencing efficiency of mutant p53 in tissue culture and animal models for the treatment of osteosarcoma.

mei-9/sup a/ mutant of Drosophila melanogaster increases mutagen sensitivity and decreases excision repair

International Nuclear Information System (INIS)

Boyd, J.B.; Golino, M.D.; Setlow, R.B.

1976-01-01

The mei-9/sup a/ mutant of Drosophila melanogaster, which reduces meiotic recombination in females, is deficient in the excision of uv-induced pyrimidine dimers in both sexes. Assays were performed in primary cultures and established cell lines derived from embryos. An endonuclease preparation from M. luteus, which is specific for pyrimidine dimers, was employed to monitor uv-induced dimers in cellular DNA. The rate of disappearance of endonuclease-sensitive sites from DNA of control cells is 10-20 times faster than that from mei-9/sup a/ cells. The mutant mei-218, which is also deficient in meiotic recombination, removes nuclease-sensitive sites at control rates. The mei-9/sup a/ cells exhibit control levels of photorepair, postreplication repair and repair of single strand breaks. In mei-9 cells DNA synthesis and possibly postreplication repair are weakly sensitive to caffeine. Larvae which are hemizygous for either of the two mutants that define the mei-9 locus are hypersensitive to killing by the mutagens methyl methanesulfonate, nitrogen mustard and 2-acetylaminofluorene. Larvae hemizygous for the mei-218 mutant are insensitive to each of these reagents. These data demonstrate that the mei-9 locus is active in DNA repair of somatic cells. Thus functions involved in meiotic recombination are also active in DNA repair in this higher eukaryote. The results are consistent with the earlier suggestions that the mei-9 locus functions in the exchange events of meiosis. The mei-218 mutation behaves differently in genetic tests and our data suggest its function may be restricted to meiosis. These studies demonstrate that currently recognized modes of DNA repair can be efficiently detected in primary cell cultures derived from Drosophila embryos

How Life History Can Sway the Fixation Probability of Mutants

Science.gov (United States)

Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

2016-01-01

In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

Genetic Analysis and Molecular Mapping of a Novel Chlorophyll-Deficit Mutant Gene in Rice

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Xiao-qun HUANG

2008-03-01

Full Text Available A rice etiolation mutant 824ys featured with chlorophyll deficiency was identified from a normal green rice variety 824B. It showed whole green-yellow plant from the seedling stage, reduced number of tillers and longer growth duration. The contents of chlorophyll, chlorophyll a, chlorophyll b and net photosynthetic rate in leaves of the mutant obviously decreased, as well as the number of spikelets per panicle, seed setting rate and 1000-grain weight compared with its wild-type parent. Genetic analyses on F1 and F2 generations of 824ys crossed with three normal green varieties showed that the chlorophyll-deficit mutant character was controlled by a pair of recessive nuclear gene. Genetic mapping of the mutant gene was conducted by using microsatellite markers and F2 mapping population of 495R/824ys, and the mutant gene of 824ys was mapped on the short arm of rice chromosome 3. The genetic distances from the target gene to the markers RM218, RM282 and RM6959 were 25.6 cM, 5.2 cM and 21.8 cM, respectively. It was considered to be a new chlorophyll-deficit mutant gene and tentatively named as chl11(t.

Apoc2 loss-of-function zebrafish mutant as a genetic model of hyperlipidemia

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Chao Liu

2015-08-01

Full Text Available Apolipoprotein C-II (APOC2 is an obligatory activator of lipoprotein lipase. Human patients with APOC2 deficiency display severe hypertriglyceridemia while consuming a normal diet, often manifesting xanthomas, lipemia retinalis and pancreatitis. Hypertriglyceridemia is also an important risk factor for development of cardiovascular disease. Animal models to study hypertriglyceridemia are limited, with no Apoc2-knockout mouse reported. To develop a genetic model of hypertriglyceridemia, we generated an apoc2 mutant zebrafish characterized by the loss of Apoc2 function. apoc2 mutants show decreased plasma lipase activity and display chylomicronemia and severe hypertriglyceridemia, which closely resemble the phenotype observed in human patients with APOC2 deficiency. The hypertriglyceridemia in apoc2 mutants is rescued by injection of plasma from wild-type zebrafish or by injection of a human APOC2 mimetic peptide. Consistent with a previous report of a transient apoc2 knockdown, apoc2 mutant larvae have a minor delay in yolk consumption and angiogenesis. Furthermore, apoc2 mutants fed a normal diet accumulate lipid and lipid-laden macrophages in the vasculature, which resemble early events in the development of human atherosclerotic lesions. In addition, apoc2 mutant embryos show ectopic overgrowth of pancreas. Taken together, our data suggest that the apoc2 mutant zebrafish is a robust and versatile animal model to study hypertriglyceridemia and the mechanisms involved in the pathogenesis of associated human diseases.

A herbicide-resistant ACCase 1781 Setaria mutant shows higher fitness than wild type.

Science.gov (United States)

Wang, T; Picard, J C; Tian, X; Darmency, H

2010-10-01

It is often alleged that mutations conferring herbicide resistance have a negative impact on plant fitness. A mutant ACCase1781 allele endowing resistance to the sethoxydim herbicide was introgressed from a resistant green foxtail (Setaria viridis (L.) Beauv) population into foxtail millet (S. italica (L.) Beauv.). (1) Better and earlier growth of resistant plants was observed in a greenhouse cabinet. (2) Resistant plants of the advanced BC7 backcross generation showed more vigorous juvenile growth in the field, earlier flowering, more tillers and higher numbers of grains than susceptible plants did, especially when both genotypes were grown in mixture, but their seeds were lighter than susceptible seeds. (3) Field populations originating from segregating hybrids had the expected allele frequencies under normal growth conditions, but showed a genotype shift toward an excess of homozygous resistant plants within 3 years in stressful conditions. Lower seed size, lower germination rate and perhaps unexplored differences in seed longevity and predation could explain how the resistant plants have the same field fitness over the whole life cycle as the susceptible ones although they produce more seeds. More rapid growth kinetics probably accounted for higher fitness of the resistant plants in adverse conditions. The likelihood of a linkage with a beneficial gene is discussed versus the hypothesis of a pleiotropic effect of the ACCase resistance allele. It is suggested that autogamous species like Setaria could not develop a resistant population without the help of a linkage with a gene producing a higher fitness.

Molecular Determinants of Mutant Phenotypes, Inferred from Saturation Mutagenesis Data.

Science.gov (United States)

Tripathi, Arti; Gupta, Kritika; Khare, Shruti; Jain, Pankaj C; Patel, Siddharth; Kumar, Prasanth; Pulianmackal, Ajai J; Aghera, Nilesh; Varadarajan, Raghavan

2016-11-01

Understanding how mutations affect protein activity and organismal fitness is a major challenge. We used saturation mutagenesis combined with deep sequencing to determine mutational sensitivity scores for 1,664 single-site mutants of the 101 residue Escherichia coli cytotoxin, CcdB at seven different expression levels. Active-site residues could be distinguished from buried ones, based on their differential tolerance to aliphatic and charged amino acid substitutions. At nonactive-site positions, the average mutational tolerance correlated better with depth from the protein surface than with accessibility. Remarkably, similar results were observed for two other small proteins, PDZ domain (PSD95 pdz3 ) and IgG-binding domain of protein G (GB1). Mutational sensitivity data obtained with CcdB were used to derive a procedure for predicting functional effects of mutations. Results compared favorably with those of two widely used computational predictors. In vitro characterization of 80 single, nonactive-site mutants of CcdB showed that activity in vivo correlates moderately with thermal stability and solubility. The inability to refold reversibly, as well as a decreased folding rate in vitro, is associated with decreased activity in vivo. Upon probing the effect of modulating expression of various proteases and chaperones on mutant phenotypes, most deleterious mutants showed an increased in vivo activity and solubility only upon over-expression of either Trigger factor or SecB ATP-independent chaperones. Collectively, these data suggest that folding kinetics rather than protein stability is the primary determinant of activity in vivo This study enhances our understanding of how mutations affect phenotype, as well as the ability to predict fitness effects of point mutations. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

High yielding mutants of blackgram variety 'PH-25'

International Nuclear Information System (INIS)

Misra, R.C.; Mohapatra, B.D.; Panda, B.S.

2001-01-01

Seeds of blackgram (Vigna mungo L.) variety 'PH-5' were treated with chemical mutagens ethyl methanesulfonate (EMS), nitrosoguanidine (NG), maleic hydrazide (MH) and sodium azide (NaN 3 ), each at 3 different concentrations. Thirty six mutant lines developed from mutagenic treatments along with parent varieties were tested in M 4 generation. The mutants showed wide variation in most of the traits and multivariante D 2 analysis showed genetic divergence among themselves. Twenty of the thirty mutants showed genetic divergence from parent. Ten selected high yielding mutants were tested in M 5 . Yield and other productive traits of five high yielding mutants in M 4 and M 5 are presented

Lifespan decrease in a Caenorhabditis elegans mutant lacking TRX-1, a thioredoxin expressed in ASJ sensory neurons.

Science.gov (United States)

Miranda-Vizuete, Antonio; Fierro González, Juan Carlos; Gahmon, Gabriele; Burghoorn, Jan; Navas, Plácido; Swoboda, Peter

2006-01-23

Thioredoxins are a class of small proteins that play a key role in regulating many cellular redox processes. We report here the characterization of the first member of the thioredoxin family in metazoans that is mainly associated with neurons. The Caenorhabditis elegans gene B0228.5 encodes a thioredoxin (TRX-1) that is expressed in ASJ ciliated sensory neurons, and to some extent also in the posterior-most intestinal cells. TRX-1 is active at reducing protein disulfides in the presence of a heterologous thioredoxin reductase. A mutant worm strain carrying a null allele of the trx-1 gene displays a reproducible decrease in both mean and maximum lifespan when compared to wild-type. The identification and characterization of TRX-1 paves the way to use C. elegans as an in vivo model to study the role of thioredoxins in lifespan and nervous system physiology and pathology.

A fasciclin-like arabinogalactan-protein (FLA mutant of Arabidopsis thaliana, fla1, shows defects in shoot regeneration.

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Kim L Johnson

Full Text Available BACKGROUND: The fasciclin-like arabinogalactan-proteins (FLAs are an enigmatic class of 21 members within the larger family of arabinogalactan-proteins (AGPs in Arabidopsis thaliana. Located at the cell surface, in the cell wall/plasma membrane, they are implicated in many developmental roles yet their function remains largely undefined. Fasciclin (FAS domains are putative cell-adhesion domains found in extracellular matrix proteins of organisms from all kingdoms, but the juxtaposition of FAS domains with highly glycosylated AGP domains is unique to plants. Recent studies have started to elucidate the role of FLAs in Arabidopsis development. FLAs containing a single FAS domain are important for the integrity and elasticity of the plant cell wall matrix (FLA11 and FLA12 and FLA3 is involved in microspore development. FLA4/SOS5 with two FAS domains and two AGP domains has a role in maintaining proper cell expansion under salt stressed conditions. The role of other FLAs remains to be uncovered. METHOD/PRINCIPAL FINDINGS: Here we describe the characterisation of a T-DNA insertion mutant in the FLA1 gene (At5g55730. Under standard growth conditions fla1-1 mutants have no obvious phenotype. Based on gene expression studies, a putative role for FLA1 in callus induction was investigated and revealed that fla1-1 has a reduced ability to regenerate shoots in an in vitro shoot-induction assay. Analysis of FLA1p:GUS reporter lines show that FLA1 is expressed in several tissues including stomata, trichomes, the vasculature of leaves, the primary root tip and in lateral roots near the junction of the primary root. CONCLUSION: The results of the developmental expression of FLA1 and characterisation of the fla1 mutant support a role for FLA1 in the early events of lateral root development and shoot development in tissue culture, prior to cell-type specification.

The three catalases in Deinococcus radiodurans: Only two show catalase activity

Energy Technology Data Exchange (ETDEWEB)

Jeong, Sun-Wook [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of); Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of); Lim, Heon-Man [Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon, 305-764 (Korea, Republic of); Lim, Sangyong, E-mail: saylim@kaeri.re.kr [Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 580-185 (Korea, Republic of)

2016-01-15

Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H{sub 2}O{sub 2}) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H{sub 2}O{sub 2} treatments, whereas ΔdrA0146 showed no change in its H{sub 2}O{sub 2} resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H{sub 2}O{sub 2}, but DRA0146 does not have catalase activity and is not involved in the resistance to H{sub 2}O{sub 2} stress. - Highlights: • The dr1998 mutant strain lost 90% of its total catalase activity. • Increased ROS levels and decreased H{sub 2}O{sub 2} resistance were observed in dr1998 mutants. • Lack of drA0146 did not affect any oxidative stress-related phenotypes. • The purified DRA0146 did not show catalase activity.

The three catalases in Deinococcus radiodurans: Only two show catalase activity

International Nuclear Information System (INIS)

Jeong, Sun-Wook; Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong; Lim, Heon-Man; Lim, Sangyong

2016-01-01

Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H_2O_2) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H_2O_2 treatments, whereas ΔdrA0146 showed no change in its H_2O_2 resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H_2O_2, but DRA0146 does not have catalase activity and is not involved in the resistance to H_2O_2 stress. - Highlights: • The dr1998 mutant strain lost 90% of its total catalase activity. • Increased ROS levels and decreased H_2O_2 resistance were observed in dr1998 mutants. • Lack of drA0146 did not affect any oxidative stress-related phenotypes. • The purified DRA0146 did not show catalase activity.

Semi-dwarf mutants for rice improvement

International Nuclear Information System (INIS)

Othman, Ramli; Osman, Mohammad; Ibrahim, Rusli

1990-01-01

Full text: MARDI and the National University of Malaysia embarked on a programme to induce resistance against blast in rice in 1978. MARDI also obtained semi dwarf mutants of cvs 'Mahsuri', 'Muda', 'Pongsu seribu' and 'Jarum Mas', which are under evaluation. The popular local rice variety 'Manik' was subjected to gamma irradiation (15-40 krad) and 101 promising semidwarf mutants have been obtained following selection in M 2 -M 6 . 29 of them show grain yields of 6.0-7.3 t/ha, compared with 5.7t for 'Manik'. Other valuable mutants were found showing long grain, less shattering, earlier maturity, and glutinous endosperm. One mutant, resistant to brown plant hopper yields 6.3t/ha. (author)

Analysis of Lysophospholipid Content in Low Phytate Rice Mutants.

Science.gov (United States)

Tong, Chuan; Chen, Yaling; Tan, Yuanyuan; Liu, Lei; Waters, Daniel L E; Rose, Terry J; Shu, Qingyao; Bao, Jinsong

2017-07-05

As a fundamental component of nucleic acids, phospholipids, and adenosine triphosphate, phosphorus (P) is critical to all life forms, however, the molecular mechanism of P translocation and distribution in rice grains are still not understood. Here, with the use of five different low phytic acid (lpa) rice mutants, the redistribution in the main P-containing compounds in rice grain, phytic acid (PA), lysophospholipid (LPL), and inorganic P (Pi), was investigated. The lpa mutants showed a significant decrease in PA and phytate-phosphorus (PA-P) concentration with a concomitant increase in Pi concentration. Moreover, defects in the OsST and OsMIK genes result in a great reduction of specific LPL components and LPL-phosphorus (LPL-P) contents in rice grain. In contrast, defective OsMRP5 and Os2-PGK genes led to a significant increase in individual LPL components. The effect of the Os2-PGK gene on the LPL accumulation was validated using breeding lines derived from a cross between KBNT-lpa (Os2-PGK mutation) and Jiahe218. This study demonstrates that these rice lpa mutants lead to the redistribution of Pi in endosperm and modify LPL biosynthesis. Increase LPLs in the endosperm in the lpa mutants may have practical applications in rice breeding to produce "healthier" rice.

Induction of short culm mutants for bread wheat by using gamma rays

International Nuclear Information System (INIS)

Sobieh, S.S.

2002-01-01

This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, Inshas in order to select some short culm mutants from the local wheat varieties; Sid's-5, Sid's-6 and Sid's-7 after gamma irradiation. The obtained results indicated that: 1-M 4 mutants progenies retained the features of their M 3 selections. 2-Some short culm mutants exhibited high grain yield/plant as compared to their original varieties. 3-There were significant decreases in plant height varied from 21.4 to 35.4%. This reduction was due to the shorting of culm inter nods length. As well as, the reduction diameter/culm especially diameter of the inter nods/culm did not differed between original varieties and the mutants. 4-The correlation between grain yield/plant and number of spikes/plant was positive and highly significant for most mutants and the original varieties as well. Data also showed that there were positive relationship between grain yield/plant and number of grains/spike and and length of the inter nods/culm. Positive or negative association between grain yield/plant and plant height as well as diameters of inter nods/culm for mutants and original varieties were detected

Isozyme differences in barley mutants

International Nuclear Information System (INIS)

AI-Jibouri, A.A.M.; Dham, K.M.

1990-01-01

Full text: Thirty mutants (M 11 ) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

Functional rescue of mutant ABCA1 proteins by sodium 4-phenylbutyrate.

Science.gov (United States)

Sorrenson, Brie; Suetani, Rachel J; Williams, Michael J A; Bickley, Vivienne M; George, Peter M; Jones, Gregory T; McCormick, Sally P A

2013-01-01

Mutations in the ATP-binding cassette transporter A1 (ABCA1) are a major cause of decreased HDL cholesterol (HDL-C), which infers an increased risk of cardiovascular disease (CVD). Many ABCA1 mutants show impaired localization to the plasma membrane. The aim of this study was to investigate whether the chemical chaperone, sodium 4-phenylbutyrate (4-PBA) could improve cellular localization and function of ABCA1 mutants. Nine different ABCA1 mutants (p.A594T, p.I659V, p.R1068H, p.T1512M, p.Y1767D, p.N1800H, p.R2004K, p.A2028V, p.Q2239N) expressed in HEK293 cells, displaying different degrees of mislocalization to the plasma membrane and discrete impacts on cholesterol efflux, were subject to treatment with 4-PBA. Treatment restored localization to the plasma membrane and increased cholesterol efflux function for the majority of mutants. Treatment with 4-PBA also increased ABCA1 protein expression in all transfected cell lines. In fibroblast cells obtained from low HDL-C subjects expressing two of the ABCA1 mutants (p.R1068H and p.N1800H), 4-PBA increased cholesterol efflux without any increase in ABCA1 expression. Our study is the first to investigate the effect of the chemical chaperone, 4-PBA on ABCA1 and shows that it is capable of restoring plasma membrane localization and enhancing the cholesterol efflux function of mutant ABCA1s both in vitro and ex vivo. These results suggest 4-PBA may warrant further investigation as a potential therapy for increasing cholesterol efflux and HDL-C levels.

The N54-αs Mutant Has Decreased Affinity for βγ and Suggests a Mechanism for Coupling Heterotrimeric G Protein Nucleotide Exchange with Subunit Dissociation.

Science.gov (United States)

Cleator, John H; Wells, Christopher A; Dingus, Jane; Kurtz, David T; Hildebrandt, John D

2018-05-01

Ser54 of G s α binds guanine nucleotide and Mg 2+ as part of a conserved sequence motif in GTP binding proteins. Mutating the homologous residue in small and heterotrimeric G proteins generates dominant-negative proteins, but by protein-specific mechanisms. For α i/o , this results from persistent binding of α to βγ , whereas for small GTP binding proteins and α s this results from persistent binding to guanine nucleotide exchange factor or receptor. This work examined the role of βγ interactions in mediating the properties of the Ser54-like mutants of G α subunits. Unexpectedly, WT- α s or N54- α s coexpressed with α 1B -adrenergic receptor in human embryonic kidney 293 cells decreased receptor stimulation of IP3 production by a cAMP-independent mechanism, but WT- α s was more effective than the mutant. One explanation for this result would be that α s , like Ser47 α i/o , blocks receptor activation by sequestering βγ ; implying that N54- α S has reduced affinity for βγ since it was less effective at blocking IP3 production. This possibility was more directly supported by the observation that WT- α s was more effective than the mutant in inhibiting βγ activation of phospholipase C β 2. Further, in vitro synthesized N54- α s bound biotinylated- βγ with lower apparent affinity than did WT- α s The Cys54 mutation also decreased βγ binding but less effectively than N54- α s Substitution of the conserved Ser in α o with Cys or Asn increased βγ binding, with the Cys mutant being more effective. This suggests that Ser54 of α s is involved in coupling changes in nucleotide binding with altered subunit interactions, and has important implications for how receptors activate G proteins. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

Phosphoribosylpyrophosphate synthetase of Escherichia coli, Identification of a mutant enzyme

DEFF Research Database (Denmark)

Hove-Jensen, Bjarne; Nygaard, Per

1982-01-01

, stimulated the mutant enzyme. The activity of PRib-PP synthetase in crude extract was higher in the mutant than in the parent. When starved for purines an accumulation of PRib-PP was observed in the parent strain, while the pool decreased in the mutant. During pyrimidine starvation derepression of PRib...

Genetical, cytological and physiological studies on the induced mutants with special regard to effective methods for obtaining useful mutants in perennial woody plants

International Nuclear Information System (INIS)

Kukimura, H.; Ikeda, F.; Fujita, H.; Maeta, T.; Nakajima, K.; Katagiri, K.; Nakahira, K.; Somegou, M.

1975-01-01

The study was aimed at elucidating the biological aspects of artificially induced mutations in perennial tree crops and at promoting the utilization of such mutations in a practical breeding programme. A number of mutants obtained particularly in Cryptomeria and mulberry (Morus spp.) by means of gamma radiation were examined for their practical usefulness. Doses from 7.5 to 15.0 kR were used. In mulbery, some mutant strains showed increased shoot growth, and one mutant strain showed a remarkable increase also in rooting ability. Entire leaf mutants were investigated for their breeding behaviour. None of the mutant strains showed acquired disease resistance. Changes in the number of isozyme bands and different staining intensity was observed in all the mutant strains compared to the original strains

Isozyme differences in barley mutants

Energy Technology Data Exchange (ETDEWEB)

AI-Jibouri, A A.M.; Dham, K M [Department of Botany, Nuclear Research Centre, Baghdad (Iraq)

1990-01-01

Full text: Thirty mutants (M{sub 11}) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

Spontaneous Chloroplast Mutants Mostly Occur by Replication Slippage and Show a Biased Pattern in the Plastome of Oenothera.

Science.gov (United States)

Massouh, Amid; Schubert, Julia; Yaneva-Roder, Liliya; Ulbricht-Jones, Elena S; Zupok, Arkadiusz; Johnson, Marc T J; Wright, Stephen I; Pellizzer, Tommaso; Sobanski, Johanna; Bock, Ralph; Greiner, Stephan

2016-04-01

Spontaneous plastome mutants have been used as a research tool since the beginning of genetics. However, technical restrictions have severely limited their contributions to research in physiology and molecular biology. Here, we used full plastome sequencing to systematically characterize a collection of 51 spontaneous chloroplast mutants in Oenothera (evening primrose). Most mutants carry only a single mutation. Unexpectedly, the vast majority of mutations do not represent single nucleotide polymorphisms but are insertions/deletions originating from DNA replication slippage events. Only very few mutations appear to be caused by imprecise double-strand break repair, nucleotide misincorporation during replication, or incorrect nucleotide excision repair following oxidative damage. U-turn inversions were not detected. Replication slippage is induced at repetitive sequences that can be very small and tend to have high A/T content. Interestingly, the mutations are not distributed randomly in the genome. The underrepresentation of mutations caused by faulty double-strand break repair might explain the high structural conservation of seed plant plastomes throughout evolution. In addition to providing a fully characterized mutant collection for future research on plastid genetics, gene expression, and photosynthesis, our work identified the spectrum of spontaneous mutations in plastids and reveals that this spectrum is very different from that in the nucleus. © 2016 American Society of Plant Biologists. All rights reserved.

Mesophyll conductance decreases in the wild type but not in an ABA-deficient mutant (aba1) of Nicotiana plumbaginifolia under drought conditions.

Science.gov (United States)

Mizokami, Yusuke; Noguchi, Ko; Kojima, Mikiko; Sakakibara, Hitoshi; Terashima, Ichiro

2015-03-01

Under drought conditions, leaf photosynthesis is limited by the supply of CO2 . Drought induces production of abscisic acid (ABA), and ABA decreases stomatal conductance (gs ). Previous papers reported that the drought stress also causes the decrease in mesophyll conductance (gm ). However, the relationships between ABA content and gm are unclear. We investigated the responses of gm to the leaf ABA content [(ABA)L ] using an ABA-deficient mutant, aba1, and the wild type (WT) of Nicotiana plumbaginifolia. We also measured leaf water potential (ΨL ) because leaf hydraulics may be related to gm . Under drought conditions, gm decreased with the increase in (ABA)L in WT, whereas both (ABA)L and gm were unchanged by the drought treatment in aba1. Exogenously applied ABA decreased gm in both WT and aba1 in a dose-dependent manner. ΨL in WT was decreased by the drought treatment to -0.7 MPa, whereas ΨL in aba1 was around -0.8 MPa even under the well-watered conditions and unchanged by the drought treatment. From these results, we conclude that the increase in (ABA)L is crucial for the decrease in gm under drought conditions. We discuss possible relationships between the decrease in gm and changes in the leaf hydraulics. © 2014 John Wiley & Sons Ltd.

Evaluation of tall rice mutant

International Nuclear Information System (INIS)

Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

1989-01-01

One tall mutant (Mut NS1) of rice variety Nizersail was put to multilocation on-farm trial. It showed improvement over the parent in respect of by earlier maturity and higher grain yield at all locations and thus it appears as an improved mutant of Nizersail. (author). 6 refs

Sharing mutants and experimental information prepublication using FgMutantDb (https://scabusa.org/FgMutantDb).

Science.gov (United States)

Baldwin, Thomas T; Basenko, Evelina; Harb, Omar; Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E; Bregitzer, Phil P

2018-06-01

There is no comprehensive storage for generated mutants of Fusarium graminearum or data associated with these mutants. Instead, researchers relied on several independent and non-integrated databases. FgMutantDb was designed as a simple spreadsheet that is accessible globally on the web that will function as a centralized source of information on F. graminearum mutants. FgMutantDb aids in the maintenance and sharing of mutants within a research community. It will serve also as a platform for disseminating prepublication results as well as negative results that often go unreported. Additionally, the highly curated information on mutants in FgMutantDb will be shared with other databases (FungiDB, Ensembl, PhytoPath, and PHI-base) through updating reports. Here we describe the creation and potential usefulness of FgMutantDb to the F. graminearum research community, and provide a tutorial on its use. This type of database could be easily emulated for other fungal species. Published by Elsevier Inc.

Hyperoxia exposure induced hormesis decreases mitochondrial superoxide radical levels via Ins/IGF-1 signaling pathway in a long-lived age-1 mutant of Caenorhabditis elegans

International Nuclear Information System (INIS)

Yanase, Sumino; Ishii, Naoaki

2008-01-01

The hormetic effect, which extends the lifespan by various stressors, has been confirmed in Caenorhabditis elegans (C. elegans). We have previously reported that oxidative stress resistance in a long-lived mutant age-1 is associated with the hormesis. In the age-1 allele, which activates an insulin/insulin-like growth factor-1 (Ins/IGF-1) signaling pathway, the superoxide dismutase (SOD) and catalase activities increased during normal aging. We now demonstrate changes in the mitochondrial superoxide radical (O 2 - ) levels of the hormetic conditioned age-related strains. The O 2 - levels in age-1 strain significantly decreased after intermittent hyperoxia exposure. On the other hand, this phenomenon was not observed in a daf-16 null mutant. This hormesis-dependent reduction of the O 2 - levels was observed even if the mitochondrial Mn-SOD was experimentally reduced. Therefore, it is indicated that the hormesis is mediated by events that suppress the mitochondrial O 2 - production. Moreover, some SOD gene expressions in the hormetic conditioned age-1 mutant were induced over steady state messenger ribonucleic acid (mRNA) levels. These data suggest that oxidative stress-inducible hormesis is associated with a reduction of the mitochondrial O 2 - production by activation of the antioxidant system via the Ins/IGF-1 signaling pathway. (author)

Radiation induced mutants in cassava (Manihot esculenta Crantz)

International Nuclear Information System (INIS)

Nayar, G.G.; Rajendran, P.G.

1987-01-01

Full text: Stem cuttings and true seeds of three promising cultivars of cassava were exposed respectively to 1 to 5 kR and 10 to 50 kR acute gamma rays from a 60 Co source. Treatments of stem cuttings beyond 5 kR and seeds beyond 50 kR were lethal. One mutant each in the cultivars M4, H-165 and H-2304 was obtained from the stem irradiated populations. Another mutant was found in the seed irradiated progeny of H-2304. The mutant of M4 is characterised by light green (chlorina) leaves. The mutant of H-165 shows significantly shorter petiole (22,5 against 35.2 cm) and narrow leaf lobes, while the H-2304 mutant shows speckled leaves, branching and early flowering. The mutant found in the seed irradiated progeny of H-2304 is having yellow tuber flesh indicating the presence of carotene. The mutants may be useful in studies related to basic information as well as in practical breeding. The chlorina mutant in M4 showed slow growth and high HCN content in leaves. Late branching may be a useful trait in the traditionally non-branching clones of cassava to maintain the desirable leaf area index during high leaf fall period. Early flowering could be useful in a recombinant breeding programme. The tuber yield of the short petiole mutant in H-165 increased by 20% - 25% through closer planting. The narrow leaf lobes of this mutant permit better light penetration to lower leaves. (author)

Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

DEFF Research Database (Denmark)

Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

2002-01-01

as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition...... activity was also induced by the protein kinase inhibitor staurosporine and antagonized by the protein phosphatase inhibitor okadaic acid. FLUC bio-imaging, RNA gel-blot analysis and progeny analyses identified three recessive mutants that underexpress the FLUC reporter, designated jue1, 2 and 3, as well...

Defective processing of methylated single-stranded DNA by E. coli alkB mutants

Science.gov (United States)

Dinglay, Suneet; Trewick, Sarah C.; Lindahl, Tomas; Sedgwick, Barbara

2000-01-01

Escherichia coli alkB mutants are very sensitive to DNA methylating agents. Despite these mutants being the subject of many studies, no DNA repair or other function has been assigned to the AlkB protein or to its human homolog. Here, we report that reactivation of methylmethanesulfonate (MMS)-treated single-stranded DNA phages, M13, f1, and G4, was decreased dramatically in alkB mutants. No such decrease occurred when using methylated λ phage or M13 duplex DNA. These data show that alkB mutants have a marked defect in processing methylation damage in single-stranded DNA. Recombinant AlkB protein bound more efficiently to single- than double-stranded DNA. The single-strand damage processed by AlkB was primarily cytotoxic and not mutagenic and was induced by SN2 methylating agents, MMS, DMS, and MeI but not by SN1 agent N-methyl-N-nitrosourea or by γ irradiation. Strains lacking other DNA repair activities, alkA tag, xth nfo, uvrA, mutS, and umuC, were not defective in reactivation of methylated M13 phage and did not enhance the defect of an alkB mutant. A recA mutation caused a small but additive defect. Thus, AlkB functions in a novel pathway independent of these activities. We propose that AlkB acts on alkylated single-stranded DNA in replication forks or at transcribed regions. Consistent with this theory, stationary phase alkB cells were less MMS sensitive than rapidly growing cells. PMID:10950872

Modified Starch of Sorghum Mutant Line Zh-30 for High Fiber Muffin Products

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D.D.S. Santosa

2009-01-01

Full Text Available Sorghum mutant line Zh-30 is a breeding line developed at the Center for the Application of Isotope and Radiation Technology, BATAN by using mutation techniques. Gamma irradiation with the dose of 300 Gy was used to induce sorghum genetic variation. Through selection processes in several generations, the mutant line Zh-30 was identified to have better agronomic characteristics, better grain quality and higher grain yield than the original variety. Research on modified starch quality of this mutant line was done to identify its potential use in food industry. Functionality of pregelatinized, hydroxypropyl and crosslinked starch of this mutant line (Mutant TexInstant 30 has been studied for its use in high fiber muffin products. Characteristics of high fiber muffins containing 1.50; 3.50 and 5.50% of Mutant Tex-Instant 30 replacement levels to wheat flour were evaluated using both sensory panel and physical test methods. With regard to the sensory parameters, the high fiber muffins containing 1.50 - 5.50 % Mutant Tex-Instant 30 in general were not significantly different compared to the standard reference muffin. Results of physical evaluations showed that all Mutant Tex-Instant 30 containing products retained more moisture during baking than the standard reference. Tenderness of all products decreased at similar rate following 24 and 48 hr of room temperature storage and seven days at freezer temperature. These results suggested that sorghum mutant line Zh-30 starch could be modified and potentially used in food industry as a subtitute of wheat flour.

Modified Starch of Sorghum Mutant Line Zh-30 For High Fiber Muffin Products

International Nuclear Information System (INIS)

Santosa, D. D. S; Human, S

2009-01-01

Sorghum mutant line Zh-30 is a breeding line developed at the Center for the Application of Isotope and Radiation Technology, BATAN by using mutation techniques. Gamma irradiation with the dose of 300 Gy was used to induce sorghum genetic variation. Through selection processes in several generations, the mutant line Zh-30 was identified to have better agronomic characteristics, better grain quality and higher grain yield than the original variety. Research on modified starch quality of this mutant line was done to identify its potential use in food industry. Functionality of pregelatinized, hydroxypropyl and crosslinked starch of this mutant line (Mutant TexInstant 30) has been studied for its use in high fiber muffin products. Characteristics of high fiber muffins containing 1.50; 3.50 and 5.50% of Mutant Tex-Instant 30 replacement levels to wheat flour were evaluated using both sensory panel and physical test methods. With regard to the sensory parameters, the high fiber muffins containing 1.50 - 5.50 % Mutant Tex-Instant 30 in general were not significantly different compared to the standard reference muffin. Results of physical evaluations showed that all Mutant Tex-Instant 30 containing products retained more moisture during baking than the standard reference. Tenderness of all products decreased at similar rate following 24 and 48 hr of room temperature storage and seven days at freezer temperature. These results suggested that sorghum mutant line Zh-30 starch could be modified and potentially used in food industry as a subtitute of wheat flour (author)

Molecular analysis of waxy mutants in rice

International Nuclear Information System (INIS)

Yatou, O.; Amano, E.

1990-01-01

Full text: The 'waxy' gene is a structural gene coding a glycosyl transferase which synthesises amylose in the endosperm tissue. 'Non-waxy' rice cultivars have an active gene and their amylose content is 18-25% depending upon gene performance and modifier genes. In 'waxy' rice, no amylose is found because the enzyme is absent. In mutants induced by gamma rays, neutrons, EI or EMS, amylose content ranged from 0 to 20%, i.e. there are intermediate phenotypes as well. Some of them had the same amount of the enzyme as a 'non-waxy' cultivar, even fully 'waxy' mutants showed a certain amount of the enzyme. This suggests that in mutants there may be no structural change in the enzyme gene but the enzyme produced might be less active. By molecular analysis of the mutants' genes it was found that only two mutants induced by thermal neutrons show structural alterations, the changes in other mutants are either too small to be detected by Southern analysis or are outside the structural gene in question. (author)

Dwarf mutant of rice variety Seratus Malam

International Nuclear Information System (INIS)

Mugiono, P. S.; Soemanggono, A.M.R.

1989-01-01

Full text: Seeds of 'Seratus Malam', a local tall upland variety with long panicles and high yield potential were irradiated with 10-50 krad gamma rays in 1983. From 50,000 M 2 plants, 130 semidwarf mutants and 1 dwarf mutant were selected. The dwarf mutant M-362 was obtained from the 10 krad treatment. The mutant shows about 50% reduction in plant height, but also in number of productive tillers. Thus the yield per plant is also significantly less. However, the mutant gene is not allelic to DGWG and therefore may be useful in cross breeding. (author)

Spontaneous Chloroplast Mutants Mostly Occur by Replication Slippage and Show a Biased Pattern in the Plastome of Oenothera[OPEN

Science.gov (United States)

Massouh, Amid; Schubert, Julia; Yaneva-Roder, Liliya; Ulbricht-Jones, Elena S.; Johnson, Marc T.J.; Wright, Stephen I.; Pellizzer, Tommaso; Sobanski, Johanna; Greiner, Stephan

2016-01-01

Spontaneous plastome mutants have been used as a research tool since the beginning of genetics. However, technical restrictions have severely limited their contributions to research in physiology and molecular biology. Here, we used full plastome sequencing to systematically characterize a collection of 51 spontaneous chloroplast mutants in Oenothera (evening primrose). Most mutants carry only a single mutation. Unexpectedly, the vast majority of mutations do not represent single nucleotide polymorphisms but are insertions/deletions originating from DNA replication slippage events. Only very few mutations appear to be caused by imprecise double-strand break repair, nucleotide misincorporation during replication, or incorrect nucleotide excision repair following oxidative damage. U-turn inversions were not detected. Replication slippage is induced at repetitive sequences that can be very small and tend to have high A/T content. Interestingly, the mutations are not distributed randomly in the genome. The underrepresentation of mutations caused by faulty double-strand break repair might explain the high structural conservation of seed plant plastomes throughout evolution. In addition to providing a fully characterized mutant collection for future research on plastid genetics, gene expression, and photosynthesis, our work identified the spectrum of spontaneous mutations in plastids and reveals that this spectrum is very different from that in the nucleus. PMID:27053421

Design and introduction of a disulfide bridge in firefly luciferase: increase of thermostability and decrease of pH sensitivity.

Science.gov (United States)

Imani, Mehdi; Hosseinkhani, Saman; Ahmadian, Shahin; Nazari, Mahboobeh

2010-08-01

The thermal sensitivity and pH-sensitive spectral properties of firefly luciferase have hampered its application in a variety of fields. It is proposed that the stability of a protein can be increased by introduction of disulfide bridge that decreases the configurational entropy of unfolding. A disulfide bridge is introduced into Photinus pyralis firefly luciferase to make two separate mutant enzymes with a single bridge. Even though the A103C/S121C mutant showed remarkable thermal stability, its specific activity decreased, whereas the A296C/A326C mutant showed tremendous thermal stability, relative pH insensitivity and 7.3-fold increase of specific activity. Moreover, the bioluminescence emission spectrum of A296C/A326C was resistant against higher temperatures (37 degrees C). Far-UV CD analysis showed slight secondary structure changes for both mutants. Thermal denaturation analysis showed that conformational stabilities of A103C/S121C and A296C/A326C are more than native firefly luciferase. It is proposed that since A296 and A326 are situated in the vicinity of the enzyme active site microenvironment in comparison with A103 and S121, the formation of a disulfide bridge in this region has more impact on enzyme kinetic characteristics.

Evaluation of Yield and Chemical Characteristics of some Peanut Mutants Induced by Gamma Irradiation

International Nuclear Information System (INIS)

Abd El-daem, G.A.; Anwar, M.M.

2013-01-01

This study was conducted to evaluate some promising mutants in peanut for yielding ability over three generation (M5, M6 and M7) and to evaluate yield attributes as will as chemical characteristics of these mutants in M7 generation induced by 100 Gy gamma radiation. The obtained results showed that the increase of yield / plot over three generation as a percentage of control was 5% for mutant 7, 10.2 % for mutant 10; 22% for mutant 9 and 22.9% for mutant 8. This increase in yield may be due to increase of one or more of yield attributes for most mutant lines. The significant increase for. No .of pods and seeds/ plant, weight of pods and seeds/ plant and 100- seed weight in M7 as compared to the control. For saturated fatty acid composition, results revealed that total saturated fatty acids ranged from 17.79% for mutant 8 to 21.75 for mutant 2 compared to 24.21% for control. Reduction of total saturated fatty acid was noticed for different mutants compared to that of the original variety. However, for total unsaturated fatty acids, results indicated that total unsaturated fatty acid composition ranged from 77.95% for mutant 9 to 82.09% for mutant 8 compared to 75.49% for control. Higher total unsaturated fatty acids for all mutant lines were obtained than that of the control, however, total saturated (TS)/ total unsaturated (TU) ratio was decreased for all mutants compared to control. The physical and chemical contents of Peanut oils showed that the refractive indices were ranged from 1.4620 to 1.4718 specific gravity were in range of 0.9146 to 0.9177. Acid value was range from 0.54 to 0.89% lodine value was ranged from 94.56 to 101.85. Saponification value was ranged from 185.2 to 190.7 and unsaponifiable matter was ranged from 0.98 to 1.33. The peroxide values ranged from 1.15 to 2.33 meq/kg oil. Also, fortified yoghurt made with replaced mutant peanut oil by 50% as milk fat substitute. Data showed that chemical composition and organolyptic properties had the

Characterization of a Weak Allele of Zebrafish cloche Mutant

Science.gov (United States)

Ma, Ning; Huang, Zhibin; Chen, Xiaohui; He, Fei; Wang, Kun; Liu, Wei; Zhao, Linfeng; Xu, Xiangmin; Liao, Wangjun; Ruan, Hua; Luo, Shenqiu; Zhang, Wenqing

2011-01-01

Hematopoiesis is a complicated and dynamic process about which the molecular mechanisms remain poorly understood. Danio rerio (zebrafish) is an excellent vertebrate system for studying hematopoiesis and developmental mechanisms. In the previous study, we isolated and identified a cloche 172 (clo 172) mutant, a novel allele compared to the original cloche (clo) mutant, through using complementation test and initial mapping. Here, according to whole mount in-situ hybridization, we report that the endothelial cells in clo 172 mutant embryos, although initially developed, failed to form the functional vascular system eventually. In addition, further characterization indicates that the clo 172 mutant exhibited weaker defects instead of completely lost in primitive erythroid cells and definitive hematopoietic cells compared with the clo s5 mutant. In contrast, primitive myeloid cells were totally lost in clo 172 mutant. Furthermore, these reappeared definitive myeloid cells were demonstrated to initiate from the remaining hematopoietic stem cells (HSCs) in clo 172 mutant, confirmed by the dramatic decrease of lyc in clo 172 runx1w84x double mutant. Collectively, the clo 172 mutant is a weak allele compared to the clo s5 mutant, therefore providing a model for studying the early development of hematopoietic and vascular system, as well as an opportunity to further understand the function of the cloche gene. PMID:22132109

Induction of Mutants in Durum Wheat

International Nuclear Information System (INIS)

AL-Ubaidi, M.; Ibrahim, I.; AL-Hadithi, A.

2002-01-01

This investigation presents a breeding program for induction and development of a new genotype of durum wheat, resistant to lodging with high yield, by irradiation durum wheat hybrids (F2) with gamma rays 100 Gy, during 1990-1997 cultivation seasons. This program involves: induction of variability, selection evaluation of the mutants at three locations: Twaitha (Baghdad) Latifya ( Babylon) and Swari (Kutt). All mutants showed resistance to lodging and there was a significant reduction in plant height. Mutant SIXIZ-22 surpassed other mutants and its origin in lodging resistance and plant height (83.5,82.8 and 89.4 cm) in the three locations at generation M5 and M6, respectively. Also, there were significant differences between mutant and their origin in the number of spikes/M 2 and grain yild during the two successive generation. On the other hand, mutant IZxCO-105 surpassed other mutants in the number of spikes/M 2 (231.8,242.3 and 292) and grain yield (4336,3376 and 5232 kg/ha) in all testing location, respectively . (authors) 14 refs., 4 tabs

Stress-tolerant mutants induced by heavy-ion beams

International Nuclear Information System (INIS)

Abe, Tomoko; Yoshida, Shigeo; Bae, Chang-Hyu; Ozaki, Takuo

2000-01-01

Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M 1 seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M 3 progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to 14 N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M 1 progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M 1 seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

Studies on reduced height mutants in rice

International Nuclear Information System (INIS)

Narahari, P.; Bhagwat, S.G.

1984-01-01

Two cross-bred derivatives of the mutant TR5xTR17 and TR21 continued to show promise and were advanced to wider scale testing. TR5 was found to carry a semi-dwarfing gene different from that in IR8. New semi-dwarf mutants were screened from M 2 through M 4 from two separate radiation experiments. The gibberellin response of seedlings of mutant and tester strains was evaluated and crosses of tester stocks and mutant semi-dwarfs were made for genetic analyses. (author)

A sorghum (Sorghum bicolor mutant with altered carbon isotope ratio.

Directory of Open Access Journals (Sweden)

Govinda Rizal

Full Text Available Recent efforts to engineer C4 photosynthetic traits into C3 plants such as rice demand an understanding of the genetic elements that enable C4 plants to outperform C3 plants. As a part of the C4 Rice Consortium's efforts to identify genes needed to support C4 photosynthesis, EMS mutagenized sorghum populations were generated and screened to identify genes that cause a loss of C4 function. Stable carbon isotope ratio (δ13C of leaf dry matter has been used to distinguishspecies with C3 and C4 photosynthetic pathways. Here, we report the identification of a sorghum (Sorghum bicolor mutant with a low δ13C characteristic. A mutant (named Mut33 with a pale phenotype and stunted growth was identified from an EMS treated sorghum M2 population. The stable carbon isotope analysis of the mutants showed a decrease of 13C uptake capacity. The noise of random mutation was reduced by crossing the mutant and its wildtype (WT. The back-cross (BC1F1 progenies were like the WT parent in terms of 13C values and plant phenotypes. All the BC1F2 plants with low δ13C died before they produced their 6th leaf. Gas exchange measurements of the low δ13C sorghum mutants showed a higher CO2 compensation point (25.24 μmol CO2.mol-1air and the maximum rate of photosynthesis was less than 5μmol.m-2.s-1. To identify the genetic determinant of this trait, four DNA pools were isolated; two each from normal and low δ13C BC1F2 mutant plants. These were sequenced using an Illumina platform. Comparison of allele frequency of the single nucleotide polymorphisms (SNPs between the pools with contrasting phenotype showed that a locus in Chromosome 10 between 57,941,104 and 59,985,708 bps had an allele frequency of 1. There were 211 mutations and 37 genes in the locus, out of which mutations in 9 genes showed non-synonymous changes. This finding is expected to contribute to future research on the identification of the causal factor differentiating C4 from C3 species that can be used

Mutants induced in winter rye (Secale cereale L.): Short straw-mutant No. 2714 and late-senescence mutant

Energy Technology Data Exchange (ETDEWEB)

Muszynski, S; Darlewska, M [Department of Plant Breeding and Seed Science, Warsaw Agricultural University, Warsaw (Poland)

1990-01-01

Full text: Mutants were induced by treating dormant seeds with ionizing radiation (fast neutrons) or chemicals (N-nitroso-N-ethyl urea or sodium azide). Among several mutants obtained, of special value is the short-straw mutant No. 2714 and a late senescent mutant. (author)

Photosynthetic Characteristics of Flag Leaves in Rice White Stripe Mutant 6001 During Senescence Process

Directory of Open Access Journals (Sweden)

Xiao-hui ZHEN

2014-11-01

Full Text Available Physiological, biochemical and electron microscopy analyses were used to investigate the photosynthetic performance of flag leaves in rice white stripe mutant 6001 during the senescence process. Results showed that the chlorophyll content at the heading and milk-ripe stages in rice mutant 6001 were about 34.78% and 3.00% less than those in wild type 6028, respectively. However, the chlorophyll content at the fully-ripe stage in rice mutant 6001 was higher than that in wild type 6028. At the heading stage, the net photosynthetic rate (Pn in rice mutant 6001 was lower than that in wild type 6028. Rice mutant 6001 also exhibited a significantly slower decrease rate of Pn than wild type 6028 during the senescence progress, especially at the later stage. Furthermore, Ca2+-ATPase, Mg2+-ATPase and photophosphorylation activities exhibited the similar trends as the Pn. During the senescence process, the 68 kDa polypeptide concentrations in the thylakoid membrane proteins exhibited a significant change, which was one of the critical factors that contributed to the observed change in photosynthesis. We also observed that the chloroplasts of rice mutant 6001 exhibited higher integrity than those of wild type 6028, and the chloroplast membrane of rice mutant 6001 disintegrated more slow during the senescence process. In general, rice mutant 6001 had a relatively slower senescence rate than wild type 6028, and exhibited anti-senescence properties.

A zebrafish model of glucocorticoid resistance shows serotonergic modulation of the stress response

Directory of Open Access Journals (Sweden)

Brian eGriffiths

2012-10-01

Full Text Available One function of glucocorticoids is to restore homeostasis after an acute stress response by providing negative feedback to stress circuits in the brain. Loss of this negative feedback leads to elevated physiological stress and may contribute to depression, anxiety and post-traumatic stress disorder. We investigated the early, developmental effects of glucocorticoid signaling deficits on stress physiology and related behaviors using a mutant zebrafish, grs357, with non-functional glucocorticoid receptors. These mutants are morphologically inconspicuous and adult-viable. A previous study of adult grs357 mutants showed loss of glucocorticoid-mediated negative feedback and elevated physiological and behavioral stress markers. Already at five days post-fertilization, mutant larvae had elevated whole body cortisol, increased expression of pro-opiomelanocortin (POMC, the precursor of adrenocorticotropic hormone (ACTH, and failed to show normal suppression of stress markers after dexamethasone treatment. Mutant larvae had larger auditory-evoked startle responses compared to wildtype sibling controls (grwt, despite having lower spontaneous activity levels. Fluoxetine (Prozac treatment in mutants decreased startle responding and increased spontaneous activity, making them behaviorally similar to wildtype. This result mirrors known effects of selective serotonin reuptake inhibitors (SSRIs in modifying glucocorticoid signaling and alleviating stress disorders in human patients. Our results suggest that larval grs357 zebrafish can be used to study behavioral, physiological and molecular aspects of stress disorders. Most importantly, interactions between glucocorticoid and serotonin signaling appear to be highly conserved among vertebrates, suggesting deep homologies at the neural circuit level and opening up new avenues for research into psychiatric conditions.

Heterozygous inactivation of tsc2 enhances tumorigenesis in p53 mutant zebrafish

Directory of Open Access Journals (Sweden)

Seok-Hyung Kim

2013-07-01

Tuberous sclerosis complex (TSC is a multi-organ disorder caused by mutations of the TSC1 or TSC2 genes. A key function of these genes is to inhibit mTORC1 (mechanistic target of rapamycin complex 1 kinase signaling. Cells deficient for TSC1 or TSC2 have increased mTORC1 signaling and give rise to benign tumors, although, as a rule, true malignancies are rarely seen. In contrast, other disorders with increased mTOR signaling typically have overt malignancies. A better understanding of genetic mechanisms that govern the transformation of benign cells to malignant ones is crucial to understand cancer pathogenesis. We generated a zebrafish model of TSC and cancer progression by placing a heterozygous mutation of the tsc2 gene in a p53 mutant background. Unlike tsc2 heterozygous mutant zebrafish, which never exhibited cancers, compound tsc2;p53 mutants had malignant tumors in multiple organs. Tumorigenesis was enhanced compared with p53 mutant zebrafish. p53 mutants also had increased mTORC1 signaling that was further enhanced in tsc2;p53 compound mutants. We found increased expression of Hif1-α, Hif2-α and Vegf-c in tsc2;p53 compound mutant zebrafish compared with p53 mutant zebrafish. Expression of these proteins probably underlies the increased angiogenesis seen in compound mutant zebrafish compared with p53 mutants and might further drive cancer progression. Treatment of p53 and compound mutant zebrafish with the mTORC1 inhibitor rapamycin caused rapid shrinkage of tumor size and decreased caliber of tumor-associated blood vessels. This is the first report using an animal model to show interactions between tsc2, mTORC1 and p53 during tumorigenesis. These results might explain why individuals with TSC rarely have malignant tumors, but also suggest that cancer arising in individuals without TSC might be influenced by the status of TSC1 and/or TSC2 mutations and be potentially treatable with mTORC1 inhibitors.

Isoenzymes performance of some rice varieties and their mutants

International Nuclear Information System (INIS)

Winarno, Ermin; Suliwarno, Ambyah; Ismachin, M.

1992-01-01

Isoenzymes performance of some rice varieties and their mutants. Genetics studies on alcohol dehydrogenase, malic enzyme, peroxidase, acid phosphase, and aminopeptidase isoenzymes were carried out on several groups of rice varieties and their mutant lines. The first groups consisted of Atomita I, Pelita I/1, A227/5, Mudgo, TN-1, and IR-26. The second group was Cisadane variety and its five mutants, namely OBS 18, OBS 208, OBS 297, OBS 306, and OBS 330. The third group was mutants line 627-10-3 and its mutants, namely 1063, 1066, 1067, 1076, and 1090. Isoenzymes extracts of the rice leaves were fractionated using polyacrylamide gel disc electrophoresis. The pattern of acid phosphate isoenzyme shows the specific character of rice mutants susceptible to brown plant hopper biotype 1. The gene(s) controlling malic enzyme in Cisadane's mutants is (are) estimated more resistant toward gamma irradiation than gene(s) responsible for controlling the other enzymes. Generally, the isoenzymes zymograms show that gene(s) controlling the mutants enzyme have undergone mutation. This case is shown by the changes of Rm value, as well as the amount and intensity of mutants bands. (authors). 7 refs., 7 figs

Over-expression of p53 mutants in LNCaP cells alters tumor growth and angiogenesis in vivo

International Nuclear Information System (INIS)

Perryman, L.A.; Blair, J.M.; Kingsley, E.A.; Szymanska, B.; Ow, K.T.; Wen, V.W.; MacKenzie, K.L.; Vermeulen, P.B.; Jackson, P.; Russell, P.J.

2006-01-01

This study has investigated the impact of three specific dominant-negative p53 mutants (F134L, M237L, and R273H) on tumorigenesis by LNCaP prostate cancer cells. Mutant p53 proteins were associated with an increased subcutaneous 'take rate' in NOD-SCID mice, and increased production of PSA. Tumors expressing F134L and R273H grew slower than controls, and were associated with decreased necrosis and apoptosis, but not hypoxia. Interestingly, hypoxia levels were increased in tumors expressing M237L. There was less proliferation in F134L-bearing tumors compared to control, but this was not statistically significant. Angiogenesis was decreased in tumors expressing F134L and R273H compared with M237L, or controls. Conditioned medium from F134L tumors inhibited growth of normal human umbilical-vein endothelial cells but not telomerase-immortalized bone marrow endothelial cells. F134L tumor supernatants showed lower levels of VEGF and endostatin compared with supernatants from tumors expressing other mutants. Our results support the possibility that decreased angiogenesis might account for reduced growth rate of tumor cells expressing the F134L p53 mutation

Thermosensitive mutant of Bacillus subtilis deficient in uracil and cell division

Energy Technology Data Exchange (ETDEWEB)

Nagai, K; Some, H; Tamura, G

1976-01-01

Thermonsensitive division mutants were derived from Bacillus subtilis Marburg 168 thy trp/sub 2/ by means of membrane filtration after nitrosoguanidine mutagenesis. Among them, ts42 requiring uracil for normal growth at 48/sup 0/C was investigated. In the absence of uracil, the mutant cells grew normally at 37/sup 0/C and stopped dividing after temperature shift to 48/sup 0/C resulting in filaments of two to four times length of normal rods. The total cell number after the temperature shift increased two to three fold in 90 min and remained constant thereafter. The viable count after the temperature shift to 48/sup 0/C, increased 1.5 to 2 fold in initial 60 min and then decreased exponentially. A rapid restoration of colony forming ability was shown when the mutant cells were shifted back to the permissive temperature after 120 to 180 min of incubation at 48/sup 0/C or when uracil was introduced to the culture at 48/sup 0/C. This recovery of viability was partly observed even in the presence of chloramphenicol. The synthesis of RNA of this mutant was shown to decline 20 min after the temperature shift to 48/sup 0/C whereas the syntheses of DNA and protein proceeded for more than 80 min at that temperature. No newly isolated uracil requiring mutants formed filaments in the medium lacking uracil or showed growth pattern like ts42.

Inactivation of carbenicillin by some radioresistant mutant strains

International Nuclear Information System (INIS)

Zahiera, T.S.; Mahmoud, M.I.; Bashandy, A.A.

1990-01-01

Sensitivity test of five bacterial species to carbenicillin was performed microbiologically. The bacterial species were previously isolated from high level radiation environment. All the studied species could either highly decrease the antibiotic activity or even inactivate it completely. Detailed study of the inactivation of carbenicillin by the radioresistant mutant strains B. Laterosporus, B. firmus and M. roseus was performed, in the present study. Using high performace liquid chromatography technique. The gram-positive m. roseus mutant strain seemed to be the most active mutant in degrading the antibiotic. The left over of the antibiotic attained a value of 9% of the original amount after 14 day incubation of the antibiotic with this mutant strain, while the value of the left over reached 36% and 32% after the same period of incubation with the mutants B. laterosporus and B. firmus respectively. In the case of bacillus species, the degradation of the antibiotic started at the same moment when it was added to the bacterial cultures. This fact may indicate that the inactivation of the studied antibiotic by these bacillus species was due to extracellular enzymes extracted rapidly in the surrounding medium. In the case of M. roseus the inactivation process started later. after the addition of the antibiotic to the mutant culture

Mutant p53 protein localized in the cytoplasm inhibits autophagy.

Science.gov (United States)

Morselli, Eugenia; Tasdemir, Ezgi; Maiuri, Maria Chiara; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Vicencio, José Miguel; Soussi, Thierry; Kroemer, Guido

2008-10-01

The knockout, knockdown or chemical inhibition of p53 stimulates autophagy. Moreover, autophagy-inducing stimuli such as nutrient depletion, rapamycin or lithium cause the depletion of cytoplasmic p53, which in turn is required for the induction of autophagy. Here, we show that retransfection of p53(-/-) HCT 116 colon carcinoma cells with wild type p53 decreases autophagy down to baseline levels. Surprisingly, one third among a panel of 22 cancer-associated p53 single amino acid mutants also inhibited autophagy when transfected into p53(-/-) cells. Those variants of p53 that preferentially localize to the cytoplasm effectively repressed autophagy, whereas p53 mutants that display a prominently nuclear distribution failed to inhibit autophagy. The investigation of a series of deletion mutants revealed that removal of the DNA-binding domain from p53 fails to interfere with its role in the regulation of autophagy. Altogether, these results identify the cytoplasmic localization of p53 as the most important feature for p53-mediated autophagy inhibition. Moreover, the structural requirements for the two biological activities of extranuclear p53, namely induction of apoptosis and inhibition of autophagy, are manifestly different.

Inhibition of cell division in hupA hupB mutant bacteria lacking HU protein.

Science.gov (United States)

Dri, A M; Rouviere-Yaniv, J; Moreau, P L

1991-01-01

Escherichia coli hupA hypB double mutants that lack HU protein have severe cellular defects in cell division, DNA folding, and DNA partitioning. Here we show that the sfiA11 mutation, which alters the SfiA cell division inhibitor, reduces filamentation and production of anucleate cells in AB1157 hupA hupB strains. However, lexA3(Ind-) and sfiB(ftsZ)114 mutations, which normally counteract the effect of the SfiA inhibitor, could not restore a normal morphology to hupA hupB mutant bacteria. The LexA repressor, which controls the expression of the sfiA gene, was present in hupA hupB mutant bacteria in concentrations half of those of the parent bacteria, but this decrease was independent of the specific cleavage of the LexA repressor by activated RecA protein. One possibility to account for the filamentous morphology of hupA hupB mutant bacteria is that the lack of HU protein alters the expression of specific genes, such as lexA and fts cell division genes. Images PMID:2019558

Stress-tolerant mutants induced by heavy-ion beams

Energy Technology Data Exchange (ETDEWEB)

Abe, Tomoko; Yoshida, Shigeo [Institute of Physical and Chemical Research, Wako, Saitama (Japan); Bae, Chang-Hyu [Sunchon National University, Sunchon (Korea); Ozaki, Takuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wang, Jing Ming [Akita Prefectural Univ. (Japan)

2000-07-01

Comparative study was made on mutagenesis in tobacco embryo induced by exposure to EMS (ethyl methane-sulfonate) ion beams during the fertilization cycle. Tobacco embryo cells immediately after pollination were exposed to heavy ion beam and the sensitivity to the irradiation was assessed in each developmental stage and compared with the effects of EMS, a chemical mutagen. Morphologically abnormality such as chlorophyll deficiency was used as a marker. A total of 17 salt-tolerant plants were selected from 3447 M{sub 1} seeds. A cell line showed salt resistance. The cell growth and chlorophyll content were each two times higher than that of WT cells in the medium containing 154 mM NaCl. Seven strains of M{sub 3} progeny of 17 salt-tolerant plants, showed strong resistance, but no salt tolerant progeny were obtained from Xanthi or Ne-ion irradiation. This shows that the sensitivity of plant embryo to this irradiation technique may vary among species. When exposed to {sup 14}N ion beam for 24-108 hours after pollination, various morphological mutants appeared at 18% in M{sub 1} progeny and herbicide tolerant and salt tolerant mutants were obtained. A strong Co-tolerant strain was obtained in two of 17 salt-tolerant strains and a total of 46 tolerant strains (0.2%) were obtained from 22,272 grains of M{sub 1} seeds. In these tolerant strains, the absorption of Co was slightly decreased, but those of Mg and Mn were increased. Mutants induced with ion-beam irradiation have potential not only for practical use in the breeding of stress-tolerant plants but also for gene analysis that will surely facilitate the molecular understanding of the tolerance mechanisms. (M.N.)

Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D

DEFF Research Database (Denmark)

Welin, M.; Skovgaard, T.; Knecht, Wolfgang

2005-01-01

The Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK) double mutant N45D/N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP, whereas the activity with 3...

The Effect of Vitamin E on the Survival Rate of unc-13 Caenorhabditis elegans mutants under Oxidative Stress

Directory of Open Access Journals (Sweden)

Jessica Porcelan

2012-01-01

Full Text Available Caenorhabditis elegans unc-13 mutants express decreased neuronal activity and thus are a good model strain for examining defective nervous systems. These unc-13 mutants as well as wild type N2 strains, show rapid mortality when under oxidative stress. However, the antioxidant vitamin E may prolong survival in unc-13 mutant and N2 strains under oxidative stress. The addition of vitamin E to organisms under oxidative stress has a protective effect in both N2 and unc-13 C. elegans strains. Interestingly, vitamin E resulted in a greater increase in survival rate in N2 worms than with unc-13 mutant worms. While both strains displayed lower mortality rates with the addition of vitamin E, this finding suggests that vitamin E more efficiently increases survival rates of C. elegans with typical nervous system function. The efficacy of vitamin E implies that use of antioxidants may lessen the damage caused by oxidative stress in both N2 and mutant worms.

Evaluation of some mutant lines of rice induced by gamma radiation treatment 1. mean performance of rice mutants in M4 generation

International Nuclear Information System (INIS)

El-Banna, M.N.; El-Wakil, H.M.F.; Ebaid, R.A.; Sallam, R.A.

2009-01-01

Grains of eight rice mutants; SC 1, SC 6, RTY 1, RTY 3, HY 14, HYI 17, EH 4 and HYPI 22 were secured from Botany Department Faculty of Agriculture Cairo university. The procedures and the methodology for induction these mutants as well as the original mean performance of such mutants are presented else where; Sabbour, (1989) and Sabbour etal. (2002). Grains were sown (M4 generation) at the experimental farm in Itai EI-Baroud Agricultural Research Station Behaira Governorate Agricultural Research Center (ARC) in the summer season (2007). The mean performance of such mutants was studied during M4 generation. The most exciting results were as follows: the selected line SC 1 showed in M4 generation superior agronomic and yield traits. Sc 1 mutant line is not bred truly and it need more generations to reach stability. SC 6 in M4 generation showed considerable number of individuals scored low mean values toward the negative direction and lowering the overall trait mean performance. The rice lines RTY 1 and RTY 3 proved that, the average number of fertile tillers per plant of the selected lines maintained previously recorded mean values of M3 generation in M4. The traits showed significant differences among their progeny that recorded high CV% values as compared with those showed no significant differences. The rice lines HY 14 and HYI 17 showed a true breeding signs and no more breeding generations are required. Rice lines EH 4, showed a considerable reduction in number of days elapsed from date of cultivation till harvest. As, this mutant maintained 86.58 days till heading. Rice mutant line HYPI 22 did not bred truly for the original selected traits (high yield and high protein content) and it still need more generations of selection to reach considerable stability

Promising semi-dwarf mutant in wheat variety K68

Energy Technology Data Exchange (ETDEWEB)

Kumar, D [Banaras Hindu Univ. (India). Dept. of Genetics and Plant Breeding

1977-04-01

A semi-dwarf mutant (HUW-SDf 1) was induced from common wheat Var. K68 through the exposure of /sup 60/Co ..gamma..-rays at 15 kR. This mutant along with other induced mutants and control was assessed for yield components, yield and grain quality (M/sub 4/ generation); internode length reduction pattern and the yielding ability at three levels of nitrogen (M/sub 5/ generation). The mutant was significantly shorter in height and almost equal in tillers per plant and grains per spike to K68. However, it showed marked reduction in spike length and spikelets per spike. On the other hand, it possessed significantly higher (50.04 g) 1000-grain weight against control (41.15 g). The mutant gave 56.0% higher yield than the control. Grain quality studies indicated that the mutant possessed significantly higher (14.15%) total protein than K68. It was equally as good as K68 in lysine content. Pelshenke value (62.5 min) of the mutant indicated medium hard nature of gluten as compared to hard nature (198.0) of the control. The mutant showed 24.0% reduction in total culm length compared to K68. Reduction occurred due to maximum and almost equal reduction in 5th and 4th internodes (ca 34.0%) followed by 3rd, 2nd and 1st. The mutant showed similar yield and yield response to increasing nitrogen levels (80 to 160 kg per ha.) as for current commercial semi-dwarf varieties.

Quality characteristics of soybean pasted (Doenjang) manufactured with 2 soybean mutant lines derived from cv. baekwon

International Nuclear Information System (INIS)

Lee, Kyung Jun; Kang, Si Yong; Choi, Hong Il; Kim, Jin Baek

2016-01-01

In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine >Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste

Quality characteristics of soybean pasted (Doenjang) manufactured with 2 soybean mutant lines derived from cv. baekwon

Energy Technology Data Exchange (ETDEWEB)

Lee, Kyung Jun; Kang, Si Yong; Choi, Hong Il; Kim, Jin Baek [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2016-11-15

In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine >Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste.

Comparative metabolic profiling of mce1 operon mutant vs wild-type Mycobacterium tuberculosis strains.

Science.gov (United States)

Queiroz, Adriano; Medina-Cleghorn, Daniel; Marjanovic, Olivera; Nomura, Daniel K; Riley, Lee W

2015-11-01

Mycobacterium tuberculosis disrupted in a 13-gene operon (mce1) accumulates free mycolic acids (FM) in its cell wall and causes accelerated death in mice. Here, to more comprehensively analyze differences in their cell wall lipid composition, we used an untargeted metabolomics approach to compare the lipid profiles of wild-type and mce1 operon mutant strains. By liquid chromatography-mass spectrometry, we identified >400 distinct lipids significantly altered in the mce1 mutant compared to wild type. These lipids included decreased levels of saccharolipids and glycerophospholipids, and increased levels of alpha-, methoxy- and keto mycolic acids (MA), and hydroxyphthioceranic acid. The mutant showed reduced expression of mmpL8, mmpL10, stf0, pks2 and papA2 genes involved in transport and metabolism of lipids recognized to induce proinflammatory response; these lipids were found to be decreased in the mutant. In contrast, the transcripts of mmpL3, fasI, kasA, kasB, acpM and RV3451 involved in MA transport and metabolism increased; MA inhibits inflammatory response in macrophages. Since the mce1 operon is known to be regulated in intracellular M. tuberculosis, we speculate that the differences we observed in cell wall lipid metabolism and composition may affect host response to M. tuberculosis infection and determine the clinical outcome of such an infection. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Reversion of autocrine transformation by a dominant negative platelet-derived growth factor mutant.

Science.gov (United States)

Vassbotn, F S; Andersson, M; Westermark, B; Heldin, C H; Ostman, A

1993-07-01

A non-receptor-binding mutant of the platelet-derived growth factor (PDGF) A chain, PDGF-0, was generated by exchanging 7 amino acids in the sequence. The mutant chains formed dimers that were similar to wild-type PDGF-AA with regard to stability and rate of processing to the mature 30-kDa secreted forms. Moreover, the mutant chains formed disulfide-bonded heterodimers with the PDGF B chain in NIH 3T3 cells heterodimer underwent the same processing and secretion as PDGF-AB. Transfection of c-sis-expressing 3T3 cells with PDGF-0 significantly inhibited the transformed phenotype of these cells, as determined by the following criteria. (i) Compared with PDGF-0-negative clones, PDGF-0-producing clones showed a reverted morphology. (ii) Clones producing PDGF-0 grew more slowly than PDGF-0-negative clones, with a fivefold difference in cell number after 14 days in culture. (iii) The expression of PDGF-0 completely inhibited the ability of the c-sis-expressing 3T3 cells to form colonies in soft agar; this inhibition was overcome by the addition of recombinant PDGF-BB to the culture medium, showing that the lack of colony formation of these cells was not due to a general unresponsiveness to PDGF. The specific expression of a PDGF-0/PDGF wild-type heterodimer in COS cells revealed that the affinity of the mutant heterodimer for the PDGF alpha receptor was decreased by approximately 50-fold compared with that of PDGF-AA. Thus, we show that a non-receptor-binding PDGF A-chain mutant neutralizes in a trans-dominant manner the autocrine transforming potential of the c-sis/PDGF B chain by forming low-affinity heterodimers with wild-type PDGF chains. This method of specifically antagonizing the effect of PDGF may be useful in investigations of the role of PDGF in normal and pathological conditions.

Indy mutants: live long and prosper

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Stewart eFrankel

2012-02-01

Full Text Available Indy encodes the fly homologue of a mammalian transporter of di and tricarboxylatecomponents of the Krebs cycle. Reduced expression of fly Indy or two of the C. elegansIndy homologs leads to an increase in life span. Fly and worm tissues that play key roles inintermediary metabolism are also the places where Indy genes are expressed. One of themouse homologs of Indy (mIndy is mainly expressed in the liver. It has been hypothesizedthat decreased INDY activity creates a state similar to caloric restriction (CR. Thishypothesis is supported by the physiological similarities between Indy mutant flies on highcalorie food and control flies on CR, such as increased physical activity and decreases inweight, egg production, triglyceride levels, starvation resistance, and insulin signaling. Inaddition, Indy mutant flies undergo changes in mitochondrial biogenesis also observed inCR animals. Recent findings with mIndy knockout mice support and extend the findingsfrom flies. mIndy-/- mice display an increase in hepatic mitochondrial biogenesis, lipidoxidation and decreased hepatic lipogenesis. When mIndy-/- mice are fed high calorie foodthey are protected from adiposity and insulin resistance. These findings point to INDY as apotential drug target for the treatment of metabolic syndrome, type 2 diabetes and obesity.

Serrated leaf mutant in mungbean (Vigna radiata (L) Wilczek)

International Nuclear Information System (INIS)

Malik, I.A.; Ghulam, Sarwar; Yousaf, Ali; Saleem, M.

1988-01-01

Dry dormant seeds of mungbean (Vigna radiata (L) Wilczek) were treated with gamma rays (15, 30 and 60 kR). The serrated leaf mutation was noticed in M 2 of cultivar Pak 32 treated with 60 kR. Cf 14 plants, 3 showed the altered leaf structure and the others were normal. The feature of this mutant was the deep serration of leaflet margins. The mutant had large thick leaflets with prominent venation. The mutant bred true in the M 3 and successive generation. Details of the morphological characteristics of the mutant are presented. The mutant exhibited slower growth particularly during the early stages of development, flowered later and attained shorter height. There was an increase in the number of pods, in seed weight and in seed protein content, but number of seed per pod was considerably reduced. The seed coat colour showed a change from green to yellowish green. In the mutant's flowers the stamina were placed much below the stigma level and the stigma sometimes protruded the corolla. Outcrossing of 4% recorded in some of the mutant lines revealed a reduced cleistogamy. The low number of seeds per pod in the mutant could be due to reduced pollen fertility. The mutant behaved as monogenic recessive. The symbols SL/sl are proposed for this allelic pair. The mutant may have use as a green manure crop because of its large foliage and for the breeders as a genetic marker

Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats.

Science.gov (United States)

Atta, Hussein; El-Rehany, Mahmoud; Roeb, Elke; Abdel-Ghany, Hend; Ramzy, Maggie; Gaber, Shereen

2016-02-01

Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats. Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment. Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64). Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Chemotaxis-defective mutants of the nematode Caenorhabditis elegans.

Science.gov (United States)

Dusenbery, D B; Sheridan, R E; Russell, R L

1975-06-01

The technique of countercurrent separation has been used to isolate 17 independent chemotaxis-defective mutants of the nematode Caenorhabditis elegans. The mutants, selected to be relatively insensitive to the normally attractive salt NaCl, show varying degrees of residual sensitivity; some are actually weakly repelled by NaCl. The mutants are due to single gene defects, are autosomal and recessive, and identify at least five complementation groups.

Variation of several agronomic and biochemical traits in γ-ray induced mutant soybeans

International Nuclear Information System (INIS)

Shim, Kyo Moon; Kim, Sun Hyung; Kim, Nam Soo; Son, Hi Sup; Rhee, Hae Ik

1996-01-01

Two soybean cultivars(Paldalkong and Bangsakong) were irradiated with gamma-ray to reduce seed size, which is an important trait for soybean sprout and the derived mutant soybeans were analyzed in several agronomic and biochemical traits. There were high levels of variations in quantitative traits among the mutants. Several mutant lines showed higher yield and smaller seed than their parents. Qualitative traits such as seed coat color or pubescent color were also changed in a few lines. Biochemical variations were also observed among the mutants. In seed storage protein analysis, many mutant lines showed reduced intensities in β-subunits in 7S globulin than their parents and an additional band in the acidic subunit at 31KDa. Two mutant lines derived from Paldalkong showed an additional band and a shifted band of protease inhibitor by electrophoretic analysis. Variations in isozymes and RAPD were also observed among the mutants. Six isozymes(Adh, Est, Gdh, Idh, Mdh and Pgm) among eleven isozymes showed some variations and six out of ten primers showed polymorphic amplified DNA fragments among the mutants. (author)

Temperature sensitive riboflavin mutants of Penicillium vermiculatum Dangeard

International Nuclear Information System (INIS)

Mitra, J.; Chaudhari, K.L.

1974-01-01

Two temperature sensitive UV induced riboflavin mutants rib 1 and rib 6 have been physiologically and genetically characterized. The two mutants behave differently with regard to their temperature sensitivity. The rib 1 mutant exhibits a leaky growth in minimal medium between 15 0 C and 30 0 C but grows well when the medium is supplemented with riboflavin. At 35 0 C the growth response of the mutant is at its max. and at 40 0 C and below 15 0 C it ceases to grow. The rib 6 mutant which is red brown in colour shows wild type character at temp. below 25 0 C in minimal medium but requires riboflavin at 30 0 C and above. Heterokaryotic analysis revealed the nonallelic nature of the two temperature mutants. Genetic tests of allelic relationship between riboflavin markers by crossing were also done. (author)

Brief report on development of indigofera pseudotinctoria mats high flavonoid mutant and anti-oxidation of its exacts

International Nuclear Information System (INIS)

Shen Xiaoxia; Mei Shufang; Shu Xiaoli; Wu Dianxing

2010-01-01

Mutant high in flavonoid was successfully developed after the dry seeds of Indigofera pseudotinctoria Mats were irradiated by 300 Gy 60 Co gamma rays. The contents of flavonoid in different tissues of mutant line MJ-HF1 were all higher than that of the wild type, especially in the seeds and leaves, which was 5.89 and 1.46 times of the wild type. Anti-oxidation testing showed that the flavonoid exacts from MJ-HF1 could decrease the contents of malondialdehyde(MDA) and increase the activities of superoxide dismutase (SOD) in the aged white mice in a 30-day feeding test. (authors)

Data supporting mitochondrial morphological changes by SPG13-associated HSPD1 mutants

Directory of Open Access Journals (Sweden)

Yuki Miyamoto

2016-03-01

Full Text Available The data is related to the research article entitled “Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics” [1]. In addition to hypomyelinating leukodystrophy (HLD 4 (OMIM no. 612233, it is known that spastic paraplegia (SPG 13 (OMIM no. 605280 is caused by HSPD1’s amino acid mutation. Two amino acid mutations Val-98-to-Ile (V98I and Gln-461-to-Glu (Q461E are associated with SPG13 [2]. In order to investigate the effects of HSPD1’s V98I or Q461E mutant on mitochondrial morphological changes, we transfected each of the respective mutant-encoding genes into Cos-7 cells. Either of V98I or Q461E mutant exhibited increased number of mitochondria and short length mitochondrial morphologies. Using MitoTracker dye-incorporating assay, decreased mitochondrial membrane potential was also observed in both cases. The data described here supports that SPG13-associated HSPD1 mutant participates in causing aberrant mitochondrial morphological changes with decreased activities. Keywords: SPG13, HSPD1, Mitochondrion, Morphological change

Influence of ultraviolet light on arising of induced mutants in Cercospora beticola sacc

Energy Technology Data Exchange (ETDEWEB)

Brillova, D [Institute of Experimental Phytopathology and Entomology of the Slovak Academy of Sciences, Ivanka pri Dunaji (Czechoslovakia)

1976-01-01

Ultraviolet radiation of wavelengths of 254 and 350 nm respectively, applied for 30 to 480 seconds to the conidia of Cercospora beticola, induced a large number of mutants. According to their appearance, the occurring mutants can be considered as visible with effect on morphology and colour. A considerable part of the mutants lost its ability to form reproductive organs in in vitro conditions, as well as on the host plant; they became avirulent. Moreover, mutants occurred with decreased virulence, with a weak forming of conidia and prolonged incubation period. In few cases, also reverse mutations were induced characterized by increased virulence.

Analysis of AtCry1 and Mutants

Science.gov (United States)

Burdick, Derek; Purvis, Adam; Ahmad, Margaret; Link, Justin J.; Engle, Dorothy

Cryptochrome is an incredibly versatile protein that influences numerous biological processes such as plant growth, bird migration, and sleep cycles. Due to the versatility of this protein, understanding the mechanism would allow for advances in numerous fields such as crop growth, animal behavior, and sleep disorders. It is known that cryptochrome requires blue light to function, but the exact processes in the regulation of biological activity are still not fully understood. It is believed that the c-terminal domain of the protein undergoes a conformational change when exposed to blue light which allows for biological function. Three different non-functioning mutants were tested during this study to gain insight on the mechanism of cryptochrome. Absorbance spectra showed a difference between two of the mutants and the wild type with one mutant showing little difference. Immunoprecipitation experiments were also conducted to identify the different c-terminal responses of the mutants. By studying non functioning mutants of this protein, the mechanism of the protein can be further characterized. This two-month research experience in Paris allowed us to experience international and interdisciplinary collaborations in science and immerse in a different culture. The Borcer Fund for Student Research, Xavier University, Cincinnati, OH, and John Hauck Foundation.

Overexpression of an Outer Membrane Protein Associated with Decreased Susceptibility to Carbapenems in Proteus mirabilis

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Tsai, Yi-Lin; Wang, Min-Cheng; Hsueh, Po-Ren; Liu, Ming-Che; Hu, Rouh-Mei; Wu, Yue-Jin; Liaw, Shwu-Jen

2015-01-01

Proteus mirabilis isolates commonly have decreased susceptibility to imipenem. Previously, we found P. mirabilis hfq mutant was more resistant to imipenem and an outer membrane protein (OMP) could be involved. Therefore, we investigated the role of this OMP in carbapenem susceptibility. By SDS-PAGE we found this OMP (named ImpR) was increased in hfq mutant and LC-MS/MS revealed it to be the homologue of Salmonella YbfM, which is a porin for chitobiose and subject to MicM (a small RNA) regulation. We demonstrated that ImpR overexpression resulted in increased carbapenem MICs in the laboratory strain and clinical isolates. Chitobiose induced expression of chb (a chitobiose utilization operon). Real-time RT-PCR and SDS-PAGE were performed to elucidate the relationship of hfq, impR, chb and MicM in P. mirabilis. We found MicM RNA was decreased in hfq mutant and chbBC-intergenic region (chbBC-IGR) overexpression strain (chbIGRov), while impR mRNA was increased in hfq mutant, micM mutant and chbIGRov strain. In addition, mutation of hfq or micM and overexpression of chbBC-IGR increased ImpR protein level. Accordingly, chitobiose made wild-type have higher levels of ImpR protein and are more resistant to carbapenems. Hfq- and MicM-complemented strains restored wild-type MICs. Mutation of both impR and hfq eliminated the increase in carbapenem MICs observed in hfq mutant and ImpR-complementation of hfq/impR double mutant resulted in MICs as hfq mutant, indicating that the ImpR-dependent decreased carbapenem susceptibility of hfq mutant. These indicate MicM was antisense to impR mRNA and was negatively-regulated by chbBC-IGR. Together, overexpression of ImpR contributed to the decreased carbapenem susceptibility in P. mirabilis. PMID:25756370

Molecular analysis of mutant and wild type alcohol dehydrogenase alleles from Drosophila

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Batzer, M.A.

1988-01-01

Wild type alcohol dehydrogenase polypeptides (ADH) from Drosophila melanogaster transformants were examined using western blots and polyclonal antiserum specific for Drosophila melanogaster ADH. Mutants induced in Drosophila spermatozoa at the alcohol dehydrogenase (Adh) locus using X-rays, 1-ethyl-1-nitrosourea (ENU) or ethyl methanesulfonate (EMS) were characterized using genetic complementation tests, western blots, Southern blots, northern blots and enzymatic amplification of the Adh locus. Genetic complementation tests showed that 22/30 X-ray-induced mutants, and 3/13 ENU and EMS induced mutants were multi-locus deficiencies. Western blot analysis of the intragenic mutations showed that 4/7 X-ray-induced mutants produced detectable polypeptides, one of which was normal in molecular weight and charge. In contrast 8/10 intragenic ENU and EMS induced mutants produced normal polypeptides. Southern blot analysis showed that 5/7 intragenic X-ray induced mutants and all 10 of the intragenic ENU and EMS induced mutants were normal with respect to the alleles they were derived from

The yeast complex I equivalent NADH dehydrogenase rescues pink1 mutants.

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Sven Vilain

2012-01-01

Full Text Available Pink1 is a mitochondrial kinase involved in Parkinson's disease, and loss of Pink1 function affects mitochondrial morphology via a pathway involving Parkin and components of the mitochondrial remodeling machinery. Pink1 loss also affects the enzymatic activity of isolated Complex I of the electron transport chain (ETC; however, the primary defect in pink1 mutants is unclear. We tested the hypothesis that ETC deficiency is upstream of other pink1-associated phenotypes. We expressed Saccaromyces cerevisiae Ndi1p, an enzyme that bypasses ETC Complex I, or sea squirt Ciona intestinalis AOX, an enzyme that bypasses ETC Complex III and IV, in pink1 mutant Drosophila and find that expression of Ndi1p, but not of AOX, rescues pink1-associated defects. Likewise, loss of function of subunits that encode for Complex I-associated proteins displays many of the pink1-associated phenotypes, and these defects are rescued by Ndi1p expression. Conversely, expression of Ndi1p fails to rescue any of the parkin mutant phenotypes. Additionally, unlike pink1 mutants, fly parkin mutants do not show reduced enzymatic activity of Complex I, indicating that Ndi1p acts downstream or parallel to Pink1, but upstream or independent of Parkin. Furthermore, while increasing mitochondrial fission or decreasing mitochondrial fusion rescues mitochondrial morphological defects in pink1 mutants, these manipulations fail to significantly rescue the reduced enzymatic activity of Complex I, indicating that functional defects observed at the level of Complex I enzymatic activity in pink1 mutant mitochondria do not arise from morphological defects. Our data indicate a central role for Complex I dysfunction in pink1-associated defects, and our genetic analyses with heterologous ETC enzymes suggest that Ndi1p-dependent NADH dehydrogenase activity largely acts downstream of, or in parallel to, Pink1 but upstream of Parkin and mitochondrial remodeling.

Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

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Zha, Guodong; Wang, Bochu; Liu, Junyu; Yan, Jie; Zhu, Liqing; Yang, Xingyan

2016-01-01

The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

Isolation and characteristics of minute plaque forming mutant of cyanophage AS-1

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Amla, D.V.

1981-01-01

Minute plaque forming mutant (m) of cyanophage AS-1 infecting unicellular blue-green algae was isolated spontaneously and after mutagenic treatment. Compared to wild type m mutant formed small plaques, adsorption rate was slow and the burst-size was significantly decreased with prolonged eclipse and latent period. The plaque forming ability of mutant phage was sensitive to pH, heat, EDTA shock, distilled water and photosensitisation with acriflavine whereas ultraviolet sensitivity of free and intracellular phage was identical to the parent. The spontaneous reversion frequencies of mutant phage to wild type were between 10 -5 to 10 -3 and appeared to be clonal property. Reversion studies suggested possibilities of frame-shift or base-pair substitution for m mutation. (author)

Induction of diphtheria toxin-resistant mutants in human cells by ultraviolet light

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Rocchi, P.; Ferreri, A.M.; Capucci, A.; Prodi, G.

1981-01-01

Stable spontaneous mutants resistant to the protein synthesis inhibitor diphtheria toxin (DT) have been selected in human cell line EUE at a very low frequency (less than 8 x 10(-6)). U.v.-induced mutation has been quantitatively measured: treatment of cells with u.v. light increased the frequencies of diphtheria toxin resistant (DTr) mutants up to 1000-fold. The maximum recovery of DTr mutants was observed after a short expression period, for all u.v. doses tested, and was followed by a decrease in mutation frequency on subsequent passages

Induction of diphtheria toxin-resistant mutants in human cells by ultraviolet light

International Nuclear Information System (INIS)

Rocchi, P.; Ferreri, A.M.; Capucci, A.; Prodi, G.

1981-01-01

Stable spontaneous mutants resistant to the protein synthesis inhibitor diphtheria toxin (DT) have been selected in human cell line EUE at a very low frequency ( -6 ). U.v.-induced mutation has been quantitatively measured: treatment of cells with u.v. light increased the frequencies of diphtheria toxin resistant (DTsup(r)) mutants up to 1000-fold. The maximum recovery of DTsup(r) mutants was observed after a short expression period, for all u.v. doses tested, and was followed by a decrease in mutation frequency on subsequent passages. (author)

Gamma ray induced male sterility mutant in lentil

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Srivastava, A.; Yadav, A.K.

2001-01-01

Full text: Male sterility refers to the failure of pollen grains to bring about effective fertilization, either due to structural default or physiological disfunctioning and has special significance in hybridization programmes. Male steriles have been produced in a number of crop plants like red gram, pigeon pea, mung bean, khesari and lentil. A completely male sterile mutant was isolated in Lens culinaris Medik, after seed treatment with 100 Gy dose of gamma rays. The male sterile mutant showed 100% pollen sterility but was morphologically more vigorous than the parent plants. It showed more branches and its leaves were bigger, more oblong and dark green. The number of flowers borne by the mutant was significantly higher than any other plant of the treatment. The size of the flowers was also increased but the anthers were smaller in size. Pollen grains were few in number, round in shape but empty and did not take up any stain, indicating that normal microsporogenesis had not taken place. This male sterile mutant was used as the female parent and pollinated with pollen of a parent. Four pods with one seed in each were formed indicating that the mutant was female fertile. The seeds were smaller than those of the parent variety and also dark coloured. The mutant showed increased vigour and flower number as compared to parental plants. Lentil is an important pulse crop and induction of variability in its germplasm is necessary for its improvement. Male steriles can be used conveniently in lentil hybridization programmes. (author)

Isolation and characterization of xylitol-assimilating mutants of recombinant Saccharomyces cerevisiae.

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Tani, Tatsunori; Taguchi, Hisataka; Fujimori, Kazuhiro E; Sahara, Takehiko; Ohgiya, Satoru; Kamagata, Yoichi; Akamatsu, Takashi

2016-10-01

To clarify the mechanisms of xylitol utilization, three xylitol-assimilating mutants were isolated from recombinant Saccharomyces cerevisiae strains showing highly efficient xylose-utilization. The nucleotide sequences of the mutant genomes were analyzed and compared with those of the wild-type strains and the mutation sites were identified. gal80 mutations were common to all the mutants, and recessive to the wild-type allele. Hence we constructed a gal80Δ mutant and confirmed that the gal80Δ mutant showed a xylitol-assimilation phenotype. When the constructed gal80Δ mutant was crossed with the three isolated mutants, all diploid hybrids showed xylitol assimilation, indicating that the mutations were all located in the GAL80. We analyzed the role of the galactose permease Gal2, controlled by the regulatory protein Gal80, in assimilating xylitol. A gal2Δ gal80Δ double mutant did not show xylitol assimilation, whereas expression of GAL2 under the control of the TDH3 promoter in the GAL80 strain did result in assimilation. These data indicate that Gal2 was needed for xylitol assimilation in the wild-type strain. When the gal80 mutant with an initial cell concentration of A660 = 20 was used for batch fermentation in a complex medium containing 20 g/L xylose or 20 g/L xylitol at pH 5.0 and 30°C under oxygen limitation, the gal80 mutant consumed 100% of the xylose within 12 h, but xylitol within 100 h, indicating that xylose reductase is required for xylitol consumption in oxygen-limited conditions. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Collection of rice mutants and application studies of their agronomic characters

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Sun Shuxiang; Jin Wei; Luo Qian; Sheng Ping; Huang Rongmin

1993-01-01

More than 1600 accessions of rice mutant germplasm have been collected since 1980, and 1142 accessions of mutants have been identified according to their agronomy and pattern characters. A part of mutants were compared with their original cultivars in eight main agronomic characters. The results showed that the agronomic characters of mutants induced by ionizing radiations changed to both positive and negative directions compared with their original cultivars. Only 6.3% mutants varied in single agronomic character, and 91.1% mutants varied in two to six agronomic characters. Tenetic analysis and Cellular observations were carried out for two kinds of early mutants. It showed that early mutants 'Yuan Feng Zao' are controlled by two independent and incomplete dominant genes. For the dwarf, the reduction of the number of longitudinal cell layers causes the stem shorter and the increase of the number of horizontal cell layers causes the stem wall thicker. More than 100 preserved accessions of mutants were supplied to breeding units as parents or for genetic studies. Sixteen cultivars (lines) were bred from the parents which played an important role in raising the output of rice production

The 7B-1 mutant in tomato shows blue-light-specific resistance to osmotic stress and abscisic acid.

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Fellner, Martin; Sawhney, Vipen K

2002-03-01

Germination of wild-type (WT) tomato ( Lycopersicon esculentum Mill.) seed is inhibited by mannitol (100-140 mM) in light, but not in darkness, suggesting that light amplifies the responsiveness of the seed to osmotic stress (M. Fellner, V.K. Sawhney (2001) Theor Appl Genet 102:215-221). Here we report that white light (W) and especially blue light (B) strongly enhance the mannitol-induced inhibition of seed germination, and that the effect of red light (R) is weak or nil. The inhibitory effect of mannitol could be completely overcome by fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, indicating that mannitol inhibits seed germination via ABA accumulation in seeds. The inhibition of WT seed germination by exogenous ABA was also amplified by W or B, but not by R. In a recessive, ABA-overproducing, 7B-1 mutant of tomato, seed germination and hypocotyl growth were resistant to inhibition by mannitol or exogenous ABA, both in W or B. Experiments with fluridone suggested that inhibition of hypocotyl growth by W or B is also partially via ABA accumulation. De-etiolation in the mutant was especially less in B compared to the WT, and there was no difference in hypocotyl growth between the two genotypes in R. Our data suggest that B amplifies the responsiveness of tomato seeds and hypocotyls to mannitol and ABA, and that W- or B-specific resistance of the 7B-1 mutant to osmotic stress or ABA is a consequence of a defect in B perception or signal transduction.

Generation of a Mutant Mucor hiemalis Endoglycosidase That Acts on Core-fucosylated N-Glycans.

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Katoh, Toshihiko; Katayama, Takane; Tomabechi, Yusuke; Nishikawa, Yoshihide; Kumada, Jyunichi; Matsuzaki, Yuji; Yamamoto, Kenji

2016-10-28

Endo-β-N-acetylglucosaminidase M (Endo-M), an endoglycosidase from the fungus Mucor hiemalis, is a useful tool for chemoenzymatic synthesis of glycoconjugates, including glycoprotein-based therapeutics having a precisely defined glycoform, by virtue of its transglycosylation activity. Although Endo-M has been known to act on various N-glycans, it does not act on core-fucosylated N-glycans, which exist widely in mammalian glycoproteins, thus limiting its application. Therefore, we performed site-directed mutagenesis on Endo-M to isolate mutant enzymes that are able to act on mammalian-type core-α1,6-fucosylated glycans. Among the Endo-M mutant enzymes generated, those in which the tryptophan at position 251 was substituted with alanine or asparagine showed altered substrate specificities. Such mutant enzymes exhibited increased hydrolysis of a synthetic α1,6-fucosylated trimannosyl core structure, whereas their activity on the afucosylated form decreased. In addition, among the Trp-251 mutants, the W251N mutant was most efficient in hydrolyzing the core-fucosylated substrate. W251N mutants could act on the immunoglobulin G-derived core-fucosylated glycopeptides and human lactoferrin glycoproteins. This mutant was also capable of transferring the sialyl glycan from an activated substrate intermediate (sialyl glyco-oxazoline) onto an α1,6-fucosyl-N-acetylglucosaminyl biotin. Furthermore, the W251N mutant gained a glycosynthase-like activity when a N175Q substitution was introduced and it caused accumulation of the transglycosylation products. These findings not only give insights into the substrate recognition mechanism of glycoside hydrolase family 85 enzymes but also widen their scope of application in preparing homogeneous glycoforms of core-fucosylated glycoproteins for the production of potent glycoprotein-based therapeutics. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

X-ray-sensitive mutants of Chinese hamster ovary cell line

International Nuclear Information System (INIS)

Jeggo, P.A.; Kemp, L.M.

1983-01-01

A standard technique of microbial genetics, which involves the transfer of cells from single colonies by means of sterile toothpicks, has been adapted to somatic cell genetics. Its use has been demonstrated in the isolation of X-ray-sensitive mutants of CHO cells. 9000 colonies have been tested and 6 appreciably X-ray-sensitive mutants were isolated. (D 10 values 5-10-fold of wild-type D 10 value.) A further 6 mutants were obtained which showed a slight level of sensitivity (D 10 values less than 2-fold of wild-type D 10 value). The 6 more sensitive mutants were also sensitive to bleomycin, a chemotherapeutic agent inducing X-ray-like damage. Cross-sensitivity to UV-irradiation and treatment with the alkylating agents, MMS, EMS and MNNG, was investigated for these mutants. Some sensitivity to these other agents was observed, but in all cases it was less severe than the level of sensitivity to X-irradiation. Each mutant showed a different overall response to the spectrum of agents examined and these appear to represent new mutant phenotypes derived from cultured mammalian cell lines. One mutant strain, xrs-7, was cross-sensitive to all the DNA-damaging agents, but was proficient in the repair of single-strand breaks. (Auth.)

Reduced starch granule number per chloroplast in the dpe2/phs1 mutant is dependent on initiation of starch degradation.

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Malinova, Irina; Fettke, Joerg

2017-01-01

An Arabidopsis double knock-out mutant lacking cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) revealed a dwarf-growth phenotype, reduced starch content, an uneven distribution of starch within the plant rosette, and a reduced number of starch granules per chloroplast under standard growth conditions. In contrast, the wild type contained 5-7 starch granules per chloroplast. Mature and old leaves of the double mutant were essentially starch free and showed plastidial disintegration. Several analyses revealed that the number of starch granules per chloroplast was affected by the dark phase. So far, it was unclear if it was the dark phase per se or starch degradation in the dark that was connected to the observed decrease in the number of starch granules per chloroplast. Therefore, in the background of the double mutant dpe2/phs1, a triple mutant was generated lacking the initial starch degrading enzyme glucan, water dikinase (GWD). The triple mutant showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to wild type. However, starch granule morphology was only slightly affected by the lack of GWD as in the triple mutant and, like in dpe2/phs1, more spherical starch granules were observed. The characterized triple mutant was discussed in the context of the generation of starch granules and the formation of starch granule morphology.

Study on ionizing radiosensitivity of respiratory deficiency yeast mutants

International Nuclear Information System (INIS)

Mao Shuhong; Chinese Academy of Sciences, Beijing; Jin Genming; Wei Zengquan; Xie Hongmei

2006-01-01

The radiosensitivity of respiratory deficiency yeast mutants has been studied in this work. The mutants which were screened from the yeasts after ionizing irradiation were irradiated with 12 C 6+ at different doses. Because of the great change in its mitochondria and mitochondrial DNA, the respiratory deficiency yeast mutants show radio-sensitivity at dose less than 1 Gy and radioresistance at doses higher than 1 Gy. (authors)

The application of shortened upper leaf mutant in barley breeding

International Nuclear Information System (INIS)

Jin Hua

2004-01-01

The shortened upper leaf mutant was induced from Fuji Nigo by γ-ray irradiation. Fuji Nigo, the mutant, cross-cut F 1 , F 2 and back-cross F 1 , F 2 were used to analyze mutant heredity by comparative study. The yield, chlorophyll content, light intensity, dry matter of mutant were investigated. The results showed that (1) the mutant character was controlled by a couple of nuclear genes which were partial dominance; (2) the transmittance of the mutant colony was better than that of Fuji Nigo and bottom dry matter was much more than that of Fuji Nigo; (3) under the condition of high fertilizer and high plant population , the yield of mutant was higher than that of Fuji Nigo; (4) the content of chlorophyll a in the mutant was higher than that in Fuji Nigo

bioA mutant of Mycobacterium tuberculosis shows severe growth defect and imparts protection against tuberculosis in guinea pigs

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Kar, Ritika; Nangpal, Prachi; Mathur, Shubhita; Singh, Swati

2017-01-01

Owing to the devastation caused by tuberculosis along with the unsatisfactory performance of the Bacillus Calmette–Guérin (BCG) vaccine, a more efficient vaccine than BCG is required for the global control of tuberculosis. A number of studies have demonstrated an essential role of biotin biosynthesis in the growth and survival of several microorganisms, including mycobacteria, through deletion of the genes involved in de novo biotin biosynthesis. In this study, we demonstrate that a bioA mutant of Mycobacterium tuberculosis (MtbΔbioA) is highly attenuated in the guinea pig model of tuberculosis when administered aerogenically as well as intradermally. Immunization with MtbΔbioA conferred significant protection in guinea pigs against an aerosol challenge with virulent M. tuberculosis, when compared with the unvaccinated animals. Booster immunization with MtbΔbioA offered no advantage over a single immunization. These experiments demonstrate the vaccinogenic potential of the attenuated M. tuberculosis bioA mutant against tuberculosis. PMID:28658275

bioA mutant of Mycobacterium tuberculosis shows severe growth defect and imparts protection against tuberculosis in guinea pigs.

Directory of Open Access Journals (Sweden)

Ritika Kar

Full Text Available Owing to the devastation caused by tuberculosis along with the unsatisfactory performance of the Bacillus Calmette-Guérin (BCG vaccine, a more efficient vaccine than BCG is required for the global control of tuberculosis. A number of studies have demonstrated an essential role of biotin biosynthesis in the growth and survival of several microorganisms, including mycobacteria, through deletion of the genes involved in de novo biotin biosynthesis. In this study, we demonstrate that a bioA mutant of Mycobacterium tuberculosis (MtbΔbioA is highly attenuated in the guinea pig model of tuberculosis when administered aerogenically as well as intradermally. Immunization with MtbΔbioA conferred significant protection in guinea pigs against an aerosol challenge with virulent M. tuberculosis, when compared with the unvaccinated animals. Booster immunization with MtbΔbioA offered no advantage over a single immunization. These experiments demonstrate the vaccinogenic potential of the attenuated M. tuberculosis bioA mutant against tuberculosis.

Gravity-dependent differentiation and root coils in Arabidopsis thaliana wild type and phospholipase-A-I knockdown mutant grown on the International Space Station.

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Scherer, G F E; Pietrzyk, P

2014-01-01

Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Poliovirus Mutants Resistant to Neutralization with Soluble Cell Receptors

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Kaplan, Gerardo; Peters, David; Racaniello, Vincent R.

1990-12-01

Poliovirus mutants resistant to neutralization with soluble cellular receptor were isolated. Replication of soluble receptor-resistant (srr) mutants was blocked by a monoclonal antibody directed against the HeLa cell receptor for poliovirus, indicating that the mutants use this receptor to enter cells. The srr mutants showed reduced binding to HeLa cells and cell membranes. However, the reduced binding phenotype did not have a major impact on viral replication, as judged by plaque size and one-step growth curves. These results suggest that the use of soluble receptors as antiviral agents could lead to the selection of neutralization-resistant mutants that are able to bind cell surface receptors, replicate, and cause disease.

A mutant of a mutant of a mutant of a ...: Irradiation of progressive radiation-induced mutants in a mutation-breeding programme with Chrysanthenum morifolium RAM

International Nuclear Information System (INIS)

Broertjes, C.; Koene, P.; Veen, J.W.H. van.

1980-01-01

Radiation-induced sports in Chrysanthemum morifolium RAM. have been reported for several years. It has become an everyday practice to produce flower-colour mutants from outstanding cross-breeding products, even before they are distributed for the commercial production of cut flowers. One of the most successful and recent examples is that of cv. Horim, of which hundreds of mutants were produced by successive use of radiation-induced mutants in the mutation-breeding programme. Over about 4 years a variety of flower-colour mutants was obtained, not only largely including the outstanding characteristics of the original cultivar but sometimes even with an appreciable improvement in quality and yield. It is expected that the latter types, the Miros group, will soon completely supersede the spontaneous or raditation-induced Horim sports and mutants and take over the leading position of the Horim group in the production of all-year-round (AYR) cut-flowers. (orig.)

Comparative analysis on inactivation kinetics of between piezotolerant and piezosensitive mutant strains of Saccharomyces cerevisiae under combinations of high hydrostatic pressure and temperature.

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Nomura, Kazuki; Kuwabara, Yuki; Kuwabara, Wataru; Takahashi, Hiroyuki; Nakajima, Kanako; Hayashi, Mayumi; Iguchi, Akinori; Shigematsu, Toru

2017-12-01

We previously obtained a pressure-tolerant (piezotolerant) and a pressure sensitive (piezosensitive) mutant strain, under ambient temperature, from Saccharomyces cerevisiae strain KA31a. The inactivation kinetics of these mutants were analyzed at 150 to 250MPa with 4 to 40°C. By a multiple regression analysis, the pressure and temperature dependency of the inactivation rate constants k values of both mutants, as well as the parent strain KA31a, were well approximated with high correlation coefficients (0.92 to 0.95). For both mutants, as well as strain KA31a, the lowest k value was shown at a low pressure levels with around ambient temperature. The k value approximately increased with increase in pressure level, and with increase and decrease in temperature. The piezosensitive mutant strain a924E1 showed piezosensitivity at all pressure and temperature levels, compared with the parent strain KA31a. In contrast, the piezotolerant mutant strain a2568D8 showed piezotolerance at 4 to 20°C, but did not show significant piezotolerance at 40°C. These results of the variable influence of temperature on pressure inactivation of these strains would be important for better understanding of piezosensitive and piezotolerant mechanisms, as well as the pressure inactivation mechanism of S. cerevisiae. Copyright © 2017 Elsevier B.V. All rights reserved.

Alcohol-tolerant mutants of cyanobacterium Synechococcus elongatus PCC 7942 obtained by single-cell mutant screening system.

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Arai, Sayuri; Hayashihara, Kayoko; Kanamoto, Yuki; Shimizu, Kazunori; Hirokawa, Yasutaka; Hanai, Taizo; Murakami, Akio; Honda, Hiroyuki

2017-08-01

Enhancement of alcohol tolerance in microorganisms is an important strategy for improving bioalcohol productivity. Although cyanobacteria can be used as a promising biocatalyst to produce various alcohols directly from CO 2 , low productivity, and low tolerance against alcohols are the main issues to be resolved. Nevertheless, to date, a mutant with increasing alcohol tolerance has rarely been reported. In this study, we attempted to select isopropanol (IPA)-tolerant mutants of Synechococcus elongatus PCC 7942 using UV-C-induced random mutagenesis, followed by enrichment of the tolerant candidates in medium containing 10 g/L IPA and screening of the cells with a high growth rate in the single cell culture system in liquid medium containing 10 g/L IPA. We successfully acquired the most tolerant strain, SY1043, which maintains the ability to grow in medium containing 30 g/L IPA. The photosynthetic oxygen-evolving activities of SY1043 were almost same in cells after 72 h incubation under light with or without 10 g/L IPA, while the activity of the wild-type was remarkably decreased after the incubation with IPA. SY1043 also showed higher tolerance to ethanol, 1-butanol, isobutanol, and 1-pentanol than the wild type. These results suggest that SY1043 would be a promising candidate to improve alcohol production using cyanobacteria. Biotechnol. Bioeng. 2017;114: 1771-1778. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Induced mutants for the improvement of sesame and hybrid seed production

International Nuclear Information System (INIS)

Murty, G.S.S.

2001-01-01

With an overall objective to develop hybrids in sesame, induced mutants were used in cross breeding and five initial yield trials were conducted. For obtaining the mutant hybrids, recessive morphological mutants were used as female, and check varieties as male parents. In each trial, seed yields of mutant hybrids were compared with: i) the original parent in which the mutants were induced, ii) best check variety and iii) best cultivar hybrid. Among 138 mutant hybrids evaluated between 1994 and 1997, 18 showed superiority. In the development of hybrids, it is also desirable to have male sterile lines. By irradiating seeds with 400 Gy gamma rays, four genetic male sterile mutants were isolated. One of them, TMST-11 appears to be promising for breeding programme showing 100% male sterility and characterised by dark green foliage. To study the percent outcrossing, a monogenic chlorina mutant which can be identified from the seedling stage, was used in experiments conducted for two years. Among open pollinated plants, 92-98% plants were found outcrossed. Based on plant to row progenies, percent outcrossing ranged between 0.0 to 13.8%. (author)

Isozyme patterns of powdery mildew resistant wheat mutants

International Nuclear Information System (INIS)

Xia Wengau; Li Zhengkui; Wang Kefeng

1989-01-01

Full Text: Wheat mutants induced by gamma irradiation and showing improved resistance to powdery mildew were analysed for isozymes. The peroxidase band 3A could be related to the disease reaction. The band 3A is absent in resistant mutants, the higher the activity of band 3A the greater the susceptibility. (author)

Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

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Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M. (Universite du Quebec a Montreal (Canada))

1989-10-01

The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population.

Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

International Nuclear Information System (INIS)

Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M.

1989-01-01

The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population

Characterization of mitomycin-C-sensitive mouse lymphoma L5178Y cell mutants

International Nuclear Information System (INIS)

Inaba, Hiroko; Shiomi, Naoko; Shiomi, Tadahiro; Sato, Koki; Yoshida, Michihiro.

1985-01-01

Twenty-six mutants showing high sensitivity to mytomicin-C (MMC) were isolated from mouse lymphoma L5178Y cells by a replica-plating technique. Twenty-five of the mutants were 5 - 10 times more sensitive to MMC than were parental cells, and showed normal sensitivity to U.V. light and x-rays. From a complementation analysis, 5 mutants (MC s ) isolated from independently mutagenized cell populations were classified into two groups. These mutants possessed recessive character for MMC-sensitivity and there were at least two genes involved in the MMC-sensitivity. As for DNA-damaging factors, such as photoadducts of 8-methoxypsoralen (8-MOP) and 3-carbethoxysoralen (3-CPs), MC s mutants showed higher sensitivity to photoadducts of 8-MOP than to (3-CPs). MC s mutants were also highly sensitive to a DNA cross-linking agent, cisplatin. Characterization of the sensitivity of mouse MC s mutants was analogous to that of Fanconi's anemia (FA)-derived cells. Low concentrations (10 ng/ml) of MMC induced chromosome aberration in a high incidence in mouse MC s cells, as well as in FA cells. The frequency of MMC-induced chromosome aberrations was normal in hybrid cells between normal human diploid somatic cells and mouse mutants and between FA cells and mouse wild cells, and hereditary deficiency became normal by hybrization. (Namekawa, K.)

Characteristics of mutant lines of sweet potato flour

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Aryanti

2012-01-01

Research on mutation induction of sweet potato Sari variety has been conducted. Flour mutant lines were obtained from selection of M1V5 tubers irradiated by gamma rays at the dose of 10 Gy. Flour was made by peeling of tubers, then dried, blended and sieved. The quality test of flour have been done by measuring degree of whiteness, proximate, amylose contents, water content, soluble water, swelling power, and flour characteristics. The result of this work showed that flour of C6.26.13 mutant line had higher protein content than the parent plant with concentration of 3.62 % and its amylose content was also higher than the other mutant lines. The soluble water value of mutant lines were significant different compared to the parent plant from 1.82 to 2.25 % and swelling power from 4.28 to 5.55 %. The flour granule of the mutant line was different compared to the parent plant. (author)

Growth and sporulation defects in Bacillus subtilis mutants with a single rrn operon can be suppressed by amplification of the rrn operon.

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Yano, Koichi; Masuda, Kenta; Akanuma, Genki; Wada, Tetsuya; Matsumoto, Takashi; Shiwa, Yuh; Ishige, Taichiro; Yoshikawa, Hirofumi; Niki, Hironori; Inaoka, Takashi; Kawamura, Fujio

2016-01-01

The genome of Bacillus subtilis strain 168 encodes ten rRNA (rrn) operons. We previously reported that strains with only a single rrn operon had a decreased growth and sporulation frequency. We report here the isolation and characterization of suppressor mutants from seven strains that each have a single rrn operon (rrnO, A, J, I, E, D or B). The suppressor mutants for strain RIK656 with a single rrnO operon had a higher frequency of larger colonies. These suppressor mutants had not only increased growth rates, but also increased sporulation frequencies and ribosome levels compared to the parental mutant strain RIK656. Quantitative PCR analyses showed that all these suppressor mutants had an increased number of copies of the rrnO operon. Suppressor mutants were also isolated from the six other strains with single rrn operons (rrnA, J, I, E, D or B). Next generation and capillary sequencing showed that all of the suppressor mutants had tandem repeats of the chromosomal locus containing the remaining rrn operon (amplicon). These amplicons varied in size from approximately 9 to 179 kb. The amplifications were likely to be initiated by illegitimate recombination between non- or micro-homologous sequences, followed by unequal crossing-over during DNA replication. These results are consistent with our previous report that rrn operon copy number has a major role in cellular processes such as cell growth and sporulation.

Identification of key uric acid synthesis pathway in a unique mutant silkworm Bombyx mori model of Parkinson's disease.

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Hiroko Tabunoki

Full Text Available Plasma uric acid (UA levels decrease following clinical progression and stage development of Parkinson's disease (PD. However, the molecular mechanisms underlying decreases in plasma UA levels remain unclear, and the potential to apply mutagenesis to a PD model has not previously been discovered. We identified a unique mutant of the silkworm Bombyx mori (B.mori op. Initially, we investigated the causality of the phenotypic "op" by microarray analysis using our constructed KAIKO functional annotation pipeline. Consequently, we found a novel UA synthesis-modulating pathway, from DJ-1 to xanthine oxidase, and established methods for large-scale analysis of gene expression in B. mori. We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented. Additionally, levels of B.mori tyrosine hydroxylase (TH and DJ-1 mRNA were significantly lower in the brain of B. mori op mutants. UA content was significantly lower in the B. mori op mutant tissues and hemolymph. The possibility that the B. mori op mutant might be due to loss of DJ-1 function was supported by the observed vulnerability to oxidative stress. These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant. In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress. Our findings are expected to provide information needed to elucidate the molecular mechanism of decreased plasma UA levels in the clinical stage progression of PD.

Development mutants of anabaena doliolum defective in repair of UV-damage

International Nuclear Information System (INIS)

Tiwari, D.N.; Singh, C.B.

1980-01-01

Nitrosoguanidine induced 'blue' pigment mutants of the blue-green alga anabaena doliolum were isolated. The blue-mutants on further characterization were grouped into three developmental phenotypes - (i) those forming doli-form blue-spores of heterogenous size i.e., Ad 011, (ii) those forming spheroidal cells in the stationary phase, some of which behave like spores on transfer to fresh medium i.e., Ad 012, and (iii) those showing no sporulation and conditionally producing abnormal cells in the presence of combined nitrogen only i.e., Ad 007. The former two classes of mutants showed the formation of abnormal cells irrespective of the presence or absence of combined nitrogen sources in the medium. The formation of abnormal cells in the filaments of the above mutants were distinguished by their larger size and irregular mode of division leading to true-branch formation. The comparative characterization of these mutant strains with the parental one showed sluggish growth, increased UV-sensitivity, almost unchanged photorepair capacity, a marked change in the pigment composition and relative resistance to nitrosoguanidine. Irregular cell division in both space and time in the mutant strains and their increased sensitivity to ultraviolet irradiation indicate the possible involvement of dark repair system in maintaining the precision of cell cylce in this alga. (orig.) 891 AJ/orig. 892 HIS

Some biochemistry characteristics of soja (Glycine Max.L.) Tshibashi and its two mutants

International Nuclear Information System (INIS)

Botula, Manyala; Kasende, Mundeke; Kembola, Kejuni.

1978-01-01

Two mutants of a variety of soybeans (Thibashi) obtained by neutron irradiation in a reactor have been compared to their parents for their proteins and lipids contents. Analysis have been made by a modified micro-kjedhal method for proteins and by gaz chromatography for lipids converted into methylic esters. A slight lysine and hyptidine increase and a slight linolenic acid decrease are observed in the two mutants

Epilepsy, Behavioral Abnormalities, and Physiological Comorbidities in Syntaxin-Binding Protein 1 (STXBP1 Mutant Zebrafish.

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Brian P Grone

Full Text Available Mutations in the synaptic machinery gene syntaxin-binding protein 1, STXBP1 (also known as MUNC18-1, are linked to childhood epilepsies and other neurodevelopmental disorders. Zebrafish STXBP1 homologs (stxbp1a and stxbp1b have highly conserved sequence and are prominently expressed in the larval zebrafish brain. To understand the functions of stxbp1a and stxbp1b, we generated loss-of-function mutations using CRISPR/Cas9 gene editing and studied brain electrical activity, behavior, development, heart physiology, metabolism, and survival in larval zebrafish. Homozygous stxbp1a mutants exhibited a profound lack of movement, low electrical brain activity, low heart rate, decreased glucose and mitochondrial metabolism, and early fatality compared to controls. On the other hand, homozygous stxbp1b mutants had spontaneous electrographic seizures, and reduced locomotor activity response to a movement-inducing "dark-flash" visual stimulus, despite showing normal metabolism, heart rate, survival, and baseline locomotor activity. Our findings in these newly generated mutant lines of zebrafish suggest that zebrafish recapitulate clinical phenotypes associated with human syntaxin-binding protein 1 mutations.

Ceramides And Stress Signalling Intersect With Autophagic Defects In Neurodegenerative Drosophila blue cheese (bchs) Mutants.

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Hebbar, Sarita; Sahoo, Ishtapran; Matysik, Artur; Argudo Garcia, Irene; Osborne, Kathleen Amy; Papan, Cyrus; Torta, Federico; Narayanaswamy, Pradeep; Fun, Xiu Hui; Wenk, Markus R; Shevchenko, Andrej; Schwudke, Dominik; Kraut, Rachel

2015-12-07

Sphingolipid metabolites are involved in the regulation of autophagy, a degradative recycling process that is required to prevent neuronal degeneration. Drosophila blue cheese mutants neurodegenerate due to perturbations in autophagic flux, and consequent accumulation of ubiquitinated aggregates. Here, we demonstrate that blue cheese mutant brains exhibit an elevation in total ceramide levels; surprisingly, however, degeneration is ameliorated when the pool of available ceramides is further increased, and exacerbated when ceramide levels are decreased by altering sphingolipid catabolism or blocking de novo synthesis. Exogenous ceramide is seen to accumulate in autophagosomes, which are fewer in number and show less efficient clearance in blue cheese mutant neurons. Sphingolipid metabolism is also shifted away from salvage toward de novo pathways, while pro-growth Akt and MAP pathways are down-regulated, and ER stress is increased. All these defects are reversed under genetic rescue conditions that increase ceramide generation from salvage pathways. This constellation of effects suggests a possible mechanism whereby the observed deficit in a potentially ceramide-releasing autophagic pathway impedes survival signaling and exacerbates neuronal death.

Characterization of three Agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.

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Metts, J; West, J; Doares, S H; Matthysse, A G

1991-02-01

Three Agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. Two of the mutants were avirulent on all hosts tested. The third mutant, Ivr-211, was a host range mutant which was avirulent on Bryophyllum diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and Daucus carota but was virulent on Zinnia elegans and Lycopersicon esculentum (tomato). That the mutant phenotype was due to the transposon insertion was determined by cloning the DNA containing the transposon insertion and using the cloned DNA to replace the wild-type DNA in the parent bacterial strain by marker exchange. The transposon insertions in the three mutants mapped at three widely separated locations on the bacterial chromosome. The effects of the mutations on various steps in tumor formation were examined. All three mutants showed no alteration in binding to carrot cells. However, none of the mutants showed any induction of vir genes by acetosyringone under conditions in which the parent strain showed vir gene induction. When the mutant bacteria were examined for changes in surface components, it was found that all three of the mutants showed a similar alteration in lipopolysaccharide (LPS). LPS from the mutants was larger in size and more heavily saccharide substituted than LPS from the parent strain. Two of the mutants showed no detectable alteration in outer membrane and periplasmic space proteins. The third mutant, Ivr-225, was missing a 79-kDa surface peptide. The reason(s) for the failure of vir gene induction in these mutants and its relationship, if any, to the observed alteration in LPS are unknown.

Analysis of triclosan-selected Salmonella enterica mutants of eight serovars revealed increased aminoglycoside susceptibility and reduced growth rates.

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Ulrike Rensch

Full Text Available The biocide triclosan (TRC is used in a wide range of household, personal care, veterinary, industrial and medical products to control microbial growth. This extended use raises concerns about a possible association between the application of triclosan and the development of antibiotic resistance. In the present study we determined triclosan mutant prevention concentrations (MPC for Salmonella enterica isolates of eight serovars and investigated selected mutants for their mechanisms mediating decreased susceptibility to triclosan. MPCTRC values were 8-64-fold higher than MIC values and ranged between 1-16 µg/ml. The frequencies at which mutants were selected varied between 1.3 x 10(-10-9.9 x 10(-11. Even if MIC values of mutants decreased by 3-7 dilution steps in the presence of the efflux pump inhibitor Phe-Arg-β-naphtylamide, only minor changes were observed in the expression of genes encoding efflux components or regulators, indicating that neither the major multidrug efflux pump AcrAB-TolC nor AcrEF are up-regulated in triclosan-selected mutants. Nucleotide sequence comparisons confirmed the absence of alterations in the regulatory regions acrRA, soxRS, marORAB, acrSE and ramRA of selected mutants. Single bp and deduced Gly93→Val amino acid exchanges were present in fabI, the target gene of triclosan, starting from a concentration of 1 µg/ml TRC used for MPC determinations. The fabI genes were up to 12.4-fold up-regulated. Complementation experiments confirmed the contribution of Gly93→Val exchanges and fabI overexpression to decreased triclosan susceptibility. MIC values of mutants compared to parent strains were even equal or resulted in a more susceptible phenotype (1-2 dilution steps for the aminoglycoside antibiotics kanamycin and gentamicin as well as for the biocide chlorhexidine. Growth rates of selected mutants were significantly lower and hence, might partly explain the rare occurrence of Salmonella field isolates exhibiting

Selection of gamma-ray induced salt tolerant rice mutants by in vitro mutagenesis

International Nuclear Information System (INIS)

Kim, Dong Sub; Chun, Jae Beom; Lee, Kyung Jun; Kim, Jin Baek; Kim, Sang Hoon; Yun, Song Jong; Kang, Si Yong

2010-01-01

The present study had been performed to select the salt tolerant rice mutant lines through an in vivo and in vitro mutagenesis with a gamma-ray. The physiological responses such as MDA and chlorophyll of the selected salt mutant lines were investigated under salt stress. For the selection of the salt tolerant rice mutants by in vitro mutagenesis with gamma-ray, we conducted a second selection procedure with 1,500 mutant lines induced from the original cv. Dongan (wild-type, WT): Ist, selection under a nutrient solution with 171 mM NaCI: 2nd, selection under in vitro conditions. Based on a growth comparison of the entries, out of mutant lines, the putative 2 salt tolerant rice mutant lines, ST-495 and ST-532, were selected. The 2 ST-lines had a lower malonaldehyde (MDA) contents than wild-type (WT) during salt stress. The survival rate of the WT, ST-495 and ST-532 were 36.6%, 70% and 50% in 171 mM NaCI, respectively. The chlorophyll and carotenoid contents were decreased more in a WT plant than the two selected mutant lines. These rice mutant lines will be released for cultivation at the reclaimed land and used as a control plot for genetic research about salt tolerance

Selection of gamma-ray induced salt tolerant rice mutants by in vitro mutagenesis

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Kim, Dong Sub; Chun, Jae Beom; Lee, Kyung Jun; Kim, Jin Baek; Kim, Sang Hoon; Yun, Song Jong; Kang, Si Yong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2010-06-15

The present study had been performed to select the salt tolerant rice mutant lines through an in vivo and in vitro mutagenesis with a gamma-ray. The physiological responses such as MDA and chlorophyll of the selected salt mutant lines were investigated under salt stress. For the selection of the salt tolerant rice mutants by in vitro mutagenesis with gamma-ray, we conducted a second selection procedure with 1,500 mutant lines induced from the original cv. Dongan (wild-type, WT): Ist, selection under a nutrient solution with 171 mM NaCI: 2nd, selection under in vitro conditions. Based on a growth comparison of the entries, out of mutant lines, the putative 2 salt tolerant rice mutant lines, ST-495 and ST-532, were selected. The 2 ST-lines had a lower malonaldehyde (MDA) contents than wild-type (WT) during salt stress. The survival rate of the WT, ST-495 and ST-532 were 36.6%, 70% and 50% in 171 mM NaCI, respectively. The chlorophyll and carotenoid contents were decreased more in a WT plant than the two selected mutant lines. These rice mutant lines will be released for cultivation at the reclaimed land and used as a control plot for genetic research about salt tolerance.

Effects of Light Intensity on Development and Chlorophyll Content in the Arabidopsis Mutant Plants with Defects in Photosynthesis

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E.Yu. Garnik

2015-12-01

Full Text Available The developmental stages and adaptability to different light intensity (150 µmol*m-2*s-1 and 100 µmol*m-2*s-1 in Arabidopsis mutant lines with defects of photosynthetic apparatus were analyzed. Plant development in the mutant lines depended on the light intensity to varying degrees. Lines ch1-1 (lack of the chlorophyllide a oxygenase and rtn16 (decreased chlorophyll a and b amounts were the most susceptible to the light decrease. No one of the investigated lines demonstrated chlorophyll a/b rate alteration under the different light conditions. The depleted chlorophyll content has had the major effect on the mutant plants development under the different light conditions. The different chlorophyll a/b rate correlated with the different adaptability of mutant plants to low light.

Exploring the regulatory role of isocitrate dehydrogenase mutant protein on glioma stem cell proliferation.

Science.gov (United States)

Lu, H-C; Ma, J; Zhuang, Z; Qiu, F; Cheng, H-L; Shi, J-X

2016-08-01

Glioma is the most lethal form of cancer that originates mostly from the brain and less frequently from the spine. Glioma is characterized by abnormal regulation of glial cell differentiation. The severity of the glioma was found to be relaxed in isocitrate dehydrogenase 1 (IDH1) mutant. The present study focused on histological discrimination and regulation of cancer stem cell between IDH1 mutant and in non-IDH1 mutant glioma tissue. Histology, immunohistochemistry and Western blotting techniques are used to analyze the glioma nature and variation in glioma stem cells that differ between IDH1 mutant and in non-IDH1 mutant glioma tissue. The aggressive form of non-IDH1 mutant glioma shows abnormal cellular histological variation with prominent larger nucleus along with abnormal clustering of cells. The longer survival form of IDH1 mutant glioma has a control over glioma stem cell proliferation. Immunohistochemistry with stem cell markers, CD133 and EGFRvIII are used to demonstrate that the IDH1 mutant glioma shows limited dependence on cancer stem cells and it shows marked apoptotic signals in TUNEL assay to regulate abnormal cells. The non-IDH1 mutant glioma failed to regulate misbehaving cells and it promotes cancer stem cell proliferation. Our finding supports that the IDH1 mutant glioma has a regulatory role in glioma stem cells and their survival.

Further studies on O2-resistant photosynthesis and photorespiration in a tobacco mutant with enhanced catalase activity

International Nuclear Information System (INIS)

Zelitch, I.

1990-01-01

The increase in net photosynthesis in M 4 progeny of an O 2 -resistant tobacco (Nicotiana tabacum) mutant relative to wild-type plants at 21 and 42% O 2 has been confirmed and further investigated. Self-pollination of an M 3 mutant produced M 4 progeny segregating high catalase phenotypes (average 40% greater than wild type) at a frequency of about 60%. The high catalase phenotype cosegregated precisely with O 2 -resistant photosynthesis. About 25% of the F 1 progeny of reciprocal crosses between the same M 3 mutant and wild type had high catalase activity, whether the mutant was used as the maternal or paternal parent, indicating nuclear inheritance. In high-catalase mutants the activity of NADH-hydroxypyruvate reductase, another peroxisomal enzyme, was the same as wild type. The mutants released 15% less photorespiratory CO 2 as a percent of net photosynthesis in CO 2 -free 21% O 2 and 36% less in CO 2 -free 42% O 2 compared with wild type. The mutant leaf tissue also released less 14 CO 2 per [1- 14 C]glycolate metabolized than wild type in normal air, consistent with less photorespiration in the mutant. The O 2 -resistant photosynthesis appears to be caused by a decrease in photorespiration especially under conditions of high O 2 where the stoichiometry of CO 2 release per glycolate metabolized is expected to be enhanced. The higher catalase activity in the mutant may decrease the nonenzymatic peroxidation of keto-acids such as hydroxypyruvate and glyoxylate by photorespiratory H 2 O 2

High lysine and high yielding mutants in wheat (Triticum aestivum) L

International Nuclear Information System (INIS)

Mohammad, T.; Mahmood, F.; Ahmad, A.; Sattar, A.; Khan, I.

1988-01-01

The dry seeds of the variety Lu-26 were irradiated with 20 krad of gamma rays. In M 2 about 300 mutant plants were selected for short stature, rust resistance and other desirable traits. As a result of further selection, in M 6 , eight superior lines were finally identified. The agronomic characteristics of these mutants, the parent variety (Lu-26) and a standard check variety (Pak-81) are shown. The selected mutants and commercially grown cultivars (Lu-26 and Pak-81) were studied for total protein content and amino acid pattern. The mutants WM-89-1, WM-6-17 and WM-81-2 showing high yield also contained comparatively high amounts of methionine and lysine. The lysine contents were 565, 410, and 370 mg/100g in the mutants WM-89-1, WM-6-17 and WM-81-2, respectively against a range value of 210-370 mg/100g in other mutants and 250-320 in the commercial cultivars. The mutant WM-81-2 was comparable to WM-56-1-5 in lysine content. The results of these experiments show a possibility of developing varieties having high yield and high amounts of essential amino acids such as lysine and methionine

Characteristics and use of wheat mutants tolerant or resistant to Septoria nodorum Berk

International Nuclear Information System (INIS)

Fossati, A.; Kleijer, G.; Fried, P.M.

1983-01-01

Mutation induction was used to obtain mutants tolerant or resistant to Septoria nodorum. This technique is valuable but many genotypes had to be treated because mutants could not be selected from all the genotypes. Short tolerant mutants could be obtained from 3 of the 15 treated tall tolerant lines. Induction of tolerance in susceptible lines of good agronomic value succeeded for 2 of 5 treated varieties. All these mutants showed a reduction in yield potential. One mutant showed partial resistance to S. nodorum. The disease development on the leaves and the spikes of this mutant was much slower than on the original variety. The characteristics of this mutant are discussed in detail. The genetics of tolerance proved to be polygenic and additive, which has consequences on the breeding method. A good way of obtaining a stable system would be the combination of high tolerance and partial resistance in the same cultivar. (author)

Fine Mapping of a Degenerated Abdominal Legs Mutant (Edl in Silkworm, Bombyx mori.

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Honglei Wang

Full Text Available In insects, abdominal appendages, also called prolegs, vary due to adaptive evolution. Mutations on prolegs within species provide insights to better understand the mechanisms underlying appendage development and diversity. In silkworm Bombyx mori, extra-crescents and degenerated abdominal legs (Edl mutant, belonging to the E pseudoallele group, is a spontaneous mutation that adds crescents and degenerates prolegs on the third abdominal segment (A3. This mutation may be a homeotic transformation of A3 to A2. In this study, the Edl locus was mapped within approximately a 211 Kb region that is 10 Kb upstream of Bmabdominal-A (Bmabd-A. RT-quantitative PCR (RT-qPCR and Western blot analysis of Bmabd-A expression showed a slight but significant decrease, while the expression of BmUltrabithorax (BmUbx was up-regulated in the Edl mutant compared to wildtype (Dazao. Moreover, we also found that BmDistal-less (BmDll, which regulated the development of distal proleg structures, was missing at the tips of the A3 prolegs in the Edl mutant compared to BmDll expression in normally developed prolegs in both the wildtype and mutant. Collectively, we identified approximately a 211 Kb region in the Edl locus that regulates BmUbx and Bmabd-A expression and found that changes in BmUbx and Bmabd-A expression may lead to the loss of distal proleg structures in B. mori.

Wheat TILLING mutants show that the vernalization gene VRN1 down-regulates the flowering repressor VRN2 in leaves but is not essential for flowering.

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Andrew Chen

Full Text Available Most of the natural variation in wheat vernalization response is determined by allelic differences in the MADS-box transcription factor VERNALIZATION1 (VRN1. Extended exposures to low temperatures during the winter (vernalization induce VRN1 expression and promote the transition of the apical meristem to the reproductive phase. In contrast to its Arabidopsis homolog (APETALA1, which is mainly expressed in the apical meristem, VRN1 is also expressed at high levels in the leaves, but its function in this tissue is not well understood. Using tetraploid wheat lines with truncation mutations in the two homoeologous copies of VRN1 (henceforth vrn1-null mutants, we demonstrate that a central role of VRN1 in the leaves is to maintain low transcript levels of the VRN2 flowering repressor after vernalization. Transcript levels of VRN2 were gradually down-regulated during vernalization in both mutant and wild-type genotypes, but were up-regulated after vernalization only in the vrn1-null mutants. The up-regulation of VRN2 delayed flowering by repressing the transcription of FT, a flowering-integrator gene that encodes a mobile protein that is transported from the leaves to the apical meristem to induce flowering. The role of VRN2 in the delayed flowering of the vrn1-null mutant was confirmed using double vrn1-vrn2-null mutants, which flowered two months earlier than the vrn1-null mutants. Both mutants produced normal flowers and seeds demonstrating that VRN1 is not essential for wheat flowering, which contradicts current flowering models. This result does not diminish the importance of VRN1 in the seasonal regulation of wheat flowering. The up-regulation of VRN1 during winter is required to maintain low transcript levels of VRN2, accelerate the induction of FT in the leaves, and regulate a timely flowering in the spring. Our results also demonstrate the existence of redundant wheat flowering genes that may provide new targets for engineering wheat

A quadruple mutant of Arabidopsis reveals a β-carotene hydroxylation activity for LUT1/CYP97C1 and a regulatory role of xanthophylls on determination of the PSI/PSII ratio.

Science.gov (United States)

Fiore, Alessia; Dall'Osto, Luca; Cazzaniga, Stefano; Diretto, Gianfranco; Giuliano, Giovanni; Bassi, Roberto

2012-04-18

Xanthophylls are oxygenated carotenoids playing an essential role as structural components of the photosynthetic apparatus. Xanthophylls contribute to the assembly and stability of light-harvesting complex, to light absorbance and to photoprotection. The first step in xanthophyll biosynthesis from α- and β-carotene is the hydroxylation of ε- and β-rings, performed by both non-heme iron oxygenases (CHY1, CHY2) and P450 cytochromes (LUT1/CYP97C1, LUT5/CYP97A3). The Arabidopsis triple chy1chy2lut5 mutant is almost completely depleted in β-xanthophylls. Here we report on the quadruple chy1chy2lut2lut5 mutant, additionally carrying the lut2 mutation (affecting lycopene ε-cyclase). This genotype lacks lutein and yet it shows a compensatory increase in β-xanthophylls with respect to chy1chy2lut5 mutant. Mutant plants show an even stronger photosensitivity than chy1chy2lut5, a complete lack of qE, the rapidly reversible component of non-photochemical quenching, and a peculiar organization of the pigment binding complexes into thylakoids. Biochemical analysis reveals that the chy1chy2lut2lut5 mutant is depleted in Lhcb subunits and is specifically affected in Photosystem I function, showing a deficiency in PSI-LHCI supercomplexes. Moreover, by analyzing a series of single, double, triple and quadruple Arabidopsis mutants in xanthophyll biosynthesis, we show a hitherto undescribed correlation between xanthophyll levels and the PSI-PSII ratio. The decrease in the xanthophyll/carotenoid ratio causes a proportional decrease in the LHCII and PSI core levels with respect to PSII. The physiological and biochemical phenotype of the chy1chy2lut2lut5 mutant shows that (i) LUT1/CYP97C1 protein reveals a major β-carotene hydroxylase activity in vivo when depleted in its preferred substrate α-carotene; (ii) xanthophylls are needed for normal level of Photosystem I and LHCII accumulation.

A quadruple mutant of Arabidopsis reveals a β-carotene hydroxylation activity for LUT1/CYP97C1 and a regulatory role of xanthophylls on determination of the PSI/PSII ratio

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Fiore Alessia

2012-04-01

Full Text Available Abstract Background Xanthophylls are oxygenated carotenoids playing an essential role as structural components of the photosynthetic apparatus. Xanthophylls contribute to the assembly and stability of light-harvesting complex, to light absorbance and to photoprotection. The first step in xanthophyll biosynthesis from α- and β-carotene is the hydroxylation of ε- and β-rings, performed by both non-heme iron oxygenases (CHY1, CHY2 and P450 cytochromes (LUT1/CYP97C1, LUT5/CYP97A3. The Arabidopsis triple chy1chy2lut5 mutant is almost completely depleted in β-xanthophylls. Results Here we report on the quadruple chy1chy2lut2lut5 mutant, additionally carrying the lut2 mutation (affecting lycopene ε-cyclase. This genotype lacks lutein and yet it shows a compensatory increase in β-xanthophylls with respect to chy1chy2lut5 mutant. Mutant plants show an even stronger photosensitivity than chy1chy2lut5, a complete lack of qE, the rapidly reversible component of non-photochemical quenching, and a peculiar organization of the pigment binding complexes into thylakoids. Biochemical analysis reveals that the chy1chy2lut2lut5 mutant is depleted in Lhcb subunits and is specifically affected in Photosystem I function, showing a deficiency in PSI-LHCI supercomplexes. Moreover, by analyzing a series of single, double, triple and quadruple Arabidopsis mutants in xanthophyll biosynthesis, we show a hitherto undescribed correlation between xanthophyll levels and the PSI-PSII ratio. The decrease in the xanthophyll/carotenoid ratio causes a proportional decrease in the LHCII and PSI core levels with respect to PSII. Conclusions The physiological and biochemical phenotype of the chy1chy2lut2lut5 mutant shows that (i LUT1/CYP97C1 protein reveals a major β-carotene hydroxylase activity in vivo when depleted in its preferred substrate α-carotene; (ii xanthophylls are needed for normal level of Photosystem I and LHCII accumulation.

Effect of abscisic acid on stomatal opening in isolated epidermal strips of abi mutants of Arabidopsis thaliana

NARCIS (Netherlands)

Roelfsema, MRG; Prins, HBA

Abscisic acid-insensitive mutants of Arabidopsis thaliana L. var. Landsberg erecta were selected for their decreased sensitivity to ABA during germination. Two of these mutants, abi-1 and abi-2, display a wilty phenotype as adult plants, indicating disturbed water relations. Experiments were

A wheat cold resistance mutant derived from space mutagenesis

International Nuclear Information System (INIS)

Li Peng; Sun Mingzhu; Zhang Fengyun; Gao Guoqiang; Qiu Denglin; Li Xinhua

2012-01-01

A cold resistance mutant, obtained by spaceflight mutagenesis on the seeds of wheat variety Han6172, and the DNA of cold resistance mutant and contrast Han6172 were compared by SRAP technique. 380 pairs of primers were screened, 6 pairs of them had polymorphisms between mutant and contrast, the rate was 1.58%, and this data indicated that there are no obvious DNA differences between mutant and contrast Six specific fragments were obtained, 3 fragments of them were amplified in mutant. Homology analysis in GenBank showed that Me3-Em7-Mt, Me4-Em11-CK, Me7-Em19-CK and Me6-Em9-Mt all had homologous sequences with wheat chromosome 3B-specific BAC library, and this result indicated that the gene and regulator sequences associated with mutant cold resistance might locate on 3B chromosome. It was speculated that space mutation induced the mutation of 3B chromosome primary structure, and influenced the expressions of cold resistance genes, which resulted in the mutation of cold resistance ability. (authors)

A wheat cold resistance mutant derived from space mutagenesis

International Nuclear Information System (INIS)

Li Peng; Sun Mingzhu; Zhang Fengyun; Gao Guoqiang; Qiu Denglin; Li Xinhua

2011-01-01

A cold resistance mutant, obtained by spaceflight mutagenesis on the seeds of wheat variety Han6172, and the DNA of cold resistance mutant and contrast Han6172 were compared by SRAP technique. 380 pairs of primers were screened, 6 pairs of them had polymorphisms between mutant and contrast, the rate was 1.58%, and this data indicated that there are no obvious DNA differences between mutant and contrast. Six specific fragments were obtained, 3 fragments of them were amplified in mutant. Homology analysis in GenBank showed that Me3-Em7-Mt, Me4-Em11-CK, Me7-Em19-CK and Me6-Em9-Mt all had homologous sequences with wheat chromosome 3B-specific BAC library, and this result indicated that the gene and regulator sequences associated with mutant cold resistance might locate on 3B chromosome. It was speculated that space mutation induced the mutation of 3B chromosome primary structure, and influenced the expressions of cold resistance genes, which resulted in the mutation of cold resistance ability. (authors)

An extra early mutant of pigeonpea

International Nuclear Information System (INIS)

Ravikesavan, R.; Kalaimagal, T.; Rathnaswamy, R.

2001-01-01

The redgram (Cajanus cajan (L.) Huth) variety 'Prabhat DT' was gamma irradiated with 100, 200, 300 and 400 Gy doses. Several mutants have been identified viz., extra early mutants, monostem mutants, obcordifoliate mutants and bi-stigmatic mutants. The extra early mutant was obtained when treated with 100 Gy dose. The mutant was selfed and forwarded from M 2 to M 4 generation. In the M 4 generation the mutant line was raised along with the parental variety. Normal cultural practices were followed and the biometrical observations were recorded. It was observed that for the characters viz., total number of branches per plant, number of pods per plants, seeds per pod, 100 seed weight and seed yield per plant there was no difference between the mutant and parent variety. Whereas, regarding the days to flowering and maturity the mutants were earlier than the parents. The observation was recorded from two hundred plants each. The mutant gives the same yield in 90 days as that of the parent variety in 107 days, which make it an economic mutant

Evaluation of dwarf mutant of cowpea (Vigna Unguiculata L. Walp.) developed through gamma irradiation for nitrogen fixation characters

International Nuclear Information System (INIS)

Anjana, G.; Thimmaiah, S.K.

2002-01-01

A dwarf mutant developed through gamma-irradiation and mutation breeding of its parent cowpea variety, namely KBC-1 has been characterized for nitrogen-fixation characters such as root nodule acetylene reduction activity (ARA) and legthemoglobin content at different days after sowing (DAS). Significant variations in these characters were noticed among the varieties and for interactions between the varieties and DAS. The ARA was nearly one-and-a half fold higher in the mutant at both 30 (12.69 μmoles)C 2 H 4 formed/h/g fr.wt. of nodules) and 50 DAS (6.74 μmoles) over its parent (9.20 and 4.46 μmoles at 30 and 50 DAS, respectively). Further, the ARA in the mutant decreased linearly with an increase in the DAS. The leghemoglobin (Lb) content was also higher in the mutant over the parent at all the DAS. However, it decreased linearly with an increase in the DAS in both the mutant and the parent. The highest leghemoglobin content was noticed at 30 DAS in both mutant (2.1 mg/g fr. wt. of nodules) and the parent (1.45 mg/g). Thus, the dwarf cowpea mutant was found to be associated with higher nitrogen-fixing ability which could be exploited in future breeding programmes. (author)

Multivariate analysis for selecting apple mutants

International Nuclear Information System (INIS)

Faedi, W.; Bagnara, G.L.; Rosati, P.; Cecchini, M.

1992-01-01

The mutlivariate analysis of four year records on several vegetative and productive traits of twenty-one apple mutants (3 of 'Jonathan', 3 of 'Ozark Gold', 14 of 'Mollie's Delicious', 1 of 'Neipling's Early Stayman)' induced by gamma radiations showed that observation of some traits of one-year-old shoots is the most efficient way to reveal compact growing apple mutants. In particular, basal cross-section area, total length and leaf area resulted the most appropriate parameters, while internode length together with conopy height and width are less appropriate. The most interesting mutants we found are: one of 'Mollie's Delicious for the best balance among tree and fruit traits and for high skin color; one of 'Neipling's Early Stayman' with an earlier and more extensively red colored apple than the original clone. (author)

Study on yeast mutant with high alcohol yield fermented in sweet sorghum juice using carbon ion irradiation

International Nuclear Information System (INIS)

Yan Yaping; Lu Dong; Wang Jufang; Dong Xicun; Gao Feng; Ma Liang; Li Wenjian

2009-01-01

Five mutants with high ability of producing alcohol were selected out by using TTC as an indicator after irradiation of the alcohol yeast with 100 MeV/u carbon ions. The fermentation experiment in sweet sorghum juice showed that the alcohol production ability of mutant T4 strain increased 18.6% compared to the control strain. The residual sugar content in the juice was decreased too. After that,the optimum fermentation conditions of the T4 strain in sweet sorghum juice were investigated. The results showed that the optimum temperature and pH value for fermentation were 30 degree C and 4.5, respectively. The verification experiment was fermented in a 10 l bio-reactor and the obtained data indicated that the fermentative rate and the ability of producing alcohol in T4 strain was higher than that in the control strain under the same fermentation condition. (authors)

early maturing mutants in Indica rice and their traits

International Nuclear Information System (INIS)

Chen Xiulan; He Zhentian; Han Yuepeng; Liu Xueyu; Yang Hefeng; Xu Chenwu; Gu Shiliang

1998-01-01

The correlation and genetic parameters of eleven agronomic characters of 50 early mature lines induced from late mature cultivar, IR 1529-68-3-2 were studied by morphological classification and correlation and regression analysis. The results showed that: 1. The early mutants could be divided into two ecotype: early mature type and medium mature type of mid-maturity rice. 2. The 1000-grain weight of early mutants negatively correlated with the length of growing period. 3. According to direct path coefficients, the relation with heading period of early mutants was in order of 1000-grain-weight>plant height>seed sterility. 4.The higher heritability in broad sense were found in plant height, 1000 grain weight and heading period of the early mutants

Mutant heterosis in rice

International Nuclear Information System (INIS)

1987-01-01

In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent

Evaluation of Brown Midrib Sorghum Mutants as a Potential Biomass Feedstock for 2,3-Butanediol Biosynthesis.

Science.gov (United States)

Guragain, Yadhu N; Srinivasa Rao, P; Vara Prasad, P V; Vadlani, Praveen V

2017-11-01

Three sorghum backgrounds [Atlas, Early Hegari (EH), and Kansas Collier (KC)] and two bmr mutants (bmr6 and bmr12) of each line were evaluated and compared for grain and biomass yield, biomass composition, and 2,3-butanediol production from biomass. The data showed that the bmr6 mutation in EH background led to a significant decrease in stover yield and increase in grain yield, whereas the stover yield was increased by 64% without affecting grain yield in KC background. The bmr mutants had 10 to 25% and 2 to 9% less lignin and structural carbohydrate contents, respectively, and 24 to 93% more non-structural sugars than their parents in all sorghum lines, except EH bmr12. The total fermentable sugars released were 22 to 36% more in bmr mutants than in parents for Atlas and KC, but not for EH. The bmr6 mutation in KC background produced the most promising feedstock, among the evaluated bmr mutants, for 2,3-butanediol production without affecting grain yield, followed by KC bmr12 and Atlas bmr6, but the bmr mutation had an adverse effect in EH background. This indicated that the genetic background of the parent line and type of bmr mutation significantly affect the biomass quality as a feedstock for biochemical production.

Defining the requirements for the pathogenic interaction between mutant calreticulin and MPL in MPN.

Science.gov (United States)

Elf, Shannon; Abdelfattah, Nouran S; Baral, April J; Beeson, Danielle; Rivera, Jeanne F; Ko, Amy; Florescu, Natalie; Birrane, Gabriel; Chen, Edwin; Mullally, Ann

2018-02-15

Mutations in calreticulin ( CALR ) are phenotypic drivers in the pathogenesis of myeloproliferative neoplasms. Mechanistic studies have demonstrated that mutant CALR binds to the thrombopoietin receptor MPL, and that the positive electrostatic charge of the mutant CALR C terminus is required for mutant CALR-mediated activation of JAK-STAT signaling. Here we demonstrate that although binding between mutant CALR and MPL is required for mutant CALR to transform hematopoietic cells; binding alone is insufficient for cytokine independent growth. We further show that the threshold of positive charge in the mutant CALR C terminus influences both binding of mutant CALR to MPL and activation of MPL signaling. We find that mutant CALR binds to the extracellular domain of MPL and that 3 tyrosine residues within the intracellular domain of MPL are required to activate signaling. With respect to mutant CALR function, we show that its lectin-dependent function is required for binding to MPL and for cytokine independent growth, whereas its chaperone and polypeptide-binding functionalities are dispensable. Together, our findings provide additional insights into the mechanism of the pathogenic mutant CALR-MPL interaction in myeloproliferative neoplasms. © 2018 by The American Society of Hematology.

Photosynthetic and nitrogen fixation capability in several soybean mutant lines

International Nuclear Information System (INIS)

Gandanegara, S.; Hendratno, K.

1987-01-01

Photosynthetic and nitrogen fixation capability in several soybean mutant lines. A greenhouse experiment has been carried out to study photosynthetic and nitrogen fixation capability of five mutant lines and two soybean varieties. An amount of 330 uCi of 14 CO 2 was fed to the plants including of the non-fixing reference crop (Chippewa non-nodulating isoline). Nitrogen fixation measurements was carried out using 15 N isotope dilution technique according to A-value concept. Results showed that beside variety/mutant lines, plant growth also has important role in photosynthetic and N fixing capability. Better growth and a higher photosynthetic capability in Orba, mutant lines nos. 63 and 65 resulted in a greater amount of N 2 fixed (mg N/plant) than other mutant lines. (author). 12 refs.; 5 figs

Mutants of Venturia ineaqualis (Cook) Wint. apple scar resistant to fungicides

International Nuclear Information System (INIS)

Bedianashvili, Ts.V.; D'yakov, Yu.T.

1987-01-01

Mutants of apple scab resistant to zineb and bayleton fungicides have been obtained upon action of UV irradiation and nitrosome-thylurea. Using tetrade analysis, two zineb resistence genes have been found. The mutations are pleiotropic and lead to increase in resistance to other fungicides, decrease in growth rate on artificial media, increase in spore size, sporulation, and aggressiveness, decrease in competitiveness at in vitro growth. The resistance is supposed to be determined by decrease in membrane permeability for fungicides

Transcriptional and proteomic analysis of the Aspergillus fumigatus ΔprtT protease-deficient mutant.

Science.gov (United States)

Hagag, Shelly; Kubitschek-Barreira, Paula; Neves, Gabriela W P; Amar, David; Nierman, William; Shalit, Itamar; Shamir, Ron; Lopes-Bezerra, Leila; Osherov, Nir

2012-01-01

Aspergillus fumigatus is the most common opportunistic mold pathogen of humans, infecting immunocompromised patients. The fungus invades the lungs and other organs, causing severe damage. Penetration of the pulmonary epithelium is a key step in the infectious process. A. fumigatus produces extracellular proteases to degrade the host structural barriers. The A. fumigatus transcription factor PrtT controls the expression of multiple secreted proteases. PrtT shows similarity to the fungal Gal4-type Zn(2)-Cys(6) DNA-binding domain of several transcription factors. In this work, we further investigate the function of this transcription factor by performing a transcriptional and a proteomic analysis of the ΔprtT mutant. Unexpectedly, microarray analysis revealed that in addition to the expected decrease in protease expression, expression of genes involved in iron uptake and ergosterol synthesis was dramatically decreased in the ΔprtT mutant. A second finding of interest is that deletion of prtT resulted in the upregulation of four secondary metabolite clusters, including genes for the biosynthesis of toxic pseurotin A. Proteomic analysis identified reduced levels of three secreted proteases (ALP1 protease, TppA, AFUA_2G01250) and increased levels of three secreted polysaccharide-degrading enzymes in the ΔprtT mutant possibly in response to its inability to derive sufficient nourishment from protein breakdown. This report highlights the complexity of gene regulation by PrtT, and suggests a potential novel link between the regulation of protease secretion and the control of iron uptake, ergosterol biosynthesis and secondary metabolite production in A. fumigatus.

Circulation of Pneumocystis dihydropteroate synthase mutants in France.

Science.gov (United States)

Le Gal, Solène; Damiani, Céline; Perrot, Maëla; Rouillé, Amélie; Virmaux, Michèle; Quinio, Dorothée; Moalic, Elodie; Saliou, Philippe; Berthou, Christian; Le Meur, Yann; Totet, Anne; Nevez, Gilles

2012-10-01

Data on the prevalence of Pneumocystis jirovecii (P. jirovecii) dihydropteroate synthase (DHPS) mutants in France are still limited. In this study, mutant prevalence in the Brest region (western France) was determined. Archival pulmonary specimens from 85 patients infected with P. jirovecii and admitted to our institution (University Hospital, Brest) from October 2007 to February 2010 were retrospectively typed at the DHPS locus using a polymerase chain reaction-restriction fragment length polymorphism assay. Type identification was successful in 66 of 85 patients. Sixty-four patients were infected with a wild type, whereas mutants were found in 2 patients (2/66, 3%). Medical chart analysis revealed that these 2 patients usually lived in Paris. Another patient usually lived on the French Riviera, whereas 63 patients were from the city of Brest. Thus, the corrected prevalence of mutants in patients who effectively lived in our geographic area was 0% (0/63). Taking into account that i) Paris is characterized by a high prevalence of mutants from 18.5% to 40%, ii) infection diagnoses were performed in the 2 Parisians during their vacation Paris to Brest through infected vacationers. The study shows that the usual city of patient residence, rather than the city of infection diagnosis, is a predictor of mutants and that P. jirovecii infections involving mutants do not represent a public health issue in western France. Copyright © 2012 Elsevier Inc. All rights reserved.

Biochemical Analysis of Two Single Mutants that Give Rise to a Polymorphic G6PD A-Double Mutant

Directory of Open Access Journals (Sweden)

Edson Jiovany Ramírez-Nava

2017-10-01

Full Text Available Glucose-6-phosphate dehydrogenase (G6PD is a key regulatory enzyme that plays a crucial role in the regulation of cellular energy and redox balance. Mutations in the gene encoding G6PD cause the most common enzymopathy that drives hereditary nonspherocytic hemolytic anemia. To gain insights into the effects of mutations in G6PD enzyme efficiency, we have investigated the biochemical, kinetic, and structural changes of three clinical G6PD variants, the single mutations G6PD A+ (Asn126AspD and G6PD Nefza (Leu323Pro, and the double mutant G6PD A− (Asn126Asp + Leu323Pro. The mutants showed lower residual activity (≤50% of WT G6PD and displayed important kinetic changes. Although all Class III mutants were located in different regions of the three-dimensional structure of the enzyme and were not close to the active site, these mutants had a deleterious effect over catalytic activity and structural stability. The results indicated that the G6PD Nefza mutation was mainly responsible for the functional and structural alterations observed in the double mutant G6PD A−. Moreover, our study suggests that the G6PD Nefza and G6PD A− mutations affect enzyme functions in a similar fashion to those reported for Class I mutations.

Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

International Nuclear Information System (INIS)

Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E.

1991-01-01

The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus

Heterozygosity for an in-frame deletion causes glutaryl-CoA dehydrogenase deficiency in a patient detected by newborn screening: investigation of the effect of the mutant allele

DEFF Research Database (Denmark)

Bross, Peter; Frederiksen, Jane B; Bie, Anne S

2012-01-01

the proband were consistent with a mild biochemical GA-1 phenotype. Recombinant expression of the mutant variant in E. coli showed that the GCDH-(p.Gly185_Ser190del) protein displayed severely decreased assembly into tetramers and enzyme activity. To discover a potential dominant negative effect of the mutant...... with the hypothesis that heterozygosity for this mutation confers a dominant negative effect resulting in a GCDH enzyme activity that is significantly lower than the expected 50%....

Preliminary Study of the Characteristics of Several Glossy Cabbage (Brassica oleracea var. capitata L. Mutants

Directory of Open Access Journals (Sweden)

Tang Jun

2015-09-01

Full Text Available To determine the characteristics and potential practical applications of glossy cabbage (Brassica oleracea var. capitata L. mutants, five different glossy mutants were studied. The amount of epicuticular wax covering the mutant leaves was only approximately 30% that of the wild-type (WT leaves. The wax crystals of WT plants were columnar and linear, while they were granular and rod-shaped in the mutants. Additionally, in WT cabbage, the primary wax components were alkanes, alcohols, fatty acids, ketones, and aldehydes. There was a significant decrease in the abundance of alkanes and ketones in the wax of the mutants. The glossy-green trait of the mutants may be the result of an inhibited alkane-forming pathway. Higher rates of chlorophyll leaching and water loss demonstrate that the mutant leaves were more permeable and sensitive to drought stress than the WT leaves. Growth curve results indicated that the growth rate of mutant-1 and mutant-3 was slower than that of the corresponding WT cabbage, resulting in shorter plants. However, the growth rate of mutant-2 was not influenced by the lack of coating wax. An investigation of the agronomic traits and heterosis of the glossy cabbage mutants indicated that all five mutants had glossy-green leaves, which was a favorable characteristic. The F1 plants derived from crosses involving mutant-2 exhibited obvious heterosis, suggesting the observed glossy-green trait is controlled by a dominant gene. Therefore, mutant-2 may be useful as a source of genetic material for future cabbage breeding experiments.

Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

International Nuclear Information System (INIS)

Kumar, V.; Bhagwat, S.G.

2011-01-01

Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

Stress Marker Signatures in Lesion Mimic Single and Double Mutants Identify a Crucial Leaf Age-Dependent Salicylic Acid Related Defense Signal.

Science.gov (United States)

Kaurilind, Eve; Brosché, Mikael

2017-01-01

Plants are exposed to abiotic and biotic stress conditions throughout their lifespans that activates various defense programs. Programmed cell death (PCD) is an extreme defense strategy the plant uses to manage unfavorable environments as well as during developmentally induced senescence. Here we investigated the role of leaf age on the regulation of defense gene expression in Arabidopsis thaliana. Two lesion mimic mutants with misregulated cell death, catalase2 (cat2) and defense no death1 (dnd1) were used together with several double mutants to dissect signaling pathways regulating defense gene expression associated with cell death and leaf age. PCD marker genes showed leaf age dependent expression, with the highest expression in old leaves. The salicylic acid (SA) biosynthesis mutant salicylic acid induction deficient2 (sid2) had reduced expression of PCD marker genes in the cat2 sid2 double mutant demonstrating the importance of SA biosynthesis in regulation of defense gene expression. While the auxin- and jasmonic acid (JA)- insensitive auxin resistant1 (axr1) double mutant cat2 axr1 also led to decreased expression of PCD markers; the expression of several marker genes for SA signaling (ISOCHORISMATE SYNTHASE 1, PR1 and PR2) were additionally decreased in cat2 axr1 compared to cat2. The reduced expression of these SA markers genes in cat2 axr1 implicates AXR1 as a regulator of SA signaling in addition to its known role in auxin and JA signaling. Overall, the current study reinforces the important role of SA signaling in regulation of leaf age-related transcript signatures.

Evaluation on selected dwarf and semidwarf mutants of upland rice

International Nuclear Information System (INIS)

Riyanti Sumanggono, A.M.

1984-01-01

Seratus malam local upland rice variety was irradiated with gamma-rays at doses of O.1, 0.2, 0.3, 0.4 and 0.5 kGy. Observation of radiation effect was carried out on root and shoot length of M 1 seedlings; plant height, panicle length and number of tiller and seed sterility in M 1 plants. Selection for dwarf and semi-dwarf characteristics were done in M 2 plants, and selected again in M 3 . Observation on radiation effect indicated that 'Seratus Malam' seems to be more resistant than the lowland rice varieties. Increasing doses of radiation caused increasing frequency of chlorophyll mutations as well as chlorophyll mutants. Whereas, selection of dwarf or semi-dwarf in M 2 plants seems that mutant and mutation frequencies decreased as the dose increased. Dose of 0.2 kGy was suitable for selection of dwarf or semi-dwarf plants. Plant height could be influenced by environmental condition. Many of the selected M 2 plants were not really dwarf or semi-dwarf mutants. M 3 evaluation of the selected M 2 plants was really beneficial in the mutant selection. (author)

Early transcriptional responses of internalization defective Brucella abortus mutants in professional phagocytes, RAW 264.7.

Science.gov (United States)

Cha, Seung Bin; Lee, Won Jung; Shin, Min Kyoung; Jung, Myung Hwan; Shin, Seung Won; Yoo, An Na; Kim, Jong Wan; Yoo, Han Sang

2013-06-27

Brucella abortus is an intracellular zoonotic pathogen which causes undulant fever, endocarditis, arthritis and osteomyelitis in human and abortion and infertility in cattle. This bacterium is able to invade and replicate in host macrophage instead of getting removed by this defense mechanism. Therefore, understanding the interaction between virulence of the bacteria and the host cell is important to control brucellosis. Previously, we generated internalization defective mutants and analyzed the envelope proteins. The present study was undertaken to evaluate the changes in early transcriptional responses between wild type and internalization defective mutants infected mouse macrophage, RAW 264.7. Both of the wild type and mutant infected macrophages showed increased expression levels in proinflammatory cytokines, chemokines, apoptosis and G-protein coupled receptors (Gpr84, Gpr109a and Adora2b) while the genes related with small GTPase which mediate intracellular trafficking was decreased. Moreover, cytohesin 1 interacting protein (Cytip) and genes related to ubiquitination (Arrdc3 and Fbxo21) were down-regulated, suggesting the survival strategy of this bacterium. However, we could not detect any significant changes in the mutant infected groups compared to the wild type infected group. In summary, it was very difficult to clarify the alterations in host cellular transcription in response to infection with internalization defective mutants. However, we found several novel gene changes related to the GPCR system, ubiquitin-proteosome system, and growth arrest and DNA damages in response to B. abortus infection. These findings may contribute to a better understanding of the molecular mechanisms underlying host-pathogen interactions and need to be studied further.

Structural features and activity of Brazzein and its mutants upon substitution of a surfaced exposed alanine.

Science.gov (United States)

Ghanavatian, Parisa; Khalifeh, Khosrow; Jafarian, Vahab

2016-12-01

Brazzein (Brz) is a member of sweet-tasting protein containing four disulfide bonds. It was reported as a compact and heat-resistant protein. Here, we have used site-directed mutagenesis and replaced a surface-exposed alanine with aspartic acid (A19D mutant), lysine (A19K mutant) and glycine (A19G mutant). Activity comparisons of wild-type (WT) and mutants using taste panel test procedure showed that A19G variant has the same activity as WT protein. However, introduction of a positive charge in A19K mutant led to significant increase in Brz's sweetness, while A19D has reduced sweetness compared to WT protein. Docking studies showed that mutation at position 19 results in slight chain mobility of protein at the binding surface and changing the patterns of interactions toward more effective binding of E9K variant in the concave surface of sweet taste receptor. Far-UV CD data spectra have a characteristic shape of beta structure for all variants, however different magnitudes of spectra suggest that beta-sheet structure in WT and A19G is more stable than that of A19D and A19K. Equilibrium unfolding studies with fluorescence spectroscopy and using urea and dithiothritol (DTT) as chemical denaturants indicates that A19G mutant gains more stability against urea denaturation; while conformational stability of A19D and A19K decreases when compared with WT and A19G variants. We concluded that the positive charge at the surface of protein is important factor responsible for the interaction of protein with the human sweet receptor and Ala 19 can be considered as a key region for investigating the mechanism of the interaction of Brz with corresponding receptor. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Photosynthetic characterization of a rolled leaf mutant of rice ( Oryza ...

African Journals Online (AJOL)

A new rolling leaf rice mutant was identified which showed an apparently straighter longitudinal shape normal transverse rolling characters at all developing stages. The chlorophyll contents per fresh weight of this mutant leaves were lower than those of wild-type. The electron transfer rate (ETR) and photochemical ...

Histological and Molecular Characterization of Grape Early Ripening Bud Mutant

Directory of Open Access Journals (Sweden)

Da-Long Guo

2016-01-01

Full Text Available An early ripening bud mutant was analyzed based on the histological, SSR, and methylation-sensitive amplified polymorphism (MSAP analysis and a layer-specific approach was used to investigate the differentiation between the bud mutant and its parent. The results showed that the thickness of leaf spongy tissue of mutant (MT is larger than that of wild type (WT and the differences are significant. The mean size of cell layer L2 was increased in the mutant and the difference is significant. The genetic background of bud mutant revealed by SSR analysis is highly uniform to its parent; just the variations from VVS2 SSR marker were detected in MT. The total methylation ratio of MT is lower than that of the corresponding WT. The outside methylation ratio in MT is much less than that in WT; the average inner methylation ratio in MT is larger than that in WT. The early ripening bud mutant has certain proportion demethylation in cell layer L2. All the results suggested that cell layer L2 of the early ripening bud mutant has changed from the WT. This study provided the basis for a better understanding of the characteristic features of the early ripening bud mutant in grape.

Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish.

Science.gov (United States)

Lim, K-H; Chang, Y-C; Chiang, Y-H; Lin, H-C; Chang, C-Y; Lin, C-S; Huang, L; Wang, W-T; Gon-Shen Chen, C; Chou, W-C; Kuo, Y-Y

2016-10-07

CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.

Mutation Induction In White Oyster Mushroom (Pleurotus Ostreatus) Using GAMMA Irradiation And Analyzing Genetic Diversity Of Induced Mutants By RAPD.PCR

International Nuclear Information System (INIS)

Mohammed, H.M; Soliman, S.S.A; Shawky, A.S.H; Mahgoub, E.M.I

2013-01-01

The present study aimed to understand the effect of gamma rays on three strains of white oyster mushroom Pleurotus ostreatus and induction of new benefit mutants. Five different doses, i.e., 0.25,0.5,0.75, and 1.00 KGy of gamma rays were used. Twelve morphological criteria were measured. The result confirmed the existence of different response of three strains to different doses of radiation. The 21 strain as a control, the first flush was misshapen, but the second flush gave normal fruit, while mutant Po 21-3 gave excellent growth performance for the shape, colour, fruit diameter and stem length, while slightly decrease in wet and dry total matter per bag and flushes numbers were found.The po 21-2 mutant considered as important mutant because slightly increased in wet and dry total matter than the control, and had short stem length. This mutant Po 21 -2 gave spores, while the control was sporeless. Control of strain 22 possessed good performance for fruit characterization but it forms fruits less than its primordial it formed (semi maturation less strain) per bag, While po 22-l and Po 22-2 appeared good performance, in addition high yielding as wet and dry total matter and faster flushing. The control of strain 66 had a good growth performance, and the four mutants for this strain is very good too they had excellent growth performance; Po 66-1 and Po 66-3 mutants had significant and highly significant values for wet matter than the control (21.04, 21.64 and 12.27) for (Po 66-1, Po 66-4, control). As well as more important criteria there were taken as short fruit stem length and fruit number/bag. These results confirmed the important of Po 66-4 followed by po 66-1 in next breeding and production programs for white oyster mushroom (Pleurotus ostreatus).the RAPD PCR results showed the oligonucleotide OPB-10, OPA-05 and OPC-02 presented the highest percentage of RAPD polymorphism (80⁒, 80⁒, 66.6⁒). The pattern obtained with OPB-10 oligonucleotide for strains

The first mouse mutants of D14Abb1e (Fam208a) show that it is critical for early development

Czech Academy of Sciences Publication Activity Database

Harten, S.K.; Bruxner, T.J.; Bharti, V.; Blewitt, M.; Nguyen, T.M.T.; Whitelaw, E.; Epp, Trevor

2014-01-01

Roč. 25, 7-8 (2014), s. 293-303 ISSN 0938-8990 Institutional support: RVO:68378050 Keywords : embryogenesis * forward genetics * mouse mutant Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.068, year: 2014

Methylammonium-resistant mutants of Nicotiana plumbaginifolia are affected in nitrate transport.

Science.gov (United States)

Godon, C; Krapp, A; Leydecker, M T; Daniel-Vedele, F; Caboche, M

1996-02-25

This work reports the isolation and preliminary characterization of Nicotiana plumbaginifolia mutants resistant to methylammonium. Nicotiana plumbaginifolia plants cannot grow on low levels of nitrate in the presence of methylammonium. Methylammonium is not used as a nitrogen source, although it can be efficiently taken up by Nicotiana plumbaginifolia cells and converted into methylglutamine, an analog of glutamine. Glutamine is known to repress the expression of the enzymes that mediate the first two steps in the nitrate assimilatory pathway, nitrate reductase (NR) and nitrite reductase (NiR). Methylammonium has therefore been used, in combination with low concentrations of nitrate, as a selective agent in order to screen for mutants in which the nitrate pathway is de-repressed. Eleven semi-dominant mutants, all belonging to the same complementation group, were identified. The mutant showing the highest resistance to methylammonium was not affected either in the utilization of ammonium, accumulation of methylammonium or in glutamine synthase activity. A series of experiments showed that utilization of nitrite by the wild-type and the mutant was comparable, in the presence or the absence of methylammonium, thus suggesting that the mutation specifically affected nitrate transport or reduction. Although NR mRNA levels were less repressed by methylammonium treatment of the wild-type than the mutant, NR activities of the mutant remained comparable with or without methylammonium, leading to the hypothesis that modified expression of NR is probably not responsible for resistance to methylammonium. Methylammonium inhibited nitrate uptake in the wild-type but had only a limited effect in the mutant. The implications of these results are discussed.

X-ray sensitive strains of CHO cells show decreased frequency of stable transfection

International Nuclear Information System (INIS)

Jeggo, P.; Smith, J.

1987-01-01

Six X-ray sensitive (xrs) strains of the Chinese hamster ovary cell line have previously been isolated and shown to have a defect in double strand break rejoining. In this study, these strains have been investigated for their ability to take up and integrate foreign DNA. All the xrs strains investigated so far have shown a decreased frequency of stable transfectants compared to their parent line, in experiments using the plasmid pSV2gpt, which contains the selectable bacterial gene, guanine phosphoribosyl transferase. This decreased frequency is observed over a wide range of DNA concentrations (0.1 to 20 μg DNA) but is more pronounced at higher DNA concentrations. In contrast, these xrs strains show the same level of transfection proficiency as the wild type parent using a transient transfection system with a plasmid containing the bacterial CAT (chloramphenicol acetyl transferase) gene. Since the level of CAT activity does not depend on integration of foreign DNA, this suggests that the xrs strains are able to take up the same amount of DNA as the parent strains, but have a defect in the integration of foreign DNA. Since this integration of foreign DNA probably occurs by non-homologous recombination, this may indicate a role of the xrs gene product in this process

Phanerochaete mutants with enhanced ligninolytic activity

International Nuclear Information System (INIS)

Kakar, S.N.; Perez, A.; Gonzales, J.

1994-01-01

In addition to lignin, the white rot fungus Phanerochaete chrysosporium has the ability to degrade a wide spectrum of recalcitrant organo pollutants in soils and aqueous media. Most of the organic compounds are degraded under ligninolytic conditions with the involvement of the extracellular enzymes, lignin peroxidases, and manganese-dependent peroxidases, which are produced as secondary metabolites triggered by conditions of nutrient starvation (e.g., nitrogen limitation). The fungus and its enzymes can thus provide alternative technologies for bioremediation, bio pulping, bio bleaching, and other industrial applications. The efficiency and effectiveness of the fungus can be enhanced by increasing production and secretion of the important enzymes in large quantities and as primary metabolites under enriched conditions. One way this can be achieved is through isolation of mutants that are deregulated, or are hyper producers or super secretors of key enzymes under enriched conditions. Through UV-light and γ-ray mutagenesis, we have isolated a variety of mutants, some of which produce key enzymes of the ligninolytic system under high-nitrogen growth conditions. One of the mutants, 76UV, produced 272 U of lignin peroxidases enzyme activity/L after 9 d under high nitrogen (although the parent strain does not produce this enzyme under these conditions). The mutant and the parent strains produced up to 54 and 62 U/L, respectively, of the enzyme activity under low nitrogen growth conditions during this period. In some experiments, the mutant showed 281 U/L of enzyme activity under high nitrogen after 17 d

Symbiotic N fixation of several soybean varieties and mutants

International Nuclear Information System (INIS)

Soertini, G.; Hendratno

1988-01-01

Symbiotic N fixation of several soybean varieties and mutants. Research activities comprising of three experiments were carried out to screen several soybean varieties and mutants for symbiotic N fixation potential. The first two experiments involved screening of seven rhizobium strains/isolate for effective N fixation. Depending on the medium used, plant response to strains was different. In sterile medium, rhizobium strain USDA 136, 142 and TAL 102 showed a high nitrogen fixation potential. In soil only rhizobium strain USDA 110 had better performance and proved to be competitive to the native strains. Nitrogen-15 dilution method was used to screen nitrogen fixing ability of several soybean varieties and mutants. Guntur variety showed a better response to high dose of N fertilizer without disturbance in its fixing ability. This variety then was considered good to be introduced in the cropping system. (author). 8 refs

Transgenic mice display hair loss and regrowth overexpressing mutant Hr gene.

Science.gov (United States)

Zhu, Kuicheng; Xu, Cunshuan; Zhang, Jintao; Chen, Yingying; Liu, Mengduan

2017-10-30

Mutations in the hairless (Hr) gene in both mice and humans have been implicated in the development of congenital atrichia, but the role of Hr in skin and hair follicle (HF) biology remains unknown. Here, we established transgenic mice (TG) overexpressing mutant Hr to investigate its specific role in the development of HF. Three transgenic lines were successfully constructed, and two of them (TG3 and TG8) displayed a pattern of hair loss and regrowth with alternation in the expression of HR protein. The mutant Hr gene inhibited the expression of the endogenous gene in transgenic individuals, which led to the development of alopecia. Interestingly, the hair regrew with the increase in the endogenous expression levels resulting from decreased mutant Hr expression. The findings of our study indicate that the changes in the expression of Hr result in hair loss or regrowth.

Deletion of Type 2 Metabotropic Glutamate Receptor Decreases Sensitivity to Cocaine Reward in Rats.

Science.gov (United States)

Yang, Hong-Ju; Zhang, Hai-Ying; Bi, Guo-Hua; He, Yi; Gao, Jun-Tao; Xi, Zheng-Xiong

2017-07-11

Cocaine users show reduced expression of the metabotropic glutamate receptor (mGluR2), but it is not clear whether this is a predisposing trait for addiction or a consequence of drug exposure. In this study, we found that a nonsense mutation at the mGluR2 gene decreased mGluR2 expression and altered the seeking and taking of cocaine. mGluR2 mutant rats show reduced sensitivity to cocaine reward, requiring more cocaine to reach satiation when it was freely available and ceasing their drug-seeking behavior sooner than controls when the response requirement was increased. mGluR2 mutant rats also show a lower propensity to relapse after a period of cocaine abstinence, an effect associated with reduced cocaine-induced dopamine and glutamate overflow in the nucleus accumbens. These findings suggest that mGluR2 polymorphisms or reduced availability of mGluR2 might be risk factors for the initial development of cocaine use but could actually protect against addiction by reducing sensitivity to cocaine reward. Published by Elsevier Inc.

Purkinje Cell Compartmentation in the Cerebellum of the Lysosomal Acid Phosphatase 2 Mutant Mouse (Nax - Naked-Ataxia Mutant Mouse)

Science.gov (United States)

Bailey, Karen; Rahimi Balaei, Maryam; Mannan, Ashraf; Del Bigio, Marc R.; Marzban, Hassan

2014-01-01

The Acp2 gene encodes the beta subunit of lysosomal acid phosphatase, which is an isoenzyme that hydrolyzes orthophosphoric monoesters. In mice, a spontaneous mutation in Acp2 results in severe cerebellar defects. These include a reduced size, abnormal lobulation, and an apparent anterior cerebellar disorder with an absent or hypoplastic vermis. Based on differential gene expression in the cerebellum, the mouse cerebellar cortex can normally be compartmentalized anteroposteriorly into four transverse zones and mediolaterally into parasagittal stripes. In this study, immunohistochemistry was performed using various Purkinje cell compartmentation markers to examine their expression patterns in the Acp2 mutant. Despite the abnormal lobulation and anterior cerebellar defects, zebrin II and PLCβ4 showed similar expression patterns in the nax mutant and wild type cerebellum. However, fewer stripes were found in the anterior zone of the nax mutant, which could be due to a lack of Purkinje cells or altered expression of the stripe markers. HSP25 expression was uniform in the central zone of the nax mutant cerebellum at around postnatal day (P) 18–19, suggesting that HSP25 immunonegative Purkinje cells are absent or delayed in stripe pattern expression compared to the wild type. HSP25 expression became heterogeneous around P22–23, with twice the number of parasagittal stripes in the nax mutant compared to the wild type. Aside from reduced size and cortical disorganization, both the posterior zone and nodular zone in the nax mutant appeared less abnormal than the rest of the cerebellum. From these results, it is evident that the anterior zone of the nax mutant cerebellum is the most severely affected, and this extends beyond the primary fissure into the rostral central zone/vermis. This suggests that ACP2 has critical roles in the development of the anterior cerebellum and it may regulate anterior and central zone compartmentation. PMID:24722417

Repair of gamma radiation damage in wild type and a radiation sensitive mutant of Deinococcus radiodurans

International Nuclear Information System (INIS)

Mizuma, Nagayo

1989-01-01

In an effort to examine production and repair of radiation-induced single and double strand breaks in the DNA, a repair-deficient wild type and a repair-deficient mutant, UV17, of Deinococcus radiodurans were subjected to Co-60 gamma irradiation at a dose rate of 6.3 kGy/hr for wild type and 3.9 kGy/hr for UV17 mutant. The shoulder of the curve of UV17 mutant was narrow but existed with the intercept of 0.7 kGy and the corresponding value of the wild type was 4.2 kGy. Mutant cells exhibited about 6 fold increases in sensitivity for the shoulder relative to the wild type. The D 37 doses in the wild type and the mutant were 0.57 kGy and 0.25 kGy, respectively. From the survival curves, difference in the sensitivity between two strains was mainly due to difference of repair capacity than the number of radiation sensitive target. Sedimentation rate of the main component in the irradiated cells of UV17 mutant increased almost to the level of unirradiated control by the postincubation at 30deg C for 3 hrs. The results indicated that this sensitive mutant also exhibited an ability to restore single strand breaks after exposure to a sublethal dose of 0.6 kGy. When restitution of double strand breaks was analyzed by sedimentation in a neutral sucrose gradient, the wild type showed restitution to DNA-membrane complex from large part of the breaks. For UV17 mutant, the apparent increase in DNA-membrane complex formation was seen after 3 hours incubation. Large part of the decrease in the activities of peak 2 was recovered in the peak 1 for the wild type. For the mutant, there was little restitution to peak 1. Almost free DNA component in UV17 mutant, therefore, was merely degraded into shorter pieces. Restoration of DNA-membrane complex from free DNA derived from gamma-ray induced double strand scission involved closely in the repair of gamma-induced damage and survival. (N.K.)

Antiproliferative and Apoptotic Effect of Dendrosomal Curcumin Nanoformulation in P53 Mutant and Wide-Type Cancer Cell Lines.

Science.gov (United States)

Montazeri, Maryam; Pilehvar-Soltanahmadi, Younes; Mohaghegh, Mina; Panahi, Alireza; Khodi, Samaneh; Zarghami, Nosratollah; Sadeghizadeh, Majid

2017-01-01

The aim of this paper is to investigate the effect of dendrosomal curcumin (DNC) on the expression of p53 in both p53 mutant cell lines SKBR3/SW480 and p53 wild-type MCF7/HCT116 in both RNA and protein levels. Curcumin, derived from Curcumin longa, is recently considered in cancer related researches for its cell growth inhibition properties. p53 is a common tumor-suppressor gene involved in cancers and its mutation not only inhibits tumor suppressor activity but also promotes oncogenic activity. Here, p53 mutant/Wild-type cells were employed to study the toxicity of DNC using MTT assay, Flow cytometry and Annexin-V, Real-time PCR and Western blot were used to analyze p53, BAX, Bcl-2, p21 and Noxa changes after treatment. During the time, DNC increased the SubG1 cells and decreased G1, S and G2/M cells, early apoptosis also indicated the inhibition of cell growth in early phase. Real-Time PCR assay showed an increased mRNA of BAX, Noxa and p21 during the time with decreased Bcl-2. The expression of p53 mutant decreased in SKBR3/SW480, and the expression of p53 wild-type increased in MCF7/HCT116. Consequently, p53 plays an important role in mediating the survival by DNC, which can prevent tumor cell growth by modulating the expression of genes involved in apoptosis and proliferation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Trehalose, glycogen and ethanol metabolism in the gcr1 mutant of Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Seker, Tamay; Hamamci, H.

2003-01-01

Since Gcr1p is pivotal in controlling the transcription of glycolytic enzymes and trehalose metabolism seems to be one of the control points of glycolysis, we examined trehalose and glycogen synthesis in response to 2 % glucose pulse during batch growth in gcr1 (glucose regulation-1) mutant lacking...... fully functional glycolytic pathway and in the wild-type strain. An increase in both trehalose and glycogen stores was observed 1 and 2 h after the pulse followed by a steady decrease in both the wild-type and the gcr1 mutant. The accumulation was faster while the following degradation was slower in gcr......1 cells compared to wild-type ones. Although there was no distinct glucose consumption in the mutant cells it seemed that the glucose repression mechanism is similar in gcr1 mutant and in wild-type strain at least with respect to trehalose and glycogen metabolism....

Detailed conformation dynamics and activation process of wild type c-Abl and T315I mutant

Science.gov (United States)

Yang, Li-Jun; Zhao, Wen-Hua; Liu, Qian

2014-10-01

Bcr-Abl is an important target for therapy against chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL). The synergistic effect between myristyl pocket and the ATP pocket has been found. But its detailed information based on molecular level still has not been achieved. In this study, conventional molecular dynamics (CMD) and target molecular dynamics (TMD) simulations were performed to explore the effect of T315I mutation on dynamics and activation process of Abl containing the N-terminal cap (Ncap). The CMD simulation results reveal the increasing flexibility of ATP pocket in kinase domain (KD) after T315I mutation which confirms the disability of ATP-pocket inhibitors to the Abl-T315I mutant. On the contrary, the T315I mutation decreased the flexibility of remote helix αI which suggests the synergistic effect between them. The mobility of farther regions containing Ncap, SH3, SH2 and SH2-KD linker were not affected by T315I mutation. The TMD simulation results show that the activation process of wild type Abl and Abl-T315I mutant experienced global conformation change. Their differences were elucidated by the activation motion of subsegments including A-loop, P-loop and Ncap. Besides, the T315I mutation caused decreasing energy barrier and increasing intermediate number in activation process, which results easier activation process. The TMD and CMD results indicate that a drug targeting only the ATP pocket is not enough to inhibit the Abl-T315I mutant. An effective way to inhibit the abnormal activity of Abl-T315I mutant is to combine the ATP-pocket inhibitors with inhibitors binding at non-ATP pockets mainly related to Ncap, SH2-KD linker and myristyl pocket.

Tolerance of some Potato Mutants Induced with Gamma Irradiation to Drought in Vitro

International Nuclear Information System (INIS)

Al-Safadi, B.; Al-Ayyoubi, Z.

2007-01-01

An in vitro selection program was conducted in order to improve potato (Solanum tuberosum,L.) tolerance to drought. Potato mutant plants were obtained through a previously conducted mutation breeding program on three potato cultivars (Draga, Spunta, and Diamant) aimed to improve potato tolerance to salinity and resistance to late blight disease. In order to apply selection pressure, growth media (MS based) were prepared with the addition of 1%, 2%, 3% concentrations of Poly Ethylene Glycol (PEG). As a result, three mutants were selected that were tolerant to water stress (i.e. drought tolerant), two of them were derived from the cultivar Draga and one came from Spunta. Physiological growth parameters (plant length, leaf number, branch number, roots number, leaf area, stomata number, and chlorophyll concentration content) were determined on the growing plantlets. The selected mutants were distinguished based on some characteristics which being associated with in their tolerance to drought. Such as an increases in leaf number, root number, and a decrease in stomata number. However a reduction in chlorophyll content was observed as compared with the control. This is considered a negative parameter which may result in a decrease in number and size of tubers. Thus it is important to continue selection for higher chlorophyll content. Also, these mutant lines will need further selection in the field for plants with larger tubers before they can be considered as certified lines.

RAPD analysis on male sterility mutant of Lilium asiatic hybrids 'pollyanna' induced by irradiation

International Nuclear Information System (INIS)

Jia Yuehui; Zhao Xiangyun; Zhang Kezhong; Huang Shangwu; Lu Changxun

2005-01-01

RAPD analysis of 80 random 10-mer primers on Lilium Asiatic hybrids 'pollyanna' and its 20 phenotype male sterility mutants induced by irradiation was carried out. Of the tested primers, 31 primers could produced ideal amplification bands on all materials, 4 primers generated stable different polymorphic bands among 9 mutants and 'pollyanna'. Different polymorphic bands of 7-18 were found among 9 mutants and 'pollyanna'. It was showed that 9 mutants were phenotype male sterility mutant of 'pollyanna'. (authors)

Long-lived mitochondrial (Mit) mutants of Caenorhabditis elegans utilize a novel metabolism.

Science.gov (United States)

Butler, Jeffrey A; Ventura, Natascia; Johnson, Thomas E; Rea, Shane L

2010-12-01

The Caenorhabditis elegans mitochondrial (Mit) mutants have disrupted mitochondrial electron transport chain (ETC) functionality, yet, surprisingly, they are long lived. We have previously proposed that Mit mutants supplement their energy needs by exploiting alternate energy production pathways normally used by wild-type animals only when exposed to hypoxic conditions. We have also proposed that longevity in the Mit mutants arises as a property of their new metabolic state. If longevity does arise as a function of metabolic state, we would expect to find a common metabolic signature among these animals. To test these predictions, we established a novel approach monitoring the C. elegans exometabolism as a surrogate marker for internal metabolic events. Using HPLC-ultraviolet-based metabolomics and multivariate analyses, we show that long-lived clk-1(qm30) and isp-1(qm150) Mit mutants have a common metabolic profile that is distinct from that of aerobically cultured wild-type animals and, unexpectedly, wild-type animals cultured under severe oxygen deprivation. Moreover, we show that 2 short-lived mitochondrial ETC mutants, mev-1(kn1) and ucr-2.3(pk732), also share a common metabolic signature that is unique. We show that removal of soluble fumarate reductase unexpectedly increases health span in several genetically defined Mit mutants, identifying at least 1 alternate energy production pathway, malate dismutation, that is operative in these animals. Our study suggests long-lived, genetically specified Mit mutants employ a novel metabolism and that life span may well arise as a function of metabolic state.

Gamma ray induced mutants in Colocasia with improved storability

International Nuclear Information System (INIS)

Vasudevan, K.; Jos, J.S.; Padmaja, G.

1989-01-01

Our mutation induction experiments with Colocasia esculenta (taro) were described before. Poor storability of tubers and acridity of tuber flesh in tubers are problems in taro. While screening for induced mutants, variability in shelf-life of tubers was observed. Tubers of the mutant CM 17 did neither spoil nor lose their viability even after storing for 180 days. Yield and results of quality analyses are presented in the Table in comparison with the control variety C 9 (locally known as ''Thamarakkannan''), the check variety Rasmi (well accepted in Kerala) and another mutant CM 1. Besides high yield and long storability, the mutant CM 17 shows a reduction in phenol and sugar, but an increase in dry matter and starch content which were found to be excellent characteristics for making taro chips as the usual browning phenomenon did not occur

Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 2. Comparison of Various Mutants

International Nuclear Information System (INIS)

Balchiuniene, L.

1995-01-01

Spontaneous and gamma-induced mutability was compared in two groups of genetically unstable barley ear structure mutants - tweaky spike (tw) and branched ear (be). Instability in different loci causes different levels of spontaneous and gamma-induced mutability. A high spontaneous level of chlorophyll mutations is peculiar to be-ust mutants. It is suggested that the high level of induced chlorophyll mutations in allelic tw mutants is a result of better surviving of chlorophyll mutation carriers in the genotypical-physiological environment created by mutant tw alleles. (author). 6 refs., 2 tabs

Evaluation of rice mutant lines for resistance to brown planthopper, nilaparvata lugens stall

International Nuclear Information System (INIS)

Mugiono

1985-01-01

The most important and common insect in rice cultivation in South East Asia is brown planthopper, nilaparvata lugens stall. Seven rice mutant lines produced by the National Atomic Energy Agency, Indonesia, were tested at IRRI, the Philippines for resistance to brown planthopper. Those mutant lines were Atomita 1, 627/10-3/PsJ, Atomita 2 and 627/4-E/PsJ originated from Pelita 1/1 which was irradiated with 0.2 kGy of gamma rays and A227/2/PsJ, A227/3/PsJ and A227/5/PsJ, originated from early maturing mutant A23/PsJ/72K from irradiated Pelita 1/1 which was irradiated with 0.1 kGy of gamma rays. Evaluation of resistance was carried out by seedling bulk screening, honeydew excretion, survival and population build up tests by using brown planthopper biotype 1, 2 and 3. Results of these tests showed that the seven tested mutant lines were resistant to biotype 1 but susceptible to biotype 2. Reaction to biotype 3 showed that six mutant lines tested were moderately resistant and only one mutant of 627/4-E/PsJ was susceptible. Reactions of the mutant lines to biotype 1, 2 and 3 were different from the resistant varieties, Mudgo or ASD-7. This indicated that mutant lines might have gene(s) for resistance which differed from those of resistant varieties. The results showed that resistance to brown planthopper is possible to be introduced in Indonesian rice varieties by means of mutations. (author)

Is auxin involved in the induction of genetic instability in barley homeotic double mutants?

Science.gov (United States)

Šiukšta, Raimondas; Vaitkūnienė, Virginija; Rančelis, Vytautas

2018-02-01

The triggers of genetic instability in barley homeotic double mutants are tweaky spike -type mutations associated with an auxin imbalance in separate spike phytomeres. Barley homeotic tweaky spike;Hooded (tw;Hd) double mutants are characterized by an inherited instability of spike and flower development, which is absent in the single parental constituents. The aim of the present study was to show that the trigger of genetic instability in the double mutants is the tw mutations, which are associated with an auxin imbalance in the developing spikes. Their pleiotropic effects on genes related to spike/flower development may cause the genetic instability of double mutants. The study of four double-mutant groups composed of different mutant alleles showed that the instability arose only if the mutant allele tw was a constituent of the double mutants. Application of auxin inhibitors and 2,4-dichlorophenoxyacetic acid (2,4-D) demonstrated the relationship of the instability of the double mutants and the phenotype of the tw mutants to auxin imbalance. 2,4-D induced phenocopies of the tw mutation in wild-type plants and rescued the phenotypes of three allelic tw mutants. The differential display (dd-PCR) method allowed the identification of several putative candidate genes in tw that may be responsible for the initiation of instability in the double mutants by pleiotropic variations of their expression in the tw mutant associated with auxin imbalance in the developing spikes. The results of the present study linked the genetic instability of homeotic double mutants with an auxin imbalance caused by one of the constituents (tw). The genetic instability of the double mutants in relation to auxin imbalance was studied for the first time. A matrocliny on instability expression was also observed.

Genetical, cytological and physiological studies on the induced mutants with special regard to effective methods for obtaining useful mutants in perennial woody plant

International Nuclear Information System (INIS)

Kukimura, H.; Ikeda, F.; Fujita, H.; Maeta, T.; Nakajima, K.; Katagiri, K.; Nakahira, K.; Somegou, M.

1976-01-01

The plants studied included apple trees, cryptomeria (japanese cedar) and mulberry. In apple, dwarf and compact types of mutants from cv. Fuji were found to be graft incompatible on Maruba-kaido(Malus prunifolia) rootstock. In Sunki mandarin(Citrus sunki), the number of nucellar embryo per seed was affected by gamma-irradiation, and morphological mutants from nucellar seedlings were obtained at high rate by irradiation at floral bud stage with 2kR exposure. In Cryptomeria, re-irradiated waxless mutants by gamma-rays showed very high rate of somatic mutation when compared to other morphological mutants. Pollen sterility and pollen shaped PMC were found in the most of gamma-induced-mutants. Mutants forming pollen shaped PMC had a genetical tendency of continuous male flower bud formation for a longer term. With mulberry, time of sprouting of induced mutants differed from the originals. Ability of root initiation of semi-softwood cuttings in morphological mutants were tested. Cytochimera induction were found at considerably high rate when actively growing diploid plants were irradiated by gamma-rays. Eight kinds of cytochimeras were induced. Frequency of 2-4-4 was extremely high(approx. 50%), then 4-2-2 and 2-4-2 chimeras followed. Seven kinds were induced by semi-acute irradiation(200R/h), while 4 kinds by acute irradiation(5kR/h). By breeding test it was cleared that the elongate and entire leaf was sexually transmissible, whereas the 'dwarf' was not obvious and the 'marginally curledleaf' was not transmissible. Pyronin-methylgreen staining method proved to be useful in some morphological mutants to distinguish the histo-genetical differences which exist in the shoot apex.

Mutants with Enhanced Nitrogenase Activity in Hydroponic Azospirillum brasilense-Wheat Associations

Science.gov (United States)

Pereg Gerk, Lily; Gilchrist, Kate; Kennedy, Ivan R.

2000-01-01

The effect of a mutation affecting flocculation, differentiation into cyst-like forms, and root colonization on nitrogenase expression by Azospirillum brasilense is described. The gene flcA of strain Sp7 restored these phenotypes in spontaneous mutants of both strains Sp7 and Sp245. Employing both constitutive pLA-lacZ and nifH-lacZ reporter fusions expressed in situ, the colony morphology, colonization pattern, and potential for nitrogenase activity of spontaneous mutants and flcA Tn5-induced mutants were established. The results of this study show that the ability of Sp7 and Sp245 mutant strains to remain in a vegetative form improved their ability to express nitrogenase activity in association with wheat in a hydroponic system. Restoring the cyst formation and colonization pattern to the spontaneous mutant Sp7-S reduced nitrogenase activity rates in association with plants to that of the wild-type Sp7. Although Tn5-induced flcA mutants showed higher potentials for nitrogenase expression than Sp7, their potentials were lower than that of Sp7-S, indicating that other factors in this strain contribute to its exceptional nitrogenase activity rates on plants. The lack of lateral flagella is not one of these factors, as Sp7-PM23, a spontaneous mutant impaired in swarming and lateral-flagellum production but not in flocculation, showed wild-type nitrogenase activity and expression. The results also suggest factors of importance in evolving an effective symbiosis between Azospirillum and wheat, such as increasing the availability of microaerobic niches along the root, increased supply of carbon sources by the plant, and the retention of the bacterial cells in vegetative form for faster metabolism. PMID:10788397

Primary study on lesion mimic mutants of rice (oryza sativa L.)

International Nuclear Information System (INIS)

Hao Zhongna; Zhang Hongzhi; Tao Rongixang

2007-01-01

Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by γ-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of all mutants were 88.17-165.33, and those of xsl19 and CK were 49.50 and 76.17. The results showed all lesion mimic mutants except xsl19 had short spikes and total grain quantity per spike increasing. All lesion mimic mutants were susceptible to Magnaporthe grisea, and they had no relationship with resistance. (authors)

A preliminary yield trial of some soybean mutant lines

International Nuclear Information System (INIS)

Ratma, Rivaie

1985-01-01

A preliminary yield trial of some soybean mutant lines, derived from irradiated Orba variety with dose of 0.40 kGy, were carried out during the wet and dry season in 1979-1982 in Muara and Citayam, Bogor. The result obtained showed that yield potential of mutant lines no. M6/40/10 was higher than that of the control in dry season in 1979 as well as in the wet season of 1979/80 in Muara. Whereas, the yield potential of the mutant lines no. M6/40/8 and no. M6/40/14 were higher than that of the control only in the wet season. The yield potential of semi dwarf mutant lines no. M6/40/68 was highly significant compared to that of the control in dry season in Muara and the wet season in 1981/82 in Citayam. Whereas, the yield potential of the mutant lines no. M6/40/69 was higher yield compared to that of the control in dry season in 1981 in Muara. (author). 10 refs

Promising rice mutants

International Nuclear Information System (INIS)

Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

1988-01-01

Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

Evaluation Of Yield And Chemical Properties Of Some Faba Bean (Vicia FABA L.) Mutants Induced By GAMMA Radiation And Ethyl Methane Sulphonate

International Nuclear Information System (INIS)

Sallam, E.M.; Nasr, E.H.; Attia, Z.M.; Shawki, H.A.

2013-01-01

This investigation aims to study the effect of physical and chemical mutagens on the yield and chemical properties as well as amino acids composition of defatted faba bean (Vicia faba L.) seeds meal as a control (Giza 2) compared with mutants produced by gamma radiation and ethyl methane sulphonate (EMS). Also, the functional properties of these samples were determined. The results indicated high differences between mutation for seed yield and its components than the untreated samples. In addition, radiation mutation of faba bean seeds showed slight increase in protein content as the main constituent of faba bean seeds as well as total oil percentages in some mutant of these seeds in return of decreasing in total carbohydrate. Furthermore, radiation mutation had detectable effects on the total amino acids contents of faba bean seeds meal which had a higher percentages on essential amino acids (EAA) and non-essential amino acids (NEAA) and mutant 3 was the highest values of EAA and NEAA as compared to the control. On the other hand, radiation mutation improved the protein functional properties of some mutant of faba bean meal flour than the other mutant samples as compared to local commercial variety

Prevention of GABA reduction during dough fermentation using a baker's yeast dal81 mutant.

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Ando, Akira; Nakamura, Toshihide

2016-10-01

γ-Aminobutyric acid (GABA) is consumed by yeasts during fermentation. To prevent GABA reduction in bread dough, a baker's yeast mutant AY77 deficient in GABA assimilation was characterized and utilized for wheat dough fermentation. An amber mutation in the DAL81 gene, which codes for a positive regulator of multiple nitrogen degradation pathways, was found in the AY77 strain. The qPCR analyses of genes involved in nitrogen utilization showed that transcriptional levels of the UGA1 and DUR3 genes encoding GABA transaminase and urea transporter, respectively, are severely decreased in the AY77 cells. The AY77 strain cultivated by fed-batch culture using cane molasses exhibited inferior gas production during dough fermentation compared to that of wild-type strain AY13. However, when fed with molasses containing 0.5% ammonium sulfate, the mutant strain exhibited gas production comparable to that of the AY13 strain. In contrast to the AY13 strain, which completely consumed GABA in dough within 5 h, the AY77 strain consumed no GABA under either culture condition. Dough fermentation with the dal81 mutant strain should be useful for suppression of GABA reduction in breads. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Characterization of mutants of yeast sensitive to x rays

International Nuclear Information System (INIS)

Strike, T.L.

1978-01-01

This study deals with the characterization of mutants at the rad50 to rad57 loci selected on the basis of their sensitivity to x rays. They were also examined for sensitivity to uv and mms and for characteristics of mutation induction, heteroallelic reversion (gene conversion), liquid holding recovery from x rays, and sporulation. All the mutants were slightly to moderately sensitive to uv though they did not show the extreme sensitivity of the rad1 to rad22 mutations, and all demonstrated cross sensitivity to both x rays and MMS. If a mutant was very sensitive to x-rays, it was usually very sensitive to MMS also

Production and characterization of radiation-sensitive meiotic mutants of Coprinus cinereus

International Nuclear Information System (INIS)

Zolan, M.E.; Tremel, C.J.; Pukkila, P.J.

1988-01-01

We have isolated four gamma-sensitive mutants of the basidiomycete Coprinus cinereus. When homozygous, two of these (rad 3-1 and rad 9-1) produce fruiting bodies with very few viable basidiospores, the products of meiosis in this organism. A less radiation-sensitive allele of RAD 3, rad 3-2, causes no apparent meiotic defect in homozygous strains. Quantitative measurements of oidial survival of rad 3-1;rad 9-1 double mutants compared to the single mutants indicated that rad 3-1 and rad 9-1 mutants are defective in the same DNA repair pathway. In the pew viable basidiospores that are produced by these two strains, essentially normal levels of meiotic recombination can be detected. None of the mutants exhibits increased sensitivity to UV radiation. Cytological examination of meiotic chromosomes from mutant and wild-type fruiting bodies showed that rad 3-1 homozygous strains fail to condense and pair homologous chromosomes during prophase I. Although rad 9-1 strains are successful at chromosome pairing, meiosis is usually not completed in these mutants

Selection of mutants of capsicum annuum induced by gamma ray

Energy Technology Data Exchange (ETDEWEB)

Lee, Y. I.; Lee, Y. B. [Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of); Lee, E. K. [Chungnam National Univ., Taejeon (Korea, Republic of)

1998-06-01

For induction and selection of mutations of Capsicum annuum L., dry seeds of pure lines No.1 and No.2 were irradiated with gamma ray of 150Gy, 200Gy and 250Gy. Various mutants were selected such as showing early maturity, short plant height, long fruit and chlorophyll mutations. Mutation frequency of No.1 line was 3.4% in the dose of 150Gy, while the frequency of No.2 line was 2.7% in the dose of 250Gy. For selection of resistant mutant to amino acid analog, the optimum concentration of 5-methyltryptophan (5-MT) and S-(2-aminoethyl)-L-cysteine were 25 ppm and 30 ppm, respectively. Four resistant mutant lines to 5-MT were selected among 400 mutant lines.

UV and gamma-ray sensitivity of meiosis-deficient mutants in Podospora anserina

International Nuclear Information System (INIS)

Simonet, J.M.

1976-01-01

Two mutants, mei1 and mei2, were isolated by screening for deficiencies occurring in the meiotic process. The sensitivity of mei1 and mei2 mutant strains to UV irradiation showed a significant increase as compared with that of the wild-type stock, hwhereas the sensitivity to γ-rays remained unchanged. The double-mutant strains were no more sensitive than each single mutant. The data indicate that both mei1 and mei2 loci are probably involved in the same pathway of excision-repair of UV-induced lesions

Modeling the dual pacemaker system of the tau mutant hamster.

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Oda, G A; Menaker, M; Friesen, W O

2000-06-01

Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.

Role of active site rigidity in activity: MD simulation and fluorescence study on a lipase mutant.

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Md Zahid Kamal

Full Text Available Relationship between stability and activity of enzymes is maintained by underlying conformational flexibility. In thermophilic enzymes, a decrease in flexibility causes low enzyme activity while in less stable proteins such as mesophiles and psychrophiles, an increase in flexibility is associated with enhanced enzyme activity. Recently, we identified a mutant of a lipase whose stability and activity were enhanced simultaneously. In this work, we probed the conformational dynamics of the mutant and the wild type lipase, particularly flexibility of their active site using molecular dynamic simulations and time-resolved fluorescence techniques. In contrast to the earlier observations, our data show that active site of the mutant is more rigid than wild type enzyme. Further investigation suggests that this lipase needs minimal reorganization/flexibility of active site residues during its catalytic cycle. Molecular dynamic simulations suggest that catalytically competent active site geometry of the mutant is relatively more preserved than wild type lipase, which might have led to its higher enzyme activity. Our study implies that widely accepted positive correlation between conformation flexibility and enzyme activity need not be stringent and draws attention to the possibility that high enzyme activity can still be accomplished in a rigid active site and stable protein structures. This finding has a significant implication towards better understanding of involvement of dynamic motions in enzyme catalysis and enzyme engineering through mutations in active site.

Characterization of T-DNA insertion mutants with decreased virulence in the entomopathogenic fungus Beauveria bassiana JEF-007.

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Kim, Sihyeon; Lee, Se Jin; Nai, Yu-Shin; Yu, Jeong Seon; Lee, Mi Rong; Yang, Yi-Ting; Kim, Jae Su

2016-10-01

The bean bug, Riptortus pedestris, is a major agricultural pest that reduces crop quality and value. Chemical pesticides have contributed to pest management, but resistance to these chemicals has significantly limited their use. Alternative strategies with different modes of action, such as entomopathogenic fungi, are therefore of great interest. Herein, we explored how entomopathogenic fungi can potentially be used to control the bean bug and focused on identifying virulence-related genes. Beauveria bassiana (JEF isolates) were assayed against bean bugs under laboratory conditions. One isolate, JEF-007, showed >80 % virulence by both spray and contact exposure methods. Agrobacterium tumefaciens-mediated transformation (AtMT) of JEF-007 generated 249 random transformants, two of which (B1-06 and C1-49) showed significantly reduced virulence against Tenebrio molitor and R. pedestris immatures. Both species were used for rapid screening of virulence-reduced mutants. The two transformants had different morphologies, conidial production, and thermotolerance than the wild type. To determine the localization of the randomly inserted T-DNA, thermal asymmetric interlaced (TAIL) PCR was conducted and analysis of the two clones found multiple T-DNA insertions (two in B1-06 and three in C1-49). Genes encoding complex I intermediate-associated protein 30 (CIA30) and the autophagy protein (Atg22) were possibly disrupted by the T-DNA insertion and might be involved in the virulence. This work provides a strong platform for future functional genetic studies of bean bug-pathogenic B. bassiana. The genes putatively involved in fungal virulence should be experimentally validated by knockdown in future studies.

Induction of mutagenized tomato populations for investigation on agronomic traits and mutant phenotyping

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Rafiul Amin Laskar

2018-01-01

Full Text Available Global demand for tomato production increased tremendously due to its diverse utility in raw, cooked and processed form of food. This necessitates the continued supply of highly nutritious and better yielding improved cultivars to the producers, considering the rapid changing agro-climatic condition. In this study, induced mutant tomato populations of widely recommended tomato genotype Arka Vikas (Sel-22 were generated using chemical mutagen ethyl methane sulfonate (EMS, hydrazine hydrates (HZ and their combined treatments. In the in vitro study, a gradual reduction in germination percentage and seedling height occurred with the increasing concentrations of mutagens. Combination of EMS and HZ caused maximum biological inhibition followed by EMS and HZ treatments alone in M1 generation. The rate of survival and fertility in M1 plants of tomato was found highly affected due to mutagenic treatment, in which sensitivity toward combined treatment was found highest followed by EMS and HZ. Inspection on induced phenotypic variations in individual plants of M2 population resulted in identification and isolation of wide range of mutants with altered phenotypes. Highest mutation frequency was resulted by combined mutagens followed by the EMS and HZ treatment. Agronomic trait analyses showed intra and inter treatment variations in three quantitative traits (Plant height, fertile branch per plant and fruits per plant of M2 mutagenized population. Assessment on rate of mutant recovery in M2 population showed highest mutant recovery is possible with combination treatments and then 0.02% HZ followed by 0.02% EMS. In the present study, phenotyping of the mutants revealed that vegetative organs (‘plant size’, ‘plant habit’ and ‘leaf morphology’ was the most sensitive category (69.33% to which most of the mutant belongs, followed by ‘fruit color and size’ (20.27% and ‘germination’ (9.79%. Comparative investigation on number of mutants and

Probiotic features of Lactobacillus plantarum mutant strains.

Science.gov (United States)

Bove, Pasquale; Gallone, Anna; Russo, Pasquale; Capozzi, Vittorio; Albenzio, Marzia; Spano, Giuseppe; Fiocco, Daniela

2012-10-01

In this study, the probiotic potential of Lactobacillus plantarum wild-type and derivative mutant strains was investigated. Bacterial survival was evaluated in an in vitro system, simulating the transit along the human oro-gastro-intestinal tract. Interaction with human gut epithelial cells was studied by assessing bacterial adhesive ability to Caco-2 cells and induction of genes involved in innate immunity. L. plantarum strains were resistant to the combined stress at the various steps of the simulated gastrointestinal tract. Major decreases in the viability of L. plantarum cells were observed mainly under drastic acidic conditions (pH ≤ 2.0) of the gastric compartment. Abiotic stresses associated to small intestine poorly affected bacterial viability. All the bacterial strains significantly adhered to Caco-2 cells, with the ΔctsR mutant strain exhibiting the highest adhesion. Induction of immune-related genes resulted higher upon incubation with heat-inactivated bacteria rather than with live ones. For specific genes, a differential transcriptional pattern was observed upon stimulation with different L. plantarum strains, evidencing a possible role of the knocked out bacterial genes in the modulation of host cell response. In particular, cells from Δhsp18.55 and ΔftsH mutants strongly triggered immune defence genes. Our study highlights the relevance of microbial genetic background in host-probiotic interaction and might contribute to identify candidate bacterial genes and molecules involved in probiosis.

Disturbed secretion of mutant adiponectin associated with the metabolic syndrome.

Science.gov (United States)

Kishida, Ken; Nagaretani, Hiroyuki; Kondo, Hidehiko; Kobayashi, Hideki; Tanaka, Sachiyo; Maeda, Norikazu; Nagasawa, Azumi; Hibuse, Toshiyuki; Ohashi, Koji; Kumada, Masahiro; Nishizawa, Hitoshi; Okamoto, Yoshihisa; Ouchi, Noriyuki; Maeda, Kazuhisa; Kihara, Shinji; Funahashi, Tohru; Matsuzawa, Yuji

2003-06-20

Adiponectin, an adipocyte-derived protein, consists of collagen-like fibrous and complement C1q-like globular domains, and circulates in human plasma in a multimeric form. The protein exhibits anti-diabetic and anti-atherogenic activities. However, adiponectin plasma concentrations are low in obese subjects, and hypoadiponectinemia is associated with the metabolic syndrome, which is a cluster of insulin resistance, type 2 diabetes mellitus, hypertension, and dyslipidemia. We have recently reported a missense mutation in the adiponectin gene, in which isoleucine at position 164 in the globular domain is substituted with threonine (I164T). Subjects with this mutation showed markedly low level of plasma adiponectin and clinical features of the metabolic syndrome. Here, we examined the molecular characteristics of the mutant protein associated with a genetic cause of hypoadiponectinemia. The current study revealed (1) the mutant protein showed an oligomerization state similar to the wild-type as determined by gel filtration chromatography and, (2) the mutant protein exhibited normal insulin-sensitizing activity, but (3) pulse-chase study showed abnormal secretion of the mutant protein from adipose tissues. Our results suggest that I164T mutation is associated with hypoadiponectinemia through disturbed secretion into plasma, which may contribute to the development of the metabolic syndrome.

A thermo-sensitive purple leaf rice mutant--PLM12 and its genetical study

International Nuclear Information System (INIS)

Wu Guanting; Wang Xianyu; Jin Wei

2001-01-01

PLM12 was a thermo-sensitive purple leaf mutant selected from Indica rice variety Luqingzao 1 treated with pingyangmycin in combination with γ-rays, and for display of its mutant character, a relatively high temperature was required. Compared with its original parent, many major agronomic traits of PLM12 changed to varied extents. Based on spikelet cutting experiment, it was believed that significant decreases in number of filled grains per panicle, fertility, and 1000-grain weight in PLM12 resulted mainly from a great decline in photosynthetic capacity and serious lack of photosynthate in purple leaves. It was indicated by genetic analysis that expression of the mutant phenotype in PLM12 was conditioned by a single recessive major nuclear gene and modified by several minor genes

Biocontrol potential of salinity tolerant mutants of Trichoderma harzianum against Fusarium oxysporum Potencial de biocontrole de mutantes sal-tolerantes de Trichoderma harzianum contra Fusarium oxysporum

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Hassan Abdel-Latif A. Mohamed

2006-06-01

Full Text Available Exposing a wild-type culture of Trichoderma harzianum to gamma irradiation induced two stable salt-tolerant mutants (Th50M6 and Th50M11. Under saline conditions, both mutants greatly surpassed their wild type strain in growth rate, sporulation and biological proficiency against Fusarium oxysporum, the causal agent of tomato wilt disease. Tolerant T. harzianum mutants detained a capability to grow and convinced sporulation in growth media containing up to 69 mM NaCl. In comparison with their parent strain, characterization of both mutants confirmed that they have reinforced contents of proline and hydroxyproline, relatively higher sodium content compared to potassium, calcium or magnesium contents, higher level of total phenols. Electrophoretic analysis of total soluble proteins in the salt tolerance mutant Th50M6 showed different bands accumulated in response to 69 mM NaCl. Data also showed that mutants produce certain active metabolites, such as chitinases, cellulases, beta-galactosidases, as well as, some antibiotics i.e., trichodermin, gliotoxin and gliovirin. Trichoderma mutants significantly reduced wilt disease incidence and improved yield and mineral contents of tomato plants under both saline and non-saline soil conditions, as well as, under infested and natural conditions. T. harzianum mutants were also more efficient in dropping the F. oxysporum growth in rhizosphere compared to the wild type strain. Population density of both mutants in rhizosphere far exceeded that of T. harzianum wild type strain.A exposição de uma cepa selvagem de Trichoderma harzianum à irradiação gama induziu dois mutantes tolerantes a sal (Th50M6 e Th50M11. Em condições salinas, os dois mutantes foram muito superiores à cepa selvagem em relação à velocidade de multiplicação, esporulação e eficiência contra Fusarium oxysporum, o agente causador da doença wilt do tomate. Os mutantes tolerantes foram capazes de multiplicação e esporulação em

Saccharomyces cerevisiae mutants with enhanced induced mutation and altered mitotic gene conversion.

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Ivanov, E L; Kovaltzova, S V; Korolev, V G

1989-08-01

We have developed a method to isolate yeast (Saccharomyces cerevisiae) mutants with enhanced induced mutagenesis based on nitrous acid-induced reversion of the ade2-42 allele. Six mutants have been isolated and designated him (high induced mutagenesis), and 4 of them were studied in more detail. The him mutants displayed enhanced reversion of the ade2-42 allele, either spontaneous or induced by nitrous acid, UV light, and the base analog 6-N-hydroxylaminopurine, but not by gamma-irradiation. It is worth noting that the him mutants turned out not to be sensitive to the lethal effects of the mutagens used. The enhancement in mutation induced by nitrous acid, UV light, and 6-N-hydroxylaminopurine has been confirmed in a forward-mutation assay (induction of mutations in the ADE1, ADE2 genes). The latter agent revealed the most apparent differences between the him mutants and the wild-type strain and was, therefore, chosen for the genetic analysis of mutants, him mutations analyzed behaved as a single Mendelian trait; complementation tests indicated 3 complementation groups (HIM1, HIM2, and HIM3), each containing 1 mutant allele. Uracil-DNA glycosylase activity was determined in crude cell extracts, and no significant differences between the wild-type and him strains were detected. Spontaneous mitotic gene conversion at the ADE2 locus is altered in him1 strains, either increased or decreased, depending on the particular heteroallelic combination. Genetic evidence strongly suggests him mutations to be involved in a process of mismatch correction of molecular heteroduplexes.

Gamma ray induced mutants in Coleus

Energy Technology Data Exchange (ETDEWEB)

Vasudevan, K; Jos, J S [Central Tuber Crops Research Institute, Trivandrum, Kerala (India)

1988-07-01

The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M{sub 1}V{sub 1} generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m{sup 2} area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing.

Gamma ray induced mutants in Coleus

International Nuclear Information System (INIS)

Vasudevan, K.; Jos, J.S.

1988-01-01

The germplasm collection of Chinese potato (Coleus parviflorus Benth) contains almost no variation for yield contributing traits. The crop does not produce seeds. Treatment of underground tubers with 1 kR, 2 kR, 3 kR and 4 kR gamma rays resulted in 50 morphologically different mutants which are maintained as mutant clones. In the M 1 V 1 generation, suspected mutant sprouts, were carefully removed and grown separately. The most interesting mutant types are the following: (i) erect mutant with spoon shaped light green leaves, 30 cm long inflorescences against 20 cm in the control, cylindrical tubers measuring ca. 7.0 cm long and 3 cm girth against 4 cm and 2.5 cm in the control (ii) early mutants 1 and 2, one having less leaf serration, the other having light green small leaves and dwarf type (iii) fleshy leaf mutant, dark green, thick and smooth leaves. Control plants spread almost in 1 m 2 area and bear tubers from the nodes of branches. In the early mutants tuber formation is mainly restricted to the base of the plant, which makes harvest easier. The crop usually matures within 150 - 160 days, the early mutants are ready for harvest 100 days after planting. As the mutants are less spreading, the yield could be increased by closer spacing

Semi-conservative synthesis of DNA in UV-sensitive mutant cells of Chinese hamster after UV-irradiation

International Nuclear Information System (INIS)

Vikhanskaya, F.L.; Khrebtukova, I.A.; Manuilova, E.S.

1985-01-01

A study was made of the rate of semi-conservative DNA synthesis in asynchronous UV-resistant (clone V79) and UV-sensitive clones (VII and XII) of Chinese hamster cells after UV-irradiation. In all 3 clones studied, UV-irradiation (5-30 J/m 2 ) induced a decrease in the rate of DNA synthesis during the subsequent 1-2 h. In the resistant clone (V79) recovery of DNA synthesis rate started after the first 2 h post-irradiation (5 J/m 2 ) and by the 3rd hour reached its maximum value, which constituted 70% of that observed in control, non-irradiated cells. The UV-sensitive mutant clones VII and XII showed no recovery in the rate of DNA synthesis during 6-7 h post-irradiation. The results obtained show that the survival of cells is correlated with the ability of DNA synthesis to recover after UV-irradiation in 3 clones studied. The observed recovery of UV-inhibited DNA synthesis in mutant clones may be due to certain defects in DNA repair. (orig.)

Development of high yielding mutants in lentil

International Nuclear Information System (INIS)

Rajput, M.A.; Sarwar, G.; Siddiqui, K.A.

2001-01-01

Full text: Lentil (Lens culinaris Medik.) locally known as Masoor, is the second most important rabi pulse crop, after chickpea, in Pakistan. It is cultivated on an area of over 63,400 ha, which constitutes about 4.83% of the total area under pulses. The annual production of the crop is 28,200 tones with an average yield of 445 kg/ha. Yield at the national level is very low, about one-half of the world's yield, which is mainly due to non-availability of high yield potential genotypes. Keeping in view the importance of mutants in developing a large number of new varieties, an induced mutations programme was initiated at AEARC, Tandojam during 1987-88, to develop high yielding varieties in lentil. For this, seeds of two lentil varieties, 'Masoor-85' and 'ICARDA-8' had been irradiated with gamma-rays ranging from 100-600 Gy in NIAB, Faisalabad during 1990. Selections were made in M2 on the basis of earliness, plant height, branches/plant and 100 grain weight. After confirming these mutants in M3 they were promoted in station yield trials and studied continuously for three consecutive years (1993- 1995). Overall results revealed that these mutants have consistent improvement of earliness in flowering and maturity. Plant height also increased in all mutant lines except AEL 23/40/91 where reduction in this attribute was observed as compared to parent variety. Mutant lines AEL 49/20/91 and AEL 13/30/91 showed improvement in 100 grain weight. The improvement of some agronomic characters enhanced the yield of mutant lines in comparison to parent varieties (Masoor-85 and ICARDA-8). The diversity in yield over the respective parents was computed from 6.94 to 60.12%. From these encouraging results it is hoped that mutant lines like AEL 12/30/91 and AEL 49/20/91 may serve as potential lentil genotypes in future. (author)

Construction and functional characterization of double and triple mutants of parallel beta-bulge of ubiquitin.

Science.gov (United States)

Sharma, Mrinal; Prabha, C Ratna

2011-12-01

Ubiquitin, a small eukaryotic protein serving as a post-translational modification on many important proteins, plays central role in cellular homeostasis and cell cycle regulation. Ubiquitin features two beta-bulges, the second beta-bulge, located at the C-terminal region of the protein along with type II turn, holds 3 residues Glu64(1), Ser65(2) and Gln2(X). Percent frequency of occurrence of such a sequence in parallel beta-bulge is very low. However, the sequence and structure have been conserved in ubiquitin through out the evolution. Present study involves replacement of residues in unusual beta-bulge of ubiquitin by introducing mutations in combination through site directed mutagenesis, generating double and triple mutants and their functional characterization. Mutant ubiquitins cloned in yeast expression vector YEp96 tested for growth profile, viability assay and heat stress complementation study have revealed significant decrease in growth rate, loss of viability and non-complementation of heat sensitive phenotype with UbE64G-S65D and UbQ2N-E64G-S65D mutations. However, UbQ2N-S65D did not show any negative effects in the above assays. Present results show that, replacement of residues in beta-bulge of ubiquitin exerts severe effects on growth and viability in Saccharomyces cerevisiae due to functional failure of the mutant ubiquitins UbE64G-S65D and UbQ2N-E64G-S65D.

Examination of WF9 mutant sublines for lodging and fusarium resistance

International Nuclear Information System (INIS)

Balint, A.; Bedo, Z.; Kiss, E.

1977-01-01

The mutants produced from the maize line WF9 in our department between 1961-67 were considered regarding stem-strength and Fusarium resistance. The treatments have essentially improved the stem strength of the original line in a great many (11 cases out of 29), and the lodging rate has considerably decreased. Regarding the Fusarium contamination, the changes are mostly disadvantageous, but we achieved definite positive changes in the cases of four mutants. This improvement is also interesting because it coincides with the improvement of the step strength in all cases, and with the considerable increase in protein content in three of the four sublines. (author)

Molecular analyses of in vivo hprt mutant T cells from atomic bomb survivors

International Nuclear Information System (INIS)

Hakoda, M.; Hirai, Y.; Kyoizumi, S.; Akiyama, M.

1989-01-01

In vivo-derived hprt-deficient mutant T cells isolated from three nonirradiated controls and two atomic bomb survivors were studied by Southern blot analysis to investigate the molecular spectra of the mutations. Mutant frequencies for the three controls were 1.8, 2.3, and 7.3 x 10(-6), and those for the two survivors (who had received radiation doses of 2.46 and 2.15 Gy, based upon the revised atomic bomb shielded kerma estimates) were 9.3 and 14.4 x 10(-6), respectively. Fourteen (13%) of 105 mutant T-cell colonies from the controls showed various structural changes in the hprt gene. The frequency of mutants with hprt gene structural changes in one atomic bomb survivor, who exhibited a mutant frequency of 9.3 x 10(-6), was 26% (16/61), which was significantly higher than that of the controls. However, the frequency of structural changes in the other survivor (14%, 8/59) was not higher than that of the controls. Two sets of mutants (in total, eight mutants) from the survivor, who showed a significantly higher frequency of mutants with hprt gross alterations than did the controls, had the same hprt changes and the same rearrangements of T-cell receptor (TcR) beta- and gamma-chain genes, indicating a clonal expansion from one progenitor mutant. This phenomenon may reflect an in vivo recovery process of T cells in the periphery after exposure to atomic bomb radiation. However, when comparing the frequency of mutations, these two sets of mutants should be reduced. After reducing the total number of mutants from the number of gross hprt changes, the frequency was not significantly higher than that of the controls

Screening of allyl alcohol resistant mutant of Rhizopus oryzae and ...

African Journals Online (AJOL)

Ethanol is a main by-product in the fermentation broth of Rhizopus oryzae during the production of high-optical purity L-lactic acid. By screening the lower activity of alcohol dehydrogenase (ADH) mutant, thus decreasing the flux of pyruvic acid to ethanol may be a virtual method for increasing the conversion rate of glucose ...

Recombination Phenotypes of Escherichia coli greA Mutants

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Poteete Anthony R

2011-03-01

Full Text Available Abstract Background The elongation factor GreA binds to RNA polymerase and modulates transcriptional pausing. Some recent research suggests that the primary role of GreA may not be to regulate gene expression, but rather, to promote the progression of replication forks which collide with RNA polymerase, and which might otherwise collapse. Replication fork collapse is known to generate dsDNA breaks, which can be recombinogenic. It follows that GreA malfunction could have consequences affecting homologous recombination. Results Escherichia coli mutants bearing substitutions of the active site acidic residues of the transcription elongation factor GreA, D41N and E44K, were isolated as suppressors of growth inhibition by a toxic variant of the bacteriophage lambda Red-beta recombination protein. These mutants, as well as a D41A greA mutant and a greA deletion, were tested for proficiency in recombination events. The mutations were found to increase the efficiency of RecA-RecBCD-mediated and RecA-Red-mediated recombination, which are replication-independent, and to decrease the efficiency of replication-dependent Red-mediated recombination. Conclusion These observations provide new evidence for a role of GreA in resolving conflicts between replication and transcription.

The Swedish mutant barley collection

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-07-01

Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

The Swedish mutant barley collection

International Nuclear Information System (INIS)

1989-01-01

Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

Ensemble-based computational approach discriminates functional activity of p53 cancer and rescue mutants.

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Özlem Demir

2011-10-01

Full Text Available The tumor suppressor protein p53 can lose its function upon single-point missense mutations in the core DNA-binding domain ("cancer mutants". Activity can be restored by second-site suppressor mutations ("rescue mutants". This paper relates the functional activity of p53 cancer and rescue mutants to their overall molecular dynamics (MD, without focusing on local structural details. A novel global measure of protein flexibility for the p53 core DNA-binding domain, the number of clusters at a certain RMSD cutoff, was computed by clustering over 0.7 µs of explicitly solvated all-atom MD simulations. For wild-type p53 and a sample of p53 cancer or rescue mutants, the number of clusters was a good predictor of in vivo p53 functional activity in cell-based assays. This number-of-clusters (NOC metric was strongly correlated (r(2 = 0.77 with reported values of experimentally measured ΔΔG protein thermodynamic stability. Interpreting the number of clusters as a measure of protein flexibility: (i p53 cancer mutants were more flexible than wild-type protein, (ii second-site rescue mutations decreased the flexibility of cancer mutants, and (iii negative controls of non-rescue second-site mutants did not. This new method reflects the overall stability of the p53 core domain and can discriminate which second-site mutations restore activity to p53 cancer mutants.

Identification of dominant male sterile mutants in rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Zhu Xudong; Rutger, J.N.

2000-01-01

Genetic male sterile mutants 1783 and 1789 were selected from US variety Orion and Kaybonnet seeds treated by gamma irradiation. Investigation of fertility characterization of pollen and spikelets of these mutants were made by progeny tests in 1783 M 7 and 1789 M 6 generations. The results showed that genetic male sterile mutants 1783 and 1789 with the fertility segregating of 1 sterile: 1 fertile were controlled by a single dominant gene. The pollen staining of mutants characterized partial sterility. Open-pollinated seed set was about 30% and bagged seed set was only 0.3%-3.5%. It is concluded that dominant genetic male sterile is a useful tool in improvement of population for rice breeding

Mutants of alfalfa mosaic virus

International Nuclear Information System (INIS)

Roosien, J.

1983-01-01

In this thesis the isolation and characterization of a number of mutants of alfalfa mosaic virus, a plant virus with a coat protein dependent genome, is described. Thermo-sensitive (ts) mutants were selected since, at least theoretically, ts mutations can be present in all virus coded functions. It was found that a high percentage of spontaneous mutants, isolated because of their aberrant symptoms, were ts. The majority of these isolates could grow at the non-permissive temperature in the presence of a single wild type (wt) component. To increase the mutation rate virus preparations were treated with several mutagens. After nitrous acid treatment or irradiation with ultraviolet light, an increase in the level of mutations was observed. UV irradiation was preferred since it did not require large amounts of purified viral components. During the preliminary characterization of potential ts mutants the author also obtained one structural and several symptom mutants which were analysed further (chapter 7, 8 and 9). The properties of the ts mutants are described in chapter 3-7. (Auth.)

Rats with decreased brain cholecystokinin levels show increased responsiveness to peripheral electrical stimulation-induced analgesia.

Science.gov (United States)

Zhang, L X; Li, X L; Wang, L; Han, J S

1997-01-16

Using the P77PMC strain of rat, which is genetically prone to audiogenic seizures, and also has decreased levels of cholecystokinin (CCK), we examined the analgesic response to peripheral electrical stimulation, which is, in part, opiate-mediated. A number of studies have suggested that CCK may function as an antagonist to endogenous opiate effects. Therefore, we hypothesized that the P77PMC animals would show an enhanced analgesic response based on their decreased CCK levels producing a diminished endogenous opiate antagonism. We found that the analgesic effect on tail flick latency produced by 100 Hz peripheral electrical stimulation was more potent and longer lasting in P77PMC rats than in control rats. Moreover, the potency of the stimulation-produced analgesia correlated with the vulnerability to audiogenic seizures in these rats. We were able to block the peripheral electrical stimulation-induced analgesia (PSIA) using a cholecystokinin octapeptide (CCK-8) administered parenterally. Radioimmunoassay showed that the content of CCK-8 in cerebral cortex, hippocampus and periaqueductal gray was much lower in P77PMC rat than in controls. These results suggest that low CCK-8 content in the central nervous system of the P77PMC rats may be related to the high analgesic response to peripheral electrical stimulation, and further support the notion that CCK may be endogenous opiate antagonist.

Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

International Nuclear Information System (INIS)

Datta, Subodh Kumar

1986-01-01

Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. (author)

Human liver cell trafficking mutants: characterization and whole exome sequencing.

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Fei Yuan

Full Text Available The HuH7 liver cell mutant Trf1 is defective in membrane trafficking and is complemented by the casein kinase 2α subunit CK2α''. Here we identify characteristic morphologies, trafficking and mutational changes in six additional HuH7 mutants Trf2-Trf7. Trf1 cells were previously shown to be severely defective in gap junction functions. Using a Lucifer yellow transfer assay, remarkable attenuation of gap junction communication was revealed in each of the mutants Trf2-Trf7. Electron microscopy and light microscopy of thiamine pyrophosphatase showed that several mutants exhibited fragmented Golgi apparatus cisternae compared to parental HuH7 cells. Intracellular trafficking was investigated using assays of transferrin endocytosis and recycling and VSV G secretion. Surface binding of transferrin was reduced in all six Trf2-Trf7 mutants, which generally correlated with the degree of reduced expression of the transferrin receptor at the cell surface. The mutants displayed the same transferrin influx rates as HuH7, and for efflux rate, only Trf6 differed, having a slower transferrin efflux rate than HuH7. The kinetics of VSV G transport along the exocytic pathway were altered in Trf2 and Trf5 mutants. Genetic changes unique to particular Trf mutants were identified by exome sequencing, and one was investigated in depth. The novel mutation Ile34Phe in the GTPase RAB22A was identified in Trf4. RNA interference knockdown of RAB22A or overexpression of RAB22AI34F in HuH7 cells caused phenotypic changes characteristic of the Trf4 mutant. In addition, the Ile34Phe mutation reduced both guanine nucleotide binding and hydrolysis activities of RAB22A. Thus, the RAB22A Ile34Phe mutation appears to contribute to the Trf4 mutant phenotype.

High-Protein Soybean Mutants by Using Irradiation Technique

International Nuclear Information System (INIS)

Yathaputanon, C.; Kumsueb, B.; Srisombun, S.

2009-07-01

Full text: Soybean variety improvement for high seed protein using induced mutation was initiated. Approximately 5,000 seeds of soybean variety Chiang Mai 60 were irradiated with gamma rays at the dose of 200 Grays at Kasetsart University. High-protein seed mutants in M2 to M4 generations were selected at Nakhon Ratchasima Field Crops Research Center during 2004-2008. The Pedigree method of selection was used. Kjeldahl method was used to analyze seed protein percentages. The M2 seeds protein content of the M2 generation was 45.2% while that of the original parent was 43.0%. M3s were seeded plant to row. In each row, the best four plants were selected for protein analysis. The average protein content of selected mutant lines was 3.9% while the check variety had average protein content of 42.4%. In the M4 generation, the result showed that the average protein contents of the selected mutant lines and the check variety were 42.8% and 42.0%, respectively. In the 2007-2008 trials, four promising mutants had and average protein content of 428%, while the check variety had and average protein content of 41.1%. The four mutants produced the mean grain yield of 2.20-2.42 t/Ha, which was 10.21% higher than that of Chiang Mai 60. The mutant lines produced both a high grain protein content and a high grain yield. They will be further tested their adaptability in the research centers and farmer fields

Properties of adenyl cyclase and cyclic adenosine 3',5'-monophosphate receptor protein-deficient mutants of Escherichia coli

International Nuclear Information System (INIS)

Kumar, S.

1976-01-01

Several spontaneous cya and crp mutants of Escherichia coli have been selected as clones simultaneously resistant to phage lambda and nalidixic acid and characterized. Both cya and crp mutants have been found to grow as cocci with increased doubling times. They have increased resistance to some mutagens (methylmethanesulfonate, ultraviolet light, gamma rays), antibiotics (nalidixic acid, ampicillin), phages (lambda, T6), sublethal heat and hypotonic shock, and decreased resistance to neutral detergents (sodium dodecyl sulfate, sodium deoxycholate), a protein synthesis inhibitor (streptomycin), and a respiratory inhibitor (sodium azide). The nature of changes in cell parameters indicate fundamental alterations in the envelope structure of the cya and crp mutant cells. The new cya and crp mutants have been found to be multiply carbohydrate negative and nonmotile in conformity with similar previously isolated mutants. Studies of revertants and phi 80 cya + and phi 80 cya transductants indicated that the pleiotropic phenotype is related to a single mutational event at the cya or the crp locus in the mutants

Increased sensitivity to salt stress in tocopherol-deficient Arabidopsis mutants growing in a hydroponic system

Science.gov (United States)

Ellouzi, Hasna; Hamed, Karim Ben; Cela, Jana; Müller, Maren; Abdelly, Chedly; Munné-Bosch, Sergi

2013-01-01

Recent studies suggest that tocopherols could play physiological roles in salt tolerance but the mechanisms are still unknown. In this study, we analyzed changes in growth, mineral and oxidative status in vte1 and vte4 Arabidopsis thaliana mutants exposed to salt stress. vte1 and vte4 mutants lack α-tocopherol, but only the vte1 mutant is additionally deficient in γ-tocopherol. Results showed that a deficiency in vitamin E leads to reduced growth and increased oxidative stress in hydroponically-grown plants. This effect was observed at early stages, not only in rosettes but also in roots. The vte1 mutant was more sensitive to salt-induced oxidative stress than the wild type and the vte4 mutant. Salt sensitivity was associated with (i) high contents of Na+, (ii) reduced efficiency of PSII photochemistry (Fv/Fm ratio) and (iii) more pronounced oxidative stress as indicated by increased hydrogen peroxide and malondialdeyde levels. The vte 4 mutant, which accumulates γ- instead of α-tocopherol showed an intermediate sensitivity to salt stress between the wild type and the vte1 mutant. Contents of abscisic acid, jasmonic acid and the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid were higher in the vte1 mutant than the vte4 mutant and wild type. It is concluded that vitamin E-deficient plants show an increased sensitivity to salt stress both in rosettes and roots, therefore indicating the positive role of tocopherols in stress tolerance, not only by minimizing oxidative stress, but also controlling Na+/K+ homeostasis and hormonal balance. PMID:23299430

Analysis of the relationship between the decrease in pH and accumulation of 3-phosphoglyceric acid in developing forespores of Bacillus species.

OpenAIRE

Magill, N G; Cowan, A E; Leyva-Vazquez, M A; Brown, M; Koppel, D E; Setlow, P

1996-01-01

Analysis of the pH decrease and 3-phosphoglyceric acid (3PGA) accumulation in the forespore compartment of sporulating cells of Bacillus subtilis showed that the pH decrease of 1 to 1.2 units at approximately 4 h of sporulation preceded 3PGA accumulation, as observed previously in B. megaterium. These data, as well as analysis of the forespore pH decrease in asporogenous mutants of B. subtilis, indicated that sigma G-dependent forespore transcription, but not sigma K-dependent mother cell tra...

Genetic fingerprinting of mutant rose cultivars

Energy Technology Data Exchange (ETDEWEB)

Kumar, S; Prasad, K V; Singh, K P; Singh, A.P. [Division of Floriculture and Landscaping, Indian Agricultural Research Institute, Pusa, New Delhi (India)], E-mail: kvprasad66@gmail.com

2008-07-01

Six rose mutants evolved at the Indian Agricultural Research Institute, New Delhi from four parent cultivars were characterized based on RAPD markers. Contrary to the earlier findings our effort has conclusively proven that the RAPD markers are indeed robust tools to discern the mutants from their parents. Among 40 primers screened, 7 primers produced inconsistent banding pattern. The number of polymorphic bands varied between 4 (OPA 14) and 10 (OPA1) with an average of 6.5 bands per primer. The percentage polymorphism ranged from 62.5 (OPM 9) to 100 percent (OPA 1). Most of the primers produced monomorphic bands between parent and mutant rose cultivars. When primer OPA 2 was used a specific band of 2.5 kb was noticed in mutant cv. Pusa Urmil and cv. Pusa Abhishek but was absent in parent cv. Jantar Mantar. A polymorphic band of 750 bp was noticed in the parent Kiss of Fire and helped in differentiating the parent from its mutant when amplified with OPK 3. Primer OPS 16 produced discriminatory band of 800 bp in mutant cv. Pink Sport of Montezuma while it was absent in its parent cv. Montezuma. Another specific band of 650 bp was present in parent cv. Montezuma and absent in its mutant cv. Pink Sport of Montezuma signifying the uniqueness of the mutant. Primer OPM 5 brought out distinct polymorphism among the parent Jantar Mantar and its three mutants with absence of a specific band of 1.5 kb in the parent. The four parents and 6 mutants were divided into four distinct groups in the Dendogram constructed by UPGMA method. The most genetically similar cultivar among the 10 cultivars analyzed are Montezuma and its pink sport of Montezuma whereas Abhisarika a mutant of cv. Kiss of Fire was distinctly different and formed a separate cluster. (author)

From one body mutant to one cell mutant. A progress of radiation breeding in crops

International Nuclear Information System (INIS)

Nagatomi, Shigeki

1996-01-01

An effective method was established to obtain non-chimeral mutants with wide spectrum of flower colors, regenerated from floral organs on which mutated sectors were come out on chronic irradiated plants. By this way, six mutant varieties of flower colors have been selected from one pink flower of chrysanthemum, and cultivated for cut-flower production. By the same method, 3 mutant varieties with small and spray type flowers were selected in Eustoma. Mutant varieties such as a rust disease resistant in sugarcane, 6 dwarfs in Cytisus and pure-white mushroom in velvet shank have been selected successively for short period. (J.P.N.)

Differential effects of lesion mimic mutants in barley on disease development by facultative pathogens

Science.gov (United States)

McGrann, Graham R. D.; Steed, , Andrew; Burt, Christopher; Nicholson, Paul; Brown, James K. M.

2015-01-01

Lesion mimic mutants display spontaneous necrotic spots and chlorotic leaves as a result of mis-regulated cell death programmes. Typically these mutants have increased resistance to biotrophic pathogens but their response to facultative fungi that cause necrotrophic diseases is less well studied. The effect of altered cell death regulation on the development of disease caused by Ramularia collo-cygni, Fusarium culmorum and Oculimacula yallundae was explored using a collection of barley necrotic (nec) lesion mimic mutants. nec8 mutants displayed lower levels of all three diseases compared to nec9 mutants, which had increased R. collo-cygni but decreased F. culmorum disease symptoms. nec1 mutants reduced disease development caused by both R. collo-cygni and F. culmorum. The severity of the nec1-induced lesion mimic phenotype and F. culmorum symptom development was reduced by mutation of the negative cell death regulator MLO. The significant reduction in R. collo-cygni symptoms caused by nec1 was completely abolished in the presence of the mlo-5 allele and both symptoms and fungal biomass were greater than in the wild-type. These results indicate that physiological pathways involved in regulation of cell death interact with one another in their effects on different fungal pathogens. PMID:25873675

Immunohistochemical studies of lens crystallins in the dysgenetic lens (dyl) mutant mice

NARCIS (Netherlands)

Brahma, S.K.; Sanyal, S.

1984-01-01

The lens in the dyl mutant mice shows a persistent lens-ectodermal connection as well as degeneration and extrusion of lens materials after the initial differentiation of the fibres. Immunohistochemical investigation of the ontogeny of the lens crystallins in this developing mutant lens has been

Analysis of nutritional quality of low phytic acid mutants in maize

International Nuclear Information System (INIS)

Yuan Ming'an; Luo Hongbing; Wang Zhonghua; Chen Jinhong; Mei Shufang; Shu Xiaoli; Wu Dianxing

2008-01-01

Major nutritional quality and components of eight low phytic acid (lpa) mutants and their corresponding wild types were studied. Compared to their corresponding wild types, the content of inorganic P (Pi) was all increased several times, while the content of total P (TP) in mutants was almost the same as their wild types. The contents of crude lipid and amylose were similar, but total starch was significantly different. Crude protein in some of mutants was increased significantly. Most of amino acids were increased, and essential amino acid-Lysine was increased except mutants derived from Q319 and X178. Mineral macronutrients and micronutrients were similar. All results showed that the lpa mutation in maize could enhance the nutritional quality and bioactivities. (authors)

Progranulin is neurotrophic in vivo and protects against a mutant TDP-43 induced axonopathy.

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Angela S Laird

Full Text Available Mislocalization, aberrant processing and aggregation of TAR DNA-binding protein 43 (TDP-43 is found in the neurons affected by two related diseases, amyotrophic lateral sclerosis (ALS and frontotemporal lobe dementia (FTLD. These TDP-43 abnormalities are seen when TDP-43 is mutated, such as in familial ALS, but also in FTLD, caused by null mutations in the progranulin gene. They are also found in many patients with sporadic ALS and FTLD, conditions in which only wild type TDP-43 is present. The common pathological hallmarks and symptomatic cross over between the two diseases suggest that TDP-43 and progranulin may be mechanistically linked. In this study we aimed to address this link by establishing whether overexpression of mutant TDP-43 or knock-down of progranulin in zebrafish embryos results in motor neuron phenotypes and whether human progranulin is neuroprotective against such phenotypes. Mutant TDP-43 (A315T mutation induced a motor axonopathy characterized by short axonal outgrowth and aberrant branching, similar, but more severe, than that induced by mutant SOD1. Knockdown of the two zebrafish progranulin genes, grna and grnb, produced a substantial decrease in axonal length, with knockdown of grna alone producing a greater decrease in axonal length than grnb. Progranulin overexpression rescued the axonopathy induced by progranulin knockdown. Interestingly, progranulin also rescued the mutant TDP-43 induced axonopathy, whilst it failed to affect the mutant SOD1-induced phenotype. TDP-43 was found to be nuclear in all conditions described. The findings described here demonstrate that progranulin is neuroprotective in vivo and may have therapeutic potential for at least some forms of motor neuron degeneration.

Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

Energy Technology Data Exchange (ETDEWEB)

Datta, Subodh Kumar

1986-06-01

Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. 3 figures, 2 tables, 4 refs.

Water-deficit tolerant classification in mutant lines of indica rice

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Suriyan Cha-um

2012-04-01

Full Text Available Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control as water deficit sensitive, using Ward's method.

Growth Hormone-Releaser Diet Attenuates Cognitive Dysfunction in Klotho Mutant Mice via Insulin-Like Growth Factor-1 Receptor Activation in a Genetic Aging Model

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Seok Joo Park

2014-09-01

Full Text Available BackgroundIt has been recognized that a defect in klotho gene expression accelerates the degeneration of multiple age-sensitive traits. Accumulating evidence indicates that aging is associated with declines in cognitive function and the activity of growth hormone (GH/insulin-like growth factor-1 (IGF-1.MethodsIn this study, we examined whether a GH-releaser diet could be effective in protecting against cognitive impairment in klotho mutant mice.ResultsThe GH-releaser diet significantly induced the expression of IGF-1 and IGF-1 receptors in the hippocampus of klotho mutant mice. Klotho mutant mice showed significant memory impairments as compared with wild-type mice. In addition, the klotho mutation significantly decreased the expression of cell survival/antiapoptotic factors, including phospho-Akt (p-Akt/phospho-glycogen synthase kinase3β (p-GSK3β, phospho-extracellular signal-related kinase (p-ERK, and Bcl-2, but significantly increased those of cell death/proapoptotic factors, such as phospho-c-jun N-terminal kinase (p-JNK, Bax, and cleaved caspase-3 in the hippocampus. Treatment with GH-releaser diet significantly attenuated both decreases in the expression of cell survival/antiapoptotic factors and increases in the expression of cell death/proapoptotic factors in the hippocampus of klotho mutant mice. In addition, klotho mutation-induced oxidative stress was significantly attenuated by the GH-releaser diet. Consequently, a GH-releaser diet significantly improved memory function in the klotho mutant mice. GH-releaser diet-mediated actions were significantly reversed by JB-1, an IGF-1 receptor antagonist.ConclusionThe results suggest that a GH-releaser diet attenuates oxidative stress, proapoptotic changes and consequent dysfunction in klotho mutant mice by promoting IGF-1 expression and IGF-1 receptor activation.

PATHOLOGICAL AND MOLECULAR GENETIC STUDIES ON SOME SOYBEAN MUTANTS INDUCED BY GAMMA RAYS IN RELATION TO CHARCOAL ROT DISEASE

International Nuclear Information System (INIS)

ASHRY, N.A.; EL-DEMERDASH, H.M.; ABD EL-RAHMAN, S.S.

2008-01-01

The Egyptian soybean cultivar Giza-22 was used to induce resistant mutants for charcoal rot disease using gamma rays. Sixteen mutants and their parental cultivar were evaluated in M3 generation for their agronomic traits and for resistance to charcoal rot disease. Four mutants showed superiority in their agronomic traits as compared with their parental cultivar. Three mutants were significantly resistant to the disease than their parental cultivar (Giza-22). These three resistant mutants showed non-significant improvement in their agronomic traits as compared with Giza-22 cultivar. DNA extractions from the three resistant mutants and their parent were used to test the differences on the molecular level. Seven random amplified polymorphic DNA (RAPD) primers were used to detect RAPD markers related to charcoal rot resistance in soybean, and to differentiate these mutants. Six RAPD-primers showed molecular markers associated with resistance to charcoal rot in soybean, where five RAPD-primers could differentiate each of the three mutants from each other and from their parental cultivar

A higher yielding mutant of black gram with improved nodule formation

International Nuclear Information System (INIS)

Singh, R.K.; Raghuvanshi, S.S.

1987-01-01

Dry seeds of black gram (Vigna mungo (L) Hopper) var. T 9 with 12.2% moisture content were irradiated at 10, 20 and 30 krad of gamma rays. This was followed by combined treatment of one set in each dose with freshly prepared 0. 25% EMS in phosphate buffer at 7.0 pH at 30± deg. C for 6 hours. In M 2 population of 20 krad two mutants with pentafoliate instead of trifoliate leaves were found. This character was true breeding in M 3 M 6 generation. Crosses revealed monogenic recessive inheritance of this character. The proposed gene symbol is p5. This mutant has normal maturity period and the plant height is the same as T 9 (ca. 50 cm). Preliminary yield trials indicate superiority of the mutant line over control. The mutant line also shows a significant improvement in number and weight of root nodules, potentially improving green manuring value. Improvement of root nodulation in mungbean mutants was reported before by others

Characterization of novel Sorghum brown midrib mutants from an EMS-mutagenized population.

Science.gov (United States)

Sattler, Scott E; Saballos, Ana; Xin, Zhanguo; Funnell-Harris, Deanna L; Vermerris, Wilfred; Pedersen, Jeffrey F

2014-09-02

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci. Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles. Copyright © 2014 Sattler et al.

Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

Science.gov (United States)

Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

2015-09-01

Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Evaluation and genetic analysis of semi-dwarf mutants in rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Awan, M.A.; Cheema, A.A.; Tahir, G.R.

1984-01-01

Four semi-dwarf mutants namely DM16-5-1, DM16-5-2, DM-2 and DM107-4 were derived from the local tall basmati cultivar. The mode of reduction of internode length was studied in DM107-4. The reduction in culm length was due to a corresponding but disproportionate reduction in all the internodes. It was inferred that reduction in internode length contributes more towards reduction in height as compared to the reduction in the total number of internodes. The effect of semi-dwarfism on some yield components (panicle characters) was studied in two semi-dwarf mutants viz. DM16-5-1 and DM107-4 compared to Basmati 370. A marginal reduction in the panicle axis, primary branches per panicle, secondary branches per primary branch per panicle, spikelets borne on secondary branches and total number of spikelets per panicle was observed in DM16-5-1, whereas, a significant reduction of these characters was observed in DM107-4. Evaluation of the semi-dwarf mutants with respect to grain yield and harvest index showed that all the mutants possess high yield potential with higher harvest index values compared to the parent cultivar. Genetic analysis for plant height in 4x4 diallel involving semi-dwarf mutants revealed that mutant DM107-4 carries mainly recessive alleles while mutant DM16-5-1 showed some dominance effects as assessed through the estimates of genetic components of variation and Vr,Wr graph analysis. The semi-dwarf mutants have good potential for use as parents in cross-breeding programmes. (author)

Molecular characterization of thymidine kinase mutants of human cells induced by densely ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Kronenberg, A; Little, J B

1989-04-01

In order to characterize the nature of mutants induced by densely ionizing radiations at an autosomal locus, the authors have isolated a series of 99 thymidine kinase (tk) mutants of human TK6 lymphoblastoid cells iraadiated with either fast neutrons or accelerated argon ions. Individual muant clones were examined for alterations in their restriction fragment pattern after hybridization with a human cDNA probe for tk. A restriction fragment length polymorphism (RFLP) allowed identification of the active tk allele. Among the neutron-induced mutants, 34/52 exhibited loss of the previously active allele while 6/52 exhibited intragenic rearrangements. Among the argon-induced mutants 27/46 exhibited allele loses and 10/46 showed rearrangements within the tk locus. The remaining mutants had restriction patterns indistinguishable from the TK6 parent. Each of the mutant clones was further examined for structural alterations within the c-erbAl locus which has been localized to chromosome 17q11-q22, at some unknown distance from the human tk locus at chromosome 17q21-q22. A substantial proportion (54%) of tk mutants induced by densely ionizing radiation showed loss of the c-erb locus on the homologous chromosome, suggesting that the mutations involve large-scale genetic changes. (author). 51 refs.; 2 figs.; 6 tabs.

ERK Regulates Renal Cell Proliferation and Renal Cyst Expansion in inv Mutant Mice

International Nuclear Information System (INIS)

Okumura, Yasuko; Sugiyama, Noriyuki; Tanimura, Susumu; Nishida, Masashi; Hamaoka, Kenji; Kohno, Michiaki; Yokoyama, Takahiko

2009-01-01

Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage kidney disease in children and young adults. Inv mice are a model for human nephronophthisis type 2 (NPHP2) and characterized by multiple renal cysts and situs inversus. Renal epithelial cells in inv cystic kidneys show increased cell proliferation. We studied the ERK pathway to understand the mechanisms that induce cell proliferation and renal cyst progression in inv kidneys. We studied the effects of ERK suppression by administering PD184352, an oral mitogen-activated protein kinase kinase (MEK) inhibitor on renal cyst expansion, extracellular signal-regulated protein kinase (ERK) activity, bromo-deoxyuridine (BrdU) incorporation and expression of cell-cycle regulators in invΔC kidneys. Phosphorylated ERK (p-ERK) level increased along with renal cyst enlargement. Cell-cycle regulators showed a high level of expression in invΔC kidneys. PD184352 successfully decreased p-ERK level and inhibited renal cyst enlargement. The inhibitor also decreased expression of cell-cycle regulators and BrdU incorporation in renal epithelial cells. The present results showed that ERK regulated renal cell proliferation and cyst expansion in inv mutants

A temperature-sensitive winter wheat chlorophyll mutant derived from space mutagenesis

International Nuclear Information System (INIS)

Zhao Hongbin; Guo Huijun; Zhao Linshu; Gu Jiayu; Zhao Shirong; Li Junhui; Liu Luxiang

2010-01-01

A temperature-sensitive winter wheat (Triticum aestivum L.) chlorophyll mutant Mt18, induced by spaceflight mutagenesis, was studied on agronomic traits, ultrastructure of chloroplast and photosynthesis characteristics. The leaf color of the mutant Mt18 showed changes from green to albino and back to green during the whole growth period. Plant height, productive tillers, spike length, grains and grain weight per plant, and 1000-grain weight of the mutant were lower than those of the wild type. The ultrastructural observation showed that no significant difference was found between the mutant and the wild type during prior albino stage, however, at the albino stage the number of granum-thylakoids and grana lamellae became fewer or completely disappeared, but the strom-thylakoid was obviously visible. After turning green,the structure of most chloroplasts recovered to normal, but number of chloroplast was still lower than that of the wild type. When exposed to photosynthetic active radiation (PAR) of 110 μmol·m -2 ·s -1 , the non-photochemical quenching (NPQ) of mutant was significantly lower than that of the wild type, and the non-regulated energy dissipation (Y NO ) was significantly higher than that of the wild type, while the change of the maximum photosystem II quantum yield (F v /F m ), potential activity of photosystem II (F v /F o ), photochemical quenching (q P ), effective quantum yield (Y PSI I) and regulated non-photochemical energy dissipation (Y NPQ ) were different at various stages. In addition, the differences of the electron transport rate (ETR), photochemical quenching (q P ), and effective quantum yield (Y PSI I) between mutant and wild type varied under different PAR conditions. It was concluded that with the change of chloroplast ultrastructure, the leaf color and photosynthesis of the wheat mutant Mt18 change correspondingly. The chloroplast ultrastructure was obviously different from that of wild type, and the photosynthetic efficiency

Root hair mutants of barley

International Nuclear Information System (INIS)

Engvild, K.C.; Rasmussen, K.

2005-01-01

Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

Identification of a Gravitropism-Deficient Mutant in Rice

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He Yan

2017-03-01

Full Text Available A gravitropism-deficient mutant M96 was isolated from a mutant bank, generated by ethyl methane sulfonate (EMS mutagenesis of indica rice accession ZJ100. The mutant was characterized as prostrate growth at the beginning of germination, and the prostrate growth phenotype ran through the whole life duration. Tiller angle and tiller number of M96 increased significantly in comparison with the wild type. Tissue section observation analysis indicated that asymmetric stem growth around the second node occurred in M96. Genetic analysis and gene mapping showed that M96 was controlled by a single recessive nuclear gene, tentatively termed as gravitropism-deficient M96 (gdM96, which was mapped to a region of 506 kb flanked by markers RM5960 and InDel8 on the long arm of chromosome 11. Sequencing analysis of the open reading frames in this region revealed a nucleotide substitution from G to T in the third exon of LOC_Os11g29840. Additionally, real-time fluorescence quantitative PCR analysis showed that the expression level of LOC_Os11g29840 in the stems was much higher than in the roots and leaves in M96. Furthermore, the expression level was more than four times in M96 stem than in the wild type stem. Our results suggested that the mutant gene was likely a new allele to the reported gene LAZY1. Isolation of this new allele would facilitate the further characterization of LAZY1.

Induction of mutants in durum wheat (triticum durum desf cv. samra) using gamma irradiation

International Nuclear Information System (INIS)

Albokari, M.

2014-01-01

A mutation breeding program was initiated in 2008 emphasizing the main constraints for sustainable production of durum wheat in Saudi Arabia. The aim of the program was to develop moderate or high yielding semi-dwarf/lodging tolerant, early maturing mutants with drought and disease tolerance from a local durum wheat cultivar (Triticum durum Desf. cv. Samra) which has the main defects of longer crop duration, lodging habit and low grain yield. Dry seeds of Samra were subjected to 150 and 200Gy doses of gamma irradiation and each treatment consisted of 2500 seeds. Irradiated seeds were grown as M1 population along with parental variety as control at Almuzahmiah Research Station of Riyadh, Saudi Arabia. Decrease in germination (%) and survival rate (%) of plants was observed. A wide variation in days to flowering and plant height was found in the M1 populations. Three seeds from each spike per plant of M1 plants were collected, bulked dose wise and grown separately as M2 in 2009 growing season. From these M2, 17 desirable putative mutant plants which varied significantly with the mother were visually selected. These putative mutants were found to be semi-dwarf and early maturing in nature with other improved agronomic traits including lodging reaction and grain yield. The selected plants, when grown in progeny lines as M3 in 2010, more or less maintained their superiority over the mother for many traits. Most of the mutant lines showed homogeneity for most of characters studied. Eleven of these 17 lines were found to be promising in respect of days to flower, plant height (for semi-dwarf) and other traits including grain yield. (author)

Heterotropic and homotropic cooperativity by a drug-metabolising mutant of cytochrome P450 BM3

NARCIS (Netherlands)

van Vugt-Lussenburg, B.M.A.; Damsten, M.C.; Maasdijk, D.M.; Vermeulen, N.P.E.; Commandeur, J.N.M.

2006-01-01

Recently, we described a triple mutant of the bacterial cytochrome P450 BM3 as the first mutant with affinity for drug-like compounds. In this paper, we show that this mutant, but not wild-type BM3, is able to metabolise testosterone and several drug-like molecules such as amodiaquine,

Mutant Huntingtin Gene-Dose Impacts on Aggregate Deposition, DARPP32 Expression and Neuroinflammation in HdhQ150 Mice

Science.gov (United States)

Young, Douglas; Mayer, Franziska; Vidotto, Nella; Schweizer, Tatjana; Berth, Ramon; Abramowski, Dorothee; Shimshek, Derya R.; van der Putten, P. Herman; Schmid, Peter

2013-01-01

Huntington's disease (HD) is an autosomal dominant, progressive and fatal neurological disorder caused by an expansion of CAG repeats in exon-1 of the huntingtin gene. The encoded poly-glutamine stretch renders mutant huntingtin prone to aggregation. HdhQ150 mice genocopy a pathogenic repeat (∼150 CAGs) in the endogenous mouse huntingtin gene and model predominantly pre-manifest HD. Treating early is likely important to prevent or delay HD, and HdhQ150 mice may be useful to assess therapeutic strategies targeting pre-manifest HD. This requires appropriate markers and here we demonstrate, that pre-symptomatic HdhQ150 mice show several dramatic mutant huntingtin gene-dose dependent pathological changes including: (i) an increase of neuronal intra-nuclear inclusions (NIIs) in brain, (ii) an increase of extra-nuclear aggregates in dentate gyrus, (iii) a decrease of DARPP32 protein and (iv) an increase in glial markers of neuroinflammation, which curiously did not correlate with local neuronal mutant huntingtin inclusion-burden. HdhQ150 mice developed NIIs also in all retinal neuron cell-types, demonstrating that retinal NIIs are not specific to human exon-1 R6 HD mouse models. Taken together, the striking and robust mutant huntingtin gene-dose related changes in aggregate-load, DARPP32 levels and glial activation markers should greatly facilitate future testing of therapeutic strategies in the HdhQ150 HD mouse model. PMID:24086450

Evaluating Genetic Variability of Sorghum Mutant Lines Tolerant to Acid Soil

International Nuclear Information System (INIS)

Puspitasari, W.; Human, S.; Wirnas, D.; Trikoesoemaningtyas

2012-01-01

High rainfall in some parts in Indonesia causes soil become acidic. The main constraint of acid soil is phosphor (P) deficiency and aluminum (Al) toxicity which decrease plant productivity. To overcome this problem, it is important to develop a crop variety tolerant to such conditions. Sorghum is probably one of the potential crops to meet that objective. Sorghum has been reported to have wide adaptability to various agro-ecology and can be used as food and animal feed. Unfortunately, sorghum is not Indonesian origin so its genetic variability is still low. From previous breeding works with induced mutation, some promising mutant lines have been developed. These mutant lines were included in the experiment carried out in Tenjo with soil condition was classified as acid soil with pH 4.8 and exchangeable-Al content 2.43 me/100 g. The objectives of this experiment were to study the magnitude of genetic variability of agronomy and grain quality characters in sorghum in order to facilitate the breeding improvement of the species. Plant materials used in this study were ten genotypes, including 6 mutant lines and 4 control varieties. The randomized block design with three replications was used in the experiment. The genetic variabilities of agronomic and grain quality characters existed among genotypes, such as plant height, number of leaves, stalk diameter, biomass weight, panicle length, grain yield per plant, 100 seed weight and tannin content in the grain. The broad sense heritabilities of agronomic characters were estimated ranging from medium to high. Grain yield showed significantly positive correlation with agronomic characters observed, but it was negatively correlated with protein content (author)

Finding Inhibitors of Mutant Superoxide Dismutase-1 for Amyotrophic Lateral Sclerosis Therapy from Traditional Chinese Medicine

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Hung-Jin Huang

2014-01-01

Full Text Available Superoxide dismutase type 1 (SOD1 mutations cause protein aggregation and decrease protein stability, which are linked to amyotrophic lateral sclerosis (ALS disease. This research utilizes the world’s largest traditional Chinese medicine (TCM database to search novel inhibitors of mutant SOD1, and molecular dynamics (MD simulations were used to analyze the stability of protein that interacted with docked ligands. Docking results show that hesperidin and 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside (THSG have high affinity to mutant SOD1 and then dopamine. For MD simulation analysis, hesperidin and THSG displayed similar value of RMSD with dopamine, and the migration analysis reveals stable fluctuation at the end of MD simulation time. Interestingly, distance between the protein and ligand has distinct difference, and hesperidin changes the position from initial binding site to the other place. In flexibility of residues analysis, the secondary structure among all complexes does not change, indicating that the structure are not affect ligand binding. The binding poses of hesperidin and THSG are similar to dopamine after molecular simulation. Our result indicated that hesperidin and THSG might be potential lead compound to design inhibitors of mutant SOD1 for ALS therapy.

Mutants of GABA transaminase (POP2 suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh mutants in Arabidopsis.

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Frank Ludewig

Full Text Available BACKGROUND: The gamma-aminubutyrate (GABA shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. In plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (GAD, the mitochondrial enzymes GABA transaminase (GABA-T; POP2 and succinic semialdehyde dehydrogenase (SSADH. We have previously shown that compromising the function of the GABA-shunt, by disrupting the SSADH gene of Arabidopsis, causes enhanced accumulation of reactive oxygen intermediates (ROIs and cell death in response to light and heat stress. However, to date, genetic investigations of the relationships between enzymes of the GABA shunt have not been reported. PRINCIPAL FINDINGS: To elucidate the role of succinic semialdehyde (SSA, gamma-hydroxybutyrate (GHB and GABA in the accumulation of ROIs, we combined two genetic approaches to suppress the severe phenotype of ssadh mutants. Analysis of double pop2 ssadh mutants revealed that pop2 is epistatic to ssadh. Moreover, we isolated EMS-generated mutants suppressing the phenotype of ssadh revealing two new pop2 alleles. By measuring thermoluminescence at high temperature, the peroxide contents of ssadh and pop2 mutants were evaluated, showing that only ssadh plants accumulate peroxides. In addition, pop2 ssadh seedlings are more sensitive to exogenous SSA or GHB relative to wild type, because GHB and/or SSA accumulate in these plants. SIGNIFICANCE: We conclude that the lack of supply of succinate and NADH to the TCA cycle is not responsible for the oxidative stress and growth retardations of ssadh mutants. Rather, we suggest that the accumulation of SSA, GHB, or both, produced downstream of the GABA-T transamination step, is toxic to the plants, resulting in high ROI levels and impaired development.

Un Nuevo Enfoque en el Estudio de la Esporotricosis: Mutantes de Sporothrix schenckii

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Haydee Torres-Guerrero

2012-02-01

Full Text Available Una cepa silvestre y cepas mutantes de Sporothrix schenckii, se han estudiado como un modelo experimental de los procesos de diferenciación y desarrollo que se presentan al ser invadidas las células huésped y causar la esporotricosis. Las cepas mutantes de S. schenckii fueron obtenidas por exposición a la luz ultravioleta y Nitrosoguanidina. Las mutantes morfológicas M-III y M-V fueron seleccionadas. Estas mutantes muestran una alteración colonial y un mayor desarrollo que las cepas silvestres. Además, las mutantes presentan mayor adhesión al sustrato. El análisis de componentes de la pared celular y la distribución de núcleos, indican que no existen diferencias significativas que implique un daño por la mutación. Los resultados indican que en las mutantes morfológicas existe una alteración en el patrón de crecimiento y su regulación. Son necesarios, estudios bioquímicos e inmunológicos, relacionados con la virulencia S. schenckii que puedan ser útiles en el diagnóstico y en un futuro contribuyan a medidas preventivas para la esporotricosis. A wild-type strain and mutant strain of Sporothrix schenckii were studied as an experimental model in the process of differentiation and development which occurs when the host cell is invaded causing sporotrichosis. The mutant strains of S. schenckii were obtained by exposure to ultraviolet light and Nitrosoguanidine. The morphological mutants M-III and M-V were selected. These mutants showed a colonial alteration and a higher growth rate than the wild-type strains. Moreover, the mutants showed greater adhesion to the substratum. An analysis of the components of the cell wall and the distribution of nuclei indicate that significant differences do not exist which involve damage by mutation. The results suggest that in morphological mutants there is an alteration of growth and its regulation in the host cell. Biochemical and immunological studies related to the virulence of S. schenkii are

PNRI mutant variety: Cordyline 'Afable'

International Nuclear Information System (INIS)

Aurigue, Fernando B.

2012-01-01

Cordyline 'Afable', registered by the Philippine Nuclear Research Institute as NSIC 2009 Or-83, is an induced mutant developed from Cordyline 'Kiwi' by treating stem cuttings with acute gamma radiation from a Cobalt-60 source. The new mutant is identical to Cordyline 'Kiwi' in growth habit but differs in foliage color, and exhibits field resistance to Phytophthora sp., a fungus that causes leaf blight and rot in Ti plants. Results of this mutation breeding experiment showed that leaf color was altered by gamma irradiation and resistance to fungal diseases was improved. It also demonstrated how mutations that occur in nature may be generated artificially. Propagation of cordyline 'Afable' is true-to-type by vegetative propagation methods, such as separation of suckers and offshoots, shoot tip cutting, and top cutting. Aside from landscaping material, terrarium or dish-garden plant, it is ideal as containerized plant for indoor and outdoor use. The leaves or shoots may be harvested as cut foliage for flower arrangements. (author)

Enhancement of yellow pigment production by intraspecific protoplast fusion of Monascus spp. yellow mutant (ade(-)) and white mutant (prototroph).

Science.gov (United States)

Klinsupa, Worawan; Phansiri, Salak; Thongpradis, Panida; Yongsmith, Busaba; Pothiratana, Chetsada

2016-01-10

To breed industrially useful strains of a slow-growing, yellow pigment producing strain of Monascus sp., protoplasts of Monascus purpureus yellow mutant (ade(-)) and rapid-growing M. purpureus white mutant (prototroph) were fused and fusants were selected on minimal medium (MM). Preliminary conventional protoplast fusion of the two strains was performed and the result showed that only white colonies were detected on MM. It was not able to differentiate the fusants from the white parental prototroph. To solve this problem, the white parental prototroph was thus pretreated with 20mM iodoacetamide (IOA) for cytoplasm inactivation and subsequently taken into protoplast fusion with slow-growing Monascus yellow mutant. Under this development technique, only the fusants, with viable cytoplasm from Monascus yellow mutant (ade(-)), could thus grow on MM, whereas neither IOA pretreated white parental prototroph nor yellow auxotroph (ade(-)) could survive. Fifty-three fusants isolated from yellow colonies obtained through this developed technique were subsequently inoculated on complete medium (MY agar). Fifteen distinguished yellow colonies from their parental yellow mutant were then selected for biochemical, morphological and fermentative properties in cassava starch and soybean flour (SS) broth. Finally, three most stable fusants (F7, F10 and F43) were then selected and compared in rice solid culture. Enhancement of yellow pigment production over the parental yellow auxotroph was found in F7 and F10, while enhanced glucoamylase activity was found in F43. The formation of fusants was further confirmed by monacolin K content, which was intermediate between the two parents (monacolin K-producing yellow auxotroph and non-monacolin K producing white prototroph). Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative production of cellulases by mutants of Trichoderma parceramosume PTCC5140

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Hoda Nouri

2017-06-01

Discussion and conclusion: Evaluation of cellulase production in mutant strains of Trichoderma parceramosume PTCC 5140 showed that use of chemical mutagenesis with 2 to 11 fold increasing in enzyme activity is a potent method to improve cellulase complex activity. In the current study, obtained mutant strains could be introduced as a potent cellulase producer for further studies in bioconversion processes.

Human T-Cell Leukemia Virus I Tax Protein Sensitizes p53-Mutant Cells to DNA Damage

Science.gov (United States)

Mihaylova, Valia T.; Green, Allison M.; Khurgel, Moshe; Semmes, Oliver J.; Kupfer, Gary M.

2018-01-01

Mutations in p53 are a common cause of resistance of cancers to standard chemotherapy and, thus, treatment failure. Reports have shown that Tax, a human T-cell leukemia virus type I encoded protein that has been associated with genomic instability and perturbation of transcription and cell cycle, sensitizes HeLa cells to UV treatment. The extent to which Tax can sensitize cells and the mechanism by which it exerts its effect are unknown. In this study, we show that Tax sensitizes p53-mutant cells to a broad range of DNA-damaging agents, including mitomycin C, a bifunctional alkylator, etoposide, a topoisomerase II drug, and UV light, but not ionizing radiation, a double-strand break agent, or vinblastine, a tubulin poison. Tax caused hypersensitivity in all p53-deleted cell lines and several, but not all, mutant-expressed p53–containing cell lines, while unexpectedly being protective in p53 wild-type (wt) cells. The effect observed in p53-deleted lines could be reversed for this by transfection of wt p53. We also show that Tax activates a p53-independent proapoptotic program through decreased expression of the retinoblastoma protein and subsequent increased E2F1 expression. The expression of several proapoptotic proteins was also induced by Tax, including Puma and Noxa, culminating in a substantial increase in Bax dimerization. Our results show that Tax can sensitize p53-mutant cells to DNA damage while protecting p53 wt cells, a side benefit that might result in reduced toxicity in normal cells. Such studies hold the promise of a novel adjunctive therapy that could make cancer chemotherapy more effective. PMID:18559532

Recombinant lines for less-spininess in steroid-bearing Solanum viarum using induced mutants as parents

International Nuclear Information System (INIS)

Krishnan, R.; Nanda Kumar, D.; Subhas Chander, M.

1988-01-01

In the domestication of the wild, spinous and steroid-bearing Solanum viarum (syn. S. khasianum var. chatterjeeanum) induced mutations play a major role. The development of Glaxo and BARC mutants catalysed commercial cultivation of this species for its berries containing solasodine, used in steroid industries. The commercially more popular Glaxo mutant population consists predominantly of plants that are totally free of spines in aerial parts except lamina where few straight spines develop. The BARC mutant still possesses spines on aerial parts including the persistent calyx. However, the laminary spines of the BARC mutant are curved and vestigial. Comparative studies on morphology, growth behaviour and agronomic characters of the two mutants, their wild progenitor and their hybrid progenies showed that the three types differ only for spine character. In F 2 generation of a cross involving the Glaxo and BARC mutants, a double mutant recombinant was recovered. The recombinant is devoid of spines in aerial parts like its Glaxo mutant parent, but possesses laminary curved vestigial spines like the BARC parent. The spine characters of the recombinant are inherited double recessive. Three advanced lines of this recombinant type (IIHR 2n - 1,2 and 3) were tested in replicated trials 1985 and 1986. They showed parity in berry yield and solasodine content with the Glaxo mutant and three promising lines evolved elsewhere viz. 'RRL (Bhuhaneswar) Y-14', 'RRL (Jorhat)' and 'Pusa'. The results indicate gainful use of induced mutants in hybridization leading to development of superior less-spiny lines of steroid bearing Solanum viarum

Ascertainment of the effect of differential growth rates of mutants on observed mutant frequencies in X-irradiated mammalian cells

International Nuclear Information System (INIS)

Knaap, A.G.A.C.; Simons, J.W.I.M.

1983-01-01

As it is not known to what extent differential growth rates of induced mutants lead to over- and under-representation of mutants in treated populations and thereby affect the determination of mutant frequencies, the mutation induction in X-irradiated L5178Y mouse lymphoma cells was determined via two methods. The first method involves the standard protocol which may suffer from the effect of differential growth rates, while the second method is based upon the fluctuation test in which the differential growth rates can be actually measured. It appeared that the standard protocol led to a mutant frequency that was similar to the mutant frequency determined in the fluctuation test. Therefore, the standard protocol appears to lead to only a minor under-estimation if any. Substantial heterogeneity in growth rates of induced mutants was observed, but the mutants with a selective advantage appear largely to compensate for the mutants that are lost because of selective disadvantage. It was calculated that the chance for isolating the same mutant twice from a treated population had been increased 2.2-fold because of the observed differential growth rates. (orig./AJ)

Loss of circadian clock accelerates aging in neurodegeneration-prone mutants.

Science.gov (United States)

Krishnan, Natraj; Rakshit, Kuntol; Chow, Eileen S; Wentzell, Jill S; Kretzschmar, Doris; Giebultowicz, Jadwiga M

2012-03-01

Circadian clocks generate rhythms in molecular, cellular, physiological, and behavioral processes. Recent studies suggest that disruption of the clock mechanism accelerates organismal senescence and age-related pathologies in mammals. Impaired circadian rhythms are observed in many neurological diseases; however, it is not clear whether loss of rhythms is the cause or result of neurodegeneration, or both. To address this important question, we examined the effects of circadian disruption in Drosophila melanogaster mutants that display clock-unrelated neurodegenerative phenotypes. We combined a null mutation in the clock gene period (per(01)) that abolishes circadian rhythms, with a hypomorphic mutation in the carbonyl reductase gene sniffer (sni(1)), which displays oxidative stress induced neurodegeneration. We report that disruption of circadian rhythms in sni(1) mutants significantly reduces their lifespan compared to single mutants. Shortened lifespan in double mutants was coupled with accelerated neuronal degeneration evidenced by vacuolization in the adult brain. In addition, per(01)sni(1) flies showed drastically impaired vertical mobility and increased accumulation of carbonylated proteins compared to age-matched single mutant flies. Loss of per function does not affect sni mRNA expression, suggesting that these genes act via independent pathways producing additive effects. Finally, we show that per(01) mutation accelerates the onset of brain pathologies when combined with neurodegeneration-prone mutation in another gene, swiss cheese (sws(1)), which does not operate through the oxidative stress pathway. Taken together, our data suggest that the period gene may be causally involved in neuroprotective pathways in aging Drosophila. Copyright © 2011 Elsevier Inc. All rights reserved.

Induction of mutants in Durum Wheat by hybridization and irradiation techniques

International Nuclear Information System (INIS)

Al Ubaidi, M.O.; Ibrahim, I.F.

2001-01-01

This investigation presents a breeding program for induction and development a new genotypes of durum wheat, resistant to lodging with high yield, by irradiated seeds (F2) of durum wheat hybrid's (Sin Al-jemal X Izraa, Sin Al-Jemal X Cocorat and Izraa X Cocorat) with gamma rays 100 Gy dose. This program involves: Induction of variability, selection, evaluation of the best mutants at three different locations, Twaitha(Baghdad), Latifya (Babylon) and Swari (Kutt), for the period 1990-1999. Results revealed that the mutants ( Si X Iz-7, Si X Iz-22, Si X Co-43, Si X Co-48, Si X Co-50, Si X Co- 87, Iz X Co-95 and Iz X Co-105) showed resistance to lodging with a significant reduction in plant heigth, but mutant Si X Iz-22 surpassed the other mutants and it is origin in lodging resistance and reduction in plant heigth (84.8, 81.9 and 86.3 cm) at Twaitha, Latifya and Babylon respectively in M7 and M8 generations. Also there were a significant differences between the mutants and their origin in yield and yield components during the two successive generations, on the other hand mutant Iz X Co-105 surpassed the other mutants in spikes/m2 ( 278.8, 263.3 and 289) and grain yield (4950, 4820 and 5320 kg/ha) in the testing locations respectively

Structure and expression of cytochrome f in an Oenothera plastome mutant.

Science.gov (United States)

Johnson, E M; Sears, B B

1990-06-01

The chloroplast mutant pm7 is one of a number of mutants derived from the plastome mutator (pm) line of Oenothera hookeri, strain Johansen. Immunoblotting showed that this mutant accumulates a protein that is cross-antigenic with cytochrome f, but five kilodaltons larger than the mature wild-type protein. Since cytochrome f is known to be translated on plastid ribosomes as a precursor with an amino-terminal extension, it is proposed that the unprocessed cytochrome f precursor accumulates in pm7. In addition to this precursor-sized cytochrome f protein, some mature-sized cytochrome f was also found in the mutant plastids. The pm7 mutation is inherited in a non-Mendelian fashion; but no alterations in chloroplast DNA restriction patterns, or differences in DNA sequence in the region encoding cytochrome f, were found in a comparison of the wild-type and pm7 chloroplast DNAs. Although the mutant was capable of synthesizing heme, no covalently-bound heme, normally found associated with mature, functional, cytochrome f was detected in the mutant at sizes expected for the presumed precursor, or for mature cytochrome f. These results indicate that the aberrant accumulation of a precursor-sized cytochrome f in pm7 is not due to a lesion directly in the plastid gene encoding cytochrome f, petA, or to a deficiency in the ability of the mutant plastids to synthesize or accumulate heme.

Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

International Nuclear Information System (INIS)

Heros, E.; Gomez, L.

2015-01-01

To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M 2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha -1 versus 6.6 t ha -1 . These mutants show lodging and shattering resistance. (Author)

Towards a "Golden Standard" for computing globin stability: Stability and structure sensitivity of myoglobin mutants.

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Kepp, Kasper P

2015-10-01

Fast and accurate computation of protein stability is increasingly important for e.g. protein engineering and protein misfolding diseases, but no consensus methods exist for important proteins such as globins, and performance may depend on the type of structural input given. This paper reports benchmarking of six protein stability calculators (POPMUSIC 2.1, I-Mutant 2.0, I-Mutant 3.0, CUPSAT, SDM, and mCSM) against 134 experimental stability changes for mutations of sperm-whale myoglobin. Six different high-resolution structures were used to test structure sensitivity that may impair protein calculations. The trend accuracy of the methods decreased as I-Mutant 2.0 (R=0.64-0.65), SDM (R=0.57-0.60), POPMUSIC2.1 (R=0.54-0.57), I-Mutant 3.0 (R=0.53-0.55), mCSM (R=0.35-0.47), and CUPSAT (R=0.25-0.48). The mean signed errors increased as SDMMean absolute errors increased as I-Mutant 2.0Mutant 3.0Mutant 3.0 (0.05)Mutant 2.0 (0.09)Mutant 2.0 is proficient for this purpose, as further validated against a data set of related cytochrome c like proteins. The results also emphasize the importance of high-quality crystal structures and reveal structure-dependent effects even in the near-atomic resolution limit. Copyright © 2015 Elsevier B.V. All rights reserved.

The three catalases in Deinococcus radiodurans: Only two show catalase activity.

Science.gov (United States)

Jeong, Sun-Wook; Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong; Lim, Heon-Man; Lim, Sangyong

2016-01-15

Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (Δdr1998, ΔdrA0146, and ΔdrA0259) of D. radiodurans. Of the three mutants, Δdr1998 exhibited the greatest decrease in hydrogen peroxide (H2O2) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H2O2 treatments, whereas ΔdrA0146 showed no change in its H2O2 resistance or ROS level. Catalase activity was not attenuated in ΔdrA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ΔdrA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H2O2, but DRA0146 does not have catalase activity and is not involved in the resistance to H2O2 stress. Copyright © 2015 Elsevier Inc. All rights reserved.

The Phosphoinositide 3-Kinaseα Selective Inhibitor, BYL719, Enhances the Effect of the Protein Kinase C Inhibitor, AEB071, in GNAQ/GNA11 Mutant Uveal Melanoma Cells

Science.gov (United States)

Musi, Elgilda; Ambrosini, Grazia; de Stanchina, Elisa; Schwartz, Gary K.

2014-01-01

G-protein mutations are one of the most common mutations occurring in uveal melanoma activating the protein kinase C (PKC)/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-Kinase (PI3K)/AKT pathways. In this study, we described the effect of dual pathway inhibition in uveal melanoma harboring GNAQ and GNA11 mutations via PKC inhibition with AEB071 (Sotrastaurin) and PI3k/AKT inhibition with BYL719, a selective PI3Kα inhibitor. Growth inhibition was observed in GNAQ/GNA11 mutant cells with AEB071 versus no activity in WT cells. In the GNAQ-mutant cells, AEB071 decreased phosphorylation of MARCKS, a substrate of PKC, along with ERK1/2 and ribosomal S6, but persistent AKT activation was present. BYL719 had minimal anti-proliferative activity in all uveal melanoma cell lines, and inhibited phosphorylation of AKT in most cell lines. In the GNA11 mutant cell line, similar effects were observed with ERK1/2 inhibition, mostly inhibited by BYL719. With the combination treatment, both GNAQ and GNA11 mutant cell lines showed synergistic inhibition of cell proliferation and apoptotic cell death. In vivo studies correlated with in vitro findings showing reduced xenograft tumor growth with the combination therapy in a GNAQ mutant model. These findings suggest a new therapy treatment option for G-protein mutant uveal melanoma with a focus on specific targeting of multiple downstream pathways as part of combination therapy. PMID:24563540

The phosphoinositide 3-kinase α selective inhibitor BYL719 enhances the effect of the protein kinase C inhibitor AEB071 in GNAQ/GNA11-mutant uveal melanoma cells.

Science.gov (United States)

Musi, Elgilda; Ambrosini, Grazia; de Stanchina, Elisa; Schwartz, Gary K

2014-05-01

G-protein mutations are one of the most common mutations occurring in uveal melanoma activating the protein kinase C (PKC)/mitogen-activated protein kinase and phosphoinositide 3-kinase (PI3K)/AKT pathways. In this study, we described the effect of dual pathway inhibition in uveal melanoma harboring GNAQ and GNA11 mutations via PKC inhibition with AEB071 (sotrastaurin) and PI3K/AKT inhibition with BYL719, a selective PI3Kα inhibitor. Growth inhibition was observed in GNAQ/GNA11-mutant cells with AEB071 versus no activity in wild-type cells. In the GNAQ-mutant cells, AEB071 decreased phosphorylation of myristoylated alanine-rich C-kinase substrate, a substrate of PKC, along with ERK1/2 and ribosomal S6, but persistent AKT activation was present. BYL719 had minimal antiproliferative activity in all uveal melanoma cell lines, and inhibited phosphorylation of AKT in most cell lines. In the GNA11-mutant cell line, similar effects were observed with ERK1/2 inhibition, mostly inhibited by BYL719. With the combination treatment, both GNAQ- and GNA11-mutant cell lines showed synergistic inhibition of cell proliferation and apoptotic cell death. In vivo studies correlated with in vitro findings showing reduced xenograft tumor growth with the combination therapy in a GNAQ-mutant model. These findings suggest a new therapy treatment option for G-protein-mutant uveal melanoma with a focus on specific targeting of multiple downstream pathways as part of combination therapy.

Morphological mutants of Neurospora crassa: possible evidence of abnormal morphology due to changes in DNA composition

Energy Technology Data Exchange (ETDEWEB)

Chaudhuri, R K; Dutta, S.K. Ojha, M.

1973-01-01

DNA from seven experimentally induced morphological mutants and the wild type strain 74A of Neurospora crassa showed typical bimodal denaturation profiles in a Gilford 2400 spectrophotometer. The ''slime'' and ''ropy'' mutants showed a comparatively high proportion of A + T rich DNA sequences. Studies on thermal denaturation, percent hybridization, and thermal stability indicate the DNA sequences of the slime mutant were distinctly different from the normal genomes of parental DNA as well as other wild type DNAs. No such difference was noticed in any other mutant and natural isolate of the species N. crassa tested. These studies indicate possible correlation between a change in DNA nucleotide sequences and abnormal morphogenesis.

Absence-like and tonic seizures in aspartoacylase/attractin double-mutant mice.

Science.gov (United States)

Gohma, Hiroshi; Kuramoto, Takashi; Matalon, Reuben; Surendran, Sankar; Tyring, Stephen; Kitada, Kazuhiro; Sasa, Masashi; Serikawa, Tadao

2007-04-01

The Spontaneously Epileptic Rat (SER), a double-mutant for tremor and zitter mutations, shows spontaneous occurrences of absence-like and tonic seizures. Several lines of evidence suggest that the combined effect of Aspa and Atrn mutations is the most likely cause of the epileptic phenotype of the SER. To address this issue, we produced a new double-mutant mouse line carrying both homozygous Aspa-knockout and Atrn(mg-3J) mutant alleles. The Aspa/Atrn double-mutant mice exhibited absence-like and tonic seizures that were characterized by the appearance of 5-7 Hz spike-wave-like complexes and low voltage fast waves on EEGs. These results demonstrate directly that the simultaneous loss of the Aspa and Atrn gene functions causes epileptic seizures in the mouse and suggest that both Aspa and Atrn deficiencies might be responsible for epileptic seizures in the SER.

Serine:glyoxylate aminotransferase mutant of barley

International Nuclear Information System (INIS)

Blackwell, R.; Murray, A.; Joy, K.; Lea, P.

1987-01-01

A photorespiratory mutant of barley (LaPr 85/84), deficient in both of the major peaks of serine:glyoxylate aminotransferase activity detected in the wild type, also lacks serine:pyruvate and asparagine:glyoxylate aminotransferase activities. Genetic analysis of the mutation demonstrated that these three activities are all carried on the same enzyme. The mutant, when placed in air, accumulated a large pool of serine, showed the expected rate (50%) of ammonia release during photorespiration but produced CO 2 at twice the wild type rate when it was fed [ 14 C] glyoxylate. Compared with the wild type, LaPr 85/84 exhibited abnormal transient changes in chlorophyll a fluorescence when the CO 2 concentration of the air was altered, indicating that the rates of the fluorescence quenching mechanisms were affected in vivo by the lack of this enzyme

Citric acid fermentation by gamma ray induced mutants of Aspergillus niger in different carbohydrate media

Energy Technology Data Exchange (ETDEWEB)

Anjuman Ara Begum; Naiyyum Choudhury; Mohammad Serajul Islam (Institute of Food and Radiation Biology, Dacca (Bangladesh))

1990-01-01

A natural isolate of Aspergillus niger, CA16, and two of its second step mutants, 136/40 and 277/30, grown on different sugar substrates gave maximum citric acid yields of 34, 70, and 126 mg/ml respectively in sucrose medium. Combination of two sugars in the medium at 50% of each improved the yields of citric acid for the sucrose: glucose, glucose: sorbitol, glucose: xylose, and xylose: sorbitol combinations with the mutant strains. Inclusion of galactose in combinations decreased the citric acid yield. (author).

Citric acid fermentation by gamma ray induced mutants of Aspergillus niger in different carbohydrate media

International Nuclear Information System (INIS)

Anjuman Ara Begum; Naiyyum Choudhury; Mohammad Serajul Islam

1990-01-01

A natural isolate of Aspergillus niger, CA16, and two of its second step mutants, 136/40 and 277/30, grown on different sugar substrates gave maximum citric acid yields of 34, 70, and 126 mg/ml respectively in sucrose medium. Combination of two sugars in the medium at 50% of each improved the yields of citric acid for the sucrose: glucose, glucose: sorbitol, glucose: xylose, and xylose: sorbitol combinations with the mutant strains. Inclusion of galactose in combinations decreased the citric acid yield. (author)

A higher yielding mutant of black gram with improved nodule formation

Energy Technology Data Exchange (ETDEWEB)

Singh, R K; Raghuvanshi, S S [Plant Genetic Unit, Department of Botany, University of Lucknow (India)

1987-07-01

Dry seeds of black gram (Vigna mungo (L) Hopper) var. T{sub 9} with 12.2% moisture content were irradiated at 10, 20 and 30 krad of gamma rays. This was followed by combined treatment of one set in each dose with freshly prepared 0. 25% EMS in phosphate buffer at 7.0 pH at 30{+-} deg. C for 6 hours. In M{sub 2} population of 20 krad two mutants with pentafoliate instead of trifoliate leaves were found. This character was true breeding in M{sub 3} M{sub 6} generation. Crosses revealed monogenic recessive inheritance of this character. The proposed gene symbol is p5. This mutant has normal maturity period and the plant height is the same as T{sub 9} (ca. 50 cm). Preliminary yield trials indicate superiority of the mutant line over control. The mutant line also shows a significant improvement in number and weight of root nodules, potentially improving green manuring value. Improvement of root nodulation in mungbean mutants was reported before by others.

Combined targeting of BRAF and CRAF or BRAF and PI3K effector pathways is required for efficacy in NRAS mutant tumors.

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Bijay S Jaiswal

Full Text Available BACKGROUND: Oncogenic RAS is a highly validated cancer target. Attempts at targeting RAS directly have so far not succeeded in the clinic. Understanding downstream RAS-effectors that mediate oncogenesis in a RAS mutant setting will help tailor treatments that use RAS-effector inhibitors either alone or in combination to target RAS-driven tumors. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we have investigated the sufficiency of targeting RAS-effectors, RAF, MEK and PI3-Kinase either alone or in combination in RAS mutant lines, using an inducible shRNA in vivo mouse model system. We find that in colon cancer cells harboring a KRAS(G13D mutant allele, knocking down KRAS alone or the RAFs in combination or the RAF effectors, MEK1 and MEK2, together is effective in delaying tumor growth in vivo. In melanoma cells harboring an NRAS(Q61L or NRAS(Q61K mutant allele, we find that targeting NRAS alone or both BRAF and CRAF in combination or both BRAF and PIK3CA together showed efficacy. CONCLUSION/SIGNIFICANCE: Our data indicates that targeting oncogenic NRAS-driven melanomas require decrease in both pERK and pAKT downstream of RAS-effectors for efficacy. This can be achieved by either targeting both BRAF and CRAF or BRAF and PIK3CA simultaneously in NRAS mutant tumor cells.

Phenotypic and epistatic grouping of hypo- and hyper-rec mus mutants in Aspergillus.

Science.gov (United States)

Kafer, E; Chae, S K

1994-03-01

The mutants musK to musS of Aspergillus nidulans are sensitive to methyl-methanesulfonate (MMS) and several of them are meiotic-defective and alter mitotic recombination frequencies. All were found to be cross-sensitive to 4-nitro-quinoline-N-oxide (4-NQO) but unexpectedly none of them was hypersensitive to gamma-rays and few to UV light. Double mus; uvs mutants were constructed to test for interactions with uvs mutations of the four epistatic groups of Aspergillus, "UvsF", "UvsC", "UvsI", and "UvsB". All meiotic-defective mus mutations caused some lethal interactions, usually with uvsF. None of them showed epistasis with UvsF or UvsB group mutants and one, musO, may represent a new group. Three mus mutations that affect recombination were assigned to the UvsC group, namely musN and K, and also musL which is recombination-defective and closely resembles uvsC. While uvsC mutants are mutators and lack UV-mutagenesis, most mus mutants had no effects on mutation. Only musR, which appeared epistatic with uvsI, showed reduced UV-reversion frequencies similar to uvsI. The recombination-proficient mus mutants appeared to be epistatic with more than one group, but in several cases sensitivities were slight and overlaps insufficient to obtain corroborating results with MMS and 4-NQO.

Problem-Solving Test: Tryptophan Operon Mutants

Science.gov (United States)

Szeberenyi, Jozsef

2010-01-01

This paper presents a problem-solving test that deals with the regulation of the "trp" operon of "Escherichia coli." Two mutants of this operon are described: in mutant A, the operator region of the operon carries a point mutation so that it is unable to carry out its function; mutant B expresses a "trp" repressor protein unable to bind…

Survival and mutant production induced by mutagenic agents in Metarhizium anisopliae Sobrevivência e obtenção de mutantes induzidos por agentes mutagênicos em Metarhizium anisopliae

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V. Kava - Cordeiro

1995-12-01

Full Text Available A wild strain of Metarhizium anisopliae, an entomopathogenic fungus, was submitted to three mutagenic agents: gamma radiation, ultraviolet light and nitrous acid. Survival curves were obtained and mutants were selected using different mutagenic doses which gave 1 to 5% survival. Morphological and auxotrophic mutants were isolated. Morphological mutants were grouped in a class with yellow conidia and other with pale vinaceous conidia as opposed to the green wild type conidia. Auxotrophic mutants had requirements for vitamin and aminoacid biosynthesis. More than 58% of the total auxotrophk mutants required proline/aipnine. Gamma radiation showed to be the most efficient mutagenic agent giving 0.2% of auxotrophk mutants followed by ultraviolet light (0.12% and nitrous acid (0.06%.The conidial colour and auxotrophk mutants isolated until now from M. anisopliae were reviewed.Uma linhagem selvagem do fungo entomopatogênico Metarhizium anisopliae foi submetida à ação de três agentes mutagênicos: radiação gama, luz ultravioleta e ácido nitroso. Curvas de sobrevivência foram obtidas para cada mutagênicos utilizado e mutantes foram selecionados a partir de doses dos mutagênicos que proporcionassem de 1 a 5% de sobrevivência. Mutantes morfológicos para a coloração de conídios e mutantes auxotróficos foram isolados. Mutantes para coloração de conidios foram agrupados em duas classes, uma com conídios amarelos e outra com conídios vinho pálido. Os mutantes auxotróficos obtidos foram deficientes para aminoácidos e vitaminas e mais de 58% deles eram auxotróficos para prolina/argmina. Radiação gama foi o mutagênico mais eficiente com uma porcentagem de obtenção de mulantes auxotróficos de aproximadamente 0,2%, seguido pela luz ultravioleta (0.12% e pelo ácido nitroso (0.06%.Os mulantes morfológicos e auxotróficos obtidos até o momento em Metarhizium anisopliae foram revistos.

MUTANTES DE LARANJA - 'PÊRA' COM NÚMERO REDUZIDO DE SEMENTES, OBTIDOS ATRAVÉS DE MUTAÇÕES INDUZIDAS SWEET ORANGE 'PÊRA' MUTANTS WITH LOW NUMBER OF SEEDS OBTAINED THROUGH MUTATION INDUCTION

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RODRIGO ROCHA LATADO

2001-08-01

Full Text Available A obtenção de cultivares de citros com pequeno número de sementes é importante quando o objetivo é a produção de frutas para o consumo in natura. O objetivo deste trabalho foi o de avaliar, por três anos (1997, 1998 e 1999, o número médio de sementes e 15 outras características agronômicas, de 127 mutantes putativos de laranja-'Pêra', selecionados após irradiação de borbulhas com raios-gama e 8 plantas selecionadas do controle não irradiado. Os mutantes foram divididos em 16 grupos baseados nos tipos de mutações observados e em cada grupo, como controle comum, foram incluídas plantas de laranja-'Pêra' comercial. Observou-se que 46 mutantes putativos e uma planta do controle não irradiado (PSC apresentaram redução significativa no número de sementes por fruto, nos três anos consecutivos, sendo que 15 mutantes apresentaram frutos com média entre uma e duas sementes e 9 mutantes, frutos com média inferior a uma semente. Dentre estes 9 mutantes, os de número 27, 28 e 58, que apresentaram também alterações significativas no diâmetro de copa ou na altura de planta, além do 59 e 101, que não apresentaram alterações nas outras 15 características avaliadas, possuem um maior potencial para serem lançados como novos mutantes de laranja-'Pêra' com pequeno número de sementes.Citrus varieties with low number of seeds are important for in natura fruit market. The objective of the present work was to evaluate, for three years (1997, 1998 and 1999, the average number of seeds per fruit and 15 other agronomic characteristics of 127 putative mutated clones of sweet orange 'Pêra', selected after gamma-irradiation of budwood and 8 non irradiated control clones. Mutants were divided in 16 groups based on the type of mutation observed 'Pêra' commercial control plants (PCC were included. It was observed that 46 putative mutants and one non-irradiated plant (PSC showed significant reduction in seed number per fruit. Fifteen

Development of One mutant line with Improved Quantitative and Qualitative Traits through Induced Mutation

International Nuclear Information System (INIS)

Saif, A. A.; Al-kibssi, M; Al-Shamiri, A; Kassem, R

2008-01-01

A field experiment was conducted in three consecutive seasons 2005, 2006 and 2007 for evaluating five mutant lines derived from Gemiza-9 variety. Gemiza-9 and Shibam-8 were used as a checks for yellow rust resistance and some agronomic characters. The mutant lines were planted in Al-erra research farm and farmer's field under rainfed condition, in particularly at Shibam and Bani-Mater regions. Results showed that the MS-5 and MS-9 mutant lines were earlier than the others and the checks. They matured on 102 - 105 days compared with 111 - 118 days for the other lines including the original variety and the Shibam-8 variety. These two mutant lines showed not only early maturing but also resistance to yellow rust disease, they scored R20% -R30%, while the all material were medium resistance including the checks. With respect to yield, the MS -5 mutant had a significant high yield (3963 kg/ha) compared with the others including the Gemiza-9 and Shibam-8 variety amounting to 35.5 % and 32.2 % for the two checks respectively. (author)

[Intragenic mitotic recombination induced by ultraviolet and gamma rays in radiosensitive mutants of Saccharomyces cerevisiae yeasts].

Science.gov (United States)

Zakharov, I A; Kasinova, G V; Koval'tsova, S V

1983-01-01

The effect of UV- and gamma-irradiation on the survival and intragenic mitotic recombination (gene conversion) of 5 radiosensitive mutants was studied in comparison with the wild type. The level of spontaneous conversion was similar for RAD, rad2 and rad15, mutations xrs2 and xrs4 increasing and rad54 significantly decreasing it. The frequency of conversion induced by UV-light was greater in rad2, rad15 and xrs2 mutants and lower in xrs4, as compared to RAD. Gamma-irradiation caused induction of gene conversion with an equal frequency in RAD, rad2, rad15. Xrs2 and xrs4 mutations slightly decreased gamma-induced conversion. In rad54 mutant, UV-and gamma-induced conversion was practically absent. In the wild type yeast, a diploid strain is more resistant than a haploid, whereas in rad54 a diploid strain has the same or an increased sensitivity, as compared to a haploid strain (the "inverse ploidy effect"). This effect and also the block of induced mitotic recombination caused by rad54 indicate the presence in the yeast Saccharomyces cerevisiae of repair pathways of UV- and gamma-induced damages acting in diploid cells and realised by recombination. The data obtained as a result of many years' investigation of genetic effects in radiosensitive mutants of yeast are summarised and considered.

Interferon β induces clearance of mutant ataxin 7 and improves locomotion in SCA7 knock-in mice.

Science.gov (United States)

Chort, Alice; Alves, Sandro; Marinello, Martina; Dufresnois, Béatrice; Dornbierer, Jean-Gabriel; Tesson, Christelle; Latouche, Morwena; Baker, Darren P; Barkats, Martine; El Hachimi, Khalid H; Ruberg, Merle; Janer, Alexandre; Stevanin, Giovanni; Brice, Alexis; Sittler, Annie

2013-06-01

We showed previously, in a cell model of spinocerebellar ataxia 7, that interferon beta induces the expression of PML protein and the formation of PML protein nuclear bodies that degrade mutant ataxin 7, suggesting that the cytokine, used to treat multiple sclerosis, might have therapeutic value in spinocerebellar ataxia 7. We now show that interferon beta also induces PML-dependent clearance of ataxin 7 in a preclinical model, SCA7(266Q/5Q) knock-in mice, and improves motor function. Interestingly, the presence of mutant ataxin 7 in the mice induces itself the expression of endogenous interferon beta and its receptor. Immunohistological studies in brains from two patients with spinocerebellar ataxia 7 confirmed that these modifications are also caused by the disease in humans. Interferon beta, administered intraperitoneally three times a week in the knock-in mice, was internalized with its receptor in Purkinje and other cells and translocated to the nucleus. The treatment induced PML protein expression and the formation of PML protein nuclear bodies and decreased mutant ataxin 7 in neuronal intranuclear inclusions, the hallmark of the disease. No reactive gliosis or other signs of toxicity were observed in the brain or internal organs. The performance of the SCA7(266Q/5Q) knock-in mice was significantly improved on two behavioural tests sensitive to cerebellar function: the Locotronic® Test of locomotor function and the Beam Walking Test of balance, motor coordination and fine movements, which are affected in patients with spinocerebellar ataxia 7. In addition to motor dysfunction, SCA7(266Q/5Q) mice present abnormalities in the retina as in patients: ataxin 7-positive neuronal intranuclear inclusions that were reduced by interferon beta treatment. Finally, since neuronal death does not occur in the cerebellum of SCA7(266Q/5Q) mice, we showed in primary cell cultures expressing mutant ataxin 7 that interferon beta treatment improves Purkinje cell survival.

Hypermutability of a UV-sensitive aphidicolin-resistant mutant of Chinese hamster fibroblasts

International Nuclear Information System (INIS)

Liu, P.K.; Chang, C.; Trosko, J.E.

1982-01-01

An ultraviolet light (UV)-sensitive thymidine auxotroph of Chinese hamster V79 cells that exhibits pleiotropic effects such as a high level of deoxycytidine triphosphate, slow growth, sensitivity to cytidine, and high frequencies of site-specific bromodeoxyuridine-dependent chromosomal aberrations was selected by its resistance to aphidicolin. The UV-induced mutability of this mutant and one of its revertants, which retains some of the phenotypes listed above, was studied in 3 mutation assay systems. The results showed that the mutant was hypermutable for ouabain and diphtheria-toxin-resistant mutations compared to wild-type V79 cells at the same UV dose or the same survival level. The mutant exhibits a delayed expression of maximal frequency of induced 6-thioguanine-resistant mutants. When maximal frequencies are compared at the same UV dose, the mutant also has higher mutation frequencies at the hypoxanthine-guanine phosphoribosyl transferase locus. The revertant was similar to the wild-type in UV sensitivity and mutability. (orig./AJ)

Homologous series of induced early mutants in Indica rice. Pt.3: The relationship between the induction of homologous series of early mutants and its different pedigree

International Nuclear Information System (INIS)

Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

2002-01-01

The percentage of homologous series of early mutants (PHSEM) induced by irradiation was closely related to its pedigree. This study showed that PHSEM for varieties with the same pedigree were similar, and there were three different level of dominance (high, low and normal) in the homologous series induced from different pedigree. The PHSEM for varieties derived form distant-relative-parents were higher than that derived from close-relative-parents. There was the dominance pedigree for the induction of homologous series of early mutants. IR8(Peta x DGWG), IR127 (Cpslo x Sigadis) and IR24 (IR8 x IR127) were dominant pedigree, and varieties derived from them could be easily induced the homologous series of early mutants

Construction of insertion and deletion mxa mutants of Methylobacterium extorquens AM1 by electroporation.

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Toyama, H; Anthony, C; Lidstrom, M E

1998-09-01

Methylobacterium extorquens AM1 is a pink-pigmented facultative methylotroph which is widely used for analyzing pathways of C1 metabolism with biochemical and molecular biological techniques. To facilitate this approach, we have applied a new method to construct insertion or disruption mutants with drug resistance genes by electroporation. By using this method, mutants were obtained in four genes present in the mxa methylotrophy gene cluster for which the functions were unknown, mxaR, mxaS, mxaC and mxaD. These mutants were unable to grow on methanol except the mutant of mxaD, which showed reduced growth on methanol.

Isolation and characterisation of a dwarf rice mutant exhibiting defective gibberellins biosynthesis.

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Ji, S H; Gururani, M A; Lee, J W; Ahn, B-O; Chun, S-C

2014-03-01

We have isolated a severe dwarf mutant derived from a Ds (Dissociation) insertion mutant rice (Oryza sativa var. japonica c.v. Dongjin). This severe dwarf phenotype, has short and dark green leaves, reduced shoot growth early in the seedling stage, and later severe dwarfism with failure to initiate flowering. When treated with bioactive GA3 , mutants are restored to the normal wild-type phenotype. Reverse transcription PCR analyses of 22 candidate genes related to the gibberellin (GA) biosynthesis pathway revealed that among 22 candidate genes tested, a dwarf mutant transcript was not expressed only in one OsKS2 gene. Genetic analysis revealed that the severe dwarf phenotype was controlled by recessive mutation of a single nuclear gene. The putative OsKS2 gene was a chromosome 4-located ent-kaurene synthase (KS), encoding the enzyme that catalyses an early step of the GA biosynthesis pathway. Sequence analysis revealed that osks2 carried a 1-bp deletion in the ORF region of OsKS2, which led to a loss-of-function mutation. The expression pattern of OsKS2 in wild-type cv Dongjin, showed that it is expressed in all organs, most prominently in the stem and floral organs. Morphological characteristics of the dwarf mutant showed dramatic modifications in internal structure and external morphology. We propose that dwarfism in this mutant is caused by a point mutation in OsKS2, which plays a significant role in growth and development of higher plants. Further investigation on OsKS2 and other OsKS-like proteins is underway and may yield better understanding of the putative role of OsKS in severe dwarf mutants. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Missense mutation Lys18Asn in dystrophin that triggers X-linked dilated cardiomyopathy decreases protein stability, increases protein unfolding, and perturbs protein structure, but does not affect protein function.

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Surinder M Singh

Full Text Available Genetic mutations in a vital muscle protein dystrophin trigger X-linked dilated cardiomyopathy (XLDCM. However, disease mechanisms at the fundamental protein level are not understood. Such molecular knowledge is essential for developing therapies for XLDCM. Our main objective is to understand the effect of disease-causing mutations on the structure and function of dystrophin. This study is on a missense mutation K18N. The K18N mutation occurs in the N-terminal actin binding domain (N-ABD. We created and expressed the wild-type (WT N-ABD and its K18N mutant, and purified to homogeneity. Reversible folding experiments demonstrated that both mutant and WT did not aggregate upon refolding. Mutation did not affect the protein's overall secondary structure, as indicated by no changes in circular dichroism of the protein. However, the mutant is thermodynamically less stable than the WT (denaturant melts, and unfolds faster than the WT (stopped-flow kinetics. Despite having global secondary structure similar to that of the WT, mutant showed significant local structural changes at many amino acids when compared with the WT (heteronuclear NMR experiments. These structural changes indicate that the effect of mutation is propagated over long distances in the protein structure. Contrary to these structural and stability changes, the mutant had no significant effect on the actin-binding function as evident from co-sedimentation and depolymerization assays. These results summarize that the K18N mutation decreases thermodynamic stability, accelerates unfolding, perturbs protein structure, but does not affect the function. Therefore, K18N is a stability defect rather than a functional defect. Decrease in stability and increase in unfolding decrease the net population of dystrophin molecules available for function, which might trigger XLDCM. Consistently, XLDCM patients have decreased levels of dystrophin in cardiac muscle.

Studies on induced partially resistant mutants of barley against powdery mildew

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Roebbelen, G.; Abdel-Hafez, A.G.; Reinhold, M.; Kwon, H.J.; Neuhaus-Steinmetz, J.P.; Heun, M.

1983-01-01

After mutagenic seed treatment of three partially resistant cultivars of spring barley with EMS and NaN 3 , 45 mutants in a first and 16 in a second experiment were selected in the M 2 -M 4 generations. The screening was done alternatively under natural infection in the field or controlled infection with a single pathotype in the greenhouse. These mutants exhibited a higher resistance and a higher susceptibility, respectively, than the initial cultivars Asse, Bomi and Vada. Some mutants expressed their altered resistance behaviour particularly during certain stages of development. High-level resistance was conditioned by mutation in the ml-o locus in three cases. For several Bomi mutants pathotype specificity with and without reversed ranking was proven as well as pathotype non-specificity in comparison with the reaction of the original cultivar. In 14 cases studied the inheritance of the involved mutants was monogenic recessive. The laevigatum locus responsible for the intermediate mildew resistance of Bomi was not affected by the mutations. Detection of groups of allelic mutants showed that there are at least two regions in the barley genome in which mutations for mildew resistance can occur rather frequently. In total, the past ten years of this mutation research have given convincing evidence that the strategies of mutant screening applied have yielded promising new material both for breeding and for progress in basic understanding of host-pathogen interactions. (author)

Mutant genes in pea breeding

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Swiecicki, W.K.

1990-01-01

Full text: Mutations of genes Dpo (dehiscing pods) and A (anthocyanin synthesis) played a role in pea domestication. A number of other genes were important in cultivar development for 3 types of usage (dry seeds, green vegetable types, fodder), e.g. fn, fna, le, p, v, fas and af. New genes (induced and spontaneous), are important for present ideotypes and are registered by the Pisum Genetics Association (PGA). Comparison of a pea variety ideotype with the variation available in gene banks shows that breeders need 'new' features. In mutation induction experiments, genotype, mutagen and method of treatment (e.g. combined or fractionated doses) are varied for broadening the mutation spectrum and selecting more genes of agronomic value. New genes are genetically analysed. In Poland, some mutant varieties with the gene afila were registered, controlling lodging by a shorter stem and a higher number of internodes. Really non-lodging pea varieties could strongly increase seed yield. But the probability of detecting a major gene for lodging resistance is low. Therefore, mutant genes with smaller influence on plant architecture are sought, to combine their effect by crossing. Promising seem to be the genes rogue, reductus and arthritic as well as a number of mutant genes not yet genetically identified. The gene det for terminal inflorescence - similarly to Vicia faba - changes plant development. Utilisation of assimilates and ripening should be better. Improvement of harvest index should give higher seed yield. A number of genes controlling disease resistance are well known (eg. Fw, Fnw, En, mo and sbm). Important in mass screening of resistance are closely linked gene markers. Pea gene banks collect respective lines, but mutants induced in highly productive cultivars would be better. Inducing gene markers sometimes seems to be easier than transfer by crossing. Mutation induction in pea breeding is probably more important because a high number of monogenic features are

Mutant power: using mutant allele collections for yeast functional genomics.

Science.gov (United States)

Norman, Kaitlyn L; Kumar, Anuj

2016-03-01

The budding yeast has long served as a model eukaryote for the functional genomic analysis of highly conserved signaling pathways, cellular processes and mechanisms underlying human disease. The collection of reagents available for genomics in yeast is extensive, encompassing a growing diversity of mutant collections beyond gene deletion sets in the standard wild-type S288C genetic background. We review here three main types of mutant allele collections: transposon mutagen collections, essential gene collections and overexpression libraries. Each collection provides unique and identifiable alleles that can be utilized in genome-wide, high-throughput studies. These genomic reagents are particularly informative in identifying synthetic phenotypes and functions associated with essential genes, including those modeled most effectively in complex genetic backgrounds. Several examples of genomic studies in filamentous/pseudohyphal backgrounds are provided here to illustrate this point. Additionally, the limitations of each approach are examined. Collectively, these mutant allele collections in Saccharomyces cerevisiae and the related pathogenic yeast Candida albicans promise insights toward an advanced understanding of eukaryotic molecular and cellular biology. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Regiospecificity determinants of human heme oxygenase: differential NADPH- and ascorbate-dependent heme cleavage by the R183E mutant.

Science.gov (United States)

Wang, Jinling; Lad, Latesh; Poulos, Thomas L; Ortiz de Montellano, Paul R

2005-01-28

The ability of the human heme oxygenase-1 (hHO-1) R183E mutant to oxidize heme in reactions supported by either NADPH-cytochrome P450 reductase or ascorbic acid has been compared. The NADPH-dependent reaction, like that of wild-type hHO-1, yields exclusively biliverdin IXalpha. In contrast, the R183E mutant with ascorbic acid as the reductant produces biliverdin IXalpha (79 +/- 4%), IXdelta (19 +/- 3%), and a trace of IXbeta. In the presence of superoxide dismutase and catalase, the yield of biliverdin IXdelta is decreased to 8 +/- 1% with a corresponding increase in biliverdin IXalpha. Spectroscopic analysis of the NADPH-dependent reaction shows that the R183E ferric biliverdin complex accumulates, because reduction of the iron, which is required for sequential iron and biliverdin release, is impaired. Reversal of the charge at position 183 makes reduction of the iron more difficult. The crystal structure of the R183E mutant, determined in the ferric and ferrous-NO bound forms, shows that the heme primarily adopts the same orientation as in wild-type hHO-1. The structure of the Fe(II).NO complex suggests that an altered active site hydrogen bonding network supports catalysis in the R183E mutant. Furthermore, Arg-183 contributes to the regiospecificity of the wild-type enzyme, but its contribution is not critical. The results indicate that the ascorbate-dependent reaction is subject to a lower degree of regiochemical control than the NADPH-dependent reaction. Ascorbate may be able to reduce the R183E ferric and ferrous dioxygen complexes in active site conformations that cannot be reduced by NADPH-cytochrome P450 reductase.

Aggregation of ALS-linked FUS mutant sequesters RNA binding proteins and impairs RNA granules formation

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Takanashi, Keisuke; Yamaguchi, Atsushi, E-mail: atsyama@restaff.chiba-u.jp

2014-09-26

Highlights: • Aggregation of ALS-linked FUS mutant sequesters ALS-associated RNA-binding proteins (FUS wt, hnRNP A1, and hnRNP A2). • Aggregation of ALS-linked FUS mutant sequesters SMN1 in the detergent-insoluble fraction. • Aggregation of ALS-linked FUS mutant reduced the number of speckles in the nucleus. • Overproduced ALS-linked FUS mutant reduced the number of processing-bodies (PBs). - Abstract: Protein aggregate/inclusion is one of hallmarks for neurodegenerative disorders including amyotrophic lateral sclerosis (ALS). FUS/TLS, one of causative genes for familial ALS, encodes a multifunctional DNA/RNA binding protein predominantly localized in the nucleus. C-terminal mutations in FUS/TLS cause the retention and the inclusion of FUS/TLS mutants in the cytoplasm. In the present study, we examined the effects of ALS-linked FUS mutants on ALS-associated RNA binding proteins and RNA granules. FUS C-terminal mutants were diffusely mislocalized in the cytoplasm as small granules in transiently transfected SH-SY5Y cells, whereas large aggregates were spontaneously formed in ∼10% of those cells. hnRNP A1, hnRNP A2, and SMN1 as well as FUS wild type were assembled into stress granules under stress conditions, and these were also recruited to FUS mutant-derived spontaneous aggregates in the cytoplasm. These aggregates stalled poly(A) mRNAs and sequestered SMN1 in the detergent insoluble fraction, which also reduced the number of nuclear oligo(dT)-positive foci (speckles) in FISH (fluorescence in situ hybridization) assay. In addition, the number of P-bodies was decreased in cells harboring cytoplasmic granules of FUS P525L. These findings raise the possibility that ALS-linked C-terminal FUS mutants could sequester a variety of RNA binding proteins and mRNAs in the cytoplasmic aggregates, which could disrupt various aspects of RNA equilibrium and biogenesis.

Quantification of Arabinose content and batter volume in elite black gram mutants induced by gamma rays and electron beam

International Nuclear Information System (INIS)

Vanniarajan, C.; Sri Subalakhshmi, V.K.I.; Se Shamyugtha; Rajeswaran, G.; Monica, R.; Veni, K.

2017-01-01

Black gram (Vignamungo (L) Hepper) is one among the mostly preferred sources of protein, especially in vegetarian diet. One of the most notable biochemical attributes of black gram is Arabinose. As it plays a vital role in the yeast metabolism, it has a direct correlation with the battering quality of Black gram. MDU 1 variety has the highest Arabinose content of 7.5 per cent and VBN(Bg)4yields higher. Both the varieties have indeterminate growth habit. Hence, these two varieties were chosen and treated with Gamma rays and Electron beam of 100–500 Gy and 200–600 Gy respectively. Twenty desirable mutants were selected in M6 generation based on determinate growth habit and high yield with short duration. These mutants were tested for the Arabinose content along with MDU 1 and VBN (Bg)4, using Bial (1902) method. The results of the selected M6 generation mutants revealed that only three mutants excelled in Arabinose content than MDU 1. Two mutants were found to retain the same Arabinose content as that of MDU 1.Three mutants containing higher Arabinose content, one with lower Arabinose content and the parents were further analysed for batter quantity. The unveiled fact is that the increase in Arabinose content increases the batter volume to a certain extent (Arabinose = 10 %). Eventually, with a due course of increase in Arabinose content, the batter volume decreases. The results were tested for significance and were found to be significant. In this present investigation, it was found that the optimum Arabinose content is 10 per cent, which showed an increased batter volume. It has to be further confirmed by using advanced biochemical and molecular methods. (author)

SRAP analysis for space induced mutant line of maize (Zea mays L.)

International Nuclear Information System (INIS)

Du Wenping; Yu Guirong; Song Jun; Xu Liyuan

2011-01-01

In order to detect the effects of space mutation on maize, 16 SRAP primers were applied for the discrimination of the maize inbred line '968' and its 93 mutant materials, 154 polymorphic fragments were amplified. The average of polymorphic bands detected by per SRAP primer combination was 9.6 with a range from 5 to 18. Genetic similarities among the 94 materials ranged from 0.481 to 1.000 with an average of 0.903, and the largest genetic distance was found between mutant line 37 and control. The 94 materials were divided into six groups with the similarity coefficient of 0.732. The phylogenetic analysis showed distinct variation among the mutants. The results indicated that SRAP markers could be used for analyzing genetic variation of mutants. (authors)

Nutrient value protein of mutant J3 of agaricus blazei by irradiation

International Nuclear Information System (INIS)

Jiang Zhihe; Lin Yong; Xiao Shuxia

2003-01-01

The studies of nutrient value protein of mutant J 3 of Agaricus blazei were carried out. The results showed that mutant J 3 had 9 kinds of essential amino acids, the compositions of essential amino acids is 46.0% of total amino acids. The amino acid score is 94.5, the essential amino acid index is 92.4, biological value is 89.0, the ratio coefficient of amino acids is 72.3, the nutrient value is 32.5. The chemical score is 74.18. These results proved that the protein of mutant J 3 had high nutrient value

Tolerance for salinity and morphoagronomic characterization of rice mutants obtained by radioinduction

International Nuclear Information System (INIS)

Gonzalez, L.M.; Ramirez Fernandez, R.; Perez Talavera, S.

1997-01-01

Tolerance for salinity, agroindustrial efficiency, and resistance to diseases were appraised in a group of rice mutants obtained by means of mutation radioinduction, starting from the J-112 variety. Results show significant differences in the analyzed characteristics of radio mutants, and differences between those radio mutans and the donating variety. Radio mutants RM-12, RM-41, and RM-42, besides standing out for their high tolerance for salinity, boasted the highest agroindustrial efficiency and a good behaviour against the main plagues and diseases, which makes of them likely candidates for new varieties in the production from areas affected by salinity

Variation of root system characters in collection of semi-dwarf spring barley mutants

International Nuclear Information System (INIS)

Nawrot, M.; Zbieszczyk, J.; Maluszynski, M.

2000-01-01

The collection of 371 semi-dwarf mutants, derived from 12 spring barley varieties has been used as material for analysis of root system. The mutants have been obtained after mutagenic treatment with N-methyl-N-nitroso urea (MNH), sodium azide (NaN3), gamma-rays and fast neutrons. The following analysis of root system were performed: seminal root growth of 8-day old seedlings, seminal and adventitious root growth of 6-week old plants and dynamics of root growth during first 6 weeks of plant growth. Seminal root length, root number and the length of the first leaf in barley mutants were investigated with the use of paper rollers. Root system analysis of 6-week old plants was performed on genotypes grown in PVC tubes filled with sand, supplemented with 1 mineral salts of MS medium. The following measurements were made: the length of the longest seminal root and the longest adventitious root, the number of adventitious roots and the number of tillers. Analysis of dynamics of root growth during the first six weeks of vegetation was performed at the end of each 7-day growth period in the PVC tubes filled with sand. Great variability in the seminal root length was found in analysed 8-day old seedling population. Almost half of the analysed mutants showed significant root length reduction, but about ten percent of semi-dwarf mutants developed roots with an increased length in comparison to parents. No significant differences were found between analysed mutants and corresponding parent varieties regarding the number of seminal roots. After six weeks of growth, the selected mutants showed differences in the reduction of root length in comparison to the 8-day old seedlings. The results of root growth dynamics indicated that analysed mutants had different patterns in comparison to the parent variety. Differences in the growth dynamics were also observed among the parent varieties. The observed differences in pattern of root growth between mutants and corresponding parents

Lipid composition of cAMP-dependent protein kinase mutants of Aspergillus niger.

Science.gov (United States)

Jernejc, Katarina; Bencina, Mojca

2003-08-29

Lipid composition of cAMP-dependent protein kinase (PKA) Aspergillus niger mutants with overexpressed or deleted genes for either regulatory and/or the catalytic subunit of PKA was analyzed. Disruption of the gene encoding the PKA regulatory subunit resulted in 20% less total lipids, 30% less neutral lipids, four times more glycolipids and two-fold higher triacylglycerol lipase activity compared to the control strain. Concomitantly a five-fold decrease in phosphatidylcholine, accompanied with 1.5-, 1.8- and 2.8-fold increases in phosphatidylethanolamine, lysophosphatidylethanolamine and phosphatidylinositol, was determined, respectively. The lack of PKA activity, due to the disruption of a gene encoding the PKA catalytic subunit, resulted in a 1.6-times increase in total lipids with two times more neutral lipids associated with lower triacylglycerol lipase activity and a decrease in phospholipids. The mutants with unrestricted PKA activity synthesized twice as much citric acid as the control strain and three times more than strains lacking PKA activity. The results indicate the involvement of cAMP-mediated PKA activity in regulation of lipid biosynthesis as well as citric acid synthesis.

Multilocation trial of potential selected mutant lines of groundnut (arachis hypogaea) at 3 location in Peninsular Malaysia

International Nuclear Information System (INIS)

Abdul Rahim Harun; Rusli Ibrahim; Khairuddin Abdul Rahim; Shuhaimi Shamsuddin

2002-01-01

Two fixed mutant lines of groundnut derived from cultivar Matjan were selected for their yield potential at M 1 0 generation. Multilocation trial of these mutants (MJ40/42 and MJ20/165-5) was carried out to evaluate genotype stability at different climate and soil types in Peninsular Malaysia. The mutant lines were planted and compared with their parent (Matjan) and control variety (MKT1). The identified locations were in Taiping (Perak), Machang (Kelantan), and Air Hitam (Johor). The soils at the locations were of the Serdang, Bungor and Rengam series, respectively. The trial was carried out simultaneously in the same year at each location. Mutant MJ20/165-5 showed stable performance at all location compared to other genotypes tested. Its yield was higher than the parent in Kelantan and Johor trial and showed similar performance in Perak. This mutant also showed better yield performance than the control varieties in the Kelantan trial. Meanwhile, mutant line MJ40/42 gave better yield in Kelantan and Johor but did not perform well in Perak as compared to its parent and control varieties. (Author)

Genetics of leaf rust-resistant mutant WH 147-LM-1 in hexaploid wheat variety WH 147

International Nuclear Information System (INIS)

Reddy, V.R.K.; Viswanathan, P.

1999-01-01

By applying gamma rays, EMS and their combination in hexaploid wheat variety WH 147, a total of 20 mutants (0.0226%) exhibiting complete leaf rust resistance were isolated from segregating M2 rows.When one of the rust-resistant mutants, WH 147-LM-1 was crossed with the universally susceptible, suggesting that the mutant character is controlled by one dominant gene and one recessive gene.The F2 plants derived by crossing the mutant WH 147-LM with seven near-isogenic wheat lines showed segregation for susceptibility, indicating that the mutant character was indeed generated through induced mutations

Pseudomonas aeruginosa mutants resistant to urea inhibition of growth on acetanilide.

Science.gov (United States)

Gregoriou, M; Brown, P R; Tata, R

1977-11-01

Pseudomonas aeruginosa AI 3 was able to grow in medium containing acetanilide (N-phenylacetamide) as a carbon source when NH4+ was the nitrogen source but not when urea was the nitrogen source. AIU mutants isolated from strain AI 3 grew on either medium. Urease levels in bacteria grown in the presence of urea were 10-fold lower when NH4+ or acetanilide was also in the medium, but there were no apparent differences in urease or its synthesis between strain AI 3 and mutant AIU 1N. The first metabolic step in the acetanilide utlization is catalyzed by an amidase. Amidases in several AIU strains showed altered physiochemical properties. Urea inhibited amidase in a time-dependent reaction, but the rates of the inhibitory reaction with amidases from the AIU mutants were slower than with AI 3 amidase. The purified amidase from AIU 1N showed a marked difference in its pH/activity profile from that obtained with purified AI 3 amidase. These observations indicate that the ability of strain AIU 1N and the other mutants to grow on acetanilide/urea medium is associated with a mutation in the amidase structural gene; this was confirmed for strain AIU 1N by transduction.

Ob/ob mouse livers show decreased oxidative phosphorylation efficiencies and anaerobic capacities after cold ischemia.

Directory of Open Access Journals (Sweden)

Michael J J Chu

Full Text Available BACKGROUND: Hepatic steatosis is a major risk factor for graft failure in liver transplantation. Hepatic steatosis shows a greater negative influence on graft function following prolonged cold ischaemia. As the impact of steatosis on hepatocyte metabolism during extended cold ischaemia is not well-described, we compared markers of metabolic capacity and mitochondrial function in steatotic and lean livers following clinically relevant durations of cold preservation. METHODS: Livers from 10-week old leptin-deficient obese (ob/ob, n = 9 and lean C57 mice (n = 9 were preserved in ice-cold University of Wisconsin solution. Liver mitochondrial function was then assessed using high resolution respirometry after 1.5, 3, 5, 8, 12, 16 and 24 hours of storage. Metabolic marker enzymes for anaerobiosis and mitochondrial mass were also measured in conjunction with non-bicarbonate tissue pH buffering capacity. RESULTS: Ob/ob and lean mice livers showed severe (>60% macrovesicular and mild (<30% microvesicular steatosis on Oil Red O staining, respectively. Ob/ob livers had lower baseline enzymatic complex I activity but similar adenosine triphosphate (ATP levels compared to lean livers. During cold storage, the respiratory control ratio and complex I-fueled phosphorylation deteriorated approximately twice as fast in ob/ob livers compared to lean livers. Ob/ob livers also demonstrated decreased ATP production capacities at all time-points analyzed compared to lean livers. Ob/ob liver baseline lactate dehydrogenase activities and intrinsic non-bicarbonate buffering capacities were depressed by 60% and 40%, respectively compared to lean livers. CONCLUSIONS: Steatotic livers have impaired baseline aerobic and anaerobic capacities compared to lean livers, and mitochondrial function indices decrease particularly from after 5 hours of cold preservation. These data provide a mechanistic basis for the clinical recommendation of shorter cold storage durations in

Kinetics, improved activity and thermostability of endoglucanase and beta glucosidase from a mutant-derivative of aspergillus niger ms82

International Nuclear Information System (INIS)

Sohail, M.; Ahmad, A.; Khan, S.A.; Uddin, F.

2013-01-01

A mutant MS301 of Aspergillus niger MS82 showed 1.5 to 2.5-fold improved endoglucanase and beta-glucosidase activity when grown on crude lignocellulosic substrates under solid-state and submerged conditions. Indicators of thermal stability of enzymes (Tm and T1/2) showed that the wild type and mutant endoglucanase was more heat-resistant compared to beta-glucosidase. However, mutant and parent enzymes shared almost the same values for melting temperatures and half-lives. Endoglucanase and beta-glucosidase from both the strains showed optimum activity under acidic pH. Energy of activation (Ea) of mutant beta-glucosidase was substantially lower than the parent enzyme while Ea of mutant endoglucanase was slightly less than the parent. The lowered Ea values can be attributed to the improved beta-glucosidase activity of the mutant strain. Moreover, the MS301 enzymes were better in hydrolyzing purified and crude cellulosic materials than the parent MS82. (author)

Mineral phosphate solubilization by wild type and radiation induced mutants of pantoea dispersa and pantoea terrae

International Nuclear Information System (INIS)

Murugesan, Senthilkumar; Lee, Young Keun; Kim, Jung Hun

2009-01-01

Three mineral phosphate solubilizing (MPS) bacteria where isolated from rhizosphere soil samples of common bean and weed plants. 16S rDNA analysis indicated that the isolate P2 and P3 are closely related to Pantoea dispersa while isolate P4 is closely related to Pantoea terrae. Islates P2 and P3 recorded 381.60 μg ml -1 of tricalcium phosphate (TCP) solubilization respectively on 3 days incubation. Isolate P4 recorded the TCP solubilization of 215.85 μg ml -1 and the pH was dropped to 4.44 on 24 h incubation. Further incubation of P4 sharply decreased the available phosphorous to 28.94 μg ml -1 and pH level was raised to 6.32. Gamma radiation induced mutagenesis was carried out at LD 99 dose of the wild type strains. The total of 14 mutant clones with enhanced MPS activity and 4 clones with decreased activity were selected based on solubilization index (SI) and phosphate solubilization assay. Mutant P2-M1 recorded the highest P-solubilizing potential among any other wild or mutnat clones by releasing 504.21 μg ml -1 of phosphorous i.e. 35% higher than its wild type by the end of day 5. A comparative evaluation of TCP solubilization by wild type isolates of Pantoea and their mutants, led to select three MPS mutant clones such as P2-M1, P3-M2 and P3-M4 with a potential to release >471.67 μg ml 1 of phosphorous from TCP. These over expressing mutant clones are considered as suitable candidates for biofertilization

Characterization of reduced height mutant of emmer wheat var. NP200 (Triticum dicoccum)

International Nuclear Information System (INIS)

Suman, Sud; Nayeem, K.A.; Bhagwat, S.G.

2006-01-01

Full text: Emmer wheat commonly known as Khapli is cultivated on limited area in Tamil Nadu, Andhra Pradesh, Karnataka, Maharashtra and Gujarat. Although cultivation of emmer wheat is confirmed to a small area, improvement work in this species is gaining importance because of its potential for diabetic patients and high dietary fibre in comparison to durum and bread wheats. Emmer wheat cultivar NP200 is a selection from local wheats of Andhra Pradesh. The cultivar NP200 is tall and is prone to lodging leading to yield loss. Therefore, systematic effort to improve cultivar NP200 is needed with the objective to reduce height and introduce lodging tolerance and to improve harvest index. The cultivar NP200 was irradiated with γ-rays. A reduced height mutant with vigorous growth and high tillering was found in M2 population. The mutant was designated as HW1095. The progeny of mutant in M3 showed 35.7 percent reduction in height as compared to parent. The HW1095 mutant was subjected to gibberellic acid treatment at seedling stage and was found to be insensitive to gibberellic acid. An allele specific marker for major dwarfing gene Rht B1b was used to check the status of dwarfing gene in semi dwarf emmer (DDK1009, DDK1025, HW5013, HW5301 and MACS2961) and tall emmer (Np200 and NP201), semi dwarf durums (HD4502, HD4530, MACS2846) along with dwarf mutant (HW1095). The validity of primer in semi dwarf durums and emmer for Rht B 1b gene was found to be perfect. The parent variety NP200 showed presence of wild type allele (Rht B1a) with the primer pair BF-WR1. All semi dwarf emmer showed a band of 237 bp with primer pair BF-MR1. However, mutant (HW1095) showed absence of amplification for both Rht B1a and Rht B1b alleles with respective primer pairs. The results indicated that the reduced height mutant carried a mutation different than from the existing allele (Rht B1b)

Nonsense mutants in the bacteriophage T4D v gene

Energy Technology Data Exchange (ETDEWEB)

Minderhout, L van; Grimbergen, J; Groot, B de [Rijksuniversiteit Leiden (Netherlands). Lab. voor Stralengenetica en Chemische Mutagenese; Cohen (J.A.) Instituut voor Radiopathologie en Stralenbescherming, Leiden (Netherlands))

1975-09-01

Ten UV-sensitive mutants of T4D with the v phenotype were isolated. Of these ten mutants, two are amber and two opal. In UV curves and in photoreactivation and multiplicity reactivation experiments the nonsense mutants show the v phenotype in su/sup -/ hosts and almost the T4/sup +/ phenotype in su/sup +/ hosts. The mutations are located between rl and e and are alleles of v/sub 1/. In crosses with irradiated and non-irradiated phages the recombinant frequency is not reduced by uvs5. Amber uvs5 propagated in CR63 su/sup +/ is with B su/sup -/ just as sensitive to UV as uvs5 propagated in B su/sup -/, which permits the conclusion that the capsid of T4 phage particles does not contain the v gene product.

Selection of high hectolitre weight mutants of winter wheat

International Nuclear Information System (INIS)

Crowley, C.; Jones, P.

1989-01-01

Grain quality in wheat includes hectolitre weight (HLW) besides protein content and thousand-grain weight (TGW). The British winter wheat variety ''Guardian'' has a very high yield potential. Although the long grain of ''Guardian'' results in a desirable high TGW the HLW is too low. To select mutants exhibiting increased HLW the character was first analyzed to identify traits that could more easily be screened for using M 2 seeds. In comparison of 6 wheat cultivars, correlation analyses with HLW resulted in coefficients of -0.86 (grain length, L:P 2 seeds for shorter, less prolate grains. Mutagenesis was carried out using EMS sulphonate (1.8 or 3.6%), sodium azide (2 or 20 mM) or X-rays (7.5 or 20 kR). 69 M 2 grains with altered shape were selected. Examination of the M 3 progeny confirmed 6 grain-shape mutants, most of them resulting from EMS treatment (Table). Two of the mutants showed TGW values significantly below the parental variety, but three mutants exhibited HLW and TGW values significantly greater than those of the parental variety. Microplot yield trails on selected M 3 lines are in progress. The influence of physical grain characteristics on HLW offers prospects for mechanical fractionation of large M 2 populations. The application of gravity separators (fractionation on the basis of grain density) and sieves (fractionation on the basis of grain length) in screening mutants possessing improved grain quality is being investigated

Concurrent Increases and Decreases in Local Stability and Conformational Heterogeneity in Cu, Zn Superoxide Dismutase Variants Revealed by Temperature-Dependence of Amide Chemical Shifts.

Science.gov (United States)

Doyle, Colleen M; Rumfeldt, Jessica A; Broom, Helen R; Sekhar, Ashok; Kay, Lewis E; Meiering, Elizabeth M

2016-03-08

The chemical shifts of backbone amide protons in proteins are sensitive reporters of local structural stability and conformational heterogeneity, which can be determined from their readily measured linear and nonlinear temperature-dependences, respectively. Here we report analyses of amide proton temperature-dependences for native dimeric Cu, Zn superoxide dismutase (holo pWT SOD1) and structurally diverse mutant SOD1s associated with amyotrophic lateral sclerosis (ALS). Holo pWT SOD1 loses structure with temperature first at its periphery and, while having extremely high global stability, nevertheless exhibits extensive conformational heterogeneity, with ∼1 in 5 residues showing evidence for population of low energy alternative states. The holo G93A and E100G ALS mutants have moderately decreased global stability, whereas V148I is slightly stabilized. Comparison of the holo mutants as well as the marginally stable immature monomeric unmetalated and disulfide-reduced (apo(2SH)) pWT with holo pWT shows that changes in the local structural stability of individual amides vary greatly, with average changes corresponding to differences in global protein stability measured by differential scanning calorimetry. Mutants also exhibit altered conformational heterogeneity compared to pWT. Strikingly, substantial increases as well as decreases in local stability and conformational heterogeneity occur, in particular upon maturation and for G93A. Thus, the temperature-dependence of amide shifts for SOD1 variants is a rich source of information on the location and extent of perturbation of structure upon covalent changes and ligand binding. The implications for potential mechanisms of toxic misfolding of SOD1 in disease and for general aspects of protein energetics, including entropy-enthalpy compensation, are discussed.

The Drosophila Neurally Altered Carbohydrate Mutant Has a Defective Golgi GDP-fucose Transporter*

Science.gov (United States)

Geisler, Christoph; Kotu, Varshika; Sharrow, Mary; Rendić, Dubravko; Pöltl, Gerald; Tiemeyer, Michael; Wilson, Iain B. H.; Jarvis, Donald L.

2012-01-01

Studying genetic disorders in model organisms can provide insights into heritable human diseases. The Drosophila neurally altered carbohydrate (nac) mutant is deficient for neural expression of the HRP epitope, which consists of N-glycans with core α1,3-linked fucose residues. Here, we show that a conserved serine residue in the Golgi GDP-fucose transporter (GFR) is substituted by leucine in nac1 flies, which abolishes GDP-fucose transport in vivo and in vitro. This loss of function is due to a biochemical defect, not to destabilization or mistargeting of the mutant GFR protein. Mass spectrometry and HPLC analysis showed that nac1 mutants lack not only core α1,3-linked, but also core α1,6-linked fucose residues on their N-glycans. Thus, the nac1 Gfr mutation produces a previously unrecognized general defect in N-glycan core fucosylation. Transgenic expression of a wild-type Gfr gene restored the HRP epitope in neural tissues, directly demonstrating that the Gfr mutation is solely responsible for the neural HRP epitope deficiency in the nac1 mutant. These results validate the Drosophila nac1 mutant as a model for the human congenital disorder of glycosylation, CDG-IIc (also known as LAD-II), which is also the result of a GFR deficiency. PMID:22745127

Interaction of a non-peptide agonist with angiotensin II AT1 receptor mutants

DEFF Research Database (Denmark)

Costa-Neto, Claudio M; Miyakawa, Ayumi A; Pesquero, João B

2002-01-01

and inositol phosphate turnover assays in COS-7 cells transiently transfected with the wild-type and mutant forms of the receptor. Mutant receptors bore modifications in the extracellular region: T88H, Y92H, G1961, G196W, and D278E. Compound L-162,313 displaced [125I]-Sar1,Leu8-AngII from the mutants G196I...... and G196W with IC50 values similar to that of the wild-type. The affinity was, however, slightly affected by the D278E mutation and more significantly by the T88H and Y92H mutations. In inositol phosphate turnover assays, the ability of L-162,313 to trigger the activation cascade was compared...... with that of angiotensin II. These assays showed that the G196W mutant reached a relative maximum activation exceeding that of the wild-type receptor; the efficacy was slightly reduced in the G1961 mutant and further reduced in the T88H, Y92H, and D278E mutants. Our data suggest that residues of the extracellular domain...

Identification and genetic assay of a high-chlorophyll-content mutant in Rice

International Nuclear Information System (INIS)

Liu Baofu; Chen Xifeng; Jin Yang; Gu Zhimin; Ma Bojun; Zhu Xudong

2011-01-01

A deep rice mutant ZM1120 was screened from the γ-rays irradiation mutation library of Zhonghua 11. Compared to the wild-type control, this mutant were darker (greener) in shoots and leaves, and after sowing 60 and 90 d, the content of chlorophyll were increased by 16.0% and 7.2%, respectively, and the content of carotenoid also increased by 23.1% and 24.2%, respectively. After sowing 90 d the net photosynthetic rate and transpiration rate were increased by 16.3% and 11.4%, respectively. The agronomical traits of this mutant significantly changed, and the traits of plant height, flag-leaf length, flag-leaf width, tiller number per plant, panicle length and setting rate decreased, but the grain length and 1000-grain weight increased by 7.9% and 2.6%. Genetic analysis revealed that the mutation phenotype was controlled by a single recessive nuclear gene, and further cloning and function assay will be useful for understanding the mechanism of photosynthesis and for rice breeding in future. (authors)

PNRI mutant variety: sansevieria 'Sword of Ibe'

International Nuclear Information System (INIS)

Aurigue, Fernando B.

2011-01-01

Sansevieria 'Sword of Ibe,' registered by the Philippine Nuclear Research Institute as NSIC 2008 Or-66, is a chlorophyll mutant of Sansevieria trifasciata 'Moonshine' developed by treating its suckers or shoots arising from a rhizome with acute gamma radiation from a Cobalt-60 source. The new mutant is identical in growth habit and vigor to Sansevieria 'Moonshine,' also known as Moonglow. Results of this mutation breeding experiment showed that leaf color and flowering were altered by gamma irradiation without changing the other characteristics of the plant. Propagation is true-to-type by separation of sucker and top cutting. The plant is recommended for use as landscaping material and as pot plant for indoor and outdoor use. The leaves may be harvested as cut foliage for Japanese flower arrangements. (author)

Allosteric Mutant IDH1 Inhibitors Reveal Mechanisms for IDH1 Mutant and Isoform Selectivity

Energy Technology Data Exchange (ETDEWEB)

Xie, Xiaoling; Baird, Daniel; Bowen, Kimberly; Capka, Vladimir; Chen, Jinyun; Chenail, Gregg; Cho, YoungShin; Dooley, Julia; Farsidjani, Ali; Fortin, Pascal; Kohls, Darcy; Kulathila, Raviraj; Lin, Fallon; McKay, Daniel; Rodrigues, Lindsey; Sage, David; Touré, B. Barry; van der Plas, Simon; Wright, Kirk; Xu, Ming; Yin, Hong; Levell, Julian; Pagliarini, Raymond A. (Novartis)

2017-03-01

Oncogenic IDH1 and IDH2 mutations contribute to cancer via production of R-2-hydroxyglutarate (2-HG). Here, we characterize two structurally distinct mutant- and isoform-selective IDH1 inhibitors that inhibit 2-HG production. Both bind to an allosteric pocket on IDH1, yet shape it differently, highlighting the plasticity of this site. Oncogenic IDH1R132H mutation destabilizes an IDH1 “regulatory segment,” which otherwise restricts compound access to the allosteric pocket. Regulatory segment destabilization in wild-type IDH1 promotes inhibitor binding, suggesting that destabilization is critical for mutant selectivity. We also report crystal structures of oncogenic IDH2 mutant isoforms, highlighting the fact that the analogous segment of IDH2 is not similarly destabilized. This intrinsic stability of IDH2 may contribute to observed inhibitor IDH1 isoform selectivity. Moreover, discrete residues in the IDH1 allosteric pocket that differ from IDH2 may also guide IDH1 isoform selectivity. These data provide a deeper understanding of how IDH1 inhibitors achieve mutant and isoform selectivity.

Studies of Genetic Differences between KDML 105 and its Photo period-insensitive Mutants using DNA techniques

International Nuclear Information System (INIS)

Boonsirichai, Kanokporn; Klakhaeng, Kanchana; Phadvibulya, Valailak

2007-08-01

Full text: Photo period-insensitive mutants of KDML 105 could be planted for grains during and outside the regular cropping season. From genetic studies, the mutant characteristics appeared recessive. A DNA-fingerprinting technique was used to compare gene expression profiles in the leaves of mutants and KDML 105. Differences in the level of expression were found for several loci. Examination of the essential part of the gene for fragrance showed no differences between the mutants and the parental KDML 105

The Arabidopsis nox mutant lacking carotene hydroxylase activity reveals a critical role for xanthophylls in photosystem I biogenesis.

Science.gov (United States)

Dall'Osto, Luca; Piques, Maria; Ronzani, Michela; Molesini, Barbara; Alboresi, Alessandro; Cazzaniga, Stefano; Bassi, Roberto

2013-02-01

Carotenes, and their oxygenated derivatives xanthophylls, are essential components of the photosynthetic apparatus. They contribute to the assembly of photosynthetic complexes and participate in light absorption and chloroplast photoprotection. Here, we studied the role of xanthophylls, as distinct from that of carotenes, by characterizing a no xanthophylls (nox) mutant of Arabidopsis thaliana, which was obtained by combining mutations targeting the four carotenoid hydroxylase genes. nox plants retained α- and β-carotenes but were devoid in xanthophylls. The phenotype included depletion of light-harvesting complex (LHC) subunits and impairment of nonphotochemical quenching, two effects consistent with the location of xanthophylls in photosystem II antenna, but also a decreased efficiency of photosynthetic electron transfer, photosensitivity, and lethality in soil. Biochemical analysis revealed that the nox mutant was specifically depleted in photosystem I function due to a severe deficiency in PsaA/B subunits. While the stationary level of psaA/B transcripts showed no major differences between genotypes, the stability of newly synthesized PsaA/B proteins was decreased and translation of psaA/B mRNA was impaired in nox with respect to wild-type plants. We conclude that xanthophylls, besides their role in photoprotection and LHC assembly, are also needed for photosystem I core translation and stability, thus making these compounds indispensable for autotrophic growth.

Abnormalities in brain structure and behavior in GSK-3alpha mutant mice

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Kaidanovich-Beilin Oksana

2009-11-01

Full Text Available Abstract Background Glycogen synthase kinase-3 (GSK-3 is a widely expressed and highly conserved serine/threonine protein kinase encoded by two genes that generate two related proteins: GSK-3α and GSK-3β. Mice lacking a functional GSK-3α gene were engineered in our laboratory; they are viable and display insulin sensitivity. In this study, we have characterized brain functions of GSK-3α KO mice by using a well-established battery of behavioral tests together with neurochemical and neuroanatomical analysis. Results Similar to the previously described behaviours of GSK-3β+/-mice, GSK-3α mutants display decreased exploratory activity, decreased immobility time and reduced aggressive behavior. However, genetic inactivation of the GSK-3α gene was associated with: decreased locomotion and impaired motor coordination, increased grooming activity, loss of social motivation and novelty; enhanced sensorimotor gating and impaired associated memory and coordination. GSK-3α KO mice exhibited a deficit in fear conditioning, however memory formation as assessed by a passive avoidance test was normal, suggesting that the animals are sensitized for active avoidance of a highly aversive stimulus in the fear-conditioning paradigm. Changes in cerebellar structure and function were observed in mutant mice along with a significant decrease of the number and size of Purkinje cells. Conclusion Taken together, these data support a role for the GSK-3α gene in CNS functioning and possible involvement in the development of psychiatric disorders.

Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams.

Science.gov (United States)

Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

2013-07-01

UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UV Tolerant Rice 319), was isolated from a mutagenized population derived from 2500 M1 seeds (of the UVB-resistant cultivar 'Sasanishiki') that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined.

Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams

International Nuclear Information System (INIS)

Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N.; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

2013-01-01

UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UVTolerantRice319), was isolated from a mutagenized population derived from 2500 M 1 seeds (of the UVB-resistant cultivar ‘Sasanishiki’) that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined

A comparative glycoproteome study of developing endosperm in the hexose-deficient miniature1 (mn1 seed mutant and its wild type Mn1 in maize

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Cecilia eSilva-Sanchez

2014-02-01

Full Text Available In maize developing seeds, transfer cells are prominently located at the basal endosperm transfer layer (BETL. As the first filial cell layer, BETL is a gateway to sugars, nutrients and water from mother plant; and anchor of numerous functions such as sucrose turnover, auxin and cytokinin biosynthesis/accumulation, energy metabolism, defense response, and signaling between maternal and filial generations. Previous studies showed that basal developing endosperms of miniature1 (mn1 mutant seeds lacking the Mn1-encoded cell wall invertase II, are also deficient for hexose. Given the role of glucose as one of the key sugars in protein glycosylation and proper protein folding; we performed a comparative large scale glycoproteome profiling of total proteins of these two genotypes (mn1 mutant vs Mn1 wild type using 2D gel electrophoresis and glycosylation/total protein staining, followed by image analysis. Protein identification was done by LC-MS/MS. A total of 413 spots were detected; from which, 113 spots matched between the two genotypes. Of these, 45 showed > 20% decrease/increase in glycosylation level and were selected for protein identification. A large number of identified proteins showed decreased glycosylation levels in mn1 developing endosperms as compared to the Mn1. Functional classification of proteins, showed mainly of post-translational modification, protein turnover, chaperone activities, carbohydrate and amino acid biosynthesis / transport, and cell wall biosynthesis. These proteins and activities were related to endoplasmic reticulum (ER stress and unfolded protein response (UPR as a result of the low glycolsylation levels of the mutant proteins. Overall, these results provide for the first time a global glycoproteome profile of maize BETL-enriched basal endosperm to better understand their role in seed development in maize.

A γA-Crystallin Mouse Mutant Secc with Small Eye, Cataract and Closed Eyelid.

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Man Hei Cheng

Full Text Available Cataract is the most common cause of visual loss in humans. A spontaneously occurred, autosomal dominant mouse mutant Secc, which displayed combined features of small eye, cataract and closed eyelid was discovered in our laboratory. In this study, we identified the mutation and characterized the cataract phenotype of this novel Secc mutant. The Secc mutant mice have eyelids that remain half-closed throughout their life. The mutant lens has a significant reduction in size and with opaque spots clustered in the centre. Histological analysis showed that in the core region of the mutant lens, the fiber cells were disorganized and clefts and vacuoles were observed. The cataract phenotype was evident from new born stage. We identified the Secc mutation by linkage analysis using whole genome microsatellite markers and SNP markers. The Secc locus was mapped at chromosome 1 flanked by SNPs rs3158129 and rs13475900. Based on the chromosomal position, the candidate cataract locus γ-crystallin gene cluster (Cryg was investigated by sequencing. A single base deletion (299delG in exon 3 of Cryga which led to a frame-shift of amino acid sequence from position 91 was identified. As a result of this mutation, the sequences of the 3rd and 4th Greek-key motifs of the γA-crystallin are replaced with an unrelated C-terminal peptide of 75 residues long. Coincidentally, the point mutation generated a HindIII restriction site, allowing the identification of the CrygaSecc mutant allele by RFLP. Western blot analysis of 3-week old lenses showed that the expression of γ-crystallins was reduced in the CrygaSecc mutant. Furthermore, in cell transfection assays using CrygaSecc mutant cDNA expression constructs in 293T, COS-7 and human lens epithelial B3 cell lines, the mutant γA-crystallins were enriched in the insoluble fractions and appeared as insoluble aggregates in the transfected cells. In conclusion, we have demonstrated that the Secc mutation leads to the

Examining the virulence of Candida albicans transcription factor mutants using Galleria mellonella and mouse infection models

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Sara eAmorim-Vaz

2015-05-01

Full Text Available The aim of the present study was to identify C. albicans transcription factors (TF involved in virulence. Although mice are considered the gold-standard model to study fungal virulence, mini-host infection models have been increasingly used. Here, barcoded TF mutants were first screened in mice by pools of strains and fungal burdens quantified in kidneys. Mutants of unannotated genes which generated a kidney fungal burden significantly different from that of wild-type were selected and individually examined in G. mellonella. In addition, mutants that could not be detected in mice were also tested in G. mellonella. Only 25 % of these mutants displayed matching phenotypes in both hosts, highlighting a significant discrepancy between the two models. To address the basis of this difference (pool or host effects, a set of 19 mutants tested in G. mellonella were also injected individually into mice. Matching fungal burden phenotypes were observed in 50 % of the cases, highlighting the bias due to host effects. In contrast, 33.4 % concordance was observed between pool and single strain infections in mice, thereby highlighting the bias introduced by the pool effect. After filtering the results obtained from the two infection models, mutants for MBF1 and ZCF6 were selected. Independent marker-free mutants were subsequently tested in both hosts to validate previous results. The MBF1 mutant showed impaired infection in both models, while the ZCF6 mutant was only significant in mice infections. The two mutants showed no obvious in vitro phenotypes compared with the wild-type, indicating that these genes might be specifically involved in in vivo adaptation.

Mitotic chromosome transmission fidelity mutants in Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Spencer, F.; Gerring, S.L.; Connelly, C.; Hieter, P.

1990-01-01

The authors have isolated 136 independent EMS-induced mutations in haploid yeast strains that exhibit decreased chromosome transmission fidelity in mitosis. Eight-five percent of the mutations are recessive and 15% are partially dominant. Complementation analysis between MATa and MATα isolates identifies 11 chromosome transmission fidelity (CTF) complementation groups, the largest of which is identical to CHL1. For 49 independent mutations, no corresponding allele has been recovered in the opposite mating type. The initial screen monitored the stability of a centromere-linked color marker on a nonessential yeast chromosome fragment; the mitotic inheritance of natural yeast chromosome III is also affected by the ctf mutations. Of the 136 isolates identified, seven were inviable at 37 degree and five were inviable at 11 degree. In all cases tested, these temperature conditional lethalities cosegregated with the chromosome instability phenotype. Five additional complementation groups (ctf12 through ctf16) have been defined by complementation analysis of the mutations causing inviability at 37 degree. All of the mutant strains showed normal sensitivity to ultraviolet and γ-irradiation

Purification and characterization of mutant miniPlasmin for thrombolytic therapy

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Lin Xiaotao

2013-01-01

Full Text Available Abstract Background Previous animal studies by us and others have indicated that catheter-administered plasmin or its des-kringle derivatives may be more appropriate alternatives to plasminogen activators for treating thrombolytic diseases, since it has a very short serum half-life and therefore does not result in hemorrhaging. We have previously produced recombinant miniPlasmin (mPlasmin that was proven suitable for treating peripheral arterial occlusion in animal models. However, our previous results showed that non-specific cleavage at position K698 of mPlasmin during activation hindered the further development of this promising therapeutic candidate. In order to minimize or eliminate the non-specific cleavage problem, we performed saturation mutagenesis at the K698 position to develop a mutant form of mPlasmin for thrombolytic therapy. Methods We changed K698 to 16 other amino acids, with preferred E. coli codons. Each of these mutants were expressed in E. coli as inclusion bodies and then refolded, purified, and subsequently characterized by detailed kinetic assays/experiments/studies which identified highly active mutants devoid of non-specific cleavage. Results Activation studies indicated that at those conditions in which the wild type enzyme is cut at the non-specific position K698, the active mutants can be activated without being cleaved at this position. Conclusions From the above results, we selected two mutants, K698Q and K698N, as our lead candidates for further thrombolytic drug developments. The selected mutants are potentially better therapeutic candidates for thrombolytic therapy.

A KAS2 cDNA complements the phenotypes of the Arabidopsis fab1 mutant that differs in a single residue bordering the substrate binding pocket

DEFF Research Database (Denmark)

Carlsson, A.S.; LaBrie, S.T.; Kinney, A.J.

2002-01-01

The fab1 mutant of Arabidopsis is partially deficient in activity of ß-ketoacyl-[acyl carrier protein] synthase II (KAS II). This defect results in increased levels of 16 : 0 fatty acid and is associated with damage and death of the mutants at low temperature. Transformation of fab1 plants with a c......DNA from Brassica napus encoding a KAS II enzyme resulted in complementation of both mutant phenotypes. The dual complementation by expression of the single gene proves that low-temperature damage is a consequence of altered membrane unsaturation. The fab1 mutation is a single nucleotide change...... chain to bend. For functional analysis the equivalent Leu207Phe mutation was introduced into the fabB gene encoding the E. coli KAS I enzyme. Compared to wild-type, the Leu207Phe protein showed a 10-fold decrease in binding affinity for the fatty acid substrate, exhibited a modified behavior during size...

Homologous series of induced early mutants in indican rice. Pt.1. The production of homologous series of early mutants

International Nuclear Information System (INIS)

Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

1999-01-01

The percentage of homologous series of early mutants induced from the same Indican rice variety were almost the same (1.37%∼1.64%) in 1983∼1993, but the ones from the different eco-typical varieties were different. The early variety was 0.73%, the mid variety was 1.51%, and the late variety was 1.97%. The percentage of homologous series of early mutants from the varieties with the same pedigree and relationship were similar, but the one from the cog nation were lower than those from distant varieties. There are basic laws and characters in the homologous series of early mutants: 1. The inhibited phenotype is the basic of the homologous series of early mutants; 2. The production of the homologous series of early mutants is closely related with the growing period of the parent; 3. The parallel mutation of the stem and leaves are simultaneously happened with the variation of early or late maturing; 4. The occurrence of the homologous series of early mutants is in a state of imbalance. According to the law of parallel variability, the production of homologous series of early mutants can be predicted as long as the parents' classification of plant, pedigree and ecological type are identified. Therefore, the early breeding can be guided by the law of homologous series of early mutants

Reduced anti-oxidative stress activities of DJ-1 mutants found in Parkinson's disease patients

International Nuclear Information System (INIS)

Takahashi-Niki, Kazuko; Niki, Takeshi; Taira, Takahiro; Iguchi-Ariga, Sanae M.M.; Ariga, Hiroyoshi

2004-01-01

DJ-1 is a multi-functional protein that plays roles in transcriptional regulation and anti-oxidative stress, and loss of its function is thought to result in onset of Parkinson's disease. We have previously reported that L166P, a mutant DJ-1 found in Parkinson's disease patients, had no activity to prevent hydrogen peroxide (H 2 O 2 )-induced cell death. In this study, we analyzed other mutants of DJ-1 found in Parkinson's disease patients, including M26I, R98Q, and D149A, as well as L166P. We first found that all of the mutants made heterodimers with wild-type DJ-1, while all of the mutants except for L166P made homodimers. We then found that M26I and L166P, both of which are derived from homozygous mutations of the DJ-1 gene, were unstable and that their stabilities were recovered, in part, in the presence of proteasome inhibitor, MG132. NIH3T3 cell lines stably expressing these mutants of DJ-1 showed that cell lines of L166P and C106S, a mutant for protease activity (-) of DJ-1, had no activity to scavenge even endogenously producing reactive oxygen species. These cell lines also showed that all of the mutants had reduced activities to eliminate exogenously added H 2 O 2 and that these activities, except for that of D149A, were parallel to those preventing H 2 O 2 -induced cell death

Traits and meiosis in mutant of impatiens balsamina induced by space treatment

International Nuclear Information System (INIS)

Tang Zesheng; Yang Jun; Zhao Yan; Yuan Haiyun

2004-01-01

A mutant of Impatiens balsamina was obtained after space induction, and its traits and meiosis were investigated. Characters such as color and form of the mutant expressed great variation. Observation of meiosis showed that most of pollen mother cells were normal in meiosis phase I, except the disproportion of chromosomal segregation, lagging chromosome and dispersal chromosome in anaphase I. Most pollen mother cells developed into microspores tetrad after meiosis, but paraspores also appeared. The number of chromosome in microspore varied from 1 to 21, even more than 30. The shape and size of the microspores fluctuated apparently, and the size of the microspores was in positive correlation to chromosome number. When staining with iodic solution, most of the pollens showed sterility, which was in consistence with the low setting percentage of the mutant plant. It was thought that space induction caused the variation of size, fertility and the abnormal meiosis

Inhibition of citric acid accumulation by manganese ions in Aspergillus niger mutants with reduced citrate control of phosphofructokinase

Energy Technology Data Exchange (ETDEWEB)

Schreferl, G.; Kubicek, C.P.; Roehr, M.

1986-03-01

Mutant strains of Aspergillus niger with reduced citrate control of carbohydrate catabolism (cic mutants) grow faster than the parent strain on media containing 5% (wt/vol) citrate. The mutants tolerated a higher intracellular citrate concentration than the parent strain. One mutant (cic-7/3) contained phosphofructokinase activity significantly less sensitive towards citrate than the enzyme from the parent strain. When this mutant was grown under citrate accumulating conditions, acidogenesis was far less sensitive to inhibition by Mn/sup 2 +/ than in the parent strain. Some of the cic mutants also showed altered citrate inhibition of NADP-specific isocitrate dehydrogenase.

Decreased expression of LamB and Odp1 complex is crucial for antibiotic resistance in Escherichia coli.

Science.gov (United States)

Lin, Xiang-min; Yang, Man-jun; Li, Hui; Wang, Chao; Peng, Xuan-Xian

2014-02-26

We previously revealed a negative regulation of LamB in chlortetracycline-resistant Escherichia coli strain. In the present study, we first showed that the negative regulation, which was characterized by decreased abundance of LamB with elevated growth of its gene-deleted mutant in medium with antibiotics, was a general response in resistance to different classes of antibiotics using 2-DE based proteomics or/and genetically gene-deletion mutant of LamB. Then, we revealed the interaction of LamB and Odp1 which catalyzes the overall conversion of pyruvate to acetyl-CoA and CO2, and found the decrease of the complex in antibiotic-resistant strains with a minimum inhibitory concentration dose-dependent manner. Further spectrofluorometry assay indicated that LamB served as a porin to influx an antibiotic. Finally, we showed that the decreased expression of LamB and Odp1 was detected in almost of all 34 multidrug-resistant strains, which suggested that LamB and Odp1 were biomarkers for identification of antibiotic-resistant E. coli. Our results indicated that the interaction of an outer membrane protein with an energy metabolic enzyme constructed an efficient pathway to resist antibiotics. These findings provide novel insights into the mechanisms of antibiotic resistance. Our data indicate that the negative regulation by LamB is widely detected in antibiotic-resistant E. coli. LamB serves as a porin to influx an antibiotic and is interacted with Odp1. The complex decreases in antibiotic-resistant strains with a MIC dose-dependent manner. Our findings indicate that interaction of outer membrane protein with energy metabolic enzyme constructs an efficient pathway to resist antibiotics and provides novel insights into the mechanisms of antibiotic resistance. Copyright © 2014 Elsevier B.V. All rights reserved.

Genetic analysis and molecular detection of the corn endosperm mutants induced by space flight

International Nuclear Information System (INIS)

Zhang Caibo; Zhou Yuanyuan; Wang Hanyu; Wang Hongwei; Wang Shengqing; Rong Tingzhao; Cao Moju

2013-01-01

In this study, two maize inbred lines 08-641 and 18-599 were carried into cosmic space by recoverable satellite 'Shijian 8', grain shrunken transparently and opaquely mutants were selected as experimental materials and their soluble sugar content in kernel were measured by annthrone colorimetry. The content of soluble sugar in mutant st1 kernels began to rise in 10 days after pollination, to reach the peak in 25 days and significantly higher than the contrast 08-641, while in mutant sol kernels it began to rise in 10 days after pollination, to reach the peak in 20 days and significantly higher than the contrast 18-599. The results of genetic analysis and allelism test showed that the trait in both mutants was all controlled by a single recessive gene, the mutant st1 was allelic to the su1 and the mutant sol was allelic to the sh2. DNA sequence alignment found 2 single-base mutations in 2 and 13 exon of su1 gene in the mutant st1 and 3 single-base mutations in 2, 5 and 16 exon of sh2 gene in mutant so1 leading to the change in amino acid sequences. So it is inferred that starch biosynthesis in the mutants may be blocked by these mutations, which lead to the increase of soluble sugar content in kernel. (authors)

Tolerance of some potato mutants induced with gamma irradiation to drought in vitro

International Nuclear Information System (INIS)

Al-Safadi, B.; Ayyoubi, Z.

2006-04-01

An in vitro selection program was conducted in order to improve potato (Solanum tuberosum) tolerance to drought. Potato mutant plants were obtained through a previously conducted mutation breeding program on three potato cultivars (Draga, Spunta, and Diamant) aimed at improving potato tolerance to salinity and resistance to late blight disease. In order to apply selection pressure, growth media (MS based) were prepared with the addition of 1%, 2%, 3% concentrations of Poly Ethylene Glycol (PEG). As a result, three mutants were selected that were tolerant to water stress (i.e. drought tolerant) two of which came from the cultivar Draga and one from Spunta. Physiological growth parameters (plant length, leaf number, branch number, roots number, leaf area, stomata number, and chlorophyll concentration content) were taken on the growing plantlets. The selected mutants were distinguished with some characteristics which can help in their tolerance to drought. Some of these characteristics were an increase in leaf number, root number, and a decrease in stomata number. However a reduction in chlorophyll content was observed as compared with the control. These mutant lines will need further selection in the field for plants with larger tubers before they can be considered as certified lines. (author)

Decreased catalytic activity and altered activation properties of PDE6C mutants associated with autosomal recessive achromatopsia

DEFF Research Database (Denmark)

Grau, Tanja; Artemyev, Nikolai O; Rosenberg, Thomas

2011-01-01

study on PDE6C mutations including the mutation spectrum, its prevalence in a large cohort of ACHM/cone dysfunction patients, the clinical phenotype and the functional characterization of mutant PDE6C proteins. Twelve affected patients from seven independent families segregating PDE6C mutations were......Mutations in the gene encoding the catalytic subunit of the cone photoreceptor phosphodiesterase (PDE6C) have been recently reported in patients with autosomal recessive inherited achromatopsia (ACHM) and early-onset cone photoreceptor dysfunction. Here we present the results of a comprehensive...... identified in our total patient cohort of 492 independent families. Eleven different PDE6C mutations were found including two nonsense mutations, three mutations affecting transcript splicing as shown by minigene assays, one 1 bp-insertion and five missense mutations. We also performed a detailed functional...

Higher antibiotic yielding mutants of bacillus subtilis by gamma radiation

International Nuclear Information System (INIS)

Ahmad, M.S.; Shaukat, G.A.; Malik, M.A.

1987-01-01

When Bacillus Subtilis AECL69 was grown in malt extract-pepetone-molasses-sugar (MPMS) medium, it could produce antibiotic substance(s) with antibacterial and antifungal properties in the culture fluid. The bacterial cells grown in MPMS medium were washed and suspended into distilled water and irradiated with gamma rays in Gammacell 220 at different doses. Higher antibiotic yielding isolates (plus mutants) were obtained from cell pollutions irradiated at 15 Kr. These gamma rays-induced plus mutants showed simultaneous higher production of antibacterial as well as antifungal activity. (author)

Characterization of Brucella abortus mutant strain Δ22915, a potential vaccine candidate.

Science.gov (United States)

Bao, Yanqing; Tian, Mingxing; Li, Peng; Liu, Jiameng; Ding, Chan; Yu, Shengqing

2017-04-04

Brucellosis, caused by Brucella spp., is an important zoonosis worldwide. Vaccination is an effective strategy for protection against Brucella infection in livestock in developing countries and in wildlife in developed countries. However, current vaccine strains including S19 and RB51 are pathogenic to humans and pregnant animals, limiting their use. In this study, we constructed the Brucella abortus (B. abortus) S2308 mutant strain Δ22915, in which the putative lytic transglycosylase gene BAB_RS22915 was deleted. The biological properties of mutant strain Δ22915 were characterized and protection of mice against virulent S2308 challenge was evaluated. The mutant strain Δ22915 showed reduced survival within RAW264.7 cells and survival in vivo in mice. In addition, the mutant strain Δ22915 failed to escape fusion with lysosomes within host cells, and caused no observable pathological damage. RNA-seq analysis indicated that four genes associated with amino acid/nucleotide transport and metabolism were significantly upregulated in mutant strain Δ22915. Furthermore, inoculation of ∆22915 at 10 5 colony forming units induced effective host immune responses and long-term protection of BALB/c mice. Therefore, mutant strain ∆22915 could be used as a novel vaccine candidate in the future to protect animals against B. abortus infection.

Solution NMR structure of the V27A drug resistant mutant of influenza A M2 channel

Energy Technology Data Exchange (ETDEWEB)

Pielak, Rafal M. [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 (United States); Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115 (United States); Chou, James J., E-mail: chou@cmcd.hms.harvard.edu [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 (United States)

2010-10-08

Research highlights: {yields} This paper reports the structure of the V27A drug resistant mutant of the M2 channel of influenza A virus. {yields} High quality NMR data allowed a better-defined structure for the C-terminal region of the M2 channel. {yields} Using the structure, we propose a proton transfer pathway during M2 proton conduction. {yields} Structural comparison between the wildtype, V27A and S31N variants allowed an in-depth analysis of possible modes of drug resistance. {yields} Distinct feature of the V27A channel pore also provides an explanation for its faster rate of proton conduction. -- Abstract: The M2 protein of influenza A virus forms a proton-selective channel that is required for viral replication. It is the target of the anti-influenza drugs, amantadine and rimantadine. Widespread drug resistant mutants, however, has greatly compromised the effectiveness of these drugs. Here, we report the solution NMR structure of the highly pathogenic, drug resistant mutant V27A. The structure reveals subtle structural differences from wildtype that maybe linked to drug resistance. The V27A mutation significantly decreases hydrophobic packing between the N-terminal ends of the transmembrane helices, which explains the looser, more dynamic tetrameric assembly. The weakened channel assembly can resist drug binding either by destabilizing the rimantadine-binding pocket at Asp44, in the case of the allosteric inhibition model, or by reducing hydrophobic contacts with amantadine in the pore, in the case of the pore-blocking model. Moreover, the V27A structure shows a substantially increased channel opening at the N-terminal end, which may explain the faster proton conduction observed for this mutant. Furthermore, due to the high quality NMR data recorded for the V27A mutant, we were able to determine the structured region connecting the channel domain to the C-terminal amphipathic helices that was not determined in the wildtype structure. The new structural

Use of wheat and maize protein mutants in breeding for improved protein quantity and quality

International Nuclear Information System (INIS)

Denic, M.; Dumanovic, J.; Misevic, D.; Konstantinov, K.; Fidler, D.; Stojanovic, Z.

1984-01-01

Selected offspring progenies (50 mutant lines) originating from mutation experiments with hexaploid wheat (cv. Bezostaya 1) were analysed for induced heritable variation in protein content, lysine content, grain yield and protein and lysine yields. Ten of these mutant lines were crossed with 11 local varieties. The protein and lysine contents were measured in the progenies of these crossings. The data showed better correlations of grain yield with protein and lysine yields than the protein and lysine contents with their corresponding yields. F 1 seeds showed higher lysine and protein contents than local varieties. Data with maize showed that: (1) the total endosperm protein content of modified opaque-2 types increases with an increase in the degree of normalization; (2) the lysine content in dry matter and protein in normalized o 2 kernels usually decreases with the increasing degree of normalization; (3) the lysine content in protein of modified o 2 kernels, is, in general, satisfactory up to the normalization of about 50% of endosperm. A desirable modification of o 2 endosperm within line A632o 2 was selected and crossed with o 2 lines. Most of the tested hybrids had a good protein quality, but endosperm modification was not evident in all hybrids. The o 2 gene was incorporated into high protein backgrounds. Besides a high protein content and quality, some of the hybrids tested had a comparable or higher yield than the o 2 check. (author)

Induction and use of artificial mutants in sweet potato

International Nuclear Information System (INIS)

Marumine, Shokichi

1984-01-01

X-ray, ethylene imine, 32 P and 60 Co were used as mutagen for sweet potato mutation breeding and visible variations were observed for all mutagen. In the case of 60 Co irradiation, mutation rate of skin color is 0.5-1.3% based on cutting. Direction and variation of dry matter and tuber yield of mutants which were induced by 32 P and/or 60 Co irradiation showed more deteriorative variation than progressive variation but some induced mutant lines show same or superior characters than original line. In the case of 32 P irradiation to tuber, obstruction is not so much up to dese of 10,000 μci per tuber but treatment of 330 μci per cutting approximate to LD 50 . By tuber treatment with 60 Co gamma rays, suppression of sprouting occurred in dose of 30kR. Tendency to increase a variation was not observed at higher doses. 50-200 μci per cutting or 300-500 μci per tuber in 32 P treatment and 15 kR in 60 Co gamma-irradiation for tuber seemed to be optimum dosages. Hybrid seed of mutant selected for dry matter content was compared with that of original line and it was concluded that the variation of selected line was genetic. Mutant induced by 32 P and 60 Co treatment was used as a parental material and progeny of the cross was selected for practical characters. As a result, a line of higher starch yield with high resistance to pest and disease was selected and this line was used as parental material of further breeding. (author)

Evaluation of yield and N2 fixation of mutant lines of groundnut in Malaysia

International Nuclear Information System (INIS)

Rusli, I.; Harun, A.R.; Rahman, K.A.; Shamsuddin, S.; Rahim, K.A.; Danso, S.K.A.

1998-01-01

The 15 N-dilution technique was used to evaluate N 2 fixation in groundnut (Arachis hypogaea L.) in three field trials of cultivars Matjan and V-13 (parents), their selected mutant lines, and a other local and foreign genotypes. Matjan mutant MJ/40/42 consistently produced the highest pod yields, at above 4 t ha -1 , 14-22% higher yields than the parent. In contrast, none of the V-13 mutants had consistently better yields than the parent. The mutant lines did not show consistent agronomic performance from year to year. Total dry matter yield did not correlate with pod yield, and pod yield did not correlate with amount of N fixed

Evaluation of artemisia mutant lines conducted from gamma irradiation treatment

International Nuclear Information System (INIS)

Ragapadmi Purnamaningsih; EG Lestari; M Syukur

2010-01-01

Cases of Malaria diseases attack in Indonesia has been increasing. Plasmodium falciparum the cause of malaria disease is now resistant to the usual medicine. One of malaria medicine which recommended by WHO is artemisinine compound extracted from Artemisia annua L plant. Low artemisinine content is one problem of Artemisia development in Indonesia. Increasing genetic variation using gamma irradiation is one alternative method to improve artemisinin content. In 2007, induce mutation had been done to artemisia seeds using gamma irradiation at dosage of 10-100 Gy. The good rooting planlet was regenerated and acclimatized in the green house, and then the seedling (M0 generation) was planted in the field at 1545 m asl. Plants derived from seeds without gamma irradiation treatment and cultured in vitro (in vitro control) were used as control. The result showed there were some morphological variations between the mutant lines (plant height, shape of the leaves and time of flowering). Ten mutant lines were selected based on biomass yield and analyzed for the artemisinine content.The result showed that artemisinine content of the mutant lines ranged from 0.44 - 1.41%, and it was significantly higher than that of in vitro control (0.43%). (author)

Early nodule senescence is activated in symbiotic mutants of pea (Pisum sativum L.) forming ineffective nodules blocked at different nodule developmental stages.

Science.gov (United States)

Serova, Tatiana A; Tsyganova, Anna V; Tsyganov, Viktor E

2018-04-03

Plant symbiotic mutants are useful tool to uncover the molecular-genetic mechanisms of nodule senescence. The pea (Pisum sativum L.) mutants SGEFix - -1 (sym40), SGEFix - -3 (sym26), and SGEFix - -7 (sym27) display an early nodule senescence phenotype, whereas the mutant SGEFix - -2 (sym33) does not show premature degradation of symbiotic structures, but its nodules show an enhanced immune response. The nodules of these mutants were compared with each other and with those of the wild-type SGE line using seven marker genes that are known to be activated during nodule senescence. In wild-type SGE nodules, transcript levels of all of the senescence-associated genes were highest at 6 weeks after inoculation (WAI). The senescence-associated genes showed higher transcript abundance in mutant nodules than in wild-type nodules at 2 WAI and attained maximum levels in the mutant nodules at 4 WAI. Immunolocalization analyses showed that the ethylene precursor 1-aminocyclopropane-1-carboxylate accumulated earlier in the mutant nodules than in wild-type nodules. Together, these results showed that nodule senescence was activated in ineffective nodules blocked at different developmental stages in pea lines that harbor mutations in four symbiotic genes.

New applications of CRISPR/Cas9 system on mutant DNA detection.

Science.gov (United States)

Jia, Chenqiang; Huai, Cong; Ding, Jiaqi; Hu, Lingna; Su, Bo; Chen, Hongyan; Lu, Daru

2018-01-30

The detection of mutant DNA is critical for precision medicine, but low-frequency DNA mutation is very hard to be determined. CRISPR/Cas9 is a robust tool for in vivo gene editing, and shows the potential for precise in vitro DNA cleavage. Here we developed a DNA mutation detection system based on CRISPR/Cas9 that can detect gene mutation efficiently even in a low-frequency condition. The system of CRISPR/Cas9 cleavage in vitro showed a high accuracy similar to traditional T7 endonuclease I (T7E1) assay in estimating mutant DNA proportion in the condition of normal frequency. The technology was further used for low-frequency mutant DNA detection of EGFR and HBB somatic mutations. To the end, Cas9 was employed to cleave the wild-type (WT) DNA and to enrich the mutant DNA. Using amplified fragment length polymorphism analysis (AFLPA) and Sanger sequencing, we assessed the sensitivity of CRISPR/Cas9 cleavage-based PCR, in which mutations at 1%-10% could be enriched and detected. When combined with blocker PCR, its sensitivity reached up to 0.1%. Our results suggested that this new application of CRISPR/Cas9 system is a robust and potential method for heterogeneous specimens in the clinical diagnosis and treatment management. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of CCS on the accumulation of FALS SOD1 mutant-containing aggregates and on mitochondrial translocation of SOD1 mutants: implication of a free radical hypothesis.

Science.gov (United States)

Kim, Ha Kun; Chung, Youn Wook; Chock, P Boon; Yim, Moon B

2011-05-15

Missense mutations of SOD1 are linked to familial amyotrophic lateral sclerosis (FALS) through a yet-to-be identified toxic-gain-of-function. One of the proposed mechanisms involves enhanced aggregate formation. However, a recent study showed that dual transgenic mice overexpressing both G93A and CCS copper chaperone (G93A/CCS) exhibit no SOD1-positive aggregates yet show accelerated FALS symptoms with enhanced mitochondrial pathology compared to G93A mice. Using a dicistronic mRNA to simultaneously generate hSOD1 mutants, G93A, A4V and G85R, and hCCS in AAV293 cells, we revealed: (i) CCS is degraded primarily via a macroautophagy pathway. It forms a stable heterodimer with inactive G85R, and via its novel copper chaperone-independent molecular chaperone activity facilitates G85R degradation via a macroautophagy-mediated pathway. For active G93A and A4V, CCS catalyzes their maturation to form active and soluble homodimers. (ii) CCS reduces, under non-oxidative conditions, yet facilitates in the presence of H(2)O(2), mitochondrial translocation of inactive SOD1 mutants. These results, together with previous reports showing FALS SOD1 mutants enhanced free radical-generating activity, provide a mechanistic explanation for the observations with G93A/CCS dual transgenic mice and suggest that free radical generation by FALS SOD1, enhanced by CCS, may, in part, be responsible for the FALS SOD1 mutant-linked aggregation, mitochondrial translocation, and degradation. Published by Elsevier Inc.

ENU-mutagenesis mice with a non-synonymous mutation in Grin1 exhibit abnormal anxiety-like behaviors, impaired fear memory, and decreased acoustic startle response

Science.gov (United States)

2013-01-01

Background The Grin1 (glutamate receptor, ionotropic, NMDA1) gene expresses a subunit of N-methyl-D-aspartate (NMDA) receptors that is considered to play an important role in excitatory neurotransmission, synaptic plasticity, and brain development. Grin1 is a candidate susceptibility gene for neuropsychiatric disorders, including schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). In our previous study, we examined an N-ethyl-N-nitrosourea (ENU)-generated mutant mouse strain (Grin1Rgsc174/Grin1+) that has a non-synonymous mutation in Grin1. These mutant mice showed hyperactivity, increased novelty-seeking to objects, and abnormal social interactions. Therefore, Grin1Rgsc174/Grin1+ mice may serve as a potential animal model of neuropsychiatric disorders. However, other behavioral characteristics related to these disorders, such as working memory function and sensorimotor gating, have not been fully explored in these mutant mice. In this study, to further investigate the behavioral phenotypes of Grin1Rgsc174/Grin1+ mice, we subjected them to a comprehensive battery of behavioral tests. Results There was no significant difference in nociception between Grin1Rgsc174/Grin1+ and wild-type mice. The mutants did not display any abnormalities in the Porsolt forced swim and tail suspension tests. We confirmed the previous observations that the locomotor activity of these mutant mice increased in the open field and home cage activity tests. They displayed abnormal anxiety-like behaviors in the light/dark transition and the elevated plus maze tests. Both contextual and cued fear memory were severely deficient in the fear conditioning test. The mutant mice exhibited slightly impaired working memory in the eight-arm radial maze test. The startle amplitude was markedly decreased in Grin1Rgsc174/Grin1+ mice, whereas no significant differences between genotypes were detected in the prepulse inhibition (PPI) test. The mutant mice showed no obvious

Genetic analysis of DNA repair in Aspergillus: evidence for different types of MMS-sensitive hyperrec mutants.

Science.gov (United States)

Käfer, E; Mayor, O

1986-07-01

To identify genes which affect DNA repair and possibly recombination in Aspergillus nidulans, mutants hypersensitive to methyl methanesulphonate (MMS) were induced with ultraviolet light (UV) or gamma-rays. About half of them contained associated translocations and many were hypersensitive to UV and/or defective in meiosis. Two are alleles of the known uvsB gene while most others define new genes. In addition, among available uvs mutants many were found to be MMS-sensitive. Some of the various uncharacterized ones were identified as alleles of known uvs, but 5 of them were mapped in 2 new genes, uvsH and uvsJ. To identify functional and epistatic groups, mutants from each uvs gene were tested for effects on recombination and mutation, and double mutant uvs strains were compared for UV survival to their component single mutant strains. 3 epistatic pairs were identified, (1) uvsF and H, (2) uvsB and D, and (3) uvsC and E. Conclusive interpair tests were difficult, because such double mutant combinations were frequently lethal or nearly so. The first pair, uvsF and H, shared some of the properties of excision-defective mutants, both uvs being very highly sensitive to UV for mutation as well as survival. But unlike such mutants, uvsH was also sensitive to gamma-rays and defective in meiosis. Both uvs showed normal levels of meiotic recombination, but greatly increased spontaneous mitotic crossing-over, being the most "hyperrec" types among all uvs. The second pair, uvsB and uvsC, which was similarly hyperrec showed only slight increases of UV-induced mutation (less than 2-fold). As a main effect, these uvs caused very high frequencies of unbalanced, unstable segregants from diploid conidia (30 X), but few of these were recognizable aneuploids. The third pair, uvsC and E, which are known to be rec- for gene conversion, caused reduced mitotic crossing-over in diploids and increased levels of haploid segregants. These mutants are spontaneous mutators, but showed less UV

Hypoxic resistance of KRAS mutant tumor cells to 3-Bromopyruvate is counteracted by Prima-1 and reversed by N-acetylcysteine.

Science.gov (United States)

Orue, Andrea; Chavez, Valery; Strasberg-Rieber, Mary; Rieber, Manuel

2016-11-18

The metabolic inhibitor 3-bromopyruvate (3-BrPA) is a promising anti-cancer alkylating agent, shown to inhibit growth of some colorectal carcinoma with KRAS mutation. Recently, we demonstrated increased resistance to 3-BrPA in wt p53 tumor cells compared to those with p53 silencing or mutation. Since hypoxic microenvironments select for tumor cells with diminished therapeutic response, we investigated whether hypoxia unequally increases resistance to 3-BrPA in wt p53 MelJuso melanoma harbouring (Q61L)-mutant NRAS and wt BRAF, C8161 melanoma with (G12D)-mutant KRAS (G464E)-mutant BRAF, and A549 lung carcinoma with a KRAS (G12S)-mutation. Since hypoxia increases the toxicity of the p53 activator, Prima-1 against breast cancer cells irrespective of their p53 status, we also investigated whether Prima-1 reversed hypoxic resistance to 3-BrPA. In contrast to the high susceptibility of hypoxic mutant NRAS MelJuso cells to 3-BrPA or Prima-1, KRAS mutant C8161 and A549 cells revealed hypoxic resistance to 3-BrPA counteracted by Prima-1. In A549 cells, Prima-1 increased p21CDKN1mRNA, and reciprocally inhibited mRNA expression of the SLC2A1-GLUT1 glucose transporter-1 and ALDH1A1, gene linked to detoxification and stem cell properties. 3-BrPA lowered CAIX and VEGF mRNA expression. Death from joint Prima-1 and 3-BrPA treatment in KRAS mutant A549 and C8161 cells seemed mediated by potentiating oxidative stress, since it was antagonized by the anti-oxidant and glutathione precursor N-acetylcysteine. This report is the first to show that Prima-1 kills hypoxic wt p53 KRAS-mutant cells resistant to 3-BrPA, partly by decreasing GLUT-1 expression and exacerbating pro-oxidant stress.

X-rays sensitive mammalian cell mutant

International Nuclear Information System (INIS)

Utsumi, Hiroshi

1982-01-01

A phenomenon that in x-ray-sensitive mammalian-cell mutants, cellular death due to x-ray radiation was not increased by caffeine, but on the contrary, the dead cells were resuscitated by it was discussed. The survival rate of mutant cells increased by caffein in a low concentration. This suggested that caffeine may have induced some mechanism to produce x-ray resistant mutant cells. Postirradiation treatment with caffeine increased considerably the survival rate of the mutant cells, and this suggested the existence of latent caffeine-sensitive potentially lethal damage repair system. This system, after a few hours, is thought to be substituted by caffeine-resistant repair system which is induced by caffeine, and this may be further substituted by x-ray-resistant repair system. The repair system was also induced by adenine. (Ueda, J.)

Energetic basis for drug resistance of HIV-1 protease mutants against amprenavir

Science.gov (United States)

Kar, Parimal; Knecht, Volker

2012-02-01

Amprenavir (APV) is a high affinity (0.15 nM) HIV-1 protease (PR) inhibitor. However, the affinities of the drug resistant protease variants V32I, I50V, I54V, I54M, I84V and L90M to amprenavir are decreased 3 to 30-fold compared to the wild-type. In this work, the popular molecular mechanics Poisson-Boltzmann surface area method has been used to investigate the effectiveness of amprenavir against the wild-type and these mutated protease variants. Our results reveal that the protonation state of Asp25/Asp25' strongly affects the dynamics, the overall affinity and the interactions of the inhibitor with individual residues. We emphasize that, in contrast to what is often assumed, the protonation state may not be inferred from the affinities but requires pKa calculations. At neutral pH, Asp25 and Asp25' are ionized or protonated, respectively, as suggested from pKa calculations. This protonation state was thus mainly considered in our study. Mutation induced changes in binding affinities are in agreement with the experimental findings. The decomposition of the binding free energy reveals the mechanisms underlying binding and drug resistance. Drug resistance arises from an increase in the energetic contribution from the van der Waals interactions between APV and PR (V32I, I50V, and I84V mutant) or a rise in the energetic contribution from the electrostatic interactions between the inhibitor and its target (I54M and I54V mutant). For the V32I mutant, also an increased free energy for the polar solvation contributes to the drug resistance. For the L90M mutant, a rise in the van der Waals energy for APV-PR interactions is compensated by a decrease in the polar solvation free energy such that the net binding affinity remains unchanged. Detailed understanding of the molecular forces governing binding and drug resistance might assist in the design of new inhibitors against HIV-1 PR variants that are resistant against current drugs.

Estimates of selection parameters in protein mutants of spring barley

International Nuclear Information System (INIS)

Gaul, H.; Walther, H.; Seibold, K.H.; Brunner, H.; Mikaelsen, K.

1976-01-01

Detailed studies have been made with induced protein mutants regarding a possible genetic advance in selection including the estimation of the genetic variation and heritability coefficients. Estimates were obtained for protein content and protein yield. The variation of mutant lines in different environments was found to be many times as large as the variation of the line means. The detection of improved protein mutants seems therefore possible only in trials with more than one environment. The heritability of protein content and protein yield was estimated in different sets of environments and was found to be low. However, higher values were found with an increasing number of environments. At least four environments seem to be necessary to obtain reliable heritability estimates. The geneticall component of the variation between lines was significant for protein content in all environmental combinations. For protein yield some environmental combinations only showed significant differences. The expected genetic advance with one selection step was small for both protein traits. Genetically significant differences between protein micromutants give, however, a first indication that selection among protein mutants with small differences seems also possible. (author)

Grain-filling duration and grain yield relationships in wheat mutants

International Nuclear Information System (INIS)

Larik, A.S.

1987-01-01

Nine stable mutants of bread wheat along with their mother cultivars were investigated for grain-filling characteristics in relation to grain yield. Significant differences among mutants for grain-filling duration and grain-filling index were observed. Inspite of the consistent differences in grain-filling duration there was no significant association between grain-filling duration and grain yield in C-591 and Nayab mutants. Failure to detect an yield advantage due to differences in grain-filling duration in these genotypes suggests that any advantage derived from alteration of grain-filling period may have been outweighed by the coincident changes in length of the vegetative period. Other factors such as synchrony of anthesis may have limited out ability to find an association between grainfilling duration and grain yield. On the contrary, significant association between grain-filling duration and grain yield displayed by indus-66 indus-66 mutants derived from gamma rays, shows the ability of gamma rays to induce functional alternations in the pattern of gene arrangements controlling these traits. Thus, the vaability observed in these physiological traits suggests that selection for these traits could be useful in improving grain yield. (author)

Genetic Analysis of Streaked and Abnormal Floret Mutant st-fon

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De-xi CHEN

2013-07-01

Full Text Available A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant (st-fon. For this mutant, besides white streak appeared on culm, leaves and panicles, the number of floral organs increased and florets cracked. The extreme phenotype was that several small florets grew from one floret or branch rachis in small florets extended and developed into panicles. By using transmission electron microscope to observe the ultrastructure of white histocytes of leaves at the seedling stage, the white tissues which showed abnormal plastids, lamellas and thylakoids could not develop into normal chloroplast, and the development of chloroplast was blocked at the early growth stage of plastid. Scanning electron microscope and paraffin section were also used to observe the development of floral organs, and the results indicated that the development of floral meristem was out of order and unlimited, whereas in the twisty leaves, vascular bundle sheath cells grew excessively, or some bubbly cells increased. Genetic analyses carried out by means of cross and backcross with four normal-leaf-color materials revealed that the mutant is of cytoplasm inheritance.

Use of the shrunken-2 (sh2) mutant to study source-sink relations in maize during reproductive development

International Nuclear Information System (INIS)

Ritchie, S.W.

1987-01-01

Leaf metabolism, 14 C-assimilate distribution, and kernel (sink) metabolism were compared in a normal wild-type (homozygous sh2) inbred (Oh43) of maize (Zea mays L.) and a genetically related shrunken-2 (homozygous sh2) inbred of Oh43. In comparison to normal starchy kernels, kernels from the shrunken-2 (sh2) mutant showed highly decreased starch contents and subsequently decreased total kernel dry matter. As measured by dry matter accumulation and 14 C-assimilate distribution patterns, sh2 kernel assimilate demand did not differ from normal kernel assimilate demand throughout most of the early linear grain-fill period. However, sh2 kernel demand began to decrease toward the end of early grain-fill and was highly decreased during all of the middle grain-fill period. During the late grain-fill period, sh2 kernel assimilate demand was non-existent. The initial evidence for decreased sh2 kernel assimilate demand was a change in 14 C label distribution in the sh2 ear tissues (husks, shank, cob, and kernels) toward the end of early grain-fill

GPNMB ameliorates mutant TDP-43-induced motor neuron cell death.

Science.gov (United States)

Nagahara, Yuki; Shimazawa, Masamitsu; Ohuchi, Kazuki; Ito, Junko; Takahashi, Hitoshi; Tsuruma, Kazuhiro; Kakita, Akiyoshi; Hara, Hideaki

2017-08-01

Glycoprotein nonmetastatic melanoma protein B (GPNMB) aggregates are observed in the spinal cord of amyotrophic lateral sclerosis (ALS) patients, but the detailed localization is still unclear. Mutations of transactive response DNA binding protein 43kDa (TDP-43) are associated with neurodegenerative diseases including ALS. In this study, we evaluated the localization of GPNMB aggregates in the spinal cord of ALS patients and the effect of GPNMB against mutant TDP-43 induced motor neuron cell death. GPNMB aggregates were not localized in the glial fibrillary acidic protein (GFAP)-positive astrocyte and ionized calcium binding adaptor molecule-1 (Iba1)-positive microglia. GPNMB aggregates were localized in the microtubule-associated protein 2 (MAP-2)-positive neuron and neurofilament H non-phosphorylated (SMI-32)-positive neuron, and these were co-localized with TDP-43 aggregates in the spinal cord of ALS patients. Mock or TDP-43 (WT, M337V, and A315T) plasmids were transfected into mouse motor neuron cells (NSC34). The expression level of GPNMB was increased by transfection of mutant TDP-43 plasmids. Recombinant GPNMB ameliorated motor neuron cell death induced by transfection of mutant TDP-43 plasmids and serum-free stress. Furthermore, the expression of phosphorylated ERK1/2 and phosphorylated Akt were decreased by this stress, and these expressions were increased by recombinant GPNMB. These results indicate that GPNMB has protective effects against mutant TDP-43 stress via activating the ERK1/2 and Akt pathways, and GPNMB may be a therapeutic target for TDP-43 proteinopathy in familial and sporadic ALS. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Defective DNA cross-link removal in Chinese hamster cell mutants hypersensitive to bifunctional alkylating agents

International Nuclear Information System (INIS)

Hoy, C.A.; Thompson, L.H.; Mooney, C.L.; Salazar, E.P.

1985-01-01

DNA repair-deficient mutants from five genetic complementation groups isolated previously from Chinese hamster cells were assayed for survival after exposure to the bifunctional alkylating agents mitomycin C or diepoxybutane. Groups 1, 3, and 5 exhibited 1.6- to 3-fold hypersensitivity compared to the wild-type cells, whereas Groups 2 and 4 exhibited extraordinary hypersensitivity. Mutants from Groups 1 and 2 were exposed to 22 other bifunctional alkylating agents in a rapid assay that compared cytotoxicity of the mutants to the wild-type parental strain, AA8. With all but two of the compounds, the Group 2 mutant (UV4) was 15- to 60-fold more sensitive than AA8 or the Group 1 mutant (UV5). UV4 showed only 6-fold hypersensitivity to quinacrine mustard. Alkaline elution measurements showed that this compound produced few DNA interstrand cross-links but numerous strand breaks. Therefore, the extreme hypersensitivity of mutants from Groups 2 and 4 appeared specific for compounds the main cytotoxic lesions of which were DNA cross-links. Mutant UV5 was only 1- to 4-fold hypersensitive to all the compounds. Although the initial number of cross-links was similar for the three cell lines, the efficiency of removal of cross-links was lowest in UV4 and intermediate in UV5. These results suggest that the different levels of sensitivity are specifically related to different efficiencies of DNA cross-link removal. The phenotype of hypersensitivity to both UV radiation and cross-link damage exhibited by the mutants in Groups 2 and 4 appears to differ from those of the known human DNA repair syndromes

Elucidating the Mechanism of Gain of Toxic Function From Mutant C1 Inhibitor Proteins in Hereditary Angioedema

Science.gov (United States)

2017-10-01

antibodies to 5 specifically blot wild-type C1INH in the pathologic polymers.. A FLAG tag was placed into the wild-type C1INH cDNA located immediately...resulted in decreased secretion of the 3x-FLAG-WT-C1INH when cotransfected with the mutant cDNA . This was an important confirmation of our...C1INH plus mutant C1INH cDNA in the presence or absence of a lactacystin, a proteasome inhibitor. As shown in figure 2, blocking degradation of

The adaptability of upland rice waxy mutant (Oryza sativa L.) to marginal land in Batumarta

International Nuclear Information System (INIS)

Dwimahyani, Ita; Mitrosuhardjo, M.M.

1998-01-01

A field experiment had been conducted at Batumarta, Lampung Province to test the adaptability of upland rice waxy mutant (DT 20.11.84) at marginal land. Similar experiments had also been conducted in fertilize soil at Ps. Jumat, Jakarta and Citayam, Kabupaten Bogor. Agronomic evaluation such as number of tiller, panicle length number of seeds per tiller, and weight of 1000 grains from waxy mutant line, which were cultivated at Batumarta showed adaptability was better than the original variety (Danau Tempe). Grains yield of waxy mutant line per ha at marginal land (Batubara) was higher than Danau Tempe i.e 2,34 and 1,89 ton/ha respectively. In addition to grain yield of waxy mutant line at Psr Jumat, Jakarta and Citayam, Bogor was lower than Danau Tempe. The Low of grain yield that waxy mutant compared with the original variety line was caused by number of tiller and panicle length of waxy mutant line also low. Results of experiment can be concluded that waxy mutant line was favourable growing at marginal land when compared with the original variety. (author)

Field Performance of Five Soybean Mutants Under Drought Stress Conditions and Molecular Analysis Using SSR Markers

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Y Yuliasti

2017-08-01

Full Text Available The objectives of this research wereto evaluate (1 the performance of soybean mutant lines under drought stress conditions, and(2 the genetic diversity and relationship among the mutant lines using SSR markers.The field evaluation was conducted during the dry season of 2011 and 2012 at the experimental Farm of Mataram University, West Nusa Tenggara, Indonesia. The field experiment was set up in a randomized block design. Ten mutant lines and two control varieties were evaluated in four replications. Genetic distance among evaluated lines were determined based on allelic diversity analysis using 40 simple sequence repeat (SSR loci. Under drought stress conditions, two mutant lines, Kdl3 and Kdl8,showed a better performance compared to the other ones. The high yielding mutant lines were Kdl3and Kdl8, which yielded 1.75 t ha-1and 1.69 t ha-1, respectively, compared to the parent and national control, Panderman 1.43 t ha-1 and Muria 1.32 t ha-1. These mutant linesrequired 30.75 to 32days to flower and 79.75 to 83.75 day to harvest with relatively short plant height 28.25 and 23.35 cmrespectively. Those mutant characters were better than those of the other three mutants, the original parents, and the control soybean species. Since the evaluated soybean mutant lines yielded more under drought stress conditions than the standard varieties, they can be used and registered as drought-tolerant soybean mutants. Moreover, the evaluated soybean accessions showed a wide genetic distance. The accessions were clustered into two groups according to their genetic background, namelygroup I (the Panderman with three mutant lines and group II (the Muria with two mutant lines. Twenty-three out of 40 evaluated SSR loci, including AW31, BE806, CMAC7L, S080, S126, S57, S171, S224, S285, S294, S393, S294, S383, S511, S511, S520, S540, S547, S551, S571, S577, and S578, provided polymorphic alleles between the parents and their mutants and could be used to differentiate

Identification of diphtheria toxin R domain mutants with enhanced inhibitory activity against HB-EGF.

Science.gov (United States)

Suzuki, Keisuke; Mizushima, Hiroto; Abe, Hiroyuki; Iwamoto, Ryo; Nakamura, Haruki; Mekada, Eisuke

2015-05-01

Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a ligand of EGF receptor, is involved in the growth and malignant progression of cancers. Cross-reacting material 197, CRM197, a non-toxic mutant of diphtheria toxin (DT), specifically binds to the EGF-like domain of HB-EGF and inhibits its mitogenic activity, thus CRM197 is currently under evaluation in clinical trials for cancer therapy. To develop more potent DT mutants than CRM197, we screened various mutant proteins of R domain of DT, the binding site for HB-EGF. A variety of R-domain mutant proteins fused with maltose-binding protein were produced and their inhibitory activity was evaluated in vitro. We found four R domain mutants that showed much higher inhibitory activity against HB-EGF than wild-type (WT) R domain. These R domain mutants suppressed HB-EGF-dependent cell proliferation more effectively than WT R domain. Surface plasmon resonance revealed their higher affinity to HB-EGF than WT R domain. CRM197(R460H) carrying the newly identified mutation showed increased cell proliferation inhibitory activity and affinity to HB-EGF. These results suggest that CRM197(R460H) or other recombinant proteins carrying newly identified mutation(s) in the R domain are potential therapeutics targeting HB-EGF. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Relations between protein production, protein quality and environmental factors in Pisum mutants

International Nuclear Information System (INIS)

Gottschalk, W.; Mueller, H.P.; Wolff, G.

1975-01-01

The seed protein content of 138 radiation-induced Pisum mutants was determined. The variability of this genetically well-defined material agrees approximately with that of the world collection of Pisum sativum. Some environmental factors to a great extent influence the protein production of the mutants and the initial line. Therefore, it is necessary to consider the relations between the genetically controlled protein production and its dependence upon the environmental factors. This is especially evident if the protein situation of the same genotypes cultivated under the moderate climatic conditions of middle Europe is compared with the subtropical conditions of India. A generally firm correlation between seed size and protein content could not be found in material regarding 148 different mutants of our assortment. Therefore, the selection of small-grained mutants does not result in a selection of protein-rich genotypes in Pisum sativum. Considering all the criteria positively and negatively influencing the protein production, a positive situation could be found in some mutants, especially in the fasciated ones. Furthermore, an improvement of the protein quality could be reached by a genetically conditioned alteration of the globulin-albumin ratio leading to an increase of some essential amino acids such as methionine and lysine. The combined action of mutant genes results in unexpected changes of the protein quantity as well as the quality of the recombinants in relation to their parental mutants. The comparison of some essential amino acids of our useful mutants with those of the varieties of other genera of the Leguminosae shows certain trends of biochemical alterations realized during evolutionary development of the family. (author)

relationship between physical characteristics and susceptibility to sitotroga cerealella (oliv.) in paddy rice mutants

International Nuclear Information System (INIS)

Boshra, S.A.; Azer, S.A.

2004-01-01

some promising mutants of rice variety Giza 180 induced by using gamma rays were tested for susceptibility to infestation by angoumois grain moth, sitotroga cerealella in relation with grain physical characters. number of F1 progeny and percentage of adult emergence showed that mutants 7/1, 4/5 and 1/7 were the most susceptible o angoumois grain moth, while mutants 13/1,16/1 and 15/6 b were least susceptible . there was positive correlation between number of F1 adult progeny and grain weight loss. the development period of the insect ranged from 33.7 days on 1/7 to 42.9 days on 15/6 b and the adults that emerged from mutants 1/7,4/5,7/1,8/1,15/1 and 11/1 lived longer than those of the other ones. Grains of the mutants with thick and pubescent or intermediate hulls were the least susceptible to attack by this pest. the rice mutants 13/1,16/1,15/6 b and their parental cultivar Giza 180 had the highest grain yield

Mutant DD genotype of NFKB1 gene is associated with the susceptibility and severity of coronary artery disease.

Science.gov (United States)

Luo, Jun-Yi; Li, Xiao-Mei; Zhou, Yun; Zhao, Qiang; Chen, Bang-Dang; Liu, Fen; Chen, Xiao-Cui; Zheng, Hong; Ma, Yi-Tong; Gao, Xiao-Ming; Yang, Yi-Ning

2017-02-01

Nuclear factor κappa B (NF-κB) is an important transcription factor in the development and progression of coronary artery disease (CAD). Recent evidence suggests that -94 ATTG ins/del mutant in the promoter of NFKB1 gene is an essential functional mutant. The present study demonstrated the frequencies of the del/del (DD) genotype and del (D) allele were significantly higher in CAD patients than in controls. CAD patients carrying mutant DD genotype had worse stenosis of diseased coronary arteries compared to those carrying ins/ins (II) or ins/del (ID) genotype. Plasma levels of endothelial nitric oxide synthase (eNOS) were lower, while inflammatory cytokine incnterlukin-6 (IL-6) was higher in CAD patients with DD genotype than those with II or ID genotype (both PDD genotype HUVECs) were more susceptible to H 2 O 2 -induced apoptosis, which was accompanied with a decreased Bcl-2 expression. Further, mutant HUVECs had lower eNOS but higher IL-6 mRNA levels and decreased phosphorylation of eNOS under H 2 O 2 -stimulation (both PDD genotype of NFKB1 gene is associated with the risk and severity of CAD. Dwonregulation of NF-κB p50 subunit leads to exacerbated endothelial dysfunction and apoptosis and enhanced inflammatory response that is the potential underlying mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Officially released mutant varieties in China

International Nuclear Information System (INIS)

Liu, L.; Van Zanten, L.; Shu, Q.Y.; Maluszynski, M.

2004-01-01

The use of mutation techniques for crop improvement in China has a long and well-established tradition of more than 50 years. As the result of intensive research in many institutes dealing with application of nuclear technologies more than 620 cultivars of 44 crop species have been released. Numerous mutant varieties have been grown on a large scale bringing significant economic impact, sustaining crop production and greatly contributing to increase of food production also in stress prone areas of the country. However, there is still missing information not only on the number of mutant varieties released in particular crop species but also on mutagens applied, selection approaches and on the use of mutants in cross breeding. Numerous Chinese scientists collected and systematized this information. Results of their work were often published in local scientific journals in the Chinese language and as such were unavailable to breeders from other countries. Having this in mind, we requested Dr. Liu Luxiang, the Director of the Department of Plant Mutation Breeding and Genetics, Institute for Application of Atomic Energy, Chinese Academy of Agricultural Sciences in Beijing to help us in finding as much information as possible on mutant varieties officially released in China. The data has been collected in close collaboration with his colleagues from various institutions all over the country and then evaluated, edited and prepared for publication by our team responsible for the FAO/IAEA Database of Officially Released Mutant Varieties. We would like to thank all Chinese colleagues who contributed to this list of Chinese mutant varieties. We hope that this publication will stimulate plant breeders in China to collect more information on released mutant varieties and especially on the use of mutated genes in cross breeding. (author)

Regulation of 1, 4, 5-triphosphate receptor channel gating dynamics by mutant presenilin in Alzheimer's disease cells

Science.gov (United States)

Wei, Fang; Li, Xiang; Cai, Meichun; Liu, Yanping; Jung, Peter; Shuai, Jianwei

2017-06-01

In neurons of patients with Alzheimer's disease, the intracellular Ca2+ concentration is increased by its release from the endoplasmic reticulum via the inositol 1, 4, 5-triphosphate receptor (IP3R). In this paper, we discuss the IP3R gating dynamics in familial Alzheimer's disease (FAD) cells induced with presenilin mutation PS1. By fitting the parameters of an IP3R channel model to experimental data of the open probability, the mean open time and the mean closed time of IP3R channels, in control cells and FAD mutant cells, we suggest that the interaction of presenilin mutation PS1 with IP3R channels leads the decrease in the unbinding rates of IP3 and the activating Ca2+ from IP3Rs. As a result, the increased affinities of IP3 and activating Ca2+ for IP3R channels induce the increase in the Ca2+ signal in FAD mutant cells. Specifically, the PS1 mutation decreases the IP3 dissociation rate of IP3R channels significantly in FAD mutant cells. Our results suggest possible novel targets for FAD therapeutic intervention.

RAF Suppression Synergizes with MEK Inhibition in KRAS Mutant Cancer Cells

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Simona Lamba

2014-09-01

Full Text Available KRAS is the most frequently mutated oncogene in human cancer, yet no therapies are available to treat KRAS mutant cancers. We used two independent reverse genetic approaches to identify components of the RAS-signaling pathways required for growth of KRAS mutant tumors. Small interfering RNA (siRNA screening of 37 KRAS mutant colorectal cancer cell lines showed that RAF1 suppression was synthetic lethal with MEK inhibition. An unbiased kinome short hairpin RNA (shRNA-based screen confirmed this synthetic lethal interaction in colorectal as well as in lung cancer cells bearing KRAS mutations. Compounds targeting RAF kinases can reverse resistance to the MEK inhibitor selumetinib. MEK inhibition induces RAS activation and BRAF-RAF1 dimerization and sustains MEK-ERK signaling, which is responsible for intrinsic resistance to selumetinib. Prolonged dual blockade of RAF and MEK leads to persistent ERK suppression and efficiently induces apoptosis. Our data underlie the relevance of developing combinatorial regimens of drugs targeting the RAF-MEK pathway in KRAS mutant tumors.

Construction and functional analysis of Trichoderma harzianum mutants that modulate maize resistance to the pathogen Curvularia lunata.

Science.gov (United States)

Fan, Lili; Fu, Kehe; Yu, Chuanjin; Ma, Jia; Li, Yaqian; Chen, Jie

2014-01-01

Agrobacterium tumefaciens-mediated transformation (ATMT) was used to generate an insertional mutant library of the mycelial fungus Trichoderma harzianum. From a total of 450 mutants, six mutants that showed significant influence on maize resistance to C. lunata were analyzed in detail. Maize coated with these mutants was more susceptible to C. lunata compared with those coated with a wild-type (WT) strain. Similar to other fungal ATMT libraries, all six mutants were single copy integrations, which occurred preferentially in noncoding regions (except two mutants) and were frequently accompanied by the loss of border sequences. Two mutants (T66 and T312) that were linked to resistance were characterized further. Maize seeds coated with T66 and T312 were more susceptible to C. lunata than those treated with WT. Moreover, the mutants affected the resistance of maize to C. lunata by enhancing jasmonate-responsive gene expression. T66 and T312 induced maize resistance to C. lunata infection through a jasmonic acid-dependent pathway.

Creating Sunflower Mutant Lines (Helianthus Annuus L.) Using Induced Mutagenesis

International Nuclear Information System (INIS)

Encheva, J.

2009-01-01

Immature sunflower zygotic embryos of sunflower fertility restorer line 374 R were treated with ultrasound and gamma radiation before plating embryos to culture medium. All plants were isolated and self-pollinated for several generations. New sunflower forms with inherited morphological and biochemical changes were obtained. The genetic changes occurring during the mutation procedure included fourteen morphological and biochemical characters. In comparison to the check line 374 R, decreasing of the mean value of the indexes was registered for 33 % of the total number of characters and vise verse, significant increasing was observed for 60 %. Mutation for resistance to the local population of Orobanche cumana race A-E was obtained from the susceptible Bulgarian control line 374 R. Two investigated mutant lines possessed 100 % resistance to Orobanche and stable inheritance in the next generations. Our results showed that induced mutagenesis in sunflower can be successfully used to develop new lines useful for heterosis breeding

Identification and Characterization of Spontaneous Auxotrophic Mutants in Fusarium langsethiae

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Olga Gavrilova

2017-03-01

Full Text Available Analysis of 49 strains of Fusarium langsethiae originating from northern Europe (Russia, Finland, Sweden, UK, Norway, and Latvia revealed the presence of spontaneous auxotrophic mutants that reflect natural intraspecific diversity. Our investigations detected that 49.0% of F. langsethiae strains were auxotrophic mutants for biotin, and 8.2% of the strains required thiamine as a growth factor. They failed to grow on vitamin-free media. For both prototrophic and auxotrophic strains, no growth defect was observed in rich organic media. Without essential vitamins, a significant reduction in the growth of the auxotrophic strains results in a decrease of the formation of T-2 toxin and diacetoxyscirpenol. In addition, all analysed F. langsethiae strains were distinguished into two subgroups based on PCR product sizes. According to our results, 26 and 23 strains of F. langsethiae belong to subgroups I and II respectively. We determined that the deletion in the intergenic spacer (IGS region of the rDNA of F. langsethiae belonging to subgroup II is linked with temperature sensitivity and causes a decrease in strain growth at 30 °C. Four thiamine auxotrophic strains were found in subgroup I, while 21 biotin auxotrophic strains were detected in subgroups II. To the best of our knowledge, the spontaneous mutations in F. langsethiae observed in the present work have not been previously reported.

Mutant of Japanese pear resistant to Black Spot Disease

International Nuclear Information System (INIS)

Sanada, T.; Nishida, T.; Ikeda, F.

1987-01-01

Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

Purification, gene cloning, gene expression, and mutants of Dps from the obligate anaerobe Porphyromonas gingivalis.

Science.gov (United States)

Ueshima, Junichi; Shoji, Mikio; Ratnayake, Dinath B; Abe, Kihachiro; Yoshida, Shinichi; Yamamoto, Kenji; Nakayama, Koji

2003-03-01

The periodontopathogen Porphyromonas gingivalis is an obligate anaerobe that is devoid of catalase but exhibits a relatively high degree of resistance to peroxide stress. In the present study, we demonstrate that P. gingivalis contains a Dps homologue that plays an important role in the protection of cells from peroxide stress. The Dps protein isolated from P. gingivalis displayed a ferritin-like spherical polymer consisting of 19-kDa subunits. Molecular cloning and sequencing of the gene encoding this protein revealed that it had a high similarity in nucleotide and amino acid sequences to Dps proteins from other species. The expression of Dps was significantly increased by exposure of P. gingivalis to atmospheric oxygen in an OxyR-dependent manner, indicating that it is regulated by the reactive oxygen species-regulating gene oxyR. The Dps-deficient mutants, including the dps single mutant and the ftn dps double mutant, showed no viability loss upon exposure to atmospheric oxygen for 6 h. In contrast to the wild type, however, these mutants exhibited the high susceptibility to hydrogen peroxide, thereby disrupting the viability. On the other hand, no significant difference in sensitivity to mitomycin C and metronidazole was observed between the wild type and the mutants. Furthermore, the dps single mutant, compared with the wild type, showed a lower viability in infected human umbilical vein endothelial cells.

A preliminary study on induction and identification of chlorophyll mutants of indica type temperature sensitive genie male-sterile rice

International Nuclear Information System (INIS)

Xia Yingwu; Liu Guifu; Shu Qingyao; Jiang Ronghua; Xie Jiahua

1995-01-01

Chlorophyll mutants of different type were obtained from indica type temperature sensitive genie male-sterile rice (cv. 2177s) by using 60 Co γ-rays irradiation. The total chlorophyll mutation frequency reached to 0.26% in M 2 generation. However only about 4.50% of these mutants could survived. Among them, 33 heritable chlorophyll mutant lines were easily distinguished, and were screened and studied. The mutants either showed chlorosis or yellowing or expressed only at seedling period or persisted all growth cycle. The expression of mutant character was stable under different environment. It is suggested that they are useful as the marker traits in two-line hybrid rice. Moreover, the agronomic traits of most of these lines changed in different levels compared with the parent line 2177S. Every mutation line seemed to be controlled by one recessive gene as the F 1 plants of reciprocal crosses between mutant and 2177S showed normal leaf color. And the ratio of green plants/mutant plants was 3:1 in the segregated F 2 population

New early-ripening wheat mutant lines from the varieties Norman and Avalon

International Nuclear Information System (INIS)

Djelepov, K.

1988-01-01

The English wheat varieties Norman and Avalon are high-productive, resistant to lodging and to diseases but late-ripening in Bulgaria. They are 10-15 days later than the variety Sadovo 1 and therefore suffer often from dry and hot weather, causing premature ripening and shrivelled seed. Dry seeds from the two varieties were irradiated with 10 and 15 kR 60 Co gamma rays. In M 2 , several earlier ripening forms were selected and they were studied also in M 3 in 1987. In the Table, four early ripening mutant lines and the respective initial varieties are compared. They vary significantly in plant height and grain size. The mutant lines of Norman produce smaller grain but all mutants show a higher hectoliter weight. The mutant lines head and mature 4 to 10 days earlier than the respective initial varieties. Some of them are as productive as the standard and other cultivated varieties. We shall continue testing their productivity and possibilities for their use in the breeding

Selection of the Mutants with High Hydroquinone Degradation Ability of Serratia Marcesscen by Plasma Mutation

International Nuclear Information System (INIS)

Yao Risheng; You Qidong; He Weijing; Zhu Huixia

2009-01-01

In this study, an efficient way by plasma induced mutation was applied to improve the hydroquinone degradation capacity of Serratia marcescens AB 90027 (SM27). The results showed that combined with the selection of hydroquinone tolerance, the mutant with high hydroquinone degradation ability induced by plasma could be achieved. The best dose for plasma mutation was 15 s, which showed a 47.0% higher positive mutation ratio. Besides, the aimed mutant was markedly different from the parent strain (SM27) in colonial traits while cultivated on Kings media. Finally, the hydroquinone degradation ratio reached 70.5% using the induced mutant strain with 1500 mg/L hydroquinone (HQ) after 15 days of cultivation as the selective conditions; however, it was only 46.7% for SM27. The improvement of the degradation capacity by the induced mutant with a high concentration of HQ selection was attributed to its faster growth and higher hydroquinone tolerance compared with that of the parent strain.

Noonan syndrome-causing SHP2 mutants impair ERK-dependent chondrocyte differentiation during endochondral bone growth.

Science.gov (United States)

Tajan, Mylène; Pernin-Grandjean, Julie; Beton, Nicolas; Gennero, Isabelle; Capilla, Florence; Neel, Benjamin G; Araki, Toshiyuki; Valet, Philippe; Tauber, Maithé; Salles, Jean-Pierre; Yart, Armelle; Edouard, Thomas

2018-04-12

Growth retardation is a constant feature of Noonan syndrome (NS) but its physiopathology remains poorly understood. We previously reported that hyperactive NS-causing SHP2 mutants impair the systemic production of insulin-like growth factor 1 (IGF1) through hyperactivation of the RAS/extracellular signal-regulated kinases (ERK) signalling pathway. Besides endocrine defects, a direct effect of these mutants on growth plate has not been explored, although recent studies have revealed an important physiological role for SHP2 in endochondral bone growth. We demonstrated that growth plate length was reduced in NS mice, mostly due to a shortening of the hypertrophic zone and to a lesser extent of the proliferating zone. These histological features were correlated with decreased expression of early chondrocyte differentiation markers, and with reduced alkaline phosphatase staining and activity, in NS murine primary chondrocytes. Although IGF1 treatment improved growth of NS mice, it did not fully reverse growth plate abnormalities, notably the decreased hypertrophic zone. In contrast, we documented a role of RAS/ERK hyperactivation at the growth plate level since 1) NS-causing SHP2 mutants enhance RAS/ERK activation in chondrocytes in vivo (NS mice) and in vitro (ATDC5 cells) and 2) inhibition of RAS/ERK hyperactivation by U0126 treatment alleviated growth plate abnormalities and enhanced chondrocyte differentiation. Similar effects were obtained by chronic treatment of NS mice with statins.In conclusion, we demonstrated that hyperactive NS-causing SHP2 mutants impair chondrocyte differentiation during endochondral bone growth through a local hyperactivation of the RAS/ERK signalling pathway, and that statin treatment may be a possible therapeutic approach in NS.

Molecular analysis of mutants of the Neurospora adenylosuccinate ...

Indian Academy of Sciences (India)

2012-08-07

Aug 7, 2012 ... and mutants induced with X-ray, UV or chemical mutagens. ... We have sequenced the ad-8 locus from 13 of these mutants and identified the molecular nature ..... mutants in yeast by selection for constitutive behavior in pig-.

Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

Science.gov (United States)

Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

2012-11-30

This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.

Gamma-ray induced mutants in castor (Ricinus communis L.)

International Nuclear Information System (INIS)

Janila, P.; Ashok Kumar, A.; Rajashekar Reddy, N.; Hemalatha, V.

2007-01-01

We report isolation of three recessive mutants in castor using dry seed irradiation with gamma rays. The crinkled leaf mutant (crf) was identified in K-55-112 M2 family and leafy mutant (lea) in H-55-577 M2 family; both are recessive lethal and thus maintained as heterozygotes. The cri mutant has highly wrinkled leaves resembling finger millet head and failed to enter reproductive phase, consequently did not produce seeds. The number of leaf lobes is reduced in lea mutant and though it produced spikes, the male and female flowers are converted to leafy appendages. The third mutant, fused (Ius) stem identified in H-55-617 M2 family is a recessive mutant. The branches of which are fused at the base and though each branch terminates in to monoceous spike like normal plant, the spike is highly condensed. The three mutants under report are valuable genetic stocks for development of linkage maps in castor, which is at infancy. (author)

Counteracting quasispecies adaptability: extinction of a ribavirin-resistant virus mutant by an alternative mutagenic treatment.

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Celia Perales

Full Text Available BACKGROUND: Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. METHODOLOGY AND PRINCIPAL FINDINGS: Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. CONCLUSIONS: (i When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a

Integrative Genomic Analysis of Cholangiocarcinoma Identifies Distinct IDH-Mutant Molecular Profiles

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Farshad Farshidfar

2017-03-01

Full Text Available Cholangiocarcinoma (CCA is an aggressive malignancy of the bile ducts, with poor prognosis and limited treatment options. Here, we describe the integrated analysis of somatic mutations, RNA expression, copy number, and DNA methylation by The Cancer Genome Atlas of a set of predominantly intrahepatic CCA cases and propose a molecular classification scheme. We identified an IDH mutant-enriched subtype with distinct molecular features including low expression of chromatin modifiers, elevated expression of mitochondrial genes, and increased mitochondrial DNA copy number. Leveraging the multi-platform data, we observed that ARID1A exhibited DNA hypermethylation and decreased expression in the IDH mutant subtype. More broadly, we found that IDH mutations are associated with an expanded histological spectrum of liver tumors with molecular features that stratify with CCA. Our studies reveal insights into the molecular pathogenesis and heterogeneity of cholangiocarcinoma and provide classification information of potential therapeutic significance.

Productive mutants of niger

International Nuclear Information System (INIS)

Misra, R.C.

2001-01-01

Seeds of six niger (Guizotia abyssinica Cass.) varieties ('GA-10', 'ONS-8', 'IGP-72', 'N-71', 'NB-9' and 'UN-4') were treated with 0.5, 0.75 and 1% ethyl methanesulphonate. After four generations of selection, 29 mutant lines were developed and those were evaluated from 1990-92 during Kharif (July to October) and Rabi (December to March) seasons. Average plant characteristics and yield data of four high yielding mutants along with 'IGP-76' (National Check), GA-10 (Zonal Check) and 'Semiliguda Local' (Local Check) are presented

Isolation and characterization of MMS-sensitive mutants of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Prakash, L.; Prakash, S.

1977-01-01

We have isolated mutants sensitive to methyl methanesulfonate (MMS) in Saccharomyces cerevisiae. Alleles of rad1, rad4, rad6, rad52, rad55 and rad57 were found among these mms mutants. Twenty-nine of the mms mutants which complement the existing radiation-sensitive (rad and rev) mutants belong to 22 new complementation groups. Mutants from five complementation groups are sensitive only to MMS. Mutants of 11 complementation groups are sensitive to uv or x rays in addition to MMS, mutants of six complementation groups are sensitive to all three agents. The cross-sensitivities of these mms mutants to uv and x rays are discussed in terms of their possible involvement in DNA repair. Sporulation is reduced or absent in homozygous diploids of mms mutants from nine complementation groups

Isolation of a novel mutant gene for soil-surface rooting in rice (Oryza sativa L.).

Science.gov (United States)

Hanzawa, Eiko; Sasaki, Kazuhiro; Nagai, Shinsei; Obara, Mitsuhiro; Fukuta, Yoshimichi; Uga, Yusaku; Miyao, Akio; Hirochika, Hirohiko; Higashitani, Atsushi; Maekawa, Masahiko; Sato, Tadashi

2013-11-20

Root system architecture is an important trait affecting the uptake of nutrients and water by crops. Shallower root systems preferentially take up nutrients from the topsoil and help avoid unfavorable environments in deeper soil layers. We have found a soil-surface rooting mutant from an M2 population that was regenerated from seed calli of a japonica rice cultivar, Nipponbare. In this study, we examined the genetic and physiological characteristics of this mutant. The primary roots of the mutant showed no gravitropic response from the seedling stage on, whereas the gravitropic response of the shoots was normal. Segregation analyses by using an F2 population derived from a cross between the soil-surface rooting mutant and wild-type Nipponbare indicated that the trait was controlled by a single recessive gene, designated as sor1. Fine mapping by using an F2 population derived from a cross between the mutant and an indica rice cultivar, Kasalath, revealed that sor1 was located within a 136-kb region between the simple sequence repeat markers RM16254 and 2935-6 on the terminal region of the short arm of chromosome 4, where 13 putative open reading frames (ORFs) were found. We sequenced these ORFs and detected a 33-bp deletion in one of them, Os04g0101800. Transgenic plants of the mutant transformed with the genomic fragment carrying the Os04g0101800 sequence from Nipponbare showed normal gravitropic responses and no soil-surface rooting. These results suggest that sor1, a rice mutant causing soil-surface rooting and altered root gravitropic response, is allelic to Os04g0101800, and that a 33-bp deletion in the coding region of this gene causes the mutant phenotypes.

Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2

Science.gov (United States)

Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris M.; Belnap, Jayne; Evans, R. David; Kuske, Cheryl R.

2012-01-01

Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested a reduction in biocrust cyanobacterial biomass in the elevated CO2 treatment relative to the ambient controls. Additionally, SSU rRNA gene libraries and shotgun metagenomes showed reduced representation of cyanobacteria in the total microbial community. Taxonomic composition of the cyanobacteria was similar under ambient and elevated CO2 conditions, indicating the decline was manifest across multiple cyanobacterial lineages. Recruitment of cyanobacteria sequences from replicate shotgun metagenomes to cyanobacterial genomes representing major biocrust orders also suggested decreased abundance of cyanobacteria sequences across the majority of genomes tested. Functional assignment of cyanobacteria-related shotgun metagenome sequences indicated that four subsystem categories, three related to oxidative stress, were differentially abundant in relation to the elevated CO2 treatment. Taken together, these results suggest that elevated CO2 affected a generalized decrease in cyanobacteria in the biocrusts and may have favoured cyanobacteria with altered gene inventories for coping with oxidative stress.

The deoxyhypusine synthase mutant dys1-1 reveals the association of eIF5A and Asc1 with cell wall integrity.

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Fabio Carrilho Galvão

Full Text Available The putative eukaryotic translation initiation factor 5A (eIF5A is a highly conserved protein among archaea and eukaryotes that has recently been implicated in the elongation step of translation. eIF5A undergoes an essential and conserved posttranslational modification at a specific lysine to generate the residue hypusine. The enzymes deoxyhypusine synthase (Dys1 and deoxyhypusine hydroxylase (Lia1 catalyze this two-step modification process. Although several Saccharomyces cerevisiae eIF5A mutants have importantly contributed to the study of eIF5A function, no conditional mutant of Dys1 has been described so far. In this study, we generated and characterized the dys1-1 mutant, which showed a strong depletion of mutated Dys1 protein, resulting in more than 2-fold decrease in hypusine levels relative to the wild type. The dys1-1 mutant demonstrated a defect in total protein synthesis, a defect in polysome profile indicative of a translation elongation defect and a reduced association of eIF5A with polysomes. The growth phenotype of dys1-1 mutant is severe, growing only in the presence of 1 M sorbitol, an osmotic stabilizer. Although this phenotype is characteristic of Pkc1 cell wall integrity mutants, the sorbitol requirement from dys1-1 is not associated with cell lysis. We observed that the dys1-1 genetically interacts with the sole yeast protein kinase C (Pkc1 and Asc1, a component of the 40S ribosomal subunit. The dys1-1 mutant was synthetically lethal in combination with asc1Δ and overexpression of TIF51A (eIF5A or DYS1 is toxic for an asc1Δ strain. Moreover, eIF5A is more associated with translating ribosomes in the absence of Asc1 in the cell. Finally, analysis of the sensitivity to cell wall-perturbing compounds revealed a more similar behavior of the dys1-1 and asc1Δ mutants in comparison with the pkc1Δ mutant. These data suggest a correlated role for eIF5A and Asc1 in coordinating the translational control of a subset of m

[Mutant prevention concentrations of antibacterial agents to ocular pathogenic bacteria].

Science.gov (United States)

Liang, Qing-Feng; Wang, Zhi-Qun; Li, Ran; Luo, Shi-Yun; Deng, Shi-Jing; Sun, Xu-Guang

2009-01-01

To establish a method to measure mutant prevention concentration (MPC) in vitro, and to measure MPC of antibacterial agents for ocular bacteria caused keratitis. It was an experimental study. Forty strains of ocular bacteria were separated from cornea in Beijing Institute of Ophthalmology, which included 8 strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Pseudomonas aeruginosa and Klebsiella pneumoniae respectively. The minimal inhibitory concentration (MIC) of the levofloxacin (LVF), ofloxacin (OFL), ciprofloxacin (CIP), norfloxacin (NFL), tobramycin (TOB) and chloromycetin (CHL) were determined by agar dilution method from National Committee of Clinical Laboratory Standard (NCCLS). The MPC were measured by accumulate-bacterial methods with bacterial population inoculated more than 1.2 x 10(10) colony forming units per milliliter with Mueller-Hinton broth and tryptic soy agar plate. With the software of SPSS 11.0, the datum such as the range of MIC, MPC, MIC90 and MPC90 were calculated, and the selection index (MPC90/ MI90) and mutant selection window (MSW) were obtained. The MI90 of LVF and TOB (4 mg/L) to Staphylococcus aureus strains were the lowest. CIP showed the lowest MIC90 (0.25 mg/L) to Pseudomonas aeruginosa among six kinds of antibacterial agents. The MIC90 of LVF to Staphylococcus epidermidis (256 mg/L), Streptococcus pneumoniae (1 mg/L) and Klebsiella pneumoniae (0.25 mg/L) were lower than other antibacterial agents. The MPC90, MSW and the MPC90/MIC90 of levofloxacin showed lower values compared with other antibacterial medicines. From all the datum, the MIC90 of CHL was the highest and the activity was the weakest. Although the activity of LVF was higher to every kind of bacteria, CIP had the highest activity antibacterial to Pseudomonas aeruginosa. The capacity of CHL and TOB was weaker than Quinolones for restricting resistant mutants on ocular bacteria. LVF had the strongest capacity for restricting resistant

Concurrent Targeting of KRAS and AKT by MiR-4689 Is a Novel Treatment Against Mutant KRAS Colorectal Cancer

Directory of Open Access Journals (Sweden)

Masayuki Hiraki

2015-01-01

Full Text Available KRAS mutations are a major cause of drug resistance to molecular-targeted therapies. Aberrant epidermal growth factor receptor (EGFR signaling may cause dysregulation of microRNA (miRNA and gene regulatory networks, which leads to cancer initiation and progression. To address the functional relevance of miRNAs in mutant KRAS cancers, we transfected exogenous KRASG12V into human embryonic kidney 293 and MRC5 cells with wild-type KRAS and BRAF genes, and we comprehensively profiled the dysregulated miRNAs. The result showed that mature miRNA oligonucleotide (miR-4689, one of the significantly down-regulated miRNAs in KRASG12V overexpressed cells, was found to exhibit a potent growth-inhibitory and proapoptotic effect both in vitro and in vivo. miR-4689 expression was significantly down-regulated in cancer tissues compared to normal mucosa, and it was particularly decreased in mutant KRAS CRC tissues. miR-4689 directly targets v-ki-ras2 kirsten rat sarcoma viral oncogene homolog (KRAS and v-akt murine thymoma viral oncogene homolog 1(AKT1, key components of two major branches in EGFR pathway, suggesting KRAS overdrives this signaling pathway through inhibition of miR-4689. Overall, this study provided additional evidence that mutant KRAS functions as a broad regulator of the EGFR signaling cascade by inhibiting miR-4689, which negatively regulates both RAS/mitogen-activated protein kinase (MAPK and phosphoinositide 3-kinase (PI3K/AKT pathways. These activities indicated that miR-4689 may be a promising therapeutic agent in mutant KRAS CRC.

Shallow Boomerang-shaped Influenza Hemagglutinin G13A Mutant Structure Promotes Leaky Membrane Fusion*

Science.gov (United States)

Lai, Alex L.; Tamm, Lukas K.

2010-01-01

Our previous studies showed that an angled boomerang-shaped structure of the influenza hemagglutinin (HA) fusion domain is critical for virus entry into host cells by membrane fusion. Because the acute angle of ∼105° of the wild-type fusion domain promotes efficient non-leaky membrane fusion, we asked whether different angles would still support fusion and thus facilitate virus entry. Here, we show that the G13A fusion domain mutant produces a new leaky fusion phenotype. The mutant fusion domain structure was solved by NMR spectroscopy in a lipid environment at fusion pH. The mutant adopted a boomerang structure similar to that of wild type but with a shallower kink angle of ∼150°. G13A perturbed the structure of model membranes to a lesser degree than wild type but to a greater degree than non-fusogenic fusion domain mutants. The strength of G13A binding to lipid bilayers was also intermediate between that of wild type and non-fusogenic mutants. These membrane interactions provide a clear link between structure and function of influenza fusion domains: an acute angle is required to promote clean non-leaky fusion suitable for virus entry presumably by interaction of the fusion domain with the transmembrane domain deep in the lipid bilayer. A shallower angle perturbs the bilayer of the target membrane so that it becomes leaky and unable to form a clean fusion pore. Mutants with no fixed boomerang angle interacted with bilayers weakly and did not promote any fusion or membrane perturbation. PMID:20826788

Mutants of Escherichia coli K-12 with enhanced resistance to ionizing radiation

International Nuclear Information System (INIS)

Verbenko, V.N.; Akhmedov, A.T.; Kalinin, V.L.

1986-01-01

By means of one-dimensional electrophoresis, it is shown that in radiation-resistant Gam 444 ad Gam 445 mutants of Escherichia coli K-12 high-molecular weight heat shock proteins are hyperproduced at 32-37 deg C and are induced more intensively during heat shock (in comparison to the parental) wild-tupe strain AB parallel 57). When the missense htp R15 mutation of the positive regulatory htpR gene for heat shock proteins was introduced by transduction into genome of the Gam 444 mutant, its enhanced radiation-resistance disappeared but could not be restored upon introduction of pKV3 plasmid bearing the htpR, gene. These data show that heat shock Protens are participating in the enhanced radioresistance of Gam mutants

Spatial constraints govern competition of mutant clones in human epidermis.

Science.gov (United States)

Lynch, M D; Lynch, C N S; Craythorne, E; Liakath-Ali, K; Mallipeddi, R; Barker, J N; Watt, F M

2017-10-24

Deep sequencing can detect somatic DNA mutations in tissues permitting inference of clonal relationships. This has been applied to human epidermis, where sun exposure leads to the accumulation of mutations and an increased risk of skin cancer. However, previous studies have yielded conflicting conclusions about the relative importance of positive selection and neutral drift in clonal evolution. Here, we sequenced larger areas of skin than previously, focusing on cancer-prone skin spanning five decades of life. The mutant clones identified were too large to be accounted for solely by neutral drift. Rather, using mathematical modelling and computational lattice-based simulations, we show that observed clone size distributions can be explained by a combination of neutral drift and stochastic nucleation of mutations at the boundary of expanding mutant clones that have a competitive advantage. These findings demonstrate that spatial context and cell competition cooperate to determine the fate of a mutant stem cell.

Biochemical characterization and cellular effects of CADASIL mutants of NOTCH3.

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He Meng

Full Text Available Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL is the best understood cause of dominantly inherited stroke and results from NOTCH3 mutations that lead to NOTCH3 protein accumulation and selective arterial smooth muscle degeneration. Previous studies show that NOTCH3 protein forms multimers. Here, we investigate protein interactions between NOTCH3 and other vascular Notch isoforms and characterize the effects of elevated NOTCH3 on smooth muscle gene regulation. We demonstrate that NOTCH3 forms heterodimers with NOTCH1, NOTCH3, and NOTCH4. R90C and C49Y mutant NOTCH3 form complexes which are more resistant to detergents than wild type NOTCH3 complexes. Using quantitative NOTCH3-luciferase clearance assays, we found significant inhibition of mutant NOTCH3 clearance. In coculture assays of NOTCH function, overexpressed wild type and mutant NOTCH3 significantly repressed NOTCH-regulated smooth muscle transcripts and potently impaired the activity of three independent smooth muscle promoters. Wildtype and R90C recombinant NOTCH3 proteins applied to cell cultures also blocked canonical Notch fuction. We conclude that CADASIL mutants of NOTCH3 complex with NOTCH1, 3, and 4, slow NOTCH3 clearance, and that overexpressed wild type and mutant NOTCH3 protein interfere with key NOTCH-mediated functions in smooth muscle cells.

Commercialization Of Orchid Mutants For Floriculture Industry

International Nuclear Information System (INIS)

Sakinah Ariffin; Zaiton Ahmad

2014-01-01

Orchids are the main contributors to cut flower industry in Malaysia with an existing good market and a huge business potential. Orchid industry has been established in Malaysia since 1960s but only started to develop and expand since 1980s. Continuous development of new orchid varieties is essential to meet customers' demands. Orchid mutagenesis research using gamma irradiation at Malaysian Nuclear Agency has successfully generated a number of new orchid varieties with commercial potentials. Therefore, Nuclear Malaysia has collaborated with an industrial partner, Hexagon Green Sdn Bhd (HGSB), to carry out commercialization research on these mutants under a Technofund project entitled 'Pre-Commercialization of Mutant Orchids for Cut Flowers Industry' from July 2011 to July 2014. Through this collaboration, Dendrobium orchid mutant plants developed by Nuclear Malaysia were transferred to HGSB's commercial orchid nursery at Bukit Changgang Agrotechnology Park, Banting, Selangor, for mass-propagation. The activities include evaluations on plant growth performance, flower quality, post harvest and market potential of these mutants. Mutants with good field performance have been identified and filed for Plant Variety Protection (PVP) with Department of Agriculture Malaysia. This paper describes outputs from this collaboration and activities undertaken in commercializing these mutants. (author)

Multidrug resistance in Botrytis cinerea associated with decreased accumulation of the azole fungicide oxpoconazole and increased transcription of the ABC transporter gene BcatrD

NARCIS (Netherlands)

Hayashi, K.; Schoonbeek, H.; Sugiura, H.; Waard, De M.A.

2001-01-01

Azole-resistant mutants of Botrytis cinerea have a multidrug resistance phenotype since they exhibit cross-resistance to unrelated chemicals. These mutants also display resistance to the new azole fungicide oxpoconazole. Resistance to oxpoconazole is associated with decreased accumulation of the

Yield and its components and some agronomic characters of four mungbean mutants induces by gamma ray

International Nuclear Information System (INIS)

Al-Mosawi, A. R. A.; Ibrahim, A. F.; Azzo, F. Z.; Khadim, A. A.; Ibrahim, W. H.; Abdul-Al-majed, A.

2012-12-01

A field experiment was carried out at the Tuwaitha research station / Iraqi Atomic Energy Commission (past) Ministry of science and Technology (now) in Agricultural seasons 2000 - 2001 to evaluate four mungbean mutants induced by gamma ray compared with local variety and Australian pedigree. The results showed that mutants AMU-45 was superiority on anther mutants and the local in date of flowering (41.50 days), maturity (71.25 days), yield (1609.88 kg/ha) and its components. (Author)

Isolation and partial characterization of carotenoid underproducing and overproducing mutants from an extremely thermophilic Thermus thermophilus HB27

International Nuclear Information System (INIS)

Hoshino, T.; Yoshino, Y.; Guevarra, E.D.; Ishida, S.; Hiruta, T.; Fujii, R.; Nakahara, T.

1994-01-01

Twenty-two carotenoid underproducing and thirteen overproducing mutants were obtained from Thermus thermophilus HB27. The strain HB27 was found to produce at least seven colored carotenoids, believed to be identical to those produced by Thermus aquaticus YT1. Based on the results of the genetic analyses performed on twelve carotenoid underproducing mutants, they were classified into three groups; groups 1, 2 and 3. No colored carotenoid was extracted from the cells of mutants belonging to groups 2 and 3, although the accumulation of phytoene, a colorless carotenoid, was observed in group 2 strains. Group 1 was subdivided into groups 1-a and 1-b, where 1-a stains produced neither colored carotenoids nor phytoene and 1-b strains produced two polar colored carotenoids. All of the overproducing mutants produced about twelve times as much seven colored carotenoid mixtures as the parental strain. The mutation loci among all the overproducing mutants were very close to one another, possibly in the same gene. Carotenoid overproducing mutants showed an extensive resistance to UV-irradiation and showed poorer growth at higher temperatures. Carotenoid underproducing mutants were slightly more UV-sensitive but they grew almost normally at higher temperatures. These results suggest that carotenoids are secondary metabolites which are not essential for growth of T. thermophilus