Forward genetic screen for auxin-deficient mutants by cytokinin

Czech Academy of Sciences Publication Activity Database

Wu, L.; Luo, P.; Di, D.W.; Wang, L.; Wang, M.; Lu, C.K.; Wei, S.D.; Zhang, L.; Zhang, T.Z.; Amakorová, Petra; Strnad, Miroslav; Novák, Ondřej; Guo, G.Q.

2015-01-01

Roč. 5, JUL 6 (2015) ISSN 2045-2322 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : ETHYLENE-INSENSITIVE MUTANTS * YUCCA FLAVIN MONOOXYGENASES * ARABIDOPSIS-THALIANA Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.228, year: 2015

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.

Genetically Engineered Cyanobacteria

Science.gov (United States)

Zhou, Ruanbao (Inventor); Gibbons, William (Inventor)

2015-01-01

The disclosed embodiments provide cyanobacteria spp. that have been genetically engineered to have increased production of carbon-based products of interest. These genetically engineered hosts efficiently convert carbon dioxide and light into carbon-based products of interest such as long chained hydrocarbons. Several constructs containing polynucleotides encoding enzymes active in the metabolic pathways of cyanobacteria are disclosed. In many instances, the cyanobacteria strains have been further genetically modified to optimize production of the carbon-based products of interest. The optimization includes both up-regulation and down-regulation of particular genes.

The types and genetic analysis of radiation induced early maturity mutants of rice

International Nuclear Information System (INIS)

Yang Hefeng; Chen Xiulan; He Zhengtian; Gu Shiliang; Xu Chenwu

1989-01-01

Observation and correlation analysis were made for 50 early mutant lines,The early mutant lines fall into late type of early-maturity rice, and early type of mid- maturity rice, some of which are valuable as materials of rice breeding.With shorter growing period, the mutants have less inter-nodes and leaf numbers on main culm, shorter leaf and panicle length, and less filled grains and yield per plant, but have higher Protein content.Among 20 traits observed, 7 were significantly correlated with the length of growing period.The genetic parameter analysis for the mutant lines indicates that the length of growing period, plant height, grain number per panicle, 1000-grain weight have high heritability, Non-filled grain rate, secondary branch, number of panicle, grain number per panicle have larger genetic coefficient of variation and larger gain of selection

Population genetics inference for longitudinally-sampled mutants under strong selection.

Science.gov (United States)

Lacerda, Miguel; Seoighe, Cathal

2014-11-01

Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

Mutational landscape of EGFR-, MYC-, and Kras-driven genetically engineered mouse models of lung adenocarcinoma.

Science.gov (United States)

McFadden, David G; Politi, Katerina; Bhutkar, Arjun; Chen, Frances K; Song, Xiaoling; Pirun, Mono; Santiago, Philip M; Kim-Kiselak, Caroline; Platt, James T; Lee, Emily; Hodges, Emily; Rosebrock, Adam P; Bronson, Roderick T; Socci, Nicholas D; Hannon, Gregory J; Jacks, Tyler; Varmus, Harold

2016-10-18

Genetically engineered mouse models (GEMMs) of cancer are increasingly being used to assess putative driver mutations identified by large-scale sequencing of human cancer genomes. To accurately interpret experiments that introduce additional mutations, an understanding of the somatic genetic profile and evolution of GEMM tumors is necessary. Here, we performed whole-exome sequencing of tumors from three GEMMs of lung adenocarcinoma driven by mutant epidermal growth factor receptor (EGFR), mutant Kirsten rat sarcoma viral oncogene homolog (Kras), or overexpression of MYC proto-oncogene. Tumors from EGFR- and Kras-driven models exhibited, respectively, 0.02 and 0.07 nonsynonymous mutations per megabase, a dramatically lower average mutational frequency than observed in human lung adenocarcinomas. Tumors from models driven by strong cancer drivers (mutant EGFR and Kras) harbored few mutations in known cancer genes, whereas tumors driven by MYC, a weaker initiating oncogene in the murine lung, acquired recurrent clonal oncogenic Kras mutations. In addition, although EGFR- and Kras-driven models both exhibited recurrent whole-chromosome DNA copy number alterations, the specific chromosomes altered by gain or loss were different in each model. These data demonstrate that GEMM tumors exhibit relatively simple somatic genotypes compared with human cancers of a similar type, making these autochthonous model systems useful for additive engineering approaches to assess the potential of novel mutations on tumorigenesis, cancer progression, and drug sensitivity.

Mutational landscape of EGFR-, MYC-, and Kras-driven genetically engineered mouse models of lung adenocarcinoma

Science.gov (United States)

McFadden, David G.; Politi, Katerina; Bhutkar, Arjun; Chen, Frances K.; Song, Xiaoling; Pirun, Mono; Santiago, Philip M.; Kim-Kiselak, Caroline; Platt, James T.; Lee, Emily; Hodges, Emily; Rosebrock, Adam P.; Bronson, Roderick T.; Socci, Nicholas D.; Hannon, Gregory J.; Jacks, Tyler; Varmus, Harold

2016-01-01

Genetically engineered mouse models (GEMMs) of cancer are increasingly being used to assess putative driver mutations identified by large-scale sequencing of human cancer genomes. To accurately interpret experiments that introduce additional mutations, an understanding of the somatic genetic profile and evolution of GEMM tumors is necessary. Here, we performed whole-exome sequencing of tumors from three GEMMs of lung adenocarcinoma driven by mutant epidermal growth factor receptor (EGFR), mutant Kirsten rat sarcoma viral oncogene homolog (Kras), or overexpression of MYC proto-oncogene. Tumors from EGFR- and Kras-driven models exhibited, respectively, 0.02 and 0.07 nonsynonymous mutations per megabase, a dramatically lower average mutational frequency than observed in human lung adenocarcinomas. Tumors from models driven by strong cancer drivers (mutant EGFR and Kras) harbored few mutations in known cancer genes, whereas tumors driven by MYC, a weaker initiating oncogene in the murine lung, acquired recurrent clonal oncogenic Kras mutations. In addition, although EGFR- and Kras-driven models both exhibited recurrent whole-chromosome DNA copy number alterations, the specific chromosomes altered by gain or loss were different in each model. These data demonstrate that GEMM tumors exhibit relatively simple somatic genotypes compared with human cancers of a similar type, making these autochthonous model systems useful for additive engineering approaches to assess the potential of novel mutations on tumorigenesis, cancer progression, and drug sensitivity. PMID:27702896

Molecular markers to assess genetic diversity and mutant identifications in Jatropha curcas

International Nuclear Information System (INIS)

Azhar Mohamad; Yie Min Kwan; Fatin Mastura Derani; Abdul Rahim Harun

2010-01-01

Jatropha curcas (Linnaeus) belongs to the Euphorbiaceae family, is a multipurpose use, drought resistant and perennial plant. It is an economic important crop, which generates wide interest in understanding the genetic diversity of the species towards selection and breeding of superior genotypes. Jatropha accessions are closely related family species. Thus, better understanding of the effectiveness of the different DNA-based markers is an important step towards plant germplasm characterization and evaluation. It is becoming a prerequisite for more effective application of marker techniques in breeding programs. Inter-simple sequence repeats (ISSRs) has shown rapid, simple, reproducible and inexpensive means in molecular taxonomy, conservation breeding and genetic diversity analysis. These markers were used to understand diversity and differentiate amongst accessions of Jatropha population and mutant lines generated by acute gamma radiation. The ISSR for marker applications are essential to facilitate management, conservation and genetic improvement programs towards improvement of bio-diesel production and medication substances. A total of 62 ISSR primers were optimized for polymorphism evaluations on five foreign accessions (Africa, India, Myanmar, Indonesia, Thailand), nine local accessions and two mutants of Jatropha. Optimization was resulted 54 ISSR primers affirmative for the polymorphism evaluation study, which encountered 12 ISSR primers, showed significance polymorphism amongst the accessions and mutants. Marker derived from ISSR profiling is a powerful method for identification and molecular classification of Jatropha from accession to generated mutant varieties. (author)

Destabilizing protein polymorphisms in the genetic background direct phenotypic expression of mutant SOD1 toxicity.

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Tali Gidalevitz

2009-03-01

Full Text Available Genetic background exerts a strong modulatory effect on the toxicity of aggregation-prone proteins in conformational diseases. In addition to influencing the misfolding and aggregation behavior of the mutant proteins, polymorphisms in putative modifier genes may affect the molecular processes leading to the disease phenotype. Mutations in SOD1 in a subset of familial amyotrophic lateral sclerosis (ALS cases confer dominant but clinically variable toxicity, thought to be mediated by misfolding and aggregation of mutant SOD1 protein. While the mechanism of toxicity remains unknown, both the nature of the SOD1 mutation and the genetic background in which it is expressed appear important. To address this, we established a Caenorhabditis elegans model to systematically examine the aggregation behavior and genetic interactions of mutant forms of SOD1. Expression of three structurally distinct SOD1 mutants in C. elegans muscle cells resulted in the appearance of heterogeneous populations of aggregates and was associated with only mild cellular dysfunction. However, introduction of destabilizing temperature-sensitive mutations into the genetic background strongly enhanced the toxicity of SOD1 mutants, resulting in exposure of several deleterious phenotypes at permissive conditions in a manner dependent on the specific SOD1 mutation. The nature of the observed phenotype was dependent on the temperature-sensitive mutation present, while its penetrance reflected the specific combination of temperature-sensitive and SOD1 mutations. Thus, the specific toxic phenotypes of conformational disease may not be simply due to misfolding/aggregation toxicity of the causative mutant proteins, but may be defined by their genetic interactions with cellular pathways harboring mildly destabilizing missense alleles.

Genetic analysis of plant height in induced mutants of aromatic rice

International Nuclear Information System (INIS)

Kole, P.C.

2005-01-01

Inheritance of plant height in five gamma-ray induced mutants of aromatic rice cultivar Gobindabhog was studied through 6 x 6 diallel cross and segregation analyses. Diallel analysis revealed presence of additive and non-additive gene action with the preponderance of the latter. Proportion of dominant and recessive alleles was distributed unequally among the parents. The direction of dominance was towards tallness. The number of groups of genes was found to be three. The segregation analysis indicated the role of a single major recessive gene for height reduction in three mutants and, in another mutant, a single major recessive gene with negative modifiers. The other semi-dwarf mutant had two major recessive genes with almost equal effect in height reduction. The mutant allele(s) of the latter two mutants were non-allelic to sd sub(1) gene, which could be used as an alternative source of Dee Gee Woo Gen to widen the genetic diversity in semi-dwarfism [it

Genetically engineered foods

Science.gov (United States)

Bioengineered foods; GMOs; Genetically modified foods ... helps speed up the process of creating new foods with desired traits. The possible benefits of genetic engineering include: More nutritious food Tastier food Disease- and ...

Temperature-sensitive mutants of fowl plague virus: isolation and genetic characterization

International Nuclear Information System (INIS)

Almond, J.W.; McGeoch, D.; Barry, R.D.

1979-01-01

Forty-nine temperature-sensitive mutants of fowl plague virus (FPV) strain Rostock and four ts mutants of FPV-strain Dobson were isolated by utilizing two methods of plaque screening, after either spontaneous or chemically induced mutagenesis. Twenty-nine of the FPV-Rostock mutants were further characterized by genetic recombination studies and were found to fall into six high frequency recombination groups. The genome segment carrying the ts mutation in each group was identified by analyzing the gene composition of ts + recombinants generated from crosses between representatives of each group and ts mutants of FPV-Dobson. It was concluded that the six groups correspond to mutations in six different genome segments, namely, those coding for the P 1 , P 2 , P 3 , HA, NP, and NS proteins

Genetic Engineering Workshop Report, 2010

Energy Technology Data Exchange (ETDEWEB)

Allen, J; Slezak, T

2010-11-03

The Lawrence Livermore National Laboratory (LLNL) Bioinformatics group has recently taken on a role in DTRA's Transformation Medical Technologies (TMT) program. The high-level goal of TMT is to accelerate the development of broad-spectrum countermeasures. To achieve this goal, there is a need to assess the genetic engineering (GE) approaches, potential application as well as detection and mitigation strategies. LLNL was tasked to coordinate a workshop to determine the scope of investments that DTRA should make to stay current with the rapid advances in genetic engineering technologies, so that accidental or malicious uses of GE technologies could be adequately detected and characterized. Attachment A is an earlier report produced by LLNL for TMT that provides some relevant background on Genetic Engineering detection. A workshop was held on September 23-24, 2010 in Springfield, Virginia. It was attended by a total of 55 people (see Attachment B). Twenty four (44%) of the attendees were academic researchers involved in GE or bioinformatics technology, 6 (11%) were from DTRA or the TMT program management, 7 (13%) were current TMT performers (including Jonathan Allen and Tom Slezak of LLNL who hosted the workshop), 11 (20%) were from other Federal agencies, and 7 (13%) were from industries that are involved in genetic engineering. Several attendees could be placed in multiple categories. There were 26 attendees (47%) who were from out of the DC area and received travel assistance through Invitational Travel Orders (ITOs). We note that this workshop could not have been as successful without the ability to invite experts from outside of the Beltway region. This workshop was an unclassified discussion of the science behind current genetic engineering capabilities. US citizenship was not required for attendance. While this may have limited some discussions concerning risk, we felt that it was more important for this first workshop to focus on the scientific state of

Selected Readings in Genetic Engineering

Science.gov (United States)

Mertens, Thomas R.; Robinson, Sandra K.

1973-01-01

Describes different sources of readings for understanding issues and concepts of genetic engineering. Broad categories of reading materials are: concerns about genetic engineering; its background; procedures; and social, ethical and legal issues. References are listed. (PS)

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)

Genetic diversity analysis in rice mutants using isozyme and Morphological markers

Energy Technology Data Exchange (ETDEWEB)

Fuentes, Jorge L; Alvarez, Alba [Centro de Estudios Aplicados al Desarrollo Nuclear, La Habana (Cuba); Deus, Juan E [Instituto de Investigaciones del Arroz. Bauta, La Habana (Cuba); Duque, Miriam C [Centro Internacional de Agricultura Tropical, Cali (Colombia); Cornide, Maria T [Centro Nacional de Investigaciones Cientificas, La Habana (Cuba)

1999-07-01

In this work, isozyme and agromorphologic variability of radiation-induced rice mutants with different cytoplasm base was surveyed. Agromorphologic data (plant type, lodging resistance, life cycle and yielding) were transformed into binary data. This markers, along with isozyme (Peroxidases, Esterases, Catalases, Alcohol Dehydrogenases and Polyphenoloxidase) data, were considered for genetic diversity analyses in order to estimate the extent of diversity generated by ionizing radiation. Genetic Similarity between individuals was obtained based on Dice's Coefficient. The UPGMA phenogram defined three main clusters that clearly corresponded to the different cytoplasm sources. However, further discrimination between control varieties and their mutants could be obtained. Bootstrapping analysis was performed to estimate the robustness of the group in the phenogram. According to their bootstrap P value (99.6%), Basmati-370 mutant lines could be considered statistically different from their control. This analysis is suggested as an useful supporting tool for an accurate varietal validation. A Multiple Correspondence Analysis (MCA) showed individuals dispersion around the three principal axis of variation. In general the UPGMA phenogram pattern was corroborated at MCA. Variables such as life cycle, presence of bands Est-a and Prx-m and the absence of Est-i, Prx-h and Prx-i accounted for the higher contribution to variation. The adequacy of morphological and isozyme descriptors for new mutant lines validation is also discussed.

Genetic diversity analysis in rice mutants using isozyme and Morphological markers

International Nuclear Information System (INIS)

Fuentes, Jorge L.; Alvarez, Alba; Deus, Juan E.; Duque, Miriam C.; Cornide, Maria T.

1999-01-01

In this work, isozyme and agromorphologic variability of radiation-induced rice mutants with different cytoplasm base was surveyed. Agromorphologic data (plant type, lodging resistance, life cycle and yielding) were transformed into binary data. This markers, along with isozyme (Peroxidases, Esterases, Catalases, Alcohol Dehydrogenases and Polyphenoloxidase) data, were considered for genetic diversity analyses in order to estimate the extent of diversity generated by ionizing radiation. Genetic Similarity between individuals was obtained based on Dice's Coefficient. The UPGMA phenogram defined three main clusters that clearly corresponded to the different cytoplasm sources. However, further discrimination between control varieties and their mutants could be obtained. Bootstrapping analysis was performed to estimate the robustness of the group in the phenogram. According to their bootstrap P value (99.6%), Basmati-370 mutant lines could be considered statistically different from their control. This analysis is suggested as an useful supporting tool for an accurate varietal validation. A Multiple Correspondence Analysis (MCA) showed individuals dispersion around the three principal axis of variation. In general the UPGMA phenogram pattern was corroborated at MCA. Variables such as life cycle, presence of bands Est-a and Prx-m and the absence of Est-i, Prx-h and Prx-i accounted for the higher contribution to variation. The adequacy of morphological and isozyme descriptors for new mutant lines validation is also discussed

Bioethanol production using genetically modified and mutant wheat and barley straws

Energy Technology Data Exchange (ETDEWEB)

Li, Z. [Washington State Univ., Pullman, WA (US). Dept. of Biological Engineering; East China Univ. of Science and Technology, Shanghai (CN). State Key Laboratory of Bioreactor Engineering; Liu, Y. [Michigan State Univ., East Lansing, MI (US). Biosystems and Agricultural Engineering; Chen, S. [Washington State Univ., Pullman, WA (US). Dept. of Biological Systems Engineering; Zemetra, R.S. [Univ. of Idaho, Moscow, ID (US). Plant, Soil, and Entomological Sciences

2011-01-15

To improve the performance of wheat and barley straws as feedstocks for ethanol biorefining, the genetic modifications of down regulating Cinnamoyl-CoA reductase and low phytic acid mutation have been introduced into wheat and barley respectively. In this study, total 252 straw samples with different genetic background and location were collected from the field experiment based on a randomized complete block design. The fiber analysis (neutral detergent fiber, acid detergent fiber, and acid detergent lignin) indicated that there were no significant differences between modified and wild type straw lines in terms of straw compositions. However, the difference did exist among straw lines on fiber utilization. 16 straw samples were further selected to conduct diluted acid pretreatment, enzymatic hydrolysis and fermentation. The data indicated that the phytic acid mutant and transgenic straws have changed the fiber structure, which significantly influences their hydrolysibility. These results may lead to a possible solution of mutant or genetic modified plant species that is capable to increase the hydrolysibility of biomass without changing their compositions and sacrificing their agronomy performance. (author)

Design of an ectoine-responsive AraC mutant and its application in metabolic engineering of ectoine biosynthesis.

Science.gov (United States)

Chen, Wei; Zhang, Shan; Jiang, Peixia; Yao, Jun; He, Yongzhi; Chen, Lincai; Gui, Xiwu; Dong, Zhiyang; Tang, Shuang-Yan

2015-07-01

Advanced high-throughput screening methods for small molecules may have important applications in the metabolic engineering of the biosynthetic pathways of these molecules. Ectoine is an excellent osmoprotectant that has been widely used in cosmetics. In this study, the Escherichia coli regulatory protein AraC was engineered to recognize ectoine as its non-natural effector and to activate transcription upon ectoine binding. As an endogenous reporter of ectoine, the mutated AraC protein was successfully incorporated into high-throughput screening of ectoine hyper-producing strains. The ectoine biosynthetic cluster from Halomonas elongata was cloned into E. coli. By engineering the rate-limiting enzyme L-2,4-diaminobutyric acid (DABA) aminotransferase (EctB), ectoine production and the specific activity of the EctB mutant were increased. Thus, these results demonstrated the effectiveness of engineering regulatory proteins into sensitive and rapid screening tools for small molecules and highlighted the importance and efficacy of directed evolution strategies applied to the engineering of genetic components for yield improvement in the biosynthesis of small molecules. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Genetic Analysis and Mapping of TWH Gene in Rice Twisted Hull Mutant

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Jin-bo LI

2009-03-01

Full Text Available A mutant with twisted hulls was found in a breeding population of rice (Oryza sativa L.. The mutant shows less grain weight and inferior grain quality in addition to twisted hulls. Genetic analysis indicated that the phenotype of mutant was controlled by a single recessive gene (temporarily designated as TWH. To map the TWH gene, an F2 population was generated by crossing the twh mutant to R725, an indica rice variety with normal hulls. For bulked segregant analysis, the bulk of mutant plants was prepared by mixing equal amount of plant tissue from 10 twisted-hull plants and the bulk of normal plants was obtained by pooling equal amount tissue of 10 normal-hull plants. Two hundred and seven pairs of simple sequence repeat (SSR primers, which are distributed on 12 rice chromosomes, were used for polymorphism analysis of the parents and the two bulks. The TWH locus was initially mapped close to the SSR marker RM526 on chromosome 2. Therefore, further mapping was performed using 50 pairs of SSR primers around the marker RM526. The TWH was delimited between the SSR markers RM14128 and RM208 on the long arm of chromosome 2 at the genetic distances of 1.4 cM and 2.7 cM, respectively. These results provide the foundation for further fine mapping, cloning and functional analysis of the TWH gene.

Evaluation of Mungbean Mutant Lines to Drought Stress and Their Genetic Relationships Using SSR Markers

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Yuliasti

2015-12-01

Full Text Available Development of mungbean cultivarstolerant to drought stress through mutation breeding approach would enable us to anticipate the crop yield-reducing effects of climate changes. The objective of this research was to evaluate the yield performance of mungbean mutant lines that showed tolerance to drought stress, and to analyze their genetic diversity and relationship among mutant lines using SSR markers. The study was conducted during the dry season of 2012 in the Muneng experimental farm, Probolinggo, East Java. The experiment was laid out in a randomized block design with four replications. Five mutant lines and two parental lines as control were tested for evaluation of yield and drought tolerance under twoenvironments of two irrigation systems as treatment. The two environmental conditions consisted of optimal irrigation (at least three times: at planting, flowering and during pod filling and suboptimal irrigation (two times at planting and flowering. To evaluate genetic variation among selected mutant lines and their discrimination from parental lines in molecular level, a cluster analysis was performed using Unweighted Pair Group Method with Arithmetic Mean (UPGMA in the NTSYS software. The results showed that three mutant lines, including PsJ30, PsJ31, PsJ32 produced the highest grain yields of 1.17, 1.01, and 1.04 ton/ha, respectively, compared to the other mutant lines and the parents Gelatik (0.85 ton/ha and Perkutut (0.87 ton/ha as control check. Of those mutant lines, PSJ31 was the most tolerant to drought with sensitivity index value of 0.47. The PSJ31 has now been officially released as a new variety ( 2013, named as Muri which was identified to have high yield and tolerant to drought. Based on 23 SSR markers used for clustering analysis of those 3 selected mutant lines,9SSR markers (MBSS R033; satt137; MBSSR008; MBSSR203; MBSSR013; MBSSR021; MBSSR016; MBSSR136; and DMBSSR013 were successfully identified the three mungbean mutant

The genetics of green thorax, a new larval colour mutant, non-linked with ruby - eye locus in the malaria mosquito, Anopheles stephensi.

Science.gov (United States)

Sanil, D; Shetty, N J

2009-06-01

Anopheles stephensi, an important vector of malaria continues to be distributed widely in the Indian subcontinent. The natural vigour of the species combined with its new tolerance, indeed resistance to insecticides has made it obligatory that we look for control methods involving genetic manipulation. Hence, there is an immediate need for greater understanding of the genetics of this vector species. One of the requirements for such genetic studies is the establishment of naturally occurring mutants, establishment of the genetic basis for the same and use of such mutants in the genetic transformation studies and other genetic control programme(s). This paper describes the isolation and genetic studies of a larval colour mutant, green thorax (gt), and linkage studies involving another autosomal recessive mutant ruby- eye (ru) in An. stephensi. After the initial discovery, the mutant green thorax was crossed inter se and pure homozygous stock of the mutant was established. The stock of the mutant ruby- eye, which has been maintained as a pure stock in the laboratory. Crosses were made between the wild type and mutant, green thorax to determine the mode of inheritance of green thorax. For linkage studies, crosses were made between the mutant green thorax and another autosomal recessive mutant ruby-eye. The percentage cross-over was calculated for the genes linkage relationship for gt and gt ru. Results of crosses between mutant and wild type showed that the inheritance of green thorax (gt) in An. stephensi is monofactorial in nature. The gt allele is recessive to wild type and is autosomal. The linkage studies showed no linkage between ru and gt. The mutant gt represents an excellent marker for An. stephensi as it is expressed in late III instar stage of larvae and is prominent in IV instar and pupal stages with complete penetrance and high viability. The said mutant could be easily identified without the aid of a microscope. This mutant can be used extensively to

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.

Genetic and agronomic evaluation of induced semi-dwarf mutants of rice

International Nuclear Information System (INIS)

Rutger, J.N.

1984-01-01

Induced semi-dwarf mutants have played an important role in California's rapid shift from nearly all tall rice varieties in 1978 to nearly all semi-dwarf varieties at present. In 1981 over half of the California rice area was planted with semi-dwarf varieties carrying the induced mutant semi-dwarfing gene sd 1 , while much of the other half was planted to a variety deriving its semi-dwarfism from IR8. The sd 1 mutant is allelic to the major semi-dwarfing gene in DGWG and IR8. Current objectives are to determine the inheritance of new semi-dwarf mutants, including allelism tests with sd 1 , and to evaluate the agronomic potential of nonallelic sources and of double-dwarfs. To date semi-dwarf mutants from 10 varieties have been partially or completely evaluated. At least three nonallelic semi-dwarfing genes, sd 1 , sd 2 , and sd 4 , have been described. Rather than attempt to determine all possible allelic relationships of new mutants, crosses are being made only to the reference sd 1 source, since sd 1 , still seems to be the most productive semi-dwarfing gene source. However, nonallelic semi-dwarf mutants in the varieties M5 and Labelle may be useful if genetic vulnerability from widespread usage of the sd 1 source becomes a problem. (author)

Genetically Engineering Entomopathogenic Fungi.

Science.gov (United States)

Zhao, H; Lovett, B; Fang, W

2016-01-01

Entomopathogenic fungi have been developed as environmentally friendly alternatives to chemical insecticides in biocontrol programs for agricultural pests and vectors of disease. However, mycoinsecticides currently have a small market share due to low virulence and inconsistencies in their performance. Genetic engineering has made it possible to significantly improve the virulence of fungi and their tolerance to adverse conditions. Virulence enhancement has been achieved by engineering fungi to express insect proteins and insecticidal proteins/peptides from insect predators and other insect pathogens, or by overexpressing the pathogen's own genes. Importantly, protein engineering can be used to mix and match functional domains from diverse genes sourced from entomopathogenic fungi and other organisms, producing insecticidal proteins with novel characteristics. Fungal tolerance to abiotic stresses, especially UV radiation, has been greatly improved by introducing into entomopathogens a photoreactivation system from an archaean and pigment synthesis pathways from nonentomopathogenic fungi. Conversely, gene knockout strategies have produced strains with reduced ecological fitness as recipients for genetic engineering to improve virulence; the resulting strains are hypervirulent, but will not persist in the environment. Coupled with their natural insect specificity, safety concerns can also be mitigated by using safe effector proteins with selection marker genes removed after transformation. With the increasing public concern over the continued use of synthetic chemical insecticides and growing public acceptance of genetically modified organisms, new types of biological insecticides produced by genetic engineering offer a range of environmentally friendly options for cost-effective control of insect pests. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic Analysis of Streaked and Abnormal Floret Mutant st-fon

Directory of Open Access Journals (Sweden)

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.

Genetic analysis of somaclonal variants and induced mutants of potato ( solanum tuberosum l.) cv. diamant using RAPD markers

International Nuclear Information System (INIS)

Afrasiab, H.; Iqbal, J.

2011-01-01

The objective of this work was to genetically analyze somaclonal variants and gamma induced mutants of potato ( Solanum tuberosum L.) cv. Diamant using RAPD-PCR technique. In the present work, callus was induced from nodes, inter nodes and leaf explants in MS medium supplemented with NAA (1.0 mg/l) and BAP (0.5 mg/l) and plants were regenerated from 14-20 weeks old calli. For gamma irradiation, ten-week old well proliferating calli were exposed to doses ranging from 5-50 Gy. All the four selected somaclonal variants and five gamma induced mutants were differentiated by banding patterns obtained from 22 primers that generated 140 polymorphic bands. The presence of polymorphic bands in variants and mutants suggest that genetic variation occurred in all the treatments as compared to control. Similarity and clustered analysis were conducted using Jaccard's coefficients and the un-weighted pair-group method using arithmetic averages. The results summarized in a dendrogram, show genetic diversity among the variants and mutants. The study shows that RAPD markers were efficient in discriminating somaclonal variants and induced mutants of potato. (author)

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)

Genetic control of some morphological mutants in sunflower [Helianthus annuus L.

International Nuclear Information System (INIS)

Nabipour, A.; Sarrafi, A.; Yazdi-Samadi, B.

2004-01-01

Inheritance study of induced mutants is an important tool in genetic and breeding programs. Sunflower is one of the most important oil crops for which mutant collection is meager. Seeds of sunflower line AS-613 were irradiated with gamma rays and mutant phenotypes were traced until M4 generation. In M5 generation, the following traits were studied: dwarfing, branching, leaf shape, albinism, rosette, lack of apex and alternative leaves. In most cases, the mutated characters were controlled by a single recessive gene, while in two cases they were controlled by two recessive genes. In M5 progenies, segregation for two albino, one alternative leaves, one dwarfism, 5 branching, one rosette, 2 lacks of apex and 5 leaf shape mutants was recorded. Amongst five cases of branching, one was controlled by two recessive genes, where at least one homozygote recessive locus was necessary for branching. In one case, the lack of apex was controlled by two recessive genes and even only one dominant allele could provoke the normal plant [it

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...

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

Genetically engineered nanocarriers for drug delivery

Directory of Open Access Journals (Sweden)

Shi P

2014-03-01

Full Text Available Pu Shi, Joshua A Gustafson, J Andrew MacKayDepartment of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USAAbstract: Cytotoxicity, low water solubility, rapid clearance from circulation, and off-target side-effects are common drawbacks of conventional small-molecule drugs. To overcome these shortcomings, many multifunctional nanocarriers have been proposed to enhance drug delivery. In concept, multifunctional nanoparticles might carry multiple agents, control release rate, biodegrade, and utilize target-mediated drug delivery; however, the design of these particles presents many challenges at the stage of pharmaceutical development. An emerging solution to improve control over these particles is to turn to genetic engineering. Genetically engineered nanocarriers are precisely controlled in size and structure and can provide specific control over sites for chemical attachment of drugs. Genetically engineered drug carriers that assemble nanostructures including nanoparticles and nanofibers can be polymeric or non-polymeric. This review summarizes the recent development of applications in drug and gene delivery utilizing nanostructures of polymeric genetically engineered drug carriers such as elastin-like polypeptides, silk-like polypeptides, and silk-elastin-like protein polymers, and non-polymeric genetically engineered drug carriers such as vault proteins and viral proteins.Keywords: polymeric drug carrier, non-polymeric drug carrier, gene delivery, GE drug carriers

PHENOTYPIC CHARACTERISATION AND GENETIC ANALYSIS OF MUTANTS OF ASPERGILLUS NIDULANS RESISTANT TO THE FUNGICIDE TOLCLOFOS-METHYL

Directory of Open Access Journals (Sweden)

A CHIBANI

2000-12-01

Full Text Available Spontaneous mutants of Aspergillus nidulans were recovered from 0,55.10+7  conidia incubated on synthetic medium supplemented with 100 mg tolclofos-methyl/ml. They differed considerably in morphology, growth rate, and level of resistance to two other fungicides. All mutants tested were cross-resistant to quintozene and vinclozolin; they produced fewer conidia than their wild-type parent. Some mutants required fungicides for maximum growth. Genetic analysis revealed that the mutants carried mutations in one gene located on linkage group III.

Modularization of genetic elements promotes synthetic metabolic engineering.

Science.gov (United States)

Qi, Hao; Li, Bing-Zhi; Zhang, Wen-Qian; Liu, Duo; Yuan, Ying-Jin

2015-11-15

In the context of emerging synthetic biology, metabolic engineering is moving to the next stage powered by new technologies. Systematical modularization of genetic elements makes it more convenient to engineer biological systems for chemical production or other desired purposes. In the past few years, progresses were made in engineering metabolic pathway using synthetic biology tools. Here, we spotlighted the topic of implementation of modularized genetic elements in metabolic engineering. First, we overviewed the principle developed for modularizing genetic elements and then discussed how the genetic modules advanced metabolic engineering studies. Next, we picked up some milestones of engineered metabolic pathway achieved in the past few years. Last, we discussed the rapid raised synthetic biology field of "building a genome" and the potential in metabolic engineering. Copyright © 2015 Elsevier Inc. All rights reserved.

Moral Fantasy in Genetic Engineering.

Science.gov (United States)

Boone, C. Keith

1984-01-01

Discusses the main ethical issues generated by the new genetics and suggests ways to think about them. Concerns include "playing God," violation of the natural order of the universe, and abuse of genetic technology. Critical distinctions for making difficult decisions about genetic engineering issues are noted. (DH)

Morphology, physiology, genetics, enigmas, and status of an extremely rare tree: Mutant tanoak

Science.gov (United States)

Philip M. McDonald; Jianwei Zhang; Randy S. Senock; Jessica W. Wright

2013-01-01

Important physical characteristics, morphological attributes, physiological functions, and genetic properties of mutant tanoak, Notholithocarpus densiflorus f. attenuato-dentatus (Fagaceae), and normal tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh, were studied on the Challenge...

Genetic variability and inter-character associations in the mutants of Indian mustard

International Nuclear Information System (INIS)

Labana, K.S.; Chaurasia, B.D.; Singh, Balwant

1980-01-01

To study the genetic variability and the inter-character associations in Indian mustard [Brassica juncea (Linn.)Czern. and Coss. subsp. juncea Linn.], 104 radiation-induced mutants (including 'RLM 198') and 'RL 18' were grown during winter season of 1976-77 at the experimental farm of the Punjab Agricultural University. Analysis of variance revealed significant differences between the mutant genotypes for all the characters under study except for the primary branch number and siliqua number of main shoot, which were non-significant. High estimates of phenotypic coefficients of variation (pcv) and genetic coefficients of variation (gcv) were observed for secondary branch number, seed yield/plant, main shoot length and seed number/siliqua. In general, pcv estimates were higher than gcv estimates. The high estimates of both heritability and genetic advance were recorded in similar order for the plant height, seed number/siliqua, main shoot length and seed yield, in which the genetic progress could be achieved through mass selection. Seed yield was positively correlated with the primary branch number, the secondary branch number and the siliqua number of main shoot and negatively with the plant height. Shorter plant height w;.th more number of primary and secondary branches and more siliquae on main shoot were found to be good selection criteria for isolating high-yielding strains. (auth.)

A study on genetic variation and selective effect of principal characters of hybrid progenies of macro-mutants in peanut

International Nuclear Information System (INIS)

Qiu Qingrong

1990-01-01

In order to make good use of macro-mutants, we have studied the law of genetic variation and selective effect on the hybrid progenies of original varieties and of two macro-mutants with steady phenotypes. The results show that the hybrid progenies of the two experimental macro-mutants in the broad-sense heritability and the genetic advance of their main economical characters as well as the effect on selection are better than those of the hybrid progenies of the two original varieties. The selection rate from the macro-mutant hybrid progenies is 72.2% which is higher than that of the hybrid progenies of the two original varieties, and and a new prospecting strain has been obtained

Possible people, complaints, and the distinction between genetic planning and genetic engineering.

Science.gov (United States)

Delaney, James J

2011-07-01

Advances in the understanding of genetics have led to the belief that it may become possible to use genetic engineering to manipulate the DNA of humans at the embryonic stage to produce certain desirable traits. Although this currently cannot be done on a large scale, many people nevertheless object in principle to such practices. Most often, they argue that genetic enhancements would harm the children who were engineered, cause societal harms, or that the risks of perfecting the procedures are too high to proceed. However, many of these same people do not have serious objections to what is called 'genetic planning' procedures (such as the selection of sperm donors with desirable traits) that essentially have the same ends. The author calls the view that genetic engineering enhancements are impermissible while genetic planning enhancements are permissible the 'popular view', and argues that the typical reasons people give for the popular view fail to distinguish the two practices. This paper provides a principle that can salvage the popular view, which stresses that offspring from genetic engineering practices have grounds for complaint because they are identical to the pre-enhanced embryo, whereas offspring who are the result of genetic planning have no such grounds.

Genetic analysis of relative traits for a drought-sensitive mutant

International Nuclear Information System (INIS)

Gao Kangning; Wang Huaqi

2009-01-01

A drought-sensitive mutant (M616), selected from Handao 616 (HD616) by 60 Co γ-irradiation at 200Gy, was used. Some morphological and yield related traits of M166 and HD616 related to drought resistance were investigated. We further developed F 1 and F 2 reciprocal hybrid combinations derived from the crosses between M616 and HD616, between M616 and IRAT109, respectively, and genetic analysis of 3 traits including plant height, culm width of main stem and seed setting rate on main panicle were camed out. The results showed that M616 showed obviously sensitive to drought stress. Analysis of variance for three traits in upland and paddy between F 1 reciprocal hybrid combinations showed that each trait had no significant difference, and indicated that there were no differences of cytoplasmic hereditary effect. In addition, 3 traits of F 2 populations, were found that the frequency distributions of culm width showed normal distribution, indicating that culm width was polygenic trait, and the frequency distribution of plant height and seed setting rate did not show normal distribution, indicating that the two traits were qualitative-quantitative traits. Genetic analysis of relative traits for a drought-sensitive mutant of upland rice was a basic work for the gene location and cloning. (authors)

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

A genetic screen for increasing metabolic flux in the isoprenoid pathway of Saccharomyces cerevisiae: Isolation of SPT15 mutants using the screen

Directory of Open Access Journals (Sweden)

M. Wadhwa

2016-12-01

Full Text Available A genetic screen to identify mutants that can increase flux in the isoprenoid pathway of yeast has been lacking. We describe a carotenoid-based visual screen built with the core carotenogenic enzymes from the red yeast Rhodosporidium toruloides. Enzymes from this yeast displayed the required, higher capacity in the carotenoid pathway. The development also included the identification of the metabolic bottlenecks, primarily phytoene dehydrogenase, that was subjected to a directed evolution strategy to yield more active mutants. To further limit phytoene pools, a less efficient version of GGPP synthase was employed. The screen was validated with a known flux increasing gene, tHMG1. New mutants in the TATA binding protein SPT15 were isolated using this screen that increased the yield of carotenoids, and an alternate isoprenoid, α-Farnesene confirming increase in overall flux. The findings indicate the presence of previously unknown links to the isoprenoid pathway that can be uncovered using this screen. Keywords: Metabolic engineering, Carotenoids, Isoprenoids, α-Farnesene, Rhodosporidium toruloides, SPT15

Safe genetically engineered plants

International Nuclear Information System (INIS)

Rosellini, D; Veronesi, F

2007-01-01

The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work

Safe genetically engineered plants

Energy Technology Data Exchange (ETDEWEB)

Rosellini, D; Veronesi, F [Dipartimento di Biologia Vegetale e Biotecnologie Agroambientali e Zootecniche, Universita degli Studi di Perugia, Borgo XX giugno 74, 06121 Perugia (Italy)

2007-10-03

The application of genetic engineering to plants has provided genetically modified plants (GMPs, or transgenic plants) that are cultivated worldwide on increasing areas. The most widespread GMPs are herbicide-resistant soybean and canola and insect-resistant corn and cotton. New GMPs that produce vaccines, pharmaceutical or industrial proteins, and fortified food are approaching the market. The techniques employed to introduce foreign genes into plants allow a quite good degree of predictability of the results, and their genome is minimally modified. However, some aspects of GMPs have raised concern: (a) control of the insertion site of the introduced DNA sequences into the plant genome and of its mutagenic effect; (b) presence of selectable marker genes conferring resistance to an antibiotic or an herbicide, linked to the useful gene; (c) insertion of undesired bacterial plasmid sequences; and (d) gene flow from transgenic plants to non-transgenic crops or wild plants. In response to public concerns, genetic engineering techniques are continuously being improved. Techniques to direct foreign gene integration into chosen genomic sites, to avoid the use of selectable genes or to remove them from the cultivated plants, to reduce the transfer of undesired bacterial sequences, and make use of alternative, safer selectable genes, are all fields of active research. In our laboratory, some of these new techniques are applied to alfalfa, an important forage plant. These emerging methods for plant genetic engineering are briefly reviewed in this work.

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)

Genetic variation of maize (Zea mays L.) mutants based on ssr analysis

Energy Technology Data Exchange (ETDEWEB)

Hongni, Qin; Yilin, Cai; Chunrong, Yang; Guoqiang, Wang [Maize Research Institute of Southwest University, Chongqing (China)

2008-12-15

52 SSR primers that gave stable profiles amplified in sample of the Maize inbred line '082' and its 48 mutants were selected from 97 primers, and produced 170 polymorphic amplified fragments. The average number of allele per SSR locus was 3.27 with a range from 2 to 6. The polymorphism information content for the SSR loci varied from 0.039 to 0.715 with an average of 0.327. Genetic similarities among the 49 materials ranged from 0.377 to 1.000 with an average of 0.823. The 49 materials were divided into 6 groups by UPGMA. The results indicated that distinct variation existed among mutants. (authors)

Genetic variation of maize (Zea mays L.) mutants based on ssr analysis

International Nuclear Information System (INIS)

Qin Hongni; Cai Yilin; Yang Chunrong; Wang Guoqiang

2008-01-01

52 SSR primers that gave stable profiles amplified in sample of the Maize inbred line '082' and its 48 mutants were selected from 97 primers, and produced 170 polymorphic amplified fragments. The average number of allele per SSR locus was 3.27 with a range from 2 to 6. The polymorphism information content for the SSR loci varied from 0.039 to 0.715 with an average of 0.327. Genetic similarities among the 49 materials ranged from 0.377 to 1.000 with an average of 0.823. The 49 materials were divided into 6 groups by UPGMA. The results indicated that distinct variation existed among mutants. (authors)

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)

Seeking perfection: a Kantian look at human genetic engineering.

Science.gov (United States)

Gunderson, Martin

2007-01-01

It is tempting to argue that Kantian moral philosophy justifies prohibiting both human germ-line genetic engineering and non-therapeutic genetic engineering because they fail to respect human dignity. There are, however, good reasons for resisting this temptation. In fact, Kant's moral philosophy provides reasons that support genetic engineering-even germ-line and non-therapeutic. This is true of Kant's imperfect duties to seek one's own perfection and the happiness of others. It is also true of the categorical imperative. Kant's moral philosophy does, however, provide limits to justifiable genetic engineering.

Gamma-radiation Mutagenesis in Genetically Unstable Barley Mutants. Pt. 3. Effects of Aging in Various Genotypes

International Nuclear Information System (INIS)

Balchiuniene, L.

1995-01-01

Gamma-irradiation effect was tested on the grain material of normal-initial barley c. 'Auksiniai II' and allelic mutants tw 1 and tw 2 . Dependence of the aging effects on genotype was obvious, especially in survival test. Differences were observed even on allelic mutants. These observations are important for the preservation strategy of plant genetical resources. (author). 11 refs., 3 tabs

Genetic engineering in biotechnology

Energy Technology Data Exchange (ETDEWEB)

Bedate, C.A.; Morales, J.C.; Lopez, E.H.

1981-09-01

The objective of this book is to encourage the use of genetic engineering for economic development. The report covers: (1) Precedents of genetic engineering; (2) a brief description of the technology, including the transfer of DNA in bacteria (vectors, E. coli and B. subtilis hosts, stages, and technical problems), practical examples of techniques used and their products (interferon; growth hormone; insulin; treatment of blood cells, Talasemia, and Lesch-Nyhan syndrome; and more nutritious soya), transfer to higher organisms, and cellular fusion; (3) biological risks and precautions; (4) possible applications (production of hydrogen, hydrocarbons, alcohol, chemicals, enzymes, peptides, viral antigens, monoclonal antibodies, genes, proteins, and insecticides; metal extraction; nitrogen fixation; biodegradation; and new varieties of plants and animals; and (5) international activities.

Genetic Engineering of Alfalfa (Medicago sativa L.).

Science.gov (United States)

Wang, Dan; Khurshid, Muhammad; Sun, Zhan Min; Tang, Yi Xiong; Zhou, Mei Liang; Wu, Yan Min

2016-01-01

Alfalfa is excellent perennial legume forage for its extensive ecological adaptability, high nutrition value, palatability and biological nitrogen fixation. It plays a very important role in the agriculture, animal husbandry and ecological construction. It is cultivated in all continents. With the development of modern plant breeding and genetic engineering techniques, a large amount of work has been carried out on alfalfa. Here we summarize the recent research advances in genetic engineering of alfalfa breeding, including transformation, quality improvement, stress resistance and as a bioreactor. The review article can enables us to understand the research method, direction and achievements of genetic engineering technology of Alfalfa.

Teacher-to-Teacher: An Annotated Bibliography on DNA and Genetic Engineering.

Science.gov (United States)

Mertens, Thomas R., Comp.

1984-01-01

Presented is an annotated bibliography of 24 books on DNA and genetic engineering. Areas considered in these books include: basic biological concepts to help understand advances in genetic engineering; applications of genetic engineering; social, legal, and moral issues of genetic engineering; and historical aspects leading to advances in…

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

Directory of Open Access Journals (Sweden)

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.

Paper Genetic Engineering.

Science.gov (United States)

MacClintic, Scott D.; Nelson, Genevieve M.

Bacterial transformation is a commonly used technique in genetic engineering that involves transferring a gene of interest into a bacterial host so that the bacteria can be used to produce large quantities of the gene product. Although several kits are available for performing bacterial transformation in the classroom, students do not always…

Development of a forward genetic screen to isolate oil mutants in the green microalga Chlamydomonas reinhardtii.

Science.gov (United States)

Cagnon, Caroline; Mirabella, Boris; Nguyen, Hoa Mai; Beyly-Adriano, Audrey; Bouvet, Séverine; Cuiné, Stéphan; Beisson, Fred; Peltier, Gilles; Li-Beisson, Yonghua

2013-12-02

Oils produced by microalgae are precursors to biodiesel. To achieve a profitable production of biodiesel from microalgae, identification of factors governing oil synthesis and turnover is desirable. The green microalga Chlamydomonas reinhardtii is amenable to genetic analyses and has recently emerged as a model to study oil metabolism. However, a detailed method to isolate various types of oil mutants that is adapted to Chlamydomonas has not been reported. We describe here a forward genetic approach to isolate mutants altered in oil synthesis and turnover from C. reinhardtii. It consists of a three-step screening procedure: a primary screen by flow cytometry of Nile red stained transformants grown in 96-deep-well plates under three sequential conditions (presence of nitrogen, then absence of nitrogen, followed by oil remobilization); a confirmation step using Nile red stained biological triplicates; and a validation step consisting of the quantification by thin layer chromatography of oil content of selected strains. Thirty-one mutants were isolated by screening 1,800 transformants generated by random insertional mutagenesis (1.7%). Five showed increased oil accumulation under the nitrogen-replete condition and 13 had altered oil content under nitrogen-depletion. All mutants were affected in oil remobilization. This study demonstrates that various types of oil mutants can be isolated in Chlamydomonas based on the method set-up here, including mutants accumulating oil under optimal biomass growth. The strategy conceived and the protocol set-up should be applicable to other microalgal species such as Nannochloropsis and Chlorella, thus serving as a useful tool in Chlamydomonas oil research and algal biotechnology.

Genetically Engineered Immunotherapy for Advanced Cancer

Science.gov (United States)

In this trial, doctors will collect T lymphocytes from patients with advanced mesothelin-expressing cancer and genetically engineer them to recognize mesothelin. The gene-engineered cells will be multiplied and infused into the patient to fight the cancer

German politics of genetic engineering and its deconstruction.

Science.gov (United States)

Gottweis, H

1995-05-01

Policy-making, as exemplified by biotechnology policy, can be understood as an attempt to manage a field of discursivity, to construct regularity in a dispersed multitude of combinable elements. Following this perspective of politics as a textual process, the paper interprets the politicization of genetic engineering in Germany as a defence of the political as a regime of heterogeneity, as a field of 'dissensus' rather than 'consensus', and a rejection of the idea that the framing of technological transformation is an autonomous process. From its beginning in the early 1970s, genetic engineering was symbolically entrenched as a key technology of the future, and as an integral element of the German politics of modernization. Attempts by new social movements and the Green Party to displace the egalitarian imaginary of democratic discourse into the politics of genetic engineering were construed by the political élites as an attack on the political order of post-World War II Germany. The 1990 Genetic Engineering Law attempted a closure of this controversy. But it is precisely the homogenizing idiom of this 'settlement' which continues to nourish the social movements and their radical challenge to the definitions and codings of the politics of genetic engineering.

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002

Energy Technology Data Exchange (ETDEWEB)

Davies, Fiona K., E-mail: fdavies@mines.edu [Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO (United States); Work, Victoria H. [Civil and Environmental Engineering Division, Colorado School of Mines, Golden, CO (United States); Beliaev, Alexander S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA (United States); Posewitz, Matthew C. [Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO (United States)

2014-06-19

The plant terpenoids limonene (C{sub 10}H{sub 16}) and α-bisabolene (C{sub 15}H{sub 24}) are hydrocarbon precursors to a range of industrially relevant chemicals. High-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L{sup −1} limonene and 0.6 mg L{sup −1} α-bisabolene through heterologous expression of the Mentha spicatal-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene or α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate, and acetate) during nitrogen-deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6- to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

Engineering limonene and bisabolene production in wild type and a glycogen-deficient mutant of Synechococcus sp. PCC 7002

Energy Technology Data Exchange (ETDEWEB)

Davies, Fiona K.; Work, Victoria H.; Beliaev, Alex S.; Posewitz, Matthew C.

2014-06-19

The plant terpenoids limonene (C10H16) and α-bisabolene (C15H24) are hydrocarbon precursors to a range of industrially-relevant chemicals. High-titer microbial synthesis of limonene and α- bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L-1 limonene and 0.6 mg L-1 α-bisabolene through heterologous expression of the Mentha spicata L-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene and α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate and acetate) during nitrogen deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6 to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002.

Science.gov (United States)

Davies, Fiona K; Work, Victoria H; Beliaev, Alexander S; Posewitz, Matthew C

2014-01-01

The plant terpenoids limonene (C10H16) and α-bisabolene (C15H24) are hydrocarbon precursors to a range of industrially relevant chemicals. High-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L(-1) limonene and 0.6 mg L(-1) α-bisabolene through heterologous expression of the Mentha spicatal-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene or α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate, and acetate) during nitrogen-deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6- to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

Engineering Limonene and Bisabolene Production in Wild Type and a Glycogen-Deficient Mutant of Synechococcus sp. PCC 7002

International Nuclear Information System (INIS)

Davies, Fiona K.; Work, Victoria H.; Beliaev, Alexander S.; Posewitz, Matthew C.

2014-01-01

The plant terpenoids limonene (C 10 H 16 ) and α-bisabolene (C 15 H 24 ) are hydrocarbon precursors to a range of industrially relevant chemicals. High-titer microbial synthesis of limonene and α-bisabolene could pave the way for advances in in vivo engineering of tailor-made hydrocarbons, and production at commercial scale. We have engineered the fast-growing unicellular euryhaline cyanobacterium Synechococcus sp. PCC 7002 to produce yields of 4 mg L −1 limonene and 0.6 mg L −1 α-bisabolene through heterologous expression of the Mentha spicatal-limonene synthase or the Abies grandis (E)-α-bisabolene synthase genes, respectively. Titers were significantly higher when a dodecane overlay was applied during culturing, suggesting either that dodecane traps large quantities of volatile limonene or α-bisabolene that would otherwise be lost to evaporation, and/or that continuous product removal in dodecane alleviates product feedback inhibition to promote higher rates of synthesis. We also investigate limonene and bisabolene production in the ΔglgC genetic background, where carbon partitioning is redirected at the expense of glycogen biosynthesis. The Synechococcus sp. PCC 7002 ΔglgC mutant excreted a suite of overflow metabolites (α-ketoisocaproate, pyruvate, α-ketoglutarate, succinate, and acetate) during nitrogen-deprivation, and also at the onset of stationary growth in nutrient-replete media. None of the excreted metabolites, however, appeared to be effectively utilized for terpenoid metabolism. Interestingly, we observed a 1.6- to 2.5-fold increase in the extracellular concentration of most excreted organic acids when the ΔglgC mutant was conferred with the ability to produce limonene. Overall, Synechococcus sp. PCC 7002 provides a highly promising platform for terpenoid biosynthetic and metabolic engineering efforts.

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)

A systematic analysis of TCA Escherichia coli mutants reveals suitable genetic backgrounds for enhanced hydrogen and ethanol production using glycerol as main carbon source.

Science.gov (United States)

Valle, Antonio; Cabrera, Gema; Muhamadali, Howbeer; Trivedi, Drupad K; Ratray, Nicholas J W; Goodacre, Royston; Cantero, Domingo; Bolivar, Jorge

2015-09-01

Biodiesel has emerged as an environmentally friendly alternative to fossil fuels; however, the low price of glycerol feed-stocks generated from the biodiesel industry has become a burden to this industry. A feasible alternative is the microbial biotransformation of waste glycerol to hydrogen and ethanol. Escherichia coli, a microorganism commonly used for metabolic engineering, is able to biotransform glycerol into these products. Nevertheless, the wild type strain yields can be improved by rewiring the carbon flux to the desired products by genetic engineering. Due to the importance of the central carbon metabolism in hydrogen and ethanol synthesis, E. coli single null mutant strains for enzymes of the TCA cycle and other related reactions were studied in this work. These strains were grown anaerobically in a glycerol-based medium and the concentrations of ethanol, glycerol, succinate and hydrogen were analysed by HPLC and GC. It was found that the reductive branch is the more relevant pathway for the aim of this work, with malate playing a central role. It was also found that the putative C4-transporter dcuD mutant improved the target product yields. These results will contribute to reveal novel metabolic engineering strategies for improving hydrogen and ethanol production by E. coli. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolution and clinical impact of co-occurring genetic alterations in advanced-stage EGFR-mutant lung cancers. | Office of Cancer Genomics

Science.gov (United States)

A widespread approach to modern cancer therapy is to identify a single oncogenic driver gene and target its mutant-protein product (for example, EGFR-inhibitor treatment in EGFR-mutant lung cancers). However, genetically driven resistance to targeted therapy limits patient survival. Through genomic analysis of 1,122 EGFR-mutant lung cancer cell-free DNA samples and whole-exome analysis of seven longitudinally collected tumor samples from a patient with EGFR-mutant lung cancer, we identified critical co-occurring oncogenic events present in most advanced-stage EGFR-mutant lung cancers.

Genetically engineered orange petunias on the market

OpenAIRE

Bashandy, Hany; Teeri, Teemu Heikki

2017-01-01

Main conclusion Unauthorized genetically engineered orange petunias were found on the market. Genetic engineering of petunia was shown to lead to novel flower color some 20?years ago. Here we show that petunia lines with orange flowers, generated for scientific purposes, apparently found their way to petunia breeding programmes, intentionally or unintentionally. Today they are widely available, but have not been registered for commerce. Electronic supplementary material The online version of ...

Effects of ion beam irradiation on size of mutant sector and genetic damage in Arabidopsis

Energy Technology Data Exchange (ETDEWEB)

Hase, Yoshihiro, E-mail: hase.yoshihiro@qst.go.jp [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Nozawa, Shigeki [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Narumi, Issay [Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Gunma 374-0193 (Japan); Oono, Yutaka [Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

2017-01-15

Size of mutant sector and genetic damage were evaluated in Arabidopsis to further our understanding of effective ion beam use in plant mutation breeding. Arabidopsis seeds, heterozygous for the GLABRA1 (GL1) gene (GL1/gl1-1), were irradiated with 15.8 MeV/u neon ions (mean linear energy transfer (LET): 352 keV/μm), 17.3 MeV/u carbon ions (113 keV/μm), or {sup 60}Co gamma rays. The frequency and size of glabrous sectors generated because of inactivation of the GL1 allele were examined. The frequency and overall size of large deletions were evaluated based on the loss of heterozygosity of DNA markers using DNA isolated from glabrous tissue. Irrespective of the radiation properties, plants with mutant sectors were obtained at similar frequencies at the same effective dosage necessary for survival reduction. Ion beams tended to induce larger mutant sectors than gamma rays. The frequency of large deletions (>several kbp) increased as the LET value increased, with chromosome regions larger than 100 kbp lost in most large deletions. The distorted segregation ratio of glabrous plants in the progenies of irradiated GL1/gl1-1 plants suggested frequent occurrence of chromosome rearrangement, especially those subjected to neon ions. Exposure to ion beams with moderate LET values (30–110 keV/μm) is thought effective for inducing mutant sectors without causing extensive genetic damage.

Genetic engineering of cyanobacteria to enhance biohydrogen production from sunlight and water.

Science.gov (United States)

Masukawa, Hajime; Kitashima, Masaharu; Inoue, Kazuhito; Sakurai, Hidehiro; Hausinger, Robert P

2012-01-01

To mitigate global warming caused by burning fossil fuels, a renewable energy source available in large quantity is urgently required. We are proposing large-scale photobiological H(2) production by mariculture-raised cyanobacteria where the microbes capture part of the huge amount of solar energy received on earth's surface and use water as the source of electrons to reduce protons. The H(2) production system is based on photosynthetic and nitrogenase activities of cyanobacteria, using uptake hydrogenase mutants that can accumulate H(2) for extended periods even in the presence of evolved O(2). This review summarizes our efforts to improve the rate of photobiological H(2) production through genetic engineering. The challenges yet to be overcome to further increase the conversion efficiency of solar energy to H(2) also are discussed.

Genetic engineering for skeletal regenerative medicine.

Science.gov (United States)

Gersbach, Charles A; Phillips, Jennifer E; García, Andrés J

2007-01-01

The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

Perspectives of genetic engineering in radiobiology

International Nuclear Information System (INIS)

Khanson, K.P.; Zvonareva, N.B.; Evtushenko, V.I.

1988-01-01

Present evidence on the use of genetic engineering methods in studying the molecular mechanism of radiation damage and repair of DNA, as well as radiation mutagenesis and carcinogenesis has been summarized. The new approach to radiobiological research has proved to be extremely fruitful. Some previously unknown types of structural disorders in DNA molecule have been discovered, some repair genes isolated and their primary structure established, some aspects of radiation mutagenesis elucidated, and research into disiphering the molecular bases of neoplastic transformations of exposed cells are being successfully investigated. The perspectives of using genetic engineering methods in radiobiology are discussed

Metabolic Engineering of Probiotic Saccharomyces boulardii.

Science.gov (United States)

Liu, Jing-Jing; Kong, In Iok; Zhang, Guo-Chang; Jayakody, Lahiru N; Kim, Heejin; Xia, Peng-Fei; Kwak, Suryang; Sung, Bong Hyun; Sohn, Jung-Hoon; Walukiewicz, Hanna E; Rao, Christopher V; Jin, Yong-Su

2016-04-01

Saccharomyces boulardiiis a probiotic yeast that has been used for promoting gut health as well as preventing diarrheal diseases. This yeast not only exhibits beneficial phenotypes for gut health but also can stay longer in the gut than Saccharomyces cerevisiae Therefore, S. boulardiiis an attractive host for metabolic engineering to produce biomolecules of interest in the gut. However, the lack of auxotrophic strains with defined genetic backgrounds has hampered the use of this strain for metabolic engineering. Here, we report the development of well-defined auxotrophic mutants (leu2,ura3,his3, and trp1) through clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-based genome editing. The resulting auxotrophic mutants can be used as a host for introducing various genetic perturbations, such as overexpression or deletion of a target gene, using existing genetic tools forS. cerevisiae We demonstrated the overexpression of a heterologous gene (lacZ), the correct localization of a target protein (red fluorescent protein) into mitochondria by using a protein localization signal, and the introduction of a heterologous metabolic pathway (xylose-assimilating pathway) in the genome ofS. boulardii We further demonstrated that human lysozyme, which is beneficial for human gut health, could be secreted by S. boulardii Our results suggest that more sophisticated genetic perturbations to improveS. boulardii can be performed without using a drug resistance marker, which is a prerequisite for in vivo applications using engineeredS. boulardii. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Recent Advances in Genetic Engineering - A Review

OpenAIRE

Sobiah Rauf; Zubair Anwar; Hussain Mustatab Wahedi; Jabar Zaman Khan Khattak; Talal Jamil

2012-01-01

Humans have been doing genetic engineering, a technology which is transforming our world, for thousands of years on a wide range of plants, animals and micro organism and have applications in the field of medicine, research, industry and agriculture. The rapid developments in the field of genetic engineering have given a new impetus to biotechnology. This introduces the possibility of tailoring organisms in order to optimize the production of established or novel metabolites of commercial imp...

Can Man Control His Biological Evolution? A Symposium on Genetic Engineering. Genetic Engineering

Science.gov (United States)

Ramsey, Paul

1972-01-01

Presented are issues related to genetic engineering. Increased knowledge of techniques to manipulate genes are apt to create confusion about moral values in relation to unborn babies and other living organisms on earth. Human beings may use this knowledge to disturb the balance maintained by nature. (PS)

Genetic Engineering: The Modification of Man

Science.gov (United States)

Sinsheimer, Robert L.

1970-01-01

Describes somatic and genetic manipulations of individual genotypes, using diabetes control as an example of the first mode that is potentially realizable be derepression or viral transduction of genes. Advocates the use of genetic engineering of the second mode to remove man from his biological limitations, but offers maxims to ensure the…

An existential analysis of genetic engineering and human rights ...

African Journals Online (AJOL)

Genetic engineering for purposes of human enhancement poses risks that justify regulation. However, this paper argues philosophically that it is inappropriate to use human rights treaties to prohibit germ-line genetic engineering whether therapeutic or for purposes of enhancement. When also looked at existentially, the ...

Mighty Dwarfs: Arabidopsis autoimmune mutants and their usages in genetic dissection of plant immunity

Directory of Open Access Journals (Sweden)

Rowan Wersch

2016-11-01

Full Text Available Plants lack the adaptive immune system possessed by mammals. Instead they rely on innate immunity to defend against pathogen attacks. Genomes of higher plants encode a large number of plant immune receptors belonging to different protein families, which are involved in the detection of pathogens and activation of downstream defense pathways. Plant immunity is tightly controlled to avoid activation of defense responses in the absence of pathogens, as failure to do so can lead to autoimmunity that compromises plant growth and development. Many autoimmune mutants have been reported, most of which are associated with dwarfism and often spontaneous cell death. In this review, we summarize previously reported Arabidopsis autoimmune mutants, categorizing them based on their functional groups. We also discuss how their obvious morphological phenotypes make them ideal tools for epistatic analysis and suppressor screens, and summarize genetic screens that have been carried out in various autoimmune mutant backgrounds.

Genetic engineering possibilities for CELSS: A bibliography and summary of techniques

Science.gov (United States)

Johnson, E. J.

1982-01-01

A bibliography of the most useful techniques employed in genetic engineering of higher plants, bacteria associated with plants, and plant cell cultures is provided. A resume of state-of-the-art genetic engineering of plants and bacteria is presented. The potential application of plant bacterial genetic engineering to CELSS (Controlled Ecological Life Support System) program and future research needs are discussed.

What Ideas Do Students Associate with "Biotechnology" and "Genetic Engineering"?

Science.gov (United States)

Hill, Ruaraidh; Stanisstreet, Martin; Boyes, Edward

2000-01-01

Explores the ideas that students aged 16-19 associate with the terms 'biotechnology' and 'genetic engineering'. Indicates that some students see biotechnology as risky whereas genetic engineering was described as ethically wrong. (Author/ASK)

Genetic and systems level analysis of Drosophila sticky/citron kinase and dFmr1 mutants reveals common regulation of genetic networks

Directory of Open Access Journals (Sweden)

Zarnescu Daniela C

2008-11-01

Full Text Available Abstract Background In Drosophila, the genes sticky and dFmr1 have both been shown to regulate cytoskeletal dynamics and chromatin structure. These genes also genetically interact with Argonaute family microRNA regulators. Furthermore, in mammalian systems, both genes have been implicated in neuronal development. Given these genetic and functional similarities, we tested Drosophila sticky and dFmr1 for a genetic interaction and measured whole genome expression in both mutants to assess similarities in gene regulation. Results We found that sticky mutations can dominantly suppress a dFmr1 gain-of-function phenotype in the developing eye, while phenotypes produced by RNAi knock-down of sticky were enhanced by dFmr1 RNAi and a dFmr1 loss-of-function mutation. We also identified a large number of transcripts that were misexpressed in both mutants suggesting that sticky and dFmr1 gene products similarly regulate gene expression. By integrating gene expression data with a protein-protein interaction network, we found that mutations in sticky and dFmr1 resulted in misexpression of common gene networks, and consequently predicted additional specific phenotypes previously not known to be associated with either gene. Further phenotypic analyses validated these predictions. Conclusion These findings establish a functional link between two previously unrelated genes. Microarray analysis indicates that sticky and dFmr1 are both required for regulation of many developmental genes in a variety of cell types. The diversity of transcripts regulated by these two genes suggests a clear cause of the pleiotropy that sticky and dFmr1 mutants display and provides many novel, testable hypotheses about the functions of these genes. As both of these genes are implicated in the development and function of the mammalian brain, these results have relevance to human health as well as to understanding more general biological processes.

Genetic engineering applied to agriculture has a long row to hoe.

Science.gov (United States)

Miller, Henry I

2018-01-02

In spite of the lack of scientific justification for skepticism about crops modified with molecular techniques of genetic engineering, they have been the most scrutinized agricultural products in human history. The assumption that "genetically engineered" or "genetically modified" is a meaningful - and dangerous - classification has led to excessive and dilatory regulation. The modern molecular techniques are an extension, or refinement, of older, less precise, less predictable methods of genetic modification, but as long as today's activists and regulators remain convinced that so called "GMOs" represent a distinct and dangerous category of research and products, genetic engineering will fall short of its potential.

RAS signaling and anti-RAS therapy: lessons learned from genetically engineered mouse models, human cancer cells, and patient-related studies.

Science.gov (United States)

Fang, Bingliang

2016-01-01

Activating mutations of oncogenic RAS genes are frequently detected in human cancers. The studies in genetically engineered mouse models (GEMMs) reveal that Kras-activating mutations predispose mice to early onset tumors in the lung, pancreas, and gastrointestinal tract. Nevertheless, most of these tumors do not have metastatic phenotypes. Metastasis occurs when tumors acquire additional genetic changes in other cancer driver genes. Studies on clinical specimens also demonstrated that KRAS mutations are present in premalignant tissues and that most of KRAS mutant human cancers have co-mutations in other cancer driver genes, including TP53, STK11, CDKN2A, and KMT2C in lung cancer; APC, TP53, and PIK3CA in colon cancer; and TP53, CDKN2A, SMAD4, and MED12 in pancreatic cancer. Extensive efforts have been devoted to develop therapeutic agents that target enzymes involved in RAS posttranslational modifications, that inhibit downstream effectors of RAS signaling pathways, and that kill RAS mutant cancer cells through synthetic lethality. Recent clinical studies have revealed that sorafenib, a pan-RAF and VEGFR inhibitor, has impressive benefits for KRAS mutant lung cancer patients. Combination therapy of MEK inhibitors with either docetaxel, AKT inhibitors, or PI3K inhibitors also led to improved clinical responses in some KRAS mutant cancer patients. This review discusses knowledge gained from GEMMs, human cancer cells, and patient-related studies on RAS-mediated tumorigenesis and anti-RAS therapy. Emerging evidence demonstrates that RAS mutant cancers are heterogeneous because of the presence of different mutant alleles and/or co-mutations in other cancer driver genes. Effective subclassifications of RAS mutant cancers may be necessary to improve patients' outcomes through personalized precision medicine. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology

Forward Genetic Screening Using Behavioral Tests in Zebrafish: A Proof of Concept Analysis of Mutants.

Science.gov (United States)

Gerlai, Robert; Poshusta, Tanya L; Rampersad, Mindy; Fernandes, Yohaan; Greenwood, Tammy M; Cousin, Margot A; Klee, Eric W; Clark, Karl J

2017-01-01

The zebrafish enjoys several advantages over other model organisms. It is small, easy to maintain, prolific, and numerous genetic tools are available for it. For example, forward genetic screens have allowed investigators to identify important genes potentially involved in a variety of functions from embryogenesis to cancer. However, despite its sophisticated behavioral repertoire, behavioral methods have rarely been utilized in forward genetic screens. Here, we employ a two-tiered strategy, a proof of concept study, to explore the feasibility of behavioral screens. We generated mutant lines using transposon-based insertional mutagenesis, allowing us to bias mutant selection with target genes expressed within the brain. Furthermore, we employed an efficient and fast behavioral pre-selection in which we investigated the locomotory response of 5-day post-fertilization old larval fish to hyperosmotic shock. Based on this assay, we selected five lines for our lower throughput secondary adult behavioral screen. The latter screen utilized tests in which computer animated image presentation and video-tracking-based automated quantification of behavior allowed us to compare heterozygous zebrafish with their wild-type siblings on their responses to a variety of stimuli. We found significant mutation induced adult behavioral alterations in 4 out of the 5 lines analyzed, including changes in response to social or fear inducing stimuli, to handling and novelty, or in habituation to novelty. We discuss the pros and cons of behavioral phenotyping and of the use of different forward genetic methods in biomedical research with zebrafish.

Effects of genetic engineering on the pharmacokinetics of antibodies

International Nuclear Information System (INIS)

Colcher, D.; Goel, A.; Pavlinkova, G.; Beresford, G.; Booth, B.; Batra, S.K.

1999-01-01

Monoclonal antibodies (MAbs) may be considered 'magic bullets' due to their ability to recognize and eradicate malignant cells. MAbs, however, have practical limitations for their rapid application in the clinics. The structure of the antibody molecules can be engineered to modify functional domains such as antigen-binding sites and/or effectors functions. Advanced in genetic engineering have provided rapid progress the development of new immunoglobulin constructs of MAbs with defined research and therapeutic application. Recombinant antibody constructs are being engineered, such as human mouse chimeric, domain-dispositioned, domain-deleted, humanized and single-chain Fv fragments. Genetically-engineered antibodies differ in size and rate of catabolism. Pharmacokinetics studies show that the intact IgG (150 kD), enzymatically derived fragments Fab' (50 kD) and single chain Fv (28 kD) have different clearance rates. These antibody forms clear 50% from the blood pool in 2.1 days, 30 minutes and 10 minutes, respectively. Genetically-engineered antibodies make a new class of immunotherapeutic tracers for cancer treatment

Genetic Optimization Algorithm for Metabolic Engineering Revisited

Directory of Open Access Journals (Sweden)

Tobias B. Alter

2018-05-01

Full Text Available To date, several independent methods and algorithms exist for exploiting constraint-based stoichiometric models to find metabolic engineering strategies that optimize microbial production performance. Optimization procedures based on metaheuristics facilitate a straightforward adaption and expansion of engineering objectives, as well as fitness functions, while being particularly suited for solving problems of high complexity. With the increasing interest in multi-scale models and a need for solving advanced engineering problems, we strive to advance genetic algorithms, which stand out due to their intuitive optimization principles and the proven usefulness in this field of research. A drawback of genetic algorithms is that premature convergence to sub-optimal solutions easily occurs if the optimization parameters are not adapted to the specific problem. Here, we conducted comprehensive parameter sensitivity analyses to study their impact on finding optimal strain designs. We further demonstrate the capability of genetic algorithms to simultaneously handle (i multiple, non-linear engineering objectives; (ii the identification of gene target-sets according to logical gene-protein-reaction associations; (iii minimization of the number of network perturbations; and (iv the insertion of non-native reactions, while employing genome-scale metabolic models. This framework adds a level of sophistication in terms of strain design robustness, which is exemplarily tested on succinate overproduction in Escherichia coli.

Studies on cytological, physiological and genetic characteristics in somatic mutant strains of Sugi (Cryptomeria japonica D. Don)

International Nuclear Information System (INIS)

Maeta, T.; Somegou, M.; Nakahira, K.; Miyazaki, Y.; Kondo, T.

1982-01-01

From microscopic observation of the pollen of induced mutant strains in Sugi (Cryptomeria japonica D. Don), it was found that there were large differences in pollen fertility among the mutant strains, and that it deviated year to year from the mother plants. The large differences in frequency of sterile pollen among mutant strains depended on the genetic characteristics of each mutant strain. Higher frequencies of sterile pollen were observed at the terminal part of branchlets in some mutant strains, and this was considered to be induced by the lateness of flower-bud formation at low temperature conditions in late summer. Delayed formation and gibberellic acid treatment applied for flower induction resulted in low fertility and abnormality of pollen in mutant strains. Chromosome aberration in mutant strains was caused either by gamma irradiation or by some mutational events that responded to environmental conditions. In the former case, aberration might have been maintained for a long period through vegetative propagation. Some of the irregularities were due to mitotic cell division, because cells with micronuclei at the pacytene stage in pollen mother cells and with fragments at MI were observed. Somatic mutability of Kuma-sugi mutants after re-irradiation was investigated. From waxless mutants morphological somatic mutations, which have fat or stout stems and thick and short needles, were frequently produced, whereas from morphological mutants the lowest somatic mutation frequency was induced. In some mutant strains higher rooting ability than the mother plants was found, and the possibility of character improvement was pointed out. (author)

Rabbit defensin (NP-1) genetic engineering of plant | Ting | African ...

African Journals Online (AJOL)

Rabbit defensin (NP-1) genetic engineering of plant. ... Log in or Register to get access to full text downloads. ... defensin genetic engineering of plant in recent years, and also focuses on the existing problems and new strategies in this area.

Plant Genetic Resources: Selected Issues from Genetic Erosion to Genetic Engineering

Directory of Open Access Journals (Sweden)

Karl Hammer

2008-04-01

Full Text Available Plant Genetic Resources (PGR continue to play an important role in the development of agriculture. The following aspects receive a special consideration:1. Definition. The term was coined in 1970. The genepool concept served as an important tool in the further development. Different approaches are discussed.2. Values of Genetic Resources. A short introduction is highlighting this problem and stressing the economic usfulness of PGR.3. Genetic Erosion. Already observed by E. Baur in 1914, this is now a key issue within PGR. The case studies cited include Ethiopia, Italy, China, S Korea, Greece and S. Africa. Modern approaches concentrate on allelic changes in varieties over time but neglect the landraces. The causes and consequences of genetic erosion are discussed.4. Genetic Resources Conservation. Because of genetic erosion there is a need for conservation. PGR should be consigned to the appropriate method of conservation (ex situ, in situ, on-farm according to the scientific basis of biodiversity (genetic diversity, species diversity, ecosystem diversity and the evolutionary status of plants (cultivated plants, weeds, related wild plants (crop wild relatives.5. GMO. The impact of genetically engineered plants on genetic diversity is discussed.6. The Conclusions and Recommendations stress the importance of PGR. Their conservation and use are urgent necessities for the present development and future survival of mankind.

Genetic engineering of cyanobacteria as biodiesel feedstock.

Energy Technology Data Exchange (ETDEWEB)

Ruffing, Anne.; Trahan, Christine Alexandra; Jones, Howland D. T.

2013-01-01

Algal biofuels are a renewable energy source with the potential to replace conventional petroleum-based fuels, while simultaneously reducing greenhouse gas emissions. The economic feasibility of commercial algal fuel production, however, is limited by low productivity of the natural algal strains. The project described in this SAND report addresses this low algal productivity by genetically engineering cyanobacteria (i.e. blue-green algae) to produce free fatty acids as fuel precursors. The engineered strains were characterized using Sandias unique imaging capabilities along with cutting-edge RNA-seq technology. These tools are applied to identify additional genetic targets for improving fuel production in cyanobacteria. This proof-of-concept study demonstrates successful fuel production from engineered cyanobacteria, identifies potential limitations, and investigates several strategies to overcome these limitations. This project was funded from FY10-FY13 through the President Harry S. Truman Fellowship in National Security Science and Engineering, a program sponsored by the LDRD office at Sandia National Laboratories.

Engineering Values Into Genetic Engineering: A Proposed Analytic Framework for Scientific Social Responsibility.

Science.gov (United States)

Sankar, Pamela L; Cho, Mildred K

2015-01-01

Recent experiments have been used to "edit" genomes of various plant, animal and other species, including humans, with unprecedented precision. Furthermore, editing the Cas9 endonuclease gene with a gene encoding the desired guide RNA into an organism, adjacent to an altered gene, could create a "gene drive" that could spread a trait through an entire population of organisms. These experiments represent advances along a spectrum of technological abilities that genetic engineers have been working on since the advent of recombinant DNA techniques. The scientific and bioethics communities have built substantial literatures about the ethical and policy implications of genetic engineering, especially in the age of bioterrorism. However, recent CRISPr/Cas experiments have triggered a rehashing of previous policy discussions, suggesting that the scientific community requires guidance on how to think about social responsibility. We propose a framework to enable analysis of social responsibility, using two examples of genetic engineering experiments.

[Research progress of genetic engineering on medicinal plants].

Science.gov (United States)

Teng, Zhong-qiu; Shen, Ye

2015-02-01

The application of genetic engineering technology in modern agriculture shows its outstanding role in dealing with food shortage. Traditional medicinal plant cultivation and collection have also faced with challenges, such as lack of resources, deterioration of environment, germplasm of recession and a series of problems. Genetic engineering can be used to improve the disease resistance, insect resistance, herbicides resistant ability of medicinal plant, also can improve the medicinal plant yield and increase the content of active substances in medicinal plants. Thus, the potent biotechnology can play an important role in protection and large area planting of medicinal plants. In the development of medicinal plant genetic engineering, the safety of transgenic medicinal plants should also be paid attention to. A set of scientific safety evaluation and judgment standard which is suitable for transgenic medicinal plants should be established based on the recognition of the particularity of medicinal plants.

Characteristics and genetic mapping of a lesion mimic mutant pl(t) in japonica rice variety zhejing 22

International Nuclear Information System (INIS)

Chen Pingping; Zhang Xiaoming; Ye Shenghai; Zhao Ningchun; Lu Yanting; Liu Heqin; Jin Qingsheng; Yang Ling

2010-01-01

A lesion mimic mutant,obtained by radiation mutagenesis on the seeds of a japonica rice variety Zhejing 22, exhibited a lesion mimic phenotype during the whole growth stage under different environments. Genetic analysis indicated that the mutant trait was controlled by a single recessive gene named spl (t). Relying on simple sequence repeat (SSR) and recessive class analysis method to map the spl (t) gene with a F 2 population was constructed by crossing the mutant spl (t) with Zhenshan 97B.spl (t) was mapped in the interval of 0.8cM between RM7195 and RM27929 near centromere region on the short arm of chromosome 12.Blue trypan dye analyses indicated that the lesion mimic trait of the mutant was caused by the programmer cell death. Further study showed that the programmer cell death was caused by H 2 O 2 oxidative burst. By inoculation of bacterial leaf blight and blast strains, the resistances of the mutant were similar to the wild variety Zhejing 22. (authors)

Genetic cytological and biochemical study of a tomato chlorophyll mutant of the xanthic type, obtained by irradiation of the seeds

International Nuclear Information System (INIS)

Lefort, M.; Duranton, J.; Galmiche, J.M.; Roux, E.

1958-01-01

Irradiation of Lycopersicum aesculantum seeds with increasing doses of X-rays and thermal neutrons leads to the appearance of chlorophyll mutations in the descendants of the irradiated seeds. A genetic study of one of these mutants of the xanthic type showed that it was a recessive mutant with typical mono-genetic separation, while the cytological study demonstrated that the differentiation of the plast stopped at the stage of elementary lamella. Finally it is shown that in the light, the mutation brings about a very large deviation of the carbon metabolism towards the synthesis of amino acids and proteins, at the expense of that of glucosides. (author) [fr

TMTI Task 1.6 Genetic Engineering Methods and Detection

Energy Technology Data Exchange (ETDEWEB)

Slezak, T; Lenhoff, R; Allen, J; Borucki, M; Vitalis, E; Gardner, S

2009-12-04

A large number of GE techniques can be adapted from other microorganisms to biothreat bacteria and viruses. Detection of GE in a microorganism increases in difficulty as the size of the genetic change decreases. In addition to the size of the engineered change, the consensus genomic sequence of the microorganism can impact the difficulty of detecting an engineered change in genomes that are highly variable from strain to strain. This problem will require comprehensive databases of whole genome sequences for more genetically variable biothreat bacteria and viruses. Preliminary work with microarrays for detecting synthetic elements or virulence genes and analytic bioinformatic approaches for whole genome sequence comparison to detect genetic engineering show promise for attacking this difficult problem but a large amount of future work remains.

Genetic Engineering and Crop Production.

Science.gov (United States)

Jones, Helen C.; Frost, S.

1991-01-01

With a spotlight upon current agricultural difficulties and environmental dilemmas, this paper considers both the extant and potential applications of genetic engineering with respect to crop production. The nonagricultural factors most likely to sway the impact of this emergent technology upon future crop production are illustrated. (JJK)

A large-scale mutant panel in wheat developed using heavy-ion beam mutagenesis and its application to genetic research

Energy Technology Data Exchange (ETDEWEB)

Murai, Koji, E-mail: murai@fpu.ac.jp [Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195 (Japan); Nishiura, Aiko [Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho, Yoshida-gun, Fukui 910-1195 (Japan); Kazama, Yusuke [RIKEN, Innovation Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Abe, Tomoko [RIKEN, Innovation Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); RIKEN, Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

2013-11-01

Mutation analysis is a powerful tool for studying gene function. Heavy-ion beam mutagenesis is a comparatively new approach to inducing mutations in plants and is particularly efficient because of its high linear energy transfer (LET). High LET radiation induces a higher rate of DNA double-strand breaks than other mutagenic methods. Over the last 12 years, we have constructed a large-scale mutant panel in diploid einkorn wheat (Triticum monococcum) using heavy-ion beam mutagenesis. Einkorn wheat seeds were exposed to a heavy-ion beam and then sown in the field. Selfed seeds from each spike of M{sub 1} plants were used to generate M{sub 2} lines. Every year, we obtained approximately 1000 M{sub 2} lines and eventually developed a mutant panel with 10,000 M{sub 2} lines in total. This mutant panel is being systematically screened for mutations affecting reproductive growth, and especially for flowering-time mutants. To date, we have identified several flowering-time mutants of great interest: non-flowering mutants (mvp: maintained vegetative phase), late-flowering mutants, and early-flowering mutants. These novel mutations will be of value for investigations of the genetic mechanism of flowering in wheat.

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

Genetic engineering including superseding microinjection: new ways to make GM pigs.

Science.gov (United States)

Galli, Cesare; Perota, Andrea; Brunetti, Dario; Lagutina, Irina; Lazzari, Giovanna; Lucchini, Franco

2010-01-01

Techniques for genetic engineering of swine are providing genetically modified animals of importance for the field of xenotransplantation, animal models for human diseases and for a variety of research applications. Many of these modifications have been directed toward avoiding naturally existing cellular and antibody responses to species-specific antigens. A number of techniques are today available to engineering the genome of mammals, these range from the well established less efficient method of DNA microinjection into the zygote, the use of viral vectors, to the more recent use of somatic cell nuclear transfer. The use of enzymatic engineering that are being developed now will refine the precision of the genetic modification combined with the use of new vectors like transposons. The use of somatic cell nuclear transfer is currently the most efficient way to generate genetically modified pigs. The development of enzymatic engineering with zinc-finger nucleases, recombinases and transposons will revolutionize the field. Nevertheless, genetic engineering in large domesticated animals will remain a challenging task. Recent improvements in several fields of cell and molecular biology offer new promises and opportunities toward an easier, cost-effective and efficient generation of transgenic pigs. © 2010 John Wiley & Sons A/S.

Refresher Course in Plant Genetic Engineering

Indian Academy of Sciences (India)

A Refresher Course in Plant Genetic Engineering for postgraduate College ... that the teachers can perform the same set of experiments in their respective College/ ... research. The teachers are encouraged to add a note on their 'expectations' ...

Genetics of Ustilago violacea. I. Carotenoid mutants and carotenogenesis

International Nuclear Information System (INIS)

Garber, E.D.; Baird, M.L.; Chapman, D.J.

1975-01-01

Wild-type strains of Ustilago violacea produce pink colonies on laboratory medium and yield white, orange, pumpkin, and yellow colonies after uv mutagenesis. The wild-type strains contain neurosporene and lycopene; one orange mutant, γ-carotene; and one yellow mutant, β-carotene. One white mutant had no detectable carotenoids. Diploid colonies heterozygous for wild type and orange, pumpkin, yellow, or white are phenotypically wild type. Diploid colonies heterozygous for yellow and orange are also phenotypically wild type. Diploid colonies heterozygous for white and orange; white and yellow; and white, yellow, and orange are phenotypically light orange, light yellow, and orange-yellow, respectively. The white mutants give a circular complementation map; the color mutants fit a linear complementation map. We propose a multienzyme of four identical dehydrogenases and one or two identical cyclases for carotenogenesis in this species. The white and color mutants represent structural mutations altering the conformation of the dehydrogenase or cyclase, respectively. Furthermore, cyclases may or may not aggregate in association with the dehydrogenase aggregate to form the multienzyme aggregate responsible for the color mutants

Genetic analysis of diaminopimelic acid- and lysine-requiring mutants of Escherichia coli.

Science.gov (United States)

Bukhari, A I; Taylor, A L

1971-03-01

Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the E. coli chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD. Two additional DAP genes map in the region between min 47 and 48, with the gene order being gua-dapA-dapE-ctr. The lys locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is serA-lysA-thyA.

Human Genetic Engineering: A Survey of Student Value Stances

Science.gov (United States)

Wilson, Sara McCormack; And Others

1975-01-01

Assesses the values of high school and college students relative to human genetic engineering and recommends that biology educators explore instructional strategies merging human genetic information with value clarification techniques. (LS)

Hydrogen production by using Rhodobacter capsulatus mutants with genetically modified electron transfer chains

Energy Technology Data Exchange (ETDEWEB)

OEztuerk, Yavuz; Yuecel, Meral; Guenduez, Ufuk [Department of Biology, Middle East Technical University, Ankara (Turkey); Daldal, Fevzi [Department of Biology, Plant Science Institute, University of Pennsylvania, Philadelphia, PA 19104-6018 (United States); Mandaci, Sevnur [TUEBITAK Research Institute for Genetic Engineering and Biotechnology, Gebze Kocaeli 41470 (Turkey); Tuerker, Lemi [Department of Chemistry, Middle East Technical University, Ankara (Turkey); Eroglu, Inci [Department of Chemical Engineering, Middle East Technical University, Ankara (Turkey)

2006-09-15

In Rhodobacter capsulatus excess reducing equivalents generated by organic acid oxidation is consumed to reduce protons into hydrogen by the activity of nitrogenase. Nitrogenase serves as a redox-balancing tool and is activated by the RegB/RegA global regulatory system during photosynthetic growth. The terminal cytochrome cbb{sub 3} oxidase and the redox state of the cyclic photosynthetic electron transfer chain serve redox signaling to the RegB/RegA regulatory systems in Rhodobacter. In this study, hydrogen production of various R. capsulatus strains harboring the genetically modified electron carrier cytochromes or lacking the cyt cbb{sub 3} oxidase or the quinol oxidase were compared with the wild type. The results indicated that hydrogen production of mutant strains with modified electron carrier cytochromes decreased 3- to 4-fold, but the rate of hydrogen production increased significantly in a cbb{sub 3}{sup -} mutant. Moreover, hydrogen production efficiency of various R. capsulatus strains further increased by inactivation of uptake hydrogenase genes. (author)

Preliminary Assessment About Genetic Diversity, The Stability Of Potential Mutants From Two Varieties Of Chrysanthemum Morifolium Ramat. (Bronze DOA And Purple Farm) Via Gamma Irradiation

International Nuclear Information System (INIS)

Nguyen Tuong Mien; Le Ngoc Trieu; Le Tien Thanh; Pham Van Nhi; Huynh Thi Trung

2014-01-01

The objects of radiation breeding were chosen, collected and in vitro propagated. The suitable modalities for acute and chronic irradiation the materials were determined. Two acute and one chronic irradiation series were executed. Thus, the irradiated materials were achieved to screening for the mutants. In this study, on farm, through screening 18 phenotypic mutants of both chrysanthemums were recorded and collected including 6 potential mutants that selected for next research based on their phenotypic differences to the originals, their aesthetic and low mosaic. These 6 potential mutants together with their original varieties were micro-propagated to induce the potential mutant lines for estimation on farm of mutant characteristic segregation rates. Six potential mutant lines of E2a, E2c, E28, E29, I7, I8 are morphologically and genetically different to their original varieties, possess the identification markers and aestheticism. They were morphologically stable on farm through 3 series of growing on farm at M1V3, M1V5 and M1V7 generations. In the genetic respect, they possessed the high stabilities through in vitro generations. All of these criteria show that, these mutant lines were already to be registered as temporary cultivars/varieties. (author)

Molecular research and genetic engineering of resistance to ...

African Journals Online (AJOL)

This paper reviews the recent research progress on genetic methods of resistance, the status and existing problems, traditional breeding, the main resistance mechanism, molecular markers and genetic engineering of resistance genes. It is hoped that new breeding methods and new varieties resistant to Verticillium wilt will ...

Mutant alcohol dehydrogenase leads to improved ethanol tolerance in Clostridium thermocellum

Energy Technology Data Exchange (ETDEWEB)

Brown, Steven D [ORNL; Guss, Adam M [ORNL; Karpinets, Tatiana V [ORNL; Parks, Jerry M [ORNL; Smolin, Nikolai [ORNL; Yang, Shihui [ORNL; Land, Miriam L [ORNL; Klingeman, Dawn Marie [ORNL; Bhandiwad, Ashwini [Thayer School of Engineering at Dartmouth; Rodriguez, Jr., Miguel [ORNL; Raman, Babu [Dow Chemical Company, The; Shao, Xiongjun [Thayer School of Engineering at Dartmouth; Mielenz, Jonathan R [ORNL; Smith, Jeremy C [ORNL; Keller, Martin [ORNL; Lynd, Lee R [Thayer School of Engineering at Dartmouth

2011-01-01

Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. Biochemical assays confirm a complete loss of NADH-dependent activity with concomitant acquisition of NADPH-dependent activity, which likely affects electron flow in the mutant. The simplicity of the genetic basis for the ethanol-tolerant phenotype observed here informs rational engineering of mutant microbial strains for cellulosic ethanol production.

Genetic engineering and sustainable production of ornamentals

DEFF Research Database (Denmark)

Lütken, Henrik Vlk; Clarke, Jihong Liu; Müller, Renate

2012-01-01

Abstract Through the last decades, environmentally and health-friendly production methods and conscientious use of resources have become crucial for reaching the goal of a more sustainable plant production. Protection of the environment requires careful consumption of limited resources and reduct......Abstract Through the last decades, environmentally and health-friendly production methods and conscientious use of resources have become crucial for reaching the goal of a more sustainable plant production. Protection of the environment requires careful consumption of limited resources....... This review presents the more recent progress of genetic engineering in ornamental breeding, delivers an overview of the biological background of the used technologies and critically evaluates the usefulness of the strategies to obtain improved ornamental plants. First, genetic engineering is addressed......, compactness can be accomplished by using a natural transformation approach without recombinant DNA technology. Secondly, metabolic engineering approaches targeting elements of the ethylene signal transduction pathway are summarized as a possible alternative to avoid the use of chemical ethylene inhibitors...

Genetic engineering, a hope for sustainable biofuel production: review

Directory of Open Access Journals (Sweden)

Sudip Paudel

2014-06-01

Full Text Available The use of recently developed genetic engineering tools in combination with organisms that have the potential to produce precursors for the production of biodiesel, promises a sustainable and environment friendly energy source. Enhanced lipid production in wild type and/or genetically engineered organisms can offer sufficient raw material for industrial transesterification of plant-based triglycerides. Bio-diesel, produced with the help of genetically modified organisms, might be one of the best alternatives to fossil fuels and to mitigate various environmental hazards. DOI: http://dx.doi.org/10.3126/ije.v3i2.10644 International Journal of the Environment Vol.3(2 2014: 311-323

Non-genetic engineering of cells for drug delivery and cell-based therapy.

Science.gov (United States)

Wang, Qun; Cheng, Hao; Peng, Haisheng; Zhou, Hao; Li, Peter Y; Langer, Robert

2015-08-30

Cell-based therapy is a promising modality to address many unmet medical needs. In addition to genetic engineering, material-based, biochemical, and physical science-based approaches have emerged as novel approaches to modify cells. Non-genetic engineering of cells has been applied in delivering therapeutics to tissues, homing of cells to the bone marrow or inflammatory tissues, cancer imaging, immunotherapy, and remotely controlling cellular functions. This new strategy has unique advantages in disease therapy and is complementary to existing gene-based cell engineering approaches. A better understanding of cellular systems and different engineering methods will allow us to better exploit engineered cells in biomedicine. Here, we review non-genetic cell engineering techniques and applications of engineered cells, discuss the pros and cons of different methods, and provide our perspectives on future research directions. Copyright © 2014 Elsevier B.V. All rights reserved.

Genetic dissimilarity of putative gamma-ray-induced 'Preciosa-AAAB-Pome type' banana (Musa sp) mutants based on multivariate statistical analysis.

Science.gov (United States)

Pestana, R K N; Amorim, E P; Ferreira, C F; Amorim, V B O; Oliveira, L S; Ledo, C A S; Silva, S O

2011-10-25

Bananas are among the most important fruit crops worldwide, being cultivated in more than 120 countries, mainly by small-scale producers. However, short-stature high-yielding bananas presenting good agronomic characteristics are hard to find. Consequently, wind continues to damage a great number of plantations each year, leading to lodging of plants and bunch loss. Development of new cultivars through conventional genetic breeding methods is hindered by female sterility and the low number of seeds. Mutation induction seems to have great potential for the development of new cultivars. We evaluated genetic dissimilarity among putative 'Preciosa' banana mutants generated by gamma-ray irradiation, using morphoagronomic characteristics and ISSR markers. The genetic distances between the putative 'Preciosa' mutants varied from 0.21 to 0.66, with a cophenetic correlation coefficient of 0.8064. We found good variability after irradiation of 'Preciosa' bananas; this procedure could be useful for banana breeding programs aimed at developing short-stature varieties with good agronomic characteristics.

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)

Industry and genetic engineering of plants

International Nuclear Information System (INIS)

Posada, Mario

1995-01-01

The paper is about the importance of the genetic engineering and their development in the plants like is the resistance to the insects, to the mushrooms, retard in the maturation of the fruits and improvement of the quality of vegetables oils, among other aspects

A rapid, simple method for the genetic discrimination of intact Arabidopsis thaliana mutant seeds using metabolic profiling by direct analysis in real-time mass spectrometry

Directory of Open Access Journals (Sweden)

Jang Young

2011-06-01

Full Text Available Abstract Background Efficient high throughput screening systems of useful mutants are prerequisite for study of plant functional genomics and lots of application fields. Advance in such screening tools, thanks to the development of analytic instruments. Direct analysis in real-time (DART-mass spectrometry (MS by ionization of complex materials at atmospheric pressure is a rapid, simple, high-resolution analytical technique. Here we describe a rapid, simple method for the genetic discrimination of intact Arabidopsis thaliana mutant seeds using metabolic profiling by DART-MS. Results To determine whether this DART-MS combined by multivariate analysis can perform genetic discrimination based on global metabolic profiling, intact Arabidopsis thaliana mutant seeds were subjected to DART-MS without any sample preparation. Partial least squares-discriminant analysis (PLS-DA of DART-MS spectral data from intact seeds classified 14 different lines of seeds into two distinct groups: Columbia (Col-0 and Landsberg erecta (Ler ecotype backgrounds. A hierarchical dendrogram based on partial least squares-discriminant analysis (PLS-DA subdivided the Col-0 ecotype into two groups: mutant lines harboring defects in the phenylpropanoid biosynthetic pathway and mutants without these defects. These results indicated that metabolic profiling with DART-MS could discriminate intact Arabidopsis seeds at least ecotype level and metabolic pathway level within same ecotype. Conclusion The described DART-MS combined by multivariate analysis allows for rapid screening and metabolic characterization of lots of Arabidopsis mutant seeds without complex metabolic preparation steps. Moreover, potential novel metabolic markers can be detected and used to clarify the genetic relationship between Arabidopsis cultivars. Furthermore this technique can be applied to predict the novel gene function of metabolic mutants regardless of morphological phenotypes.

130 FEMINISM AND HUMAN GENETIC ENGINEERING: A ...

African Journals Online (AJOL)

Ike Odimegwu

genetic engineering to reconstruct the life of the human person. Negatively .... height, beauty or intelligence. Apart from ... cloning and stem-cell researches, artificial insemination. ..... form of manufacturing children involving their quality control.

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.

Genetic screens to identify new Notch pathway mutants in Drosophila.

Science.gov (United States)

Giagtzoglou, Nikolaos

2014-01-01

Notch signaling controls a wide range of developmental processes, including proliferation, apoptosis, and cell fate specification during both development and adult tissue homeostasis. The functional versatility of the Notch signaling pathway is tightly linked with the complexity of its regulation in different cellular contexts. To unravel the complexity of Notch signaling, it is important to identify the different components of the Notch signaling pathway. A powerful strategy to accomplish this task is based on genetic screens. Given that the developmental context of signaling is important, these screens should be customized to specific cell populations or tissues. Here, I describe how to perform F1 clonal forward genetic screens in Drosophila to identify novel components of the Notch signaling pathway. These screens combine a classical EMS (ethyl methanesulfonate) chemical mutagenesis protocol along with clonal analysis via FRT-mediated mitotic recombination. These F1 clonal screens allow rapid phenotypic screening within clones of mutant cells induced at specific developmental stages and in tissues of interest, bypassing the pleiotropic effects of isolated mutations. More importantly, since EMS mutations have been notoriously difficult to map to specific genes in the past, I briefly discuss mapping methods that allow rapid identification of the causative mutations.

Genetics of dwarfness in induced mutants of hexaploid triticale and its response to exogenous GA3

International Nuclear Information System (INIS)

Reddy, V.D.; Reddy, G.M.

1991-01-01

Genetics of dwarfism in two induced mutant (d 1 and d 2 ) of hexaploid triticale, DTS 330, revealed that this trait is governed by single recessive gene. Both d 1 and d 2 were allelic to each other and d 1 was dominant over d 2 . Both d 1 , d 2 and their F 1 showed no response to exogenous GA 3 , whereas, DTS 330, d 1 x DTS 330 and d 2 x DTS 330 were responsive. The endogenous levels of GA 3 were more in the dwarf mutants than control, suggesting that dwarfness in these may be due to a partial block in the GA utilizing mechanism, rather than a block in GA biosynthesis. (author). 5 refs., 2 tabs

Genetic requirements for high constitutive SOS expression in recA730 mutants of Escherichia coli.

Science.gov (United States)

Vlašić, Ignacija; Šimatović, Ana; Brčić-Kostić, Krunoslav

2011-09-01

The RecA protein in its functional state is in complex with single-stranded DNA, i.e., in the form of a RecA filament. In SOS induction, the RecA filament functions as a coprotease, enabling the autodigestion of the LexA repressor. The RecA filament can be formed by different mechanisms, but all of them require three enzymatic activities essential for the processing of DNA double-stranded ends. These are helicase, 5'-3' exonuclease, and RecA loading onto single-stranded DNA (ssDNA). In some mutants, the SOS response can be expressed constitutively during the process of normal DNA metabolism. The RecA730 mutant protein is able to form the RecA filament without the help of RecBCD and RecFOR mediators since it better competes with the single-strand binding (SSB) protein for ssDNA. As a consequence, the recA730 mutants show high constitutive SOS expression. In the study described in this paper, we studied the genetic requirements for constitutive SOS expression in recA730 mutants. Using a β-galactosidase assay, we showed that the constitutive SOS response in recA730 mutants exhibits different requirements in different backgrounds. In a wild-type background, the constitutive SOS response is partially dependent on RecBCD function. In a recB1080 background (the recB1080 mutation retains only helicase), constitutive SOS expression is partially dependent on RecBCD helicase function and is strongly dependent on RecJ nuclease. Finally, in a recB-null background, the constitutive SOS expression of the recA730 mutant is dependent on the RecJ nuclease. Our results emphasize the importance of the 5'-3' exonuclease for high constitutive SOS expression in recA730 mutants and show that RecBCD function can further enhance the excellent intrinsic abilities of the RecA730 protein in vivo. Copyright © 2011, American Society for Microbiology. All Rights Reserved.

76 FR 5780 - Determination of Regulated Status of Alfalfa Genetically Engineered for Tolerance to the...

Science.gov (United States)

2011-02-02

...] Determination of Regulated Status of Alfalfa Genetically Engineered for Tolerance to the Herbicide Glyphosate... decision and determination on the petition regarding the regulated status of alfalfa genetically engineered... regulated status of alfalfa genetically engineered for tolerance to the herbicide glyphosate based on an...

Genetically engineered rice. The source of β-carotene

Directory of Open Access Journals (Sweden)

Karol Terlecki

2014-04-01

Full Text Available β-carotene is a precursor of vitamin A. It is converted to vitamin A in the humans intestine by the β-carotene-15,15’-monooxygenase. Vitamin A is essential to support vision, as an antioxidant it protects the body from free radicals, it helps to integrate the immune system, as well as takes part in cellular differentiation and proliferation. Vitamin A deficiency is a major public health problem especially among developing countries. Nyctalopia, commonly known as „Night Blindness” is one of the major symptoms of Vitamin A deficiency (VAD. Plants such as apricots, broccoli, carrots, and sweet potatoes are rich in β-carotene. Some of the plants are characterized by a higher content of provitamin-A. Among vegetables rich sources of β-carotene are: carrots, pumpkin, spinach, lettuce, green peas, tomatoes, watercress, broccoli and parsley leaves. Amongst fruits the highest content of β-carotene is in apricot, cherry, sweet cherry, plum, orange and mango. The aim of the present study was to analyze available literature data of increasing the content of β-carotene in genetically engineered rice. The genetically modified cultivar contains additional genes: PSY and CRTI thanks to which rice seed endosperm contains β-carotene. Genetically engineered rice with β-carotene is an effective source of vitamin A, it contains approximately 30 μg β-carotene per 1 g. Fortunately some of the advantages of Genetically Modified Food give an opportunity to reduce VAD worldwide, by introducing the rice which has been genetically engineered to be rich in β-carotene. The popularity of this plant as an element of nutrition is simultaneously a source of vitamin A.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Science.gov (United States)

Adnan, Humaira; Zhang, Zhenbo; Park, Hyun-Joo; Tailor, Chetankumar; Che, Clare; Kamani, Mustafa; Spitalny, George; Binnington, Beth; Lingwood, Clifford

2016-01-01

Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER) 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD), to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant) subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon), to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin) containing genetically inactivated (± an N-terminal polyleucine tail) A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF) mutant (5-10x), F508delCFTR Golgi maturation (glucocerobrosidase (GCC) in N370SGCC Gaucher Disease fibroblasts (3x), another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

Genetic dependence of recombination in recD mutants of Escherichia coli

International Nuclear Information System (INIS)

Lovett, S.T.; Luisi-DeLuca, C.; Kolodner, R.D.

1988-01-01

RecBCD enzyme has multiple activities including helicase, exonuclease and endonuclease activities. Mutations in the genes recB or recC, encoding two subunits of the enzyme, reduce the frequency of many types of recombinational events. Mutations in recD, encoding the third subunit, do not reduce recombination even though most of the activities of the RecBCD enzyme are severely reduced. In this study, the genetic dependence of different types of recombination in recD mutants has been investigated. The effects of mutations in genes in the RecBCD pathway (recA and recC) as well as the genes specific for the RecF pathway (recF, recJ, recN, recO, recQ, ruv and lexA) were tested on conjugational, transductional and plasmid recombination, and on UV survival. recD mutants were hyper-recombinogenic for all the monitored recombination events, especially those involving plasmids, and all recombination events in recD strains required recA and recC. In addition, unlike recD+ strains, chromosomal recombination events and the repair of UV damage to DNA in recD strains were dependent on one RecF pathway gene, recJ. Only a subset of the tested recombination events were affected by ruv, recN, recQ, recO and lexA mutations

A genetic screen for vascular mutants in zebrafish reveals dynamic roles for Vegf/Plcg1 signaling during artery development.

Science.gov (United States)

Covassin, L D; Siekmann, A F; Kacergis, M C; Laver, E; Moore, J C; Villefranc, J A; Weinstein, B M; Lawson, N D

2009-05-15

In this work we describe a forward genetic approach to identify mutations that affect blood vessel development in the zebrafish. By applying a haploid screening strategy in a transgenic background that allows direct visualization of blood vessels, it was possible to identify several classes of mutant vascular phenotypes. Subsequent characterization of mutant lines revealed that defects in Vascular endothelial growth factor (Vegf) signaling specifically affected artery development. Comparison of phenotypes associated with different mutations within a functional zebrafish Vegf receptor-2 ortholog (referred to as kdr-like, kdrl) revealed surprisingly varied effects on vascular development. In parallel, we identified an allelic series of mutations in phospholipase c gamma 1 (plcg1). Together with in vivo structure-function analysis, our results suggest a requirement for Plcg1 catalytic activity downstream of receptor tyrosine kinases. We further find that embryos lacking both maternal and zygotic plcg1 display more severe defects in artery differentiation but are otherwise similar to zygotic mutants. Finally, we demonstrate through mosaic analysis that plcg1 functions autonomously in endothelial cells. Together our genetic analyses suggest that Vegf/Plcg1 signaling acts at multiple time points and in different signaling contexts to mediate distinct aspects of artery development.

Genetic engineering for improvement of Musa production in Africa ...

African Journals Online (AJOL)

The transgenic approach shows potential for the genetic improvement of the crop using a wide set of transgenes currently available which may confer resistance to nematode pests, fungal, bacterial and viral diseases. This article discusses the applications of genetic engineering for the enhancement of Musa production.

Genetic analysis and gene mapping of a low stigma exposed mutant gene by high-throughput sequencing.

Directory of Open Access Journals (Sweden)

Xiao Ma

Full Text Available Rice is one of the main food crops and several studies have examined the molecular mechanism of the exposure of the rice plant stigma. The improvement in the exposure of the stigma in female parent hybrid combinations can enhance the efficiency of hybrid breeding. In the present study, a mutant plant with low exposed stigma (lesr was discovered among the descendants of the indica thermo-sensitive sterile line 115S. The ES% rate of the mutant decreased by 70.64% compared with the wild type variety. The F2 population was established by genetic analysis considering the mutant as the female parent and the restorer line 93S as the male parent. The results indicated a normal F1 population, while a clear division was noted for the high and low exposed stigma groups, respectively. This process was possible only by a ES of 25% in the F2 population. This was in agreement with the ratio of 3:1, which indicated that the mutant was controlled by a recessive main-effect QTL locus, temporarily named as LESR. Genome-wide comparison of the SNP profiles between the early, high and low production bulks were constructed from F2 plants using bulked segregant analysis in combination with high-throughput sequencing technology. The results demonstrated that the candidate loci was located on the chromosome 10 of the rice. Following screening of the recombinant rice plants with newly developed molecular markers, the genetic region was narrowed down to 0.25 Mb. This region was flanked by InDel-2 and InDel-2 at the physical location from 13.69 to 13.94 Mb. Within this region, 7 genes indicated base differences between parents. A total of 2 genes exhibited differences at the coding region and upstream of the coding region, respectively. The present study aimed to further clone the LESR gene, verify its function and identify the stigma variation.

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

Genetic Analysis of Diaminopimelic Acid- and Lysine-Requiring Mutants of Escherichia coli1

Science.gov (United States)

Bukhari, Ahmad I.; Taylor, Austin L.

1971-01-01

Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the E. coli chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD. Two additional DAP genes map in the region between min 47 and 48, with the gene order being gua-dapA-dapE-ctr. The lys locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is serA-lysA-thyA. PMID:4926684

Exergetic optimization of turbofan engine with genetic algorithm method

Energy Technology Data Exchange (ETDEWEB)

Turan, Onder [Anadolu University, School of Civil Aviation (Turkey)], e-mail: onderturan@anadolu.edu.tr

2011-07-01

With the growth of passenger numbers, emissions from the aeronautics sector are increasing and the industry is now working on improving engine efficiency to reduce fuel consumption. The aim of this study is to present the use of genetic algorithms, an optimization method based on biological principles, to optimize the exergetic performance of turbofan engines. The optimization was carried out using exergy efficiency, overall efficiency and specific thrust of the engine as evaluation criteria and playing on pressure and bypass ratio, turbine inlet temperature and flight altitude. Results showed exergy efficiency can be maximized with higher altitudes, fan pressure ratio and turbine inlet temperature; the turbine inlet temperature is the most important parameter for increased exergy efficiency. This study demonstrated that genetic algorithms are effective in optimizing complex systems in a short time.

Molecular profiling techniques as tools to detect potential unintended effects in genetically engineered maize

CSIR Research Space (South Africa)

Barros, E

2010-05-01

Full Text Available Molecular Profiling Techniques as Tools to Detect Potential Unintended Effects in Genetically Engineered Maize Eugenia Barros Introduction In the early stages of production and commercialization of foods derived from genetically engineered (GE) plants... systems. In a recent paper published in Plant Biotechnology Journal,4 we compared two transgenic white maize lines with the non-transgenic counterpart to investigate two possible sources of variation: genetic engineering and environmental variation...

human genetic engineering and social justice in south africa

African Journals Online (AJOL)

resources, are also acutely visible in the health-care sector. Genetic ... engineering (GE)2 from a South African perspective might not, initially, seem like an obvious ... prevalence of so-called genetic tourism, where couples from developed countries travel to countries in the developing world to undergo in vitro fertilisation ...

Genetically engineered Pseudomonas: a factory of new bioplastics with broad applications.

Science.gov (United States)

Olivera, E R; Carnicero, D; Jodra, R; Miñambres, B; García, B; Abraham, G A; Gallardo, A; Román, J S; García, J L; Naharro, G; Luengo, J M

2001-10-01

New bioplastics containing aromatic or mixtures of aliphatic and aromatic monomers have been obtained using genetically engineered strains of Pseudomonas putida. The mutation (-) or deletion (Delta) of some of the genes involved in the beta-oxidation pathway (fadA(-), fadB(-) Delta fadA or Delta fad BA mutants) elicits a strong intracellular accumulation of unusual homo- or co-polymers that dramatically alter the morphology of these bacteria, as more than 90% of the cytoplasm is occupied by these macromolecules. The introduction of a blockade in the beta-oxidation pathway, or in other related catabolic routes, has allowed the synthesis of polymers other than those accumulated in the wild type (with regard to both monomer size and relative percentage), the accumulation of certain intermediates that are rapidly catabolized in the wild type and the accumulation in the culture broths of end catabolites that, as in the case of phenylacetic acid, phenylbutyric acid, trans-cinnamic acid or their derivatives, have important medical or pharmaceutical applications (antitumoral, analgesic, radiopotentiators, chemopreventive or antihelmintic). Furthermore, using one of these polyesters (poly 3-hydroxy-6-phenylhexanoate), we obtained polymeric microspheres that could be used as drug vehicles.

"Genetic Engineering" Gains Momentum (Science/Society Case Study).

Science.gov (United States)

Moore, John W.; Moore, Elizabeth A., Eds.

1980-01-01

Reviews the benefits and hazards of genetic engineering, or "recombinant-DNA" research. Recent federal safety rules issued by NIH which ease the strict prohibitions on recombinant-DNA research are explained. (CS)

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

Directory of Open Access Journals (Sweden)

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.

Chromosome engineering: power tools for plant genetics.

Science.gov (United States)

Chan, Simon W L

2010-12-01

The term "chromosome engineering" describes technologies in which chromosomes are manipulated to change their mode of genetic inheritance. This review examines recent innovations in chromosome engineering that promise to greatly increase the efficiency of plant breeding. Haploid Arabidopsis thaliana have been produced by altering the kinetochore protein CENH3, yielding instant homozygous lines. Haploid production will facilitate reverse breeding, a method that downregulates recombination to ensure progeny contain intact parental chromosomes. Another chromosome engineering success is the conversion of meiosis into mitosis, which produces diploid gametes that are clones of the parent plant. This is a key step in apomixis (asexual reproduction through seeds) and could help to preserve hybrid vigor in the future. New homologous recombination methods in plants will potentiate many chromosome engineering applications. Copyright © 2010 Elsevier Ltd. All rights reserved.

Double-strand break repair and genetic recombination in topoisomerase and primase mutants of bacteriophage T4.

Science.gov (United States)

Shcherbakov, Victor P; Kudryashova, Elena

2014-09-01

The effects of primase and topoisomerase II deficiency on the double-strand break (DSB) repair and genetic recombination in bacteriophage T4 were studied in vivo using focused recombination. Site-specific DSBs were induced by SegC endonuclease in the rIIB gene of one of the parents. The frequency/distance relationship was determined in crosses of the wild-type phage, topoisomerase II mutant amN116 (gene 39), and primase mutant E219 (gene 61). Ordinary two-factor (i×j) and three-factor (i k×j) crosses between point rII mutations were also performed. These data provide information about the frequency and distance distribution of the single-exchange (splice) and double-exchange (patch) events. In two-factor crosses ets1×i, the topoisomerase and primase mutants had similar recombinant frequencies in crosses at ets1-i distances longer than 1000 bp, comprising about 80% of the corresponding wild-type values. They, however, differ remarkably in crosses at shorter distances. In the primase mutant, the recombinant frequencies are similar to those in the wild-type crosses at distances less than 100 bp, being a bit diminished at longer distances. In two-factor crosses ets1×i of the topoisomerase mutant, the recombinant frequencies were reduced ten-fold at the shortest distances. In three-factor crosses a6 ets1×i, where we measure patch-related recombination, the primase mutant was quite proficient across the entire range of distances. The topoisomerase mutant crosses demonstrated virtually complete absence of rII(+) recombinants at distances up to 33 bp, with the frequencies increasing steadily at longer distances. The data were interpreted as follows. The primase mutant is fully recombination-proficient. An obvious difference from the wild-type state is some shortage of EndoVII function leading to prolonged existence of HJs and thus stretched out ds-branch migration. This is also true for the topoisomerase mutant. However, the latter is deficient in the ss

A new regulatory mechanism controlling carotenogenesis in the fungus Mucor circinelloides as a target to generate β-carotene over-producing strains by genetic engineering.

Science.gov (United States)

Zhang, Yingtong; Navarro, Eusebio; Cánovas-Márquez, José T; Almagro, Lorena; Chen, Haiqin; Chen, Yong Q; Zhang, Hao; Torres-Martínez, Santiago; Chen, Wei; Garre, Victoriano

2016-06-07

Carotenoids are natural pigments with antioxidant properties that have important functions in human physiology and must be supplied through the diet. They also have important industrial applications as food colourants, animal feed additives and nutraceuticals. Some of them, such as β-carotene, are produced on an industrial scale with the use of microorganisms, including fungi. The mucoral Blakeslea trispora is used by the industry to produce β-carotene, although optimisation of production by molecular genetic engineering is unfeasible. However, the phylogenetically closely related Mucor circinelloides, which is also able to accumulate β-carotene, possesses a vast collection of genetic tools with which to manipulate its genome. This work combines classical forward and modern reverse genetic techniques to deepen the regulation of carotenoid synthesis and generate candidate strains for biotechnological production of β-carotene. Mutagenesis followed by screening for mutants with altered colour in the dark and/or in light led to the isolation of 26 mutants that, together with eight previously isolated mutants, have been analysed in this work. Although most of the mutants harboured mutations in known structural and regulatory carotenogenic genes, eight of them lacked mutations in those genes. Whole-genome sequencing of six of these strains revealed the presence of many mutations throughout their genomes, which makes identification of the mutation that produced the phenotype difficult. However, deletion of the crgA gene, a well-known repressor of carotenoid biosynthesis in M. circinelloides, in two mutants (MU206 and MU218) with high levels of β-carotene resulted in a further increase in β-carotene content to differing extents with respect to the crgA single-null strain; in particular, one strain derived from MU218 was able to accumulate up to 4 mg/g of β-carotene. The additive effect of crgA deletion and the mutations present in MU218 suggests the existence of a

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)

Genetic Engineering In BioButanol Production And Tolerance

Directory of Open Access Journals (Sweden)

Ashok Rao

Full Text Available ABSTRACT The growing need to address current energy and environmental problems has sparked an interest in developing improved biological methods to produce liquid fuels from renewable sources. Higher-chain alcohols possess chemical properties that are more similar to gasoline. Ethanol and butanol are two products which are used as biofuel. Butanol production was more concerned than ethanol because of its high octane number. Unfortunately, these alcohols are not produced efficiently in natural microorganisms, and thus economical production in industrial volumes remains a challenge. The synthetic biology, however, offers additional tools to engineer synthetic pathways in user-friendly hosts to help increase titers and productivity of bio-butanol. Knock out and over-expression of genes is the major approaches towards genetic manipulation and metabolic engineering of microbes. Yet there are TargeTron Technology, Antisense RNA and CRISPR technology has a vital role in genome manipulation of C.acetobutylicum. This review concentrates on the recent developments for efficient production of butanol and butanol tolerance by various genetically engineered microbes.

Identification of Mutant Genes and Introgressed Tiger Salamander DNA in the Laboratory Axolotl, Ambystoma mexicanum.

Science.gov (United States)

Woodcock, M Ryan; Vaughn-Wolfe, Jennifer; Elias, Alexandra; Kump, D Kevin; Kendall, Katharina Denise; Timoshevskaya, Nataliya; Timoshevskiy, Vladimir; Perry, Dustin W; Smith, Jeramiah J; Spiewak, Jessica E; Parichy, David M; Voss, S Randal

2017-01-31

The molecular genetic toolkit of the Mexican axolotl, a classic model organism, has matured to the point where it is now possible to identify genes for mutant phenotypes. We used a positional cloning-candidate gene approach to identify molecular bases for two historic axolotl pigment phenotypes: white and albino. White (d/d) mutants have defects in pigment cell morphogenesis and differentiation, whereas albino (a/a) mutants lack melanin. We identified in white mutants a transcriptional defect in endothelin 3 (edn3), encoding a peptide factor that promotes pigment cell migration and differentiation in other vertebrates. Transgenic restoration of Edn3 expression rescued the homozygous white mutant phenotype. We mapped the albino locus to tyrosinase (tyr) and identified polymorphisms shared between the albino allele (tyr a ) and tyr alleles in a Minnesota population of tiger salamanders from which the albino trait was introgressed. tyr a has a 142 bp deletion and similar engineered alleles recapitulated the albino phenotype. Finally, we show that historical introgression of tyr a significantly altered genomic composition of the laboratory axolotl, yielding a distinct, hybrid strain of ambystomatid salamander. Our results demonstrate the feasibility of identifying genes for traits in the laboratory Mexican axolotl.

Food safety evaluation of crops produced through genetic engineering--how to reduce unintended effects?

Science.gov (United States)

Jelenić, Srećko

2005-06-01

Scientists started applying genetic engineering techniques to improve crops two decades ago; about 70 varieties obtained via genetic engineering have been approved to date. Although genetic engineering offers the most precise and controllable genetic modification of crops in entire history of plant improvement, the site of insertion of a desirable gene cannot be predicted during the application of this technology. As a consequence, unintended effects might occur due to activation or silencing of genes, giving rise to allergic reactions or toxicity. Therefore, extensive chemical, biochemical and nutritional analyses are performed on each new genetically engineered variety. Since the unintended effects may be predictable on the basis of what is known about the insertion place of the transgenic DNA, an important aim of plant biotechnology is to define techniques for the insertion of transgene into the predetermined chromosomal position (gene targeting). Although gene targeting cannot be applied routinely in crop plants, given the recent advances, that goal may be reached in the near future.

A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

Science.gov (United States)

Kobayashi, Takahisa; Simon, Donald L.

2001-01-01

In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

Isolation, characterization, and genetic complementation of a cellular mutant resistant to retroviral infection

Science.gov (United States)

Agarwal, Sumit; Harada, Josephine; Schreifels, Jeffrey; Lech, Patrycja; Nikolai, Bryan; Yamaguchi, Tomoyuki; Chanda, Sumit K.; Somia, Nikunj V.

2006-01-01

By using a genetic screen, we have isolated a mammalian cell line that is resistant to infection by retroviruses that are derived from the murine leukemia virus, human immunodeficiency virus type 1, and feline immunodeficiency virus. We demonstrate that the cell line is genetically recessive for the resistance, and hence it is lacking a factor enabling infection by retroviruses. The block to infection is early in the life cycle, at the poorly understood uncoating stage. We implicate the proteasome at uncoating by completely rescuing the resistant phenotype with the proteasomal inhibitor MG-132. We further report on the complementation cloning of a gene (MRI, modulator of retrovirus infection) that can also act to reverse the inhibition of infection in the mutant cell line. These data implicate a role for the proteasome during uncoating, and they suggest that MRI is a regulator of this activity. Finally, we reconcile our findings and other published data to suggest a model for the involvement of the proteasome in the early phase of the retroviral life cycle. PMID:17043244

Genetically engineered tissue to screen for glycan function in tissue formation

DEFF Research Database (Denmark)

M., Adamopoulou; E.M., Pallesen; A., Levann

2017-01-01

engineered GlycoSkin tissue models can be used to study biological interactions involving glycan structure on lipids, or glycosaminoglycans. This engineering approach will allow us to investigate the functions of glycans in homeostasis and elucidate the role of glycans in normal epithelial formation....... We use genetic engineering with CRISPR/Cas9 combined with 3D organotypic skin models to examine how distinct glycans influence epithelial formation. We have performed knockout and knockin of more than 100 select genes in the genome of human immortalized human keratinocytes, enabling a systematic...... analysis of the impact of specific glycans in the formation and transformation of the human skin. The genetic engineered human skin models (GlycoSkin) was designed with and without all major biosynthetic pathways in mammalian glycan biosynthesis, including GalNAc-O-glycans, O-fucosylation, O...

A genetic screen in Myxococcus xanthus identifies mutants that uncouple outer membrane exchange from a downstream cellular response.

Science.gov (United States)

Dey, Arup; Wall, Daniel

2014-12-01

Upon physical contact with sibling cells, myxobacteria transiently fuse their outer membranes (OMs) and exchange OM proteins and lipids. From previous work, TraA and TraB were identified to be essential factors for OM exchange (OME) in donor and recipient cells. To define the genetic complexity of OME, we carried out a comprehensive forward genetic screen. The screen was based on the observation that Myxococcus xanthus nonmotile cells, by a Tra-dependent mechanism, block swarm expansion of motile cells when mixed. Thus, mutants defective in OME or a downstream responsive pathway were readily identified as escape flares from mixed inocula seeded on agar. This screen was surprisingly powerful, as we found >50 mutants defective in OME. Importantly, all of the mutations mapped to the traAB operon, suggesting that there may be few, if any, proteins besides TraA and TraB directly required for OME. We also found a second and phenotypically different class of mutants that exhibited wild-type OME but were defective in a responsive pathway. This pathway is postulated to control inner membrane homeostasis by covalently attaching amino acids to phospholipids. The identified proteins are homologous to the Staphylococcus aureus MprF protein, which is involved in membrane adaptation and antibiotic resistance. Interestingly, we also found that a small number of nonmotile cells were sufficient to block the swarming behavior of a large gliding-proficient population. This result suggests that an OME-derived signal could be amplified from a few nonmotile producers to act on many responder cells. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine.

Science.gov (United States)

Nowakowski, Adam; Walczak, Piotr; Janowski, Miroslaw; Lukomska, Barbara

2015-10-01

Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

Genetic engineering: a matter that requires further refinement in Spanish secondary school textbooks

Science.gov (United States)

Martínez-Gracia, M. V.; Gil-Quýlez, M. J.

2003-09-01

Genetic engineering is now an integral part of many high school textbooks but little work has been done to assess whether it is being properly addressed. A checklist with 19 items was used to analyze how genetic engineering is presented in biology textbooks commonly used in Spanish high schools, including the content, its relationship with fundamental genetic principles, and how it aims to improve the genetic literacy of students. The results show that genetic engineering was normally introduced without a clear reference to the universal genetic code, protein expression or the genetic material shared by all species. In most cases it was poorly defined, without a clear explanation of all the relevant processes involved. Some procedures (such as vectors) were explained in detail without considering previous student knowledge or skills. Some books emphasized applications such as the human genome project without describing DNA sequencing. All books included possible repercussions, but in most cases only fashionable topics such as human cloning. There was an excess of information that was not always well founded and hence was unsuitable to provide a meaningful understanding of DNA technology required for citizens in the twenty-first century.

Role of plant biotechnology and genetic engineering in crop-improvement, with special emphases on cotton: A review

International Nuclear Information System (INIS)

Akhtar, L.H.; Siddiq, S.Z.; Tariq, A.H.; Arshad, M.; Gorham, J.

2003-01-01

Plant biotechnology and genetic engineering offer novel approaches to plant-breeding, production, propagation and preservation of germplasm. In this manuscript, the population and food-requirements of Pakistan, role of biotechnology and genetic engineering in crop-improvement, along with potential uses in cotton, have been discussed. The latest position of plant biotechnology and genetic engineering in Pakistan and the advantages of biotechnology and genetic-engineering techniques over conventional plant-breeding techniques, along with critical views of various scientists have been reviewed. (author)

Possible Health Hazards from Genetically Engineered Crops ...

African Journals Online (AJOL)

The paradox of Genetic Engineering of crops is evident from the unending revolution in the seeding and growth of new multibillion naira industries while it also poses the greatest hazards to life on the planet Earth. Recombination DNA technology is used to insert, delete, transpose and substitute new genes in plants that ...

Regulation of Saccharomyces cerevisiae genetic engineering on the production of acetate esters and higher alcohols during Chinese Baijiu fermentation.

Science.gov (United States)

Li, Wei; Wang, Jian-Hui; Zhang, Cui-Ying; Ma, Hong-Xia; Xiao, Dong-Guang

2017-06-01

Acetate esters and higher alcohols greatly influence the quality and flavor profiles of Chinese Baijiu (Chinese liquor). Various mutants have been constructed to investigate the interactions of ATF1 overexpression, IAH1 deletion, and BAT2 deletion on the production of acetate esters and higher alcohols. The results showed that the overexpression of ATF1 under the control of the PGK1 promoter with BAT2 and IAH1 double-gene deletion led to a higher production of acetate esters and a lower production of higher alcohols than the overexpression of ATF1 with IAH1 deletion or overexpression of ATF1 with BAT2 deletion. Moreover, deletion of IAH1 in ATF1 overexpression strains effectively increased the production of isobutyl acetate and isoamyl acetate by reducing the hydrolysis of acetate esters. The decline in the production of higher alcohol by the ATF1 overexpression strains with BAT2 deletion is due to the interaction of ATF1 overexpression and BAT2 deletion. Mutants with varying abilities of producing acetate esters and higher alcohols were developed by genetic engineering. These strains have great potential for industrial application.

In Vivo Differences in the Virulence, Pathogenicity, and Induced Protective Immunity of wboA Mutants from Genetically Different Parent Brucella spp.

Science.gov (United States)

Wang, Zhen; Niu, Jianrui; Wang, Shuangshan

2013-01-01

To explore the effects of the genetic background on the characteristics of wboA gene deletion rough mutants generated from different parent Brucella sp. strains, we constructed the rough-mutant strains Brucella melitensis 16 M-MB6, B. abortus 2308-SB6, B. abortus S19-RB6, and B. melitensis NI-NB6 and evaluated their survival, pathogenicity, and induced protective immunity in mice and sheep. In mice, the survival times of the four mutants were very different in the virulence assay, from less than 6 weeks for B. abortus S19-RB6 to 11 weeks for B. abortus 2308-SB6 and B. melitensis NI-NB6. However, B. abortus S19-RB6 and B. melitensis 16 M-MB6, with a shorter survival time in mice, offered better protection against challenges with B. abortus 2308 in protection tests than B. abortus 2308-SB6 and B. melitensis NI-NB6. It seems that the induced protective immunity of each mutant might not be associated with its survival time in vivo. In the cross-protection assay, both B. melitensis 16 M-MB6 and B. abortus S19-RB6 induced greater protection against homologous challenges than heterologous challenges. When pregnant sheep were inoculated with B. abortus S19-RB6 and B. melitensis 16 M-MB6, B. abortus S19-RB6 did not induce abortion, whereas B. melitensis 16 M-MB6 did. These results demonstrated the differences in virulence, pathogenicity, and protective immunity in vivo in the wboA deletion mutants from genetically different parent Brucella spp. and also indicated that future rough vaccine strain development could be promising if suitable parent Brucella strains and/or genes were selected. PMID:23239800

Genetic engineering: frost damage trial halted.

Science.gov (United States)

Budiansky, S

The University of California at Berkeley has announced the postponement of a planned experiment involving the field testing of bacteria genetically engineered to reduce frost damage to crops. The action came after Jeremy Rifkin, who had earlier filed suit against the National Institutes of Health after its Recombinant DNA Advisory Committee had approved the experiment, threatened to seek a temporary restraining order against the university to halt the experiment.

Endoplasmic Reticulum-Targeted Subunit Toxins Provide a New Approach to Rescue Misfolded Mutant Proteins and Revert Cell Models of Genetic Diseases.

Directory of Open Access Journals (Sweden)

Humaira Adnan

Full Text Available Many germ line diseases stem from a relatively minor disturbance in mutant protein endoplasmic reticulum (ER 3D assembly. Chaperones are recruited which, on failure to correct folding, sort the mutant for retrotranslocation and cytosolic proteasomal degradation (ER-associated degradation-ERAD, to initiate/exacerbate deficiency-disease symptoms. Several bacterial (and plant subunit toxins, retrograde transport to the ER after initial cell surface receptor binding/internalization. The A subunit has evolved to mimic a misfolded protein and hijack the ERAD membrane translocon (dislocon, to effect cytosolic access and cytopathology. We show such toxins compete for ERAD to rescue endogenous misfolded proteins. Cholera toxin or verotoxin (Shiga toxin containing genetically inactivated (± an N-terminal polyleucine tail A subunit can, within 2-4 hrs, temporarily increase F508delCFTR protein, the major cystic fibrosis (CF mutant (5-10x, F508delCFTR Golgi maturation (<10x, cell surface expression (20x and chloride transport (2x in F508del CFTR transfected cells and patient-derived F508delCFTR bronchiolar epithelia, without apparent cytopathology. These toxoids also increase glucocerobrosidase (GCC in N370SGCC Gaucher Disease fibroblasts (3x, another ERAD-exacerbated misfiling disease. We identify a new, potentially benign approach to the treatment of certain genetic protein misfolding diseases.

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)

Characterization of a bacteriophage T4 mutant lacking DNA-dependent ATPase

International Nuclear Information System (INIS)

Behme, M.T.; Ebisuzaki, K.

1975-01-01

A DNA-dependent ATPase has previously been purified from bacteriophage T4-infected Escherichia coli. A mutant phage strain lacking this enzyme has been isolated and characterized. Although the mutant strain produced no detectable DNA-dependent ATPase, growth properties were not affected. Burst sizes were similar for the mutant phage and T4D in polAl, recB, recC, uvrA, uvrB, uvrC, and various DNA-negative E. coli. UV sensitivity and genetic recombination were normal in a variety of E. coli hosts. Mapping data indicate that the genetic locus controlling the mutant occurs near gene 56. The nonessential nature of this gene is discussed

Genetic Engineering: A Matter that Requires Further Refinement in Spanish Secondary School Textbooks

Science.gov (United States)

Martinez-Gracia, M. V.; Gil-Quylez, M. J.; Osada, J.

2003-01-01

Genetic engineering is now an integral part of many high school textbooks but little work has been done to assess whether it is being properly addressed. A checklist with 19 items was used to analyze how genetic engineering is presented in biology textbooks commonly used in Spanish high schools, including the content, its relationship with…

Agrobacterium: nature's genetic engineer.

Science.gov (United States)

Nester, Eugene W

2014-01-01

Agrobacterium was identified as the agent causing the plant tumor, crown gall over 100 years ago. Since then, studies have resulted in many surprising observations. Armin Braun demonstrated that Agrobacterium infected cells had unusual nutritional properties, and that the bacterium was necessary to start the infection but not for continued tumor development. He developed the concept of a tumor inducing principle (TIP), the factor that actually caused the disease. Thirty years later the TIP was shown to be a piece of a tumor inducing (Ti) plasmid excised by an endonuclease. In the next 20 years, most of the key features of the disease were described. The single-strand DNA (T-DNA) with the endonuclease attached is transferred through a type IV secretion system into the host cell where it is likely coated and protected from nucleases by a bacterial secreted protein to form the T-complex. A nuclear localization signal in the endonuclease guides the transferred strand (T-strand), into the nucleus where it is integrated randomly into the host chromosome. Other secreted proteins likely aid in uncoating the T-complex. The T-DNA encodes enzymes of auxin, cytokinin, and opine synthesis, the latter a food source for Agrobacterium. The genes associated with T-strand formation and transfer (vir) map to the Ti plasmid and are only expressed when the bacteria are in close association with a plant. Plant signals are recognized by a two-component regulatory system which activates vir genes. Chromosomal genes with pleiotropic functions also play important roles in plant transformation. The data now explain Braun's old observations and also explain why Agrobacterium is nature's genetic engineer. Any DNA inserted between the border sequences which define the T-DNA will be transferred and integrated into host cells. Thus, Agrobacterium has become the major vector in plant genetic engineering.

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)

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

OpenAIRE

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2010-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

76 FR 8707 - Syngenta Seeds, Inc.; Determination of Nonregulated Status for Corn Genetically Engineered To...

Science.gov (United States)

2011-02-15

... Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There... genetic engineering that are plant pests or that there is reason to believe are plant pests. Such...

The experimental study of genetic engineering human neural stem cells mediated by lentivirus to express multigene.

Science.gov (United States)

Cai, Pei-qiang; Tang, Xun; Lin, Yue-qiu; Martin, Oudega; Sun, Guang-yun; Xu, Lin; Yang, Yun-kang; Zhou, Tian-hua

2006-02-01

To explore the feasibility to construct genetic engineering human neural stem cells (hNSCs) mediated by lentivirus to express multigene in order to provide a graft source for further studies of spinal cord injury (SCI). Human neural stem cells from the brain cortex of human abortus were isolated and cultured, then gene was modified by lentivirus to express both green fluorescence protein (GFP) and rat neurotrophin-3 (NT-3); the transgenic expression was detected by the methods of fluorescence microscope, dorsal root ganglion of fetal rats and slot blot. Genetic engineering hNSCs were successfully constructed. All of the genetic engineering hNSCs which expressed bright green fluorescence were observed under the fluorescence microscope. The conditioned medium of transgenic hNSCs could induce neurite flourishing outgrowth from dorsal root ganglion (DRG). The genetic engineering hNSCs expressed high level NT-3 which could be detected by using slot blot. Genetic engineering hNSCs mediated by lentivirus can be constructed to express multigene successfully.

Isolation of New Gravitropic Mutants under Hypergravity Conditions.

Science.gov (United States)

Mori, Akiko; Toyota, Masatsugu; Shimada, Masayoshi; Mekata, Mika; Kurata, Tetsuya; Tasaka, Masao; Morita, Miyo T

2016-01-01

Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using next-generation sequencing (NGS) and single nucleotide polymorphism (SNP)-based markers. Using the endodermal-amyloplast less 1 ( eal1 ) mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g) restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene ( enhancer of eal1 ) mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis .

From Precaution to Peril: Public Relations Across Forty Years of Genetic Engineering.

Science.gov (United States)

Hogan, Andrew J

2016-12-01

The Asilomar conference on genetic engineering in 1975 has long been pointed to by scientists as a model for internal regulation and public engagement. In 2015, the organizers of the International Summit on Human Gene Editing in Washington, DC looked to Asilomar as they sought to address the implications of the new CRISPR gene editing technique. Like at Asilomar, the conveners chose to limit the discussion to a narrow set of potential CRISPR applications, involving inheritable human genome editing. The adoption by scientists in 2015 of an Asilomar-like script for discussing genetic engineering offers historians the opportunity to analyze the adjustments that have been made since 1975, and to identify the blind spots that remain in public engagement. Scientists did take important lessons from the fallout of their limited engagement with public concerns at Asilomar. Nonetheless, the scientific community has continued to overlook some of the longstanding public concerns about genetic engineering, in particular the broad and often covert genetic modification of food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

76 FR 78232 - Monsanto Co.; Determination of Nonregulated Status for Soybean Genetically Engineered To Have a...

Science.gov (United States)

2011-12-16

... peer review of safety tests, and health effects of genetically modified organisms and glyphosate. APHIS...] Monsanto Co.; Determination of Nonregulated Status for Soybean Genetically Engineered To Have a Modified... that there is reason to believe are plant pests. Such genetically engineered organisms and products are...

Effect of uv-irradiation on genetic recombination of Simian virus 40 mutants

International Nuclear Information System (INIS)

Gentil, A.; Margot, A.; Sarasin, A.

1983-01-01

Genetic recombination in monkey kidney cells has been studied using Simian virus 40 (SV40) as a molecular probe. Control or uv-irradiated cells have been co-infected with two thermosensitive mutants of SV40, tsA58 and tsA30. Recombination between the two viral genomes gives rise to a wild type virus phenotype, able to grow at the restrictive temperature of 41 0 C, which was taken as a measure of the recombination activity of the host cells. Results show that recombination takes place at a low frequency when viruses are not uv-irradiated. Irradiation of one or both viruses increases drastically recombination frequency. Pretreatment of the host cells with uv-light or mitomycin C 24 hours before being infected does not increase recombination frequency measured in our experimental conditions. 23 references, 5 tables

U.S. Adults with Agricultural Experience Report More Genetic Engineering Familiarity than Those Without

Science.gov (United States)

Stofer, Kathryn A.; Schiebel, Tracee M.

2017-01-01

Researchers and pollsters still debate the acceptance of genetic engineering technology among U.S. adults, and continue to assess their knowledge as part of this research. While decision-making may not rely entirely on knowledge, querying opinions and perceptions rely on public understanding of genetic engineering terms. Experience with…

Intrinsic Value and the Genetic Engineering of Animals.

NARCIS (Netherlands)

Vries, R.B.M. de

2008-01-01

The concept of intrinsic value is often invoked to articulate objections to the genetic engineering of animals, particularly those objections that are not directed at the negative effects the technique might have on the health and welfare of the modified animals. However, this concept was not

University Students' Knowledge and Attitude about Genetic Engineering

Science.gov (United States)

Bal, Senol; Samanci, Nilay Keskin; Bozkurt, Orçun

2007-01-01

Genetic engineering and biotechnology made possible of gene transfer without discriminating microorganism, plant, animal or human. However, although these scientific techniques have benefits, they cause arguments because of their ethical and social impacts. The arguments about ethical ad social impacts of biotechnology made clear that not only…

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

Genetic engineering with T cell receptors.

Science.gov (United States)

Zhang, Ling; Morgan, Richard A

2012-06-01

In the past two decades, human gene transfer research has been translated from a laboratory technology to clinical evaluation. The success of adoptive transfer of tumor-reactive lymphocytes to treat the patients with metastatic melanoma has led to new strategies to redirect normal T cells to recognize tumor antigens by genetic engineering with tumor antigen-specific T cell receptor (TCR) genes. This new strategy can generate large numbers of defined antigen-specific cells for therapeutic application. Much progress has been made to TCR gene transfer systems by optimizing gene expression and gene transfer protocols. Vector and protein modifications have enabled excellent expression of introduced TCR chains in human lymphocytes with reduced mis-pairing between the introduced and endogenous TCR chains. Initial clinical studies have demonstrated that TCR gene-engineered T cells could mediate tumor regression in vivo. In this review, we discuss the progress and prospects of TCR gene-engineered T cells as a therapeutic strategy for treating patients with melanoma and other cancers. Published by Elsevier B.V.

Genetic cytological and biochemical study of a tomato chlorophyll mutant of the xanthic type, obtained by irradiation of the seeds; Etude genetique, cytologique et biochimique d'un mutant chlorophyllien de tomate du type xantha, obtenu par irradiation de graines

Energy Technology Data Exchange (ETDEWEB)

Lefort, M; Duranton, J; Galmiche, J M; Roux, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Irradiation of Lycopersicum aesculantum seeds with increasing doses of X-rays and thermal neutrons leads to the appearance of chlorophyll mutations in the descendants of the irradiated seeds. A genetic study of one of these mutants of the xanthic type showed that it was a recessive mutant with typical mono-genetic separation, while the cytological study demonstrated that the differentiation of the plast stopped at the stage of elementary lamella. Finally it is shown that in the light, the mutation brings about a very large deviation of the carbon metabolism towards the synthesis of amino acids and proteins, at the expense of that of glucosides. (author) [French] L'irradiation de graines de Lycopersicum Aesculantum avec des doses croissantes de rayons X et de neutrons thermiques entraine l'apparition de mutations chlorophylliennes dans la descendance des graines irradiees. L'etude genetique d'un de ces mutants du type xantha a montre qu'il s'agissait d'un mutant recessif a disjonction monogenique typique, tandis que l'etude cytologique a revele que la differentiation du plaste s'arretait au stade de lamelles elementaires. Il est apparu enfin qu'a la lumiere la mutation entrainait une deviation tres importante du metabolisme du carbone vers la synthese des acides amines et des proteines, au detriment de celle des glucides. (auteur)

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.)

History and future of genetically engineered food animal regulation: an open request.

Science.gov (United States)

Wells, Kevin D

2016-06-01

Modern biotechnology resulted from of a series of incremental improvements in the understanding of DNA and the enzymes that nature evolved to manipulate it. As the potential impact of genetic engineering became apparent, scientists began the process of trying to identify the potential unintended consequences. Restrictions to recombinant DNA experimentation were at first self-imposed. Collaborative efforts between scientists and lawyers formalized an initial set of guidelines. These guidelines have been used to promulgate regulations around world. However, the initial guidelines were only intended as a starting point and were motivated by a specific set of concerns. As new data became available, the guidelines and regulations should have been adapted to the new knowledge. Instead, other social drivers drove the development of regulations. For most species and most applications, the framework that was established has slowly allowed some products to reach the market. However, genetically engineered livestock that are intended for food have been left in a regulatory state of limbo. To date, no genetically engineered food animal is available in the marketplace. A short history and a U.S.-based genetic engineer's perspective are presented. In addition, a request to regulatory agencies is presented for consideration as regulation continues to evolve. Regulators appear to have shown preference for the slow, random progression of evolution over the efficiency of intentional design.

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

International Nuclear Information System (INIS)

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

Perception of risks and benefits of in vitro fertilization, genetic engineering and biotechnology.

Science.gov (United States)

Macer, D R

1994-01-01

The use of new biotechnology in medicine has become an everyday experience, but many people still express concern about biotechnology. Concerns are evoked particularly by the phrases genetic engineering and in vitro fertilization (IVF), and these concerns persist despite more than a decade of their use in medicine. Mailed nationwide opinion surveys on attitudes to biotechnology were conducted in Japan, among samples of the public (N = 551), high school biology teachers (N = 228), scientists (N = 555) and nurses (N = 301). People do see more benefits coming from science than harm when balanced against the risks. There were especially mixed perceptions of benefit and risk about IVF and genetic engineering, and a relatively high degree of worry compared to other developments of science and technology. A discussion of assisted reproductive technologies and surrogacy in Japan is also made. The opinions of people in Japan were compared to the results of previous surveys conducted in Japan, and international surveys conducted in Australia, China, Europe, New Zealand, U.K. and U.S.A. Japanese have a very high awareness of biotechnology, 97% saying that they had heard of the word. They also have a high level of awareness of IVF and genetic engineering. Genetic engineering was said to be a worthwhile research area for Japan by 76%, while 58% perceived research on IVF as being worthwhile, however 61% were worried about research on IVF or genetic engineering. Japanese expressed more concern about IVF and genetic engineering than New Zealanders. The major reason cited for rejection of genetic manipulation research in Japan and New Zealand was that it was seen as interfering with nature, playing God or as unethical. The emotions concerning these technologies are complex, and we should avoid using simplistic public opinion data as measures of public perceptions. The level of concern expressed by scientists and teachers in Japan suggest that public education "technology promotion

Genetics of blue-green algae

International Nuclear Information System (INIS)

Ladha, J.K.; Kumar, H.D.

1978-01-01

Mutagenesis and genetics of cyanophyceae are reviewed. Mutant isolation, ultraviolet inactivation, reactivation and production of mutants resistant or sensitive to ultraviolet light, control of gene expression, genetic transfer and mapping are discussed. (UK)

Evaluation of terrestrial microcosms for assessing the fate and effects of genetically engineered microorganisms on ecological processes

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, J.K.; Bentjen, S.A.; Bolton, H. Jr.; Li, S.W.; Ligotke, M.W.; McFadden, K.M.; Van Voris, P.

1989-04-01

This project evaluates and modifies the existing US Environmental Protection Agency's Office of Pesticides and Toxic Substances (EPA/OPTS) terrestrial microcosm test system and test protocols such that they can be used to determine the environmental fate and ecological hazards of genetically engineered microorganisms (GEMs). The intact soil-core microcosm represents terrestrial ecosystems, and when coupled with appropriate test protocols, such microcosms may be appropriate to define and limit risks associated with the intentional release of GEMs. The terrestrial microcosm test system was used to investigate the survival and transport of two model GEMs (Azospirillum lipoferum and Pseudomonas sp. Tn5 mutants) to various trophic levels and niches and through intact soil cores. Subsequent effects on nutrient cycling and displacement of indigenous microorganisms were evaluated. The model organisms were a diazotrophic root-colonizing bacterium (A. lipoferum) and a wheat root growth-inhibiting rhizobacterium (Pseudomonas sp.). The transposable element Tn5 was used as a genetic marker for both microorganisms in two separate experiments. The organisms were subjected to transposon mutagenesis using a broad host-range-mobilizable suicide plasmid. The transposon Tn5 conferred levels of kanamycin resistance up to 500 ..mu..g/ml (Pseudomonas sp.), which allowed for selection of the bacteria from environmental samples. The presence of Tn5 DNA in the genome of the model GEMs also allowed the use of Tn5 gene probes to confirm and enumerate the microorganisms in different samples from the microcosms. Two types of root growth-inhibiting Pseudomonas sp. Tn5 mutants were obtained and used in microcosm studies: those that lacked the ability to inhibit either wheat root growth or the growth of other microorganisms in vitro (tox/sup /minus//) and those which retained these properties (tox/sup +/). 53 refs., 7 figs., 6 tabs.

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

Genetic Engineering and Human Mental Ecology: Interlocking Effects and Educational Considerations

OpenAIRE

Affifi, Ramsey

2017-01-01

This paper describes some likely semiotic consequences of genetic engineering on what Gregory Bateson has called ?the mental ecology? (1979) of future humans, consequences that are less often raised in discussions surrounding the safety of GMOs (genetically modified organisms). The effects are as follows: an increased 1) habituation to the presence of GMOs in the environment, 2) normalization of empirically false assumptions grounding genetic reductionism, 3) acceptance that humans are capabl...

Whole-Genome Sequencing of Sordaria macrospora Mutants Identifies Developmental Genes.

Science.gov (United States)

Nowrousian, Minou; Teichert, Ines; Masloff, Sandra; Kück, Ulrich

2012-02-01

The study of mutants to elucidate gene functions has a long and successful history; however, to discover causative mutations in mutants that were generated by random mutagenesis often takes years of laboratory work and requires previously generated genetic and/or physical markers, or resources like DNA libraries for complementation. Here, we present an alternative method to identify defective genes in developmental mutants of the filamentous fungus Sordaria macrospora through Illumina/Solexa whole-genome sequencing. We sequenced pooled DNA from progeny of crosses of three mutants and the wild type and were able to pinpoint the causative mutations in the mutant strains through bioinformatics analysis. One mutant is a spore color mutant, and the mutated gene encodes a melanin biosynthesis enzyme. The causative mutation is a G to A change in the first base of an intron, leading to a splice defect. The second mutant carries an allelic mutation in the pro41 gene encoding a protein essential for sexual development. In the mutant, we detected a complex pattern of deletion/rearrangements at the pro41 locus. In the third mutant, a point mutation in the stop codon of a transcription factor-encoding gene leads to the production of immature fruiting bodies. For all mutants, transformation with a wild type-copy of the affected gene restored the wild-type phenotype. Our data demonstrate that whole-genome sequencing of mutant strains is a rapid method to identify developmental genes in an organism that can be genetically crossed and where a reference genome sequence is available, even without prior mapping information.

Genetic heterogeneity of retinitis pigmentosa

OpenAIRE

Hartono, Hartono

2015-01-01

Genetic heterogeneity is a phenomenon in which a genetic disease can be transmitted by several modes of inheritance. The understanding of genetic heterogeneity is important in giving genetic counselling.The presence of genetic heterogeneity can be explained by the existence of:1.different mutant alleles at a single locus, and2.mutant alleles at different loci affecting the same enzyme or protein, or affecting different enzymes or proteins.To have an overall understanding of genetic heterogene...

PT-Flax (phenotyping and TILLinG of flax): development of a flax (Linum usitatissimum L.) mutant population and TILLinG platform for forward and reverse genetics.

Science.gov (United States)

Chantreau, Maxime; Grec, Sébastien; Gutierrez, Laurent; Dalmais, Marion; Pineau, Christophe; Demailly, Hervé; Paysant-Leroux, Christine; Tavernier, Reynald; Trouvé, Jean-Paul; Chatterjee, Manash; Guillot, Xavier; Brunaud, Véronique; Chabbert, Brigitte; van Wuytswinkel, Olivier; Bendahmane, Abdelhafid; Thomasset, Brigitte; Hawkins, Simon

2013-10-15

Flax (Linum usitatissimum L.) is an economically important fiber and oil crop that has been grown for thousands of years. The genome has been recently sequenced and transcriptomics are providing information on candidate genes potentially related to agronomically-important traits. In order to accelerate functional characterization of these genes we have generated a flax EMS mutant population that can be used as a TILLinG (Targeting Induced Local Lesions in Genomes) platform for forward and reverse genetics. A population of 4,894 M2 mutant seed families was generated using 3 different EMS concentrations (0.3%, 0.6% and 0.75%) and used to produce M2 plants for subsequent phenotyping and DNA extraction. 10,839 viable M2 plants (4,033 families) were obtained and 1,552 families (38.5%) showed a visual developmental phenotype (stem size and diameter, plant architecture, flower-related). The majority of these families showed more than one phenotype. Mutant phenotype data are organised in a database and can be accessed and searched at UTILLdb (http://urgv.evry.inra.fr/UTILLdb). Preliminary screens were also performed for atypical fiber and seed phenotypes. Genomic DNA was extracted from 3,515 M2 families and eight-fold pooled for subsequent mutant detection by ENDO1 nuclease mis-match cleavage. In order to validate the collection for reverse genetics, DNA pools were screened for two genes coding enzymes of the lignin biosynthesis pathway: Coumarate-3-Hydroxylase (C3H) and Cinnamyl Alcohol Dehydrogenase (CAD). We identified 79 and 76 mutations in the C3H and CAD genes, respectively. The average mutation rate was calculated as 1/41 Kb giving rise to approximately 9,000 mutations per genome. Thirty-five out of the 52 flax cad mutant families containing missense or codon stop mutations showed the typical orange-brown xylem phenotype observed in CAD down-regulated/mutant plants in other species. We have developed a flax mutant population that can be used as an efficient

The Effect of Case Teaching on Meaningful and Retentive Learning When Studying Genetic Engineering

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Güccük, Ahmet; Köksal, Mustafa Serdar

2017-01-01

The purpose of this study is to investigate the effects of case teaching on how students learn about genetic engineering, in terms of meaningful learning and retention of learning. The study was designed as quasi-experimental research including 63 8th graders (28 boys and 35 girls). To collect data, genetic engineering achievement tests were…

Agronomic performance of old soybean variety 'Altona' derived mutants

International Nuclear Information System (INIS)

Hodosne, K.G.; Heszky, L.E.

2001-01-01

An induced mutation program has been initiated at the Department of Genetics and Plant Breeding to develop early maturing cultivars with good yielding capacity. Some new mutants have been produced by irradiation of variety Altona with 60 Co gamma rays. Ten years of breeding resulted in two new mutant varieties named 'Noventa' and 'Gate 511'. The present study deals with agronomic performance of these mutants. Registered soybean varieties Altona and 'McCall' as well as Altona derived mutants (Gate 511 and Noventa) have been compared

Isolation of new gravitropic mutants under hypergravity conditions

Directory of Open Access Journals (Sweden)

Akiko Mori

2016-09-01

Full Text Available Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upwards. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes. In the present study, we report a new screening system using hypergravity conditions to isolate enhancers of gravitropism mutants, and we also describe a rapid and efficient genome mapping method, using Next-Generation Sequencing (NGS and Single Nucleotide Polymorphism (SNP-based markers. Using the endodermal-amyloplast less 1 (eal1 mutant, which exhibits defective development of endodermal cells and gravitropism, we found that hypergravity (10 g restored the reduced gravity responsiveness in eal1 hypocotyls and could, therefore, be used to obtain mutants with further reduction in gravitropism in the eal1 background. Using the new screening system, we successfully isolated six ene (enhancer of eal1 mutants that exhibited little or no gravitropism under hypergravity conditions, and using NGS and map-based cloning with SNP markers, we narrowed down the potential causative genes, which revealed a new genetic network for shoot gravitropism in Arabidopsis.

Ethanol production using engineered mutant E. coli

Science.gov (United States)

Ingram, Lonnie O.; Clark, David P.

1991-01-01

The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

Directory of Open Access Journals (Sweden)

Petersen Pia Damm

2012-11-01

Full Text Available Abstract Background Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production. Results Xylan is the major non-cellulosic polysaccharide in secondary cell walls, and the xylan deficient irregular xylem (irx mutants irx7, irx8 and irx9 exhibit severe dwarf growth phenotypes. The main reason for the growth phenotype appears to be xylem vessel collapse and the resulting impaired transport of water and nutrients. We developed a xylan-engineering approach to reintroduce xylan biosynthesis specifically into the xylem vessels in the Arabidopsis irx7, irx8 and irx9 mutant backgrounds by driving the expression of the respective glycosyltransferases with the vessel-specific promoters of the VND6 and VND7 transcription factor genes. The growth phenotype, stem breaking strength, and irx morphology was recovered to varying degrees. Some of the plants even exhibited increased stem strength compared to the wild type. We obtained Arabidopsis plants with up to 23% reduction in xylose levels and 18% reduction in lignin content compared to wild-type plants, while exhibiting wild-type growth patterns and morphology, as well as normal xylem vessels. These plants showed a 42% increase in saccharification yield after hot water pretreatment. The VND7 promoter yielded a more complete complementation of the irx phenotype than the VND6 promoter. Conclusions Spatial and temporal deposition of xylan in the secondary cell wall of

76 FR 80869 - Monsanto Co.; Determination of Nonregulated Status of Corn Genetically Engineered for Drought...

Science.gov (United States)

2011-12-27

... and products altered or produced through genetic engineering that are plant pests or that there is... in 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among other...

Synthetic alienation of microbial organisms by using genetic code engineering: Why and how?

Science.gov (United States)

Kubyshkin, Vladimir; Budisa, Nediljko

2017-08-01

The main goal of synthetic biology (SB) is the creation of biodiversity applicable for biotechnological needs, while xenobiology (XB) aims to expand the framework of natural chemistries with the non-natural building blocks in living cells to accomplish artificial biodiversity. Protein and proteome engineering, which overcome limitation of the canonical amino acid repertoire of 20 (+2) prescribed by the genetic code by using non-canonic amino acids (ncAAs), is one of the main focuses of XB research. Ideally, estranging the genetic code from its current form via systematic introduction of ncAAs should enable the development of bio-containment mechanisms in synthetic cells potentially endowing them with a "genetic firewall" i.e. orthogonality which prevents genetic information transfer to natural systems. Despite rapid progress over the past two decades, it is not yet possible to completely alienate an organism that would use and maintain different genetic code associations permanently. In order to engineer robust bio-contained life forms, the chemical logic behind the amino acid repertoire establishment should be considered. Starting from recent proposal of Hartman and Smith about the genetic code establishment in the RNA world, here the authors mapped possible biotechnological invasion points for engineering of bio-contained synthetic cells equipped with non-canonical functionalities. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 63278 - Bayer CropScience LP; Determination of Nonregulated Status for Cotton Genetically Engineered for...

Science.gov (United States)

2011-10-12

... part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering... regulations governing the introduction of certain genetically engineered organisms. Our determination is based... things, the introduction (importation, interstate movement, or release into the environment) of organisms...

76 FR 63279 - Monsanto Co.; Determination of Nonregulated Status for Soybean Genetically Engineered for Insect...

Science.gov (United States)

2011-10-12

... and products altered or produced through genetic engineering that are plant pests or that there is... regulations in 7 CFR part 340, ``Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,'' regulate, among other...

Genetic engineering of microorganisms for biodiesel production

Science.gov (United States)

Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

2013-01-01

Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples. PMID:23222170

An Engineered Split Intein for Photoactivated Protein Trans-Splicing.

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Stanley Wong

Full Text Available Protein splicing is mediated by inteins that auto-catalytically join two separated protein fragments with a peptide bond. Here we engineered a genetically encoded synthetic photoactivatable intein (named LOVInC, by using the light-sensitive LOV2 domain from Avena sativa as a switch to modulate the splicing activity of the split DnaE intein from Nostoc punctiforme. Periodic blue light illumination of LOVInC induced protein splicing activity in mammalian cells. To demonstrate the broad applicability of LOVInC, synthetic protein systems were engineered for the light-induced reassembly of several target proteins such as fluorescent protein markers, a dominant positive mutant of RhoA, caspase-7, and the genetically encoded Ca2+ indicator GCaMP2. Spatial precision of LOVInC was demonstrated by targeting activity to specific mammalian cells. Thus, LOVInC can serve as a general platform for engineering light-based control for modulating the activity of many different proteins.

MODEST: a web-based design tool for oligonucleotide-mediated genome engineering and recombineering

DEFF Research Database (Denmark)

Bonde, Mads; Klausen, Michael Schantz; Anderson, Mads Valdemar

2014-01-01

Recombineering and multiplex automated genome engineering (MAGE) offer the possibility to rapidly modify multiple genomic or plasmid sites at high efficiencies. This enables efficient creation of genetic variants including both single mutants with specifically targeted modifications as well......, which confers the corresponding genetic change, is performed manually. To address these challenges, we have developed the MAGE Oligo Design Tool (MODEST). This web-based tool allows designing of MAGE oligos for (i) tuning translation rates by modifying the ribosomal binding site, (ii) generating...

Genetic engineering of syringyl-enriched lignin in plants

Science.gov (United States)

Chiang, Vincent Lee; Li, Laigeng

2004-11-02

The present invention relates to a novel DNA sequence, which encodes a previously unidentified lignin biosynthetic pathway enzyme, sinapyl alcohol dehydrogenase (SAD) that regulates the biosynthesis of syringyl lignin in plants. Also provided are methods for incorporating this novel SAD gene sequence or substantially similar sequences into a plant genome for genetic engineering of syringyl-enriched lignin in plants.

Non-Genetic Engineering Approaches for Isolating and Generating Novel Yeasts for Industrial Applications

Science.gov (United States)

Chambers, P. J.; Bellon, J. R.; Schmidt, S. A.; Varela, C.; Pretorius, I. S.

Generating novel yeast strains for industrial applications should be quite straightforward; after all, research into the genetics, biochemistry and physiology of Baker's Yeast, Saccharomyces cerevisiae, has paved the way for many advances in the modern biological sciences. We probably know more about this humble eukaryote than any other, and it is the most tractable of organisms for manipulation using modern genetic engineering approaches. In many countries, however, there are restrictions on the use of genetically-modified organisms (GMOs), particularly in foods and beverages, and the level of consumer acceptance of GMOs is, at best, variable. Thus, many researchers working with industrial yeasts use genetic engineering techniques primarily as research tools, and strain development continues to rely on non-GM technologies. This chapter explores the non-GM tools and strategies available to such researchers.

Gender and Health Impacts of Genetically Engineered Crops in ...

International Development Research Centre (IDRC) Digital Library (Canada)

Gender and Health Impacts of Genetically Engineered Crops in Developing Countries ... exists, the gender and health impacts have so far received only cursory attention. ... New funding opportunity for gender equality and climate change ... social inequality, promote greater gender parity, and empower women and girls.

Engineering of Helicobacter pylori L-asparaginase: characterization of two functionally distinct groups of mutants.

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Maristella Maggi

Full Text Available Bacterial L-asparaginases have been used as anti-cancer drugs for over 4 decades though presenting, along with their therapeutic efficacy, several side effects due to their bacterial origin and, seemingly, to their secondary glutaminase activity. Helicobacter pylori type II L-asparaginase possesses interesting features, among which a reduced catalytic efficiency for L-GLN, compared to the drugs presently used in therapy. In the present study, we describe some enzyme variants with catalytic and in vitro cytotoxic activities different from the wild type enzyme. Particularly, replacements on catalytic threonines (T16D and T95E deplete the enzyme of both its catalytic activities, once more underlining the essential role of such residues. One serendipitous mutant, M121C/T169M, had a preserved efficiency vs L-asparagine but was completely unable to carry out L-glutamine hydrolysis. Interestingly, this variant did not exert any cytotoxic effect on HL-60 cells. The M121C and T169M single mutants had reduced catalytic activities (nearly 2.5- to 4-fold vs wild type enzyme, respectively. Mutant Q63E, endowed with a similar catalytic efficiency versus asparagine and halved glutaminase efficiency with respect to the wild type enzyme, was able to exert a cytotoxic effect comparable to, or higher than, the one of the wild type enzyme when similar asparaginase units were used. These findings may be relevant to determine the role of glutaminase activity of L-asparaginase in the anti-proliferative effect of the drug and to shed light on how to engineer the best asparaginase/glutaminase combination for an ever improved, patients-tailored therapy.

Induction and selection of mutants from in vitro cultured plant cells

Energy Technology Data Exchange (ETDEWEB)

Lee, Yung Il; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-07-01

Mutant cell lines are useful for biochemical, physiological and genetical material for marker in various genetic manipulation experiments and for the direct use in crop plant improvement. Mutant selection may lead to the production of plants showing resistance or tolerance to specific environmental stress, such as solinity, drought, toxed metals, herbicides, pathogens and low temperature. In this review, these included the production of the somatic variation, the selection process itself and stability of the selected characters in cell culture and regenerated plant. Which would seem to be useful for improving plants and securring genetic resources. 45 refs. (Author).

Induction and selection of mutants from in vitro cultured plant cells

International Nuclear Information System (INIS)

Lee, Yung Il; Kim, Jae Sung; Shin, In Chul; Lee, Sang Jae

1994-07-01

Mutant cell lines are useful for biochemical, physiological and genetical material for marker in various genetic manipulation experiments and for the direct use in crop plant improvement. Mutant selection may lead to the production of plants showing resistance or tolerance to specific environmental stress, such as solinity, drought, toxed metals, herbicides, pathogens and low temperature. In this review, these included the production of the somatic variation, the selection process itself and stability of the selected characters in cell culture and regenerated plant. Which would seem to be useful for improving plants and securring genetic resources. 45 refs. (Author)

Mutant genes in pea breeding

International Nuclear Information System (INIS)

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

Agrobacterium: nature’s genetic engineer

Science.gov (United States)

Nester, Eugene W.

2015-01-01

Agrobacterium was identified as the agent causing the plant tumor, crown gall over 100 years ago. Since then, studies have resulted in many surprising observations. Armin Braun demonstrated that Agrobacterium infected cells had unusual nutritional properties, and that the bacterium was necessary to start the infection but not for continued tumor development. He developed the concept of a tumor inducing principle (TIP), the factor that actually caused the disease. Thirty years later the TIP was shown to be a piece of a tumor inducing (Ti) plasmid excised by an endonuclease. In the next 20 years, most of the key features of the disease were described. The single-strand DNA (T-DNA) with the endonuclease attached is transferred through a type IV secretion system into the host cell where it is likely coated and protected from nucleases by a bacterial secreted protein to form the T-complex. A nuclear localization signal in the endonuclease guides the transferred strand (T-strand), into the nucleus where it is integrated randomly into the host chromosome. Other secreted proteins likely aid in uncoating the T-complex. The T-DNA encodes enzymes of auxin, cytokinin, and opine synthesis, the latter a food source for Agrobacterium. The genes associated with T-strand formation and transfer (vir) map to the Ti plasmid and are only expressed when the bacteria are in close association with a plant. Plant signals are recognized by a two-component regulatory system which activates vir genes. Chromosomal genes with pleiotropic functions also play important roles in plant transformation. The data now explain Braun’s old observations and also explain why Agrobacterium is nature’s genetic engineer. Any DNA inserted between the border sequences which define the T-DNA will be transferred and integrated into host cells. Thus, Agrobacterium has become the major vector in plant genetic engineering. PMID:25610442

Volatile terpenoids: multiple functions, biosynthesis, modulation and manipulation by genetic engineering.

Science.gov (United States)

Abbas, Farhat; Ke, Yanguo; Yu, Rangcai; Yue, Yuechong; Amanullah, Sikandar; Jahangir, Muhammad Muzammil; Fan, Yanping

2017-11-01

Terpenoids play several physiological and ecological functions in plant life through direct and indirect plant defenses and also in human society because of their enormous applications in the pharmaceutical, food and cosmetics industries. Through the aid of genetic engineering its role can by magnified to broad spectrum by improving genetic ability of crop plants, enhancing the aroma quality of fruits and flowers and the production of pharmaceutical terpenoids contents in medicinal plants. Terpenoids are structurally diverse and the most abundant plant secondary metabolites, playing an important role in plant life through direct and indirect plant defenses, by attracting pollinators and through different interactions between the plants and their environment. Terpenoids are also significant because of their enormous applications in the pharmaceutical, food and cosmetics industries. Due to their broad distribution and functional versatility, efforts are being made to decode the biosynthetic pathways and comprehend the regulatory mechanisms of terpenoids. This review summarizes the recent advances in biosynthetic pathways, including the spatiotemporal, transcriptional and post-transcriptional regulatory mechanisms. Moreover, we discuss the multiple functions of the terpene synthase genes (TPS), their interaction with the surrounding environment and the use of genetic engineering for terpenoid production in model plants. Here, we also provide an overview of the significance of terpenoid metabolic engineering in crop protection, plant reproduction and plant metabolic engineering approaches for pharmaceutical terpenoids production and future scenarios in agriculture, which call for sustainable production platforms by improving different plant traits.

Durable resistance to net blotch and agronomic performance in some barley mutants [Hordeum vulgare L.; Syria

International Nuclear Information System (INIS)

Arabi, M.I.E.

2004-01-01

Seeds from the net blotch (Pyrenophora teres) susceptible cultivar Thibaut were treated by gamma ray radiation and subsequently evaluated for reaction to the pathogen in the M2-M5 generations. Grain yield and agronomic characteristics of putative mutants were compared with Thibaut in two different locations. Genetic variation among some mutant lines/cv Thibaut was estimated using Amplified Fragment Length Polymorphism (AFLP) markers. Sixteen mutant lines and their mother cultivar Thibaut were analyzed with 14 EcoR1-Mse1 primer combinations. A total number of 504 AFLP bands were analyzed for each pair mutant/Thibaut. Narrow genetic variation among all genotypes was detected with an average of genetic similarity of 0.96. Cluster analysis with the entire AFLP data divided all genotypes into two major groups. The resistant mutant lines were grouped in one subcluster with 0.98 similarity index. Some resistant mutant lines to net blotch with good agronomic performances were produced [it

Spectrum of mutant characters utilized in developing improved cultivars

International Nuclear Information System (INIS)

Donini, B.; Kawai, T.; Micke, A.

1984-01-01

Although about 500 cultivars are known to have been developed by using induced mutations, the range of mutant traits seems to be rather narrow. Mutant traits have mostly been used that can be detected visually on an individual plant basis. However, in the background of such mutants other valuable mutations have been found in later generations. In cross-breeding with mutants valuable characteristics occurred, which could not be predicted from the phenotypes of the parents. It is concluded that improved attributes in the released mutant varieties do not comprise the entire genetic variation that could derive from mutagenesis. Current selection techniques are inadequate to exploit the full potential of mutagenesis for plant breeding. (author)

Engineering Escherichia coli for improved ethanol production from gluconate.

Science.gov (United States)

Hildebrand, Amanda; Schlacta, Theresa; Warmack, Rebeccah; Kasuga, Takao; Fan, Zhiliang

2013-10-10

We report on engineering Escherichia coli to produce ethanol at high yield from gluconic acid (gluconate). Knocking out genes encoding for the competing pathways (l-lactate dehydrogenase and pyruvate formate lyase A) in E. coli KO11 eliminated lactate production, lowered the carbon flow toward acetate production, and improved the ethanol yield from 87.5% to 97.5% of the theoretical maximum, while the growth rate of the mutant strain was about 70% of the wild type. The corresponding genetic modifications led to a small improvement of ethanol yield from 101.5% to 106.0% on glucose. Deletion of the pyruvate dehydrogenase gene (pdh) alone improved the ethanol yield from 87.5% to 90.4% when gluconate was a substrate. The growth rate of the mutant strain was identical to that of the wild type. The corresponding genetic modification led to no improvements on ethanol yield on glucose. Copyright © 2013 Elsevier B.V. All rights reserved.

Sodium azide mutagenesis in wheat: Mutants with golden glumes

International Nuclear Information System (INIS)

Siddiqui, K.A.; Jafri, K.A.; Arain, M.A.

1989-01-01

In bread wheat, Triticum aestivum L. (2n=6x=42, AABBDD), detection of induced mutations is hampered by the presence of duplicate and triplicate genes. Induced changes in spike characteristics are known, but mutants with changed glume colour do not seem to have been reported. Physical mutagens such as gamma rays, thermal neutrons and fast neutrons, and chemical mutagens like EMS, El, dES and NEH have been extensively used for induction of mutations in bread wheat but it seems as if these mutagens did not induce mutants with changed glume colour. We used sodium azide for inducing mutations in the widely adapted cultivar 'Sonalika', which is characterized by brown glume colour. Presoaked seeds were treated with 0.2M sodium azide for 3 hours. Three spikes were harvested from each M 1 plant. M 2 generation was space-planted as spike progeny. We were successful in identifying 3 mutants with golden glumes. The mutants resemble 'Sonalika' in other spike characteristics. The mutants glume colour was confirmed in M 3 . The mutants were also evaluated for agronomically important characteristics. Some characters were significantly different from the parent. Glume colours may be useful as genetic markers since such characters are less influenced by the environment. Our investigation confirms that also agronomically useful genetic variation may be readily induced in bread wheat through sodium azide

Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

DEFF Research Database (Denmark)

Petersen, Pia; Lau, Jane; Ebert, Berit

2012-01-01

Background: Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross......-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production...... in the xylem vessels is sufficient to complement the irx phenotype of xylan deficient mutants, while maintaining low overall amounts of xylan and lignin in the cell wall. This engineering approach has the potential to yield bioenergy crop plants that are more easily deconstructed and fermented into biofuels....

A Simple Interactive Introduction to Teaching Genetic Engineering

Science.gov (United States)

Child, Paula

2013-01-01

In the UK, at key stage 4, students aged 14-15 studying GCSE Core Science or Unit 1 of the GCSE Biology course are required to be able to describe the process of genetic engineering to produce bacteria that can produce insulin. The simple interactive introduction described in this article allows students to consider the problem, devise a model and…

Introduction to the application of genetic algorithms in engineering

Directory of Open Access Journals (Sweden)

I. S. Shaw

1998-07-01

Full Text Available Genetic algorithms constitute a new research area in the field of artificial intelligence. This work is aimed at their application in specific areas of engineering where good results have already been achieved. The purpose of this work is to provide a basic introduction for students as well as experienced engineers who wish to upgrade their knowledge. A distinctive feature of artificial intelligence is that instead of mathematical models, either direct human experience or certain functions of the human brain for the modelling of physical phenomena are used.

Genetic Engineering--A Lesson on Bioethics for the Classroom.

Science.gov (United States)

Armstrong, Kerri; Weber, Kurt

1991-01-01

A unit designed to cover the topic of genetic engineering and its ethical considerations is presented. Students are expected to learn the material while using a debate format. A list of objectives for the unit, the debate format, and the results from an opinion questionnaire are described. (KR)

Engineering allostery.

Science.gov (United States)

Raman, Srivatsan; Taylor, Noah; Genuth, Naomi; Fields, Stanley; Church, George M

2014-12-01

Allosteric proteins have great potential in synthetic biology, but our limited understanding of the molecular underpinnings of allostery has hindered the development of designer molecules, including transcription factors with new DNA-binding or ligand-binding specificities that respond appropriately to inducers. Such allosteric proteins could function as novel switches in complex circuits, metabolite sensors, or as orthogonal regulators for independent, inducible control of multiple genes. Advances in DNA synthesis and next-generation sequencing technologies have enabled the assessment of millions of mutants in a single experiment, providing new opportunities to study allostery. Using the classic LacI protein as an example, we describe a genetic selection system using a bidirectional reporter to capture mutants in both allosteric states, allowing the positions most crucial for allostery to be identified. This approach is not limited to bacterial transcription factors, and could reveal new mechanistic insights and facilitate engineering of other major classes of allosteric proteins such as nuclear receptors, two-component systems, G protein-coupled receptors, and protein kinases. Copyright © 2014 Elsevier Ltd. All rights reserved.

A FIELD STUDY WITH GENETICALLY ENGINEERED ALFALFA INOCULATED WITH RECOMBINANT SINORHIZOBIUM MELILOTI: EFFECTS ON THE SOIL ECOSYSTEM

Science.gov (United States)

The agricultural use of genetically engineered plants and microorganisms has become increasingly common. Because genetically engineered plants and microorganisms can produce compounds foreign to their environment, there is concern that they may become established outside of thei...

Genetic variation for germination and physiological traits in sunflower mutants induced by gamma rays [Helianthus annuus L.

International Nuclear Information System (INIS)

Alejo-Jaimes, A.; Jardinaud, M.F.; Maury, P.; Alibert, G.; Gentzbittel, L.; Sarrafi, A.; Grieu, P.; Petiprez, M.

2004-01-01

Seeds of sunflower line AS-613 were irradiated with gamma rays and 1,559 M4 progenies were studied for their germination characteristics and the following traits were studied: thousand seed weight, seed size, time before emergence, percentage of emerged seedlings, hypocotyl length and diameter, number of cotyledons and cotyledons pigmentation intensity. A high genetic variability was observed for all the studied traits. Through M4 progenies, 9 mutants presenting the most differences with the original genotype (AS-613) were planted in a randomized blocks design with 8 replications in a controlled greenhouse and some morphological and physiological traits were studied, which are: plant height, number of leaves, total leaf area, net photosynthesis, transpiration, stomatal conductance, water use efficiency and net carbon assimilation. When harvesting, flower head diameter, head weight, stem weight, leaves weight, total number of seeds per plant and thousand seed weight were measured. The differences between mutants and also non irradiated genotype (AS-613) were significant for most of studied traits suggesting that several developmental processes have been modified [it

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)

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)

Genetic and metabolic engineering in diatoms.

Science.gov (United States)

Huang, Weichao; Daboussi, Fayza

2017-09-05

Diatoms have attracted considerable attention due to their success in diverse environmental conditions, which probably is a consequence of their complex origins. Studies of their metabolism will provide insight into their adaptation capacity and are a prerequisite for metabolic engineering. Several years of investigation have led to the development of the genome engineering tools required for such studies, and a profusion of appropriate tools is now available for exploring and exploiting the metabolism of these organisms. Diatoms are highly prized in industrial biotechnology, due to both their richness in natural lipids and carotenoids and their ability to produce recombinant proteins, of considerable value in diverse markets. This review provides an overview of recent advances in genetic engineering methods for diatoms, from the development of gene expression cassettes and gene delivery methods, to cutting-edge genome-editing technologies. It also highlights the contributions of these rapid developments to both basic and applied research: they have improved our understanding of key physiological processes; and they have made it possible to modify the natural metabolism to favour the production of specific compounds or to produce new compounds for green chemistry and pharmaceutical applications.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'. © 2017 The Author(s).

The Plant Genetic Engineering Laboratory For Desert Adaptation

Science.gov (United States)

Kemp, John D.; Phillips, Gregory C.

1985-11-01

The Plant Genetic Engineering Laboratory for Desert Adaptation (PGEL) is one of five Centers of Technical Excellence established as a part of the state of New Mexico's Rio Grande Research Corridor (RGRC). The scientific mission of PGEL is to bring innovative advances in plant biotechnology to bear on agricultural productivity in arid and semi-arid regions. Research activities focus on molecular and cellular genetics technology development in model systems, but also include stress physiology investigations and development of desert plant resources. PGEL interacts with the Los Alamos National Laboratory (LANL), a national laboratory participating in the RGRC. PGEL also has an economic development mission, which is being pursued through technology transfer activities to private companies and public agencies.

EU member states' voting for authorizing genetically engineered crops

NARCIS (Netherlands)

Smart, Richard D.; Blum, Matthias; Wesseler, Justus

2015-01-01

Several authors suggest a gridlock of the European Union's (EU's) approval process for genetically engineered (GE) crops. We analyse the voting behaviour of EU Member States (MSs) for voting results from 2003 to 2015 on the approval of GE crops to test for a gridlock; no reliable data are

Chapter VIII. Contributions of propagation techniques and genetic modification to breeding - genetic engineering for disease resistance

Science.gov (United States)

Genetic engineering offers an opportunity to develop flower bulb crops with resistance to fungal, viral, and bacterial pathogens. Several of the flower bulb crops, Lilium spp., Gladiolus, Zantedeschia, Muscari, Hyacinthus, Narcissus, Ornithogalum, Iris, and Alstroemeria, have been transformed with t...

Perspectives for genetic engineering for the phytoremediation of arsenic-contaminated environments: from imagination to reality?

Science.gov (United States)

Zhu, Yong-Guan; Rosen, Barry P

2009-04-01

Phytoremediation to clean up arsenic-contaminated environments has been widely hailed as environmentally friendly and cost effective, and genetic engineering is believed to improve the efficiency and versatility of phytoremediation. Successful genetic engineering requires the thorough understanding of the mechanisms involved in arsenic tolerance and accumulation by natural plant species. Key mechanisms include arsenate reduction, arsenic sequestration in vacuoles of root or shoot, arsenic loading to the xylem, and volatilization through the leaves. Key advances include the identification of arsenic (As) translocation from root to shoot in the As hyperaccumulator, Pteris vittata, and the characterization of related key genes from hyperaccumulator and nonaccumulators. In this paper we have proposed three pathways for genetic engineering: arsenic sequestration in the root, hyperaccumulation of arsenic in aboveground tissues, and phytovolatilization.

Accumulation of infectious mutants in stocks during the propagation of fiber-modified recombinant adenoviruses

International Nuclear Information System (INIS)

Ugai, Hideyo; Inabe, Kumiko; Yamasaki, Takahito; Murata, Takehide; Obata, Yuichi; Hamada, Hirofumi; Yokoyama, Kazunari K.

2005-01-01

In infected cells, replication errors during viral proliferation generate mutations in adenoviruses (Ads), and the mutant Ads proliferate and evolve in the intracellular environment. Genetically fiber-modified recombinant Ads (rAd variants) were generated, by modification of the fiber gene, for therapeutic applications in host cells that lack or express reduced levels of the Coxsackievirus and adenovirus receptor. To assess the genetic modifications of rAd variants that might induce the instability of Ad virions, we examined the frequencies of mutants that accumulated in propagated stocks. Seven of 41 lines of Ad variants generated mutants in the stocks and all mutants were infectious. Moreover, all the mutations occurred in the modified region that had been added at the 3' end of the fiber gene. Our results show that some genetic modifications at the carboxyl terminus of Ad fiber protein lead to the instability of Ad virions

A field release of genetically engineered gypsy moth (Lymantria dispar L.) Nuclear Polyhedrosis Virus (LdNPV)

Science.gov (United States)

Vincent D' Amico; Joseph S. Elkinton; John D. Podgwaite; James M. Slavicek; Michael L. McManus; John P. Burand

1999-01-01

The gypsy moth (Lymantria dispar L.) nuclear polyhedrosis virus was genetically engineered for nonpersistence by removal of the gene coding for polyhedrin production and stabilized using a coocclusion process. A β-galactosidase marker gene was inserted into the genetically engineered virus (LdGEV) so that infected larvae could be tested for...

Genetic characterization of glossy-leafed mutant broccoli lines

Science.gov (United States)

Glossy mutants of Brassica oleracea L. have reduced or altered epicuticular wax on the surface of their leaves as compared to wild-type plants, conveying a shiny green appearance. Mutations conferring glossiness are common and have been found in most B. oleracea crop varieties, including cauliflower...

Comparing Artificial Intelligence and Genetic Engineering: Commercialization Lessons

OpenAIRE

Dickson, Edward M.

1984-01-01

Artificial Intelligence is rapidly leaving its academic home and moving into the marketplace. There are few precedents for an arcane academic subject becoming commercialized so rapidly. But, genetic engineering, which recently burst forth from academia to become the foundation for the hot new biotechnology industry, provides useful insights into the rites of passage awaiting the commercialization of artificial intelligence. This article examines the structural similarities and dissimilarities...

Mutation induction and evaluation of high yield rice mutants

International Nuclear Information System (INIS)

Abdul Rahim Harun; Sobri Husein; Rusli Ibrahim

2006-01-01

The successful use of plant breeding for improving crops requires the existence of genetic variation of useful traits. Unfortunately, the desired variation is often lacking. However, radiation has been used to induce mutations and thereby generate genetic variation from which desired mutants may be selected. Mutation induction has become a proven way of creating variation within a crop variety. It offers the possibility of inducing desired attributes that either cannot be expressed in nature or have been lost during evolution. Rice is security food crop in Malaysia. Efforts were undertaken to enhance rice yield from 4.0 tones per hectare in 1995 to 5.5 tones per hectare in 2010. Proper management and good varieties are two factors that require for enhancing yield of rice. In this research, purified seeds of MR211 and MR219 were gamma irradiated at 100 to 400 Gray and sown for planting as M1 generation at MARDI experimental plot. The M2 population was sown in bulk with population size around 15,000 to 20,000 plants. Individual plant selection was carried out at maturity and each selected plant became a mutant line of M3 generation. Agronomic trial of M3 mutants lines were conducted in Mardi, Tanjung Karang, Selangor. About 115 of selected mutant lines were evaluated. Each row of those mutant lines were planted in two rows at planting distance of 25cm within and between rows. These mutant lines were visually observed and data were recorded in each of every mutant line. (Author)

Current status of genetic engineering in cotton (Gossypium hirsutum L): an assessment.

Science.gov (United States)

Chakravarthy, Vajhala S K; Reddy, Tummala Papi; Reddy, Vudem Dashavantha; Rao, Khareedu Venkateswara

2014-06-01

Cotton is considered as the foremost commercially important fiber crop and is deemed as the backbone of the textile industry. The productivity of cotton crop, worldwide, is severely hampered by the occurrence of pests, weeds, pathogens apart from various environmental factors. Several beneficial agronomic traits, viz., early maturity, improved fiber quality, heat tolerance, etc. have been successfully incorporated into cotton varieties employing conventional hybridization and mutation breeding. Crop losses, due to biotic factors, are substantial and may be reduced through certain crop protection strategies. In recent years, pioneering success has been achieved through the adoption of modern biotechnological approaches. Genetically engineered cotton varieties, expressing Bacillus thuringiensis cry genes, proved to be highly successful in controlling the bollworm complex. Various other candidate genes responsible for resistance to insect pests and pathogens, tolerance to major abiotic stress factors such as temperature, drought and salinity, have been introduced into cotton via genetic engineering methods to enhance the agronomic performance of cotton cultivars. Furthermore, genes for improving the seed oil quality and fiber characteristics have been identified and introduced into cotton cultivars. This review provides a brief overview of the various advancements made in cotton through genetic engineering approaches.

The effect of genetically engineered glucagon on glucose recovery after hypoglycaemia in man

DEFF Research Database (Denmark)

Hvidberg, A; Jørgensen, S; Hilsted, J

1992-01-01

To compare the effect on glucose recovery after insulin-induced hypoglycaemia of intramuscular genetically engineered glucagon, intramuscular glucagon from pancreatic extraction and intravenous glucose, we examined 10 healthy subjects during blockage of glucose counterregulation with somatostatin...... appearance rate were far more protracted after i.m. glucagon than after i.v. glucose. These results suggest that genetically engineered glucagon and glucagon from pancreatic extraction have a similar effect on hepatic glucose production rate. Due to the protracted effect of intramuscular glucagon, a combined......, propranolol and phentolamine. Each subject was studied on three separate occasions. Thirty min after a bolus injection of 0.075 iu soluble insulin per kilogram body weight the subjects received one of the following treatments: 1 mg glucagon from pancreatic extraction intramuscularly; 1 mg genetically...

Production of amino acids - Genetic and metabolic engineering approaches.

Science.gov (United States)

Lee, Jin-Ho; Wendisch, Volker F

2017-12-01

The biotechnological production of amino acids occurs at the million-ton scale and annually about 6milliontons of l-glutamate and l-lysine are produced by Escherichia coli and Corynebacterium glutamicum strains. l-glutamate and l-lysine production from starch hydrolysates and molasses is very efficient and access to alternative carbon sources and new products has been enabled by metabolic engineering. This review focusses on genetic and metabolic engineering of amino acid producing strains. In particular, rational approaches involving modulation of transcriptional regulators, regulons, and attenuators will be discussed. To address current limitations of metabolic engineering, this article gives insights on recent systems metabolic engineering approaches based on functional tools and method such as genome reduction, amino acid sensors based on transcriptional regulators and riboswitches, CRISPR interference, small regulatory RNAs, DNA scaffolding, and optogenetic control, and discusses future prospects. Copyright © 2017 Elsevier Ltd. All rights reserved.

The ethics of using genetic engineering for sex selection.

Science.gov (United States)

Liao, S Matthew

2005-02-01

It is quite likely that parents will soon be able to use genetic engineering to select the sex of their child by directly manipulating the sex of an embryo. Some might think that this method would be a more ethical method of sex selection than present technologies such as preimplantation genetic diagnosis (PGD) because, unlike PGD, it does not need to create and destroy "wrong gendered" embryos. This paper argues that those who object to present technologies on the grounds that the embryo is a person are unlikely to be persuaded by this proposal, though for different reasons.

Yield of two mutant lines of soybean for human consumption;Rendimiento de dos lineas mutantes de soya para consumo humano

Energy Technology Data Exchange (ETDEWEB)

Salmeron E, J.; Mastache L, A. A.; Diaz V, G. E.; Valencia E, F.; Ranfla C, R.; Melendez P, M. [Colegio Superior Agropecuario del Estado de Guerrero, Vicente Guerrero No. 81, Col. Centro, 40000 Iguala, Guerrero (Mexico); Cervantes S, T. [Instituto de Recursos Geneticos y Productividad, Colegio de Postgraduados, Carretera Mexico-Texcoco Km. 36.5, Montecillo, 56230 Texcoco, Estado de Mexico (Mexico); De la Cruz T, E.; Garcia A, J. M.; Falcon B, T., E-mail: csaegro@prodigy.net.m [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

2009-07-01

The present work has the objective of to evaluate the yield and the agronomic behavior of 2 mutant lines of soybean for human consumption, obtained by means of a process of recurrent irradiation of soybean seed ISAAEG-BM{sub 2} with gammas of Co{sup 60} and selection in the generation R{sub 4}M{sub 18}. For the variable yield significant statistical differences were not observed, but considering the rest of the evaluated agronomic characteristics the mutant lines L{sub 6} and Bombona they were excellent with values of 3,934.6 and 3,806.8 Kg ha-{sup 1} to 15% of grain humidity, they also possess excellent genetic characteristics result of the irradiations and selections of these new genetic materials. (Author)

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

Metabolic engineering of a diazotrophic bacterium improves ammonium release and biofertilization of plants and microalgae.

Science.gov (United States)

Ambrosio, Rafael; Ortiz-Marquez, Juan Cesar Federico; Curatti, Leonardo

2017-03-01

The biological nitrogen fixation carried out by some Bacteria and Archaea is one of the most attractive alternatives to synthetic nitrogen fertilizers. However, with the exception of the symbiotic rhizobia-legumes system, progress towards a more extensive realization of this goal has been slow. In this study we manipulated the endogenous regulation of both nitrogen fixation and assimilation in the aerobic bacterium Azotobacter vinelandii. Substituting an exogenously inducible promoter for the native promoter of glutamine synthetase produced conditional lethal mutant strains unable to grow diazotrophically in the absence of the inducer. This mutant phenotype could be reverted in a double mutant strain bearing a deletion in the nifL gene that resulted in constitutive expression of nif genes and increased production of ammonium. Under GS non-inducing conditions both the single and the double mutant strains consistently released very high levels of ammonium (>20mM) into the growth medium. The double mutant strain grew and excreted high levels of ammonium under a wider range of concentrations of the inducer than the single mutant strain. Induced mutant cells could be loaded with glutamine synthetase at different levels, which resulted in different patterns of extracellular ammonium accumulation afterwards. Inoculation of the engineered bacteria into a microalgal culture in the absence of sources of C and N other than N 2 and CO 2 from the air, resulted in a strong proliferation of microalgae that was suppressed upon addition of the inducer. Both single and double mutant strains also promoted growth of cucumber plants in the absence of added N-fertilizer, while this property was only marginal in the parental strain. This study provides a simple synthetic genetic circuit that might inspire engineering of optimized inoculants that efficiently channel N 2 from the air into crops. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All

Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster.

Science.gov (United States)

Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

2015-01-01

The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated in

Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3 Mutants in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Imilce A Rodriguez-Fernandez

Full Text Available The Adaptor Protein (AP-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with

Perspectives for genetic engineering for the phytoremediation of arsenic-contaminated environments: from imagination to reality?

OpenAIRE

Zhu, Yong-Guan; Rosen, Barry P

2009-01-01

Phytoremediation to clean up arsenic-contaminated environments has been widely hailed as environmentally friendly and cost effective, and genetic engineering is believed to improve the efficiency and versatility of phytoremediation. Successful genetic engineering requires the thorough understanding of the mechanisms involved in arsenic tolerance and accumulation by natural plant species. Key mechanisms include arsenate reduction, arsenic sequestration in vacuoles of root or shoot, arsenic loa...

Isolation of glutathione-deficient mutants of the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Kistler, M.; Eckardt, F.; Summer, K.-H.

1986-01-01

Glutathione-deficient (gsh - ) mutants of the yeast Saccharomyces cerevisiae were isolated after UV treatment using MNNG as selective agent. For genetic and biochemical characterization 5 mutant strains were chosen which exhibited considerably decreased residual GSH contents varying from 2 to 6% of the wild-type levels. All 5 isolates showed a 2:2 segregation of the gsh - :GSH + phenotypes alluding to a monogenic recessive mutation. Complementation analysis indicates that all gsh - mutants belong to one complementation group. (Auth.)

The Discussions around Precision Genetic Engineering: Role of and Impact on Disabled People

Directory of Open Access Journals (Sweden)

Gregor Wolbring

2016-09-01

Full Text Available Genetic researchers are advancing in their abilities to extract precise genetic information from biological and human entities bringing genetic research steps closer to accurately modifying genes of biological entities, including that of humans. In this analytical essay, we focus on the discussions about precision genetic intervention that have taken place since March 2015 as they pertain to disabled people. We focus on two areas; one being the role of disabled people in the recent gene editing discussions and the second being the utility of existing legal instruments. Within our first focus we address the following questions: (a What is the visibility of disabled people in the gene-editing discussions that have taken place since March 2015? (b What has been the impact of those discussions on disabled people? (c Were social problems which disabled people face taken into account in those discussions; (d How does the reality of engagement with disabled people in these discussions fit with science, technology and innovation governance discourses that ask for more stakeholder, bottom up and anticipatory involvement? Within our second focus we address the following questions: (a What is the utility of the United Nations Convention on the Right of Persons with Disabilities (UNCRPD; and (b What is the utility of existing legal instruments covering genetic interventions: for preventing negative social consequences of genetic engineering developments for disabled people. We argue that (a the genetic engineering debates since March 2015 have portrayed disabled people dominantly through a medical lens; (b that the governance of science, technology and innovation of genetic engineering including anticipatory governance and responsible innovation discourses has not yet engaged with the social impact of gene editing on disabled people; (c that few scholars that focus on the social situation of disabled people are visible in the governance discussions of gene

Phage Genetic Engineering Using CRISPR–Cas Systems

Directory of Open Access Journals (Sweden)

Asma Hatoum-Aslan

2018-06-01

Full Text Available Since their discovery over a decade ago, the class of prokaryotic immune systems known as CRISPR–Cas have afforded a suite of genetic tools that have revolutionized research in model organisms spanning all domains of life. CRISPR-mediated tools have also emerged for the natural targets of CRISPR–Cas immunity, the viruses that specifically infect bacteria, or phages. Despite their status as the most abundant biological entities on the planet, the majority of phage genes have unassigned functions. This reality underscores the need for robust genetic tools to study them. Recent reports have demonstrated that CRISPR–Cas systems, specifically the three major types (I, II, and III, can be harnessed to genetically engineer phages that infect diverse hosts. Here, the mechanisms of each of these systems, specific strategies used, and phage editing efficacies will be reviewed. Due to the relatively wide distribution of CRISPR–Cas systems across bacteria and archaea, it is anticipated that these immune systems will provide generally applicable tools that will advance the mechanistic understanding of prokaryotic viruses and accelerate the development of novel technologies based on these ubiquitous organisms.

Improvements of methanogenesis by genetic techniques

International Nuclear Information System (INIS)

Baresi, L.

1985-01-01

The objective of this research is to characterize the genetic system of one or two strains of methanogenic bacteria. Both ultraviolet exposure and chemical screening will be used to isolate mutant species. These species will be tested for genetic recombination. Bacteriophages and plasmids will be sought. Two species, Methanococcus voltae and Methanobacterium thermoautotrophicum, will be subjected to extensive screening and manipulation. Nutritional mutants of these two strains will be studied to determine uptake rates. Once a set of satisfactory mutants is obtained, two types of genetic recombination experiments (conjugation and DNA transformation) will be carried out

Evaluation of some garlic (Allium Sativum L.) mutants resistant to white rot disease by RAPD analysis

International Nuclear Information System (INIS)

Nabulsi, I.; Al-Safadi, B.; Mir ali, N.; Arabi, M.I.E.

2002-01-01

Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic diversity among eight garlic mutants resistant to white rot disease (Sclerotium cepivorum) and two controls. Twelve of 13 synthetic random primers were found to identify polymorphism in amplification products. Mutants characterised with moderate resistance to white rot were closely related to the control using cluster and correlation analyses. On the other hand, highly resistant mutants were quite distant from the control with low correlation coefficients. The banding patterns produced by primer OPB-15 (GGAAGGGTGTT) with highly resistant mutants may be used as genetic markers for early selection of resistant plants. (author)

Isolation of new gravitropic mutants under hypergravity conditions

OpenAIRE

Akiko Mori; Masatsugu Toyota; Masatsugu Toyota; Masayoshi Shimada; Mika Mekata; Tetsuya Kurata; Masao Tasaka; Miyo Terao Morita

2016-01-01

Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upwards. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we ...

Reproductive cloning, genetic engineering and the autonomy of the child: the moral agent and the open future.

Science.gov (United States)

Mameli, M

2007-02-01

Some authors have argued that the human use of reproductive cloning and genetic engineering should be prohibited because these biotechnologies would undermine the autonomy of the resulting child. In this paper, two versions of this view are discussed. According to the first version, the autonomy of cloned and genetically engineered people would be undermined because knowledge of the method by which these people have been conceived would make them unable to assume full responsibility for their actions. According to the second version, these biotechnologies would undermine autonomy by violating these people's right to an open future. There is no evidence to show that people conceived through cloning and genetic engineering would inevitably or even in general be unable to assume responsibility for their actions; there is also no evidence for the claim that cloning and genetic engineering would inevitably or even in general rob the child of the possibility to choose from a sufficiently large array of life plans.

Genetic engineering and sustainable production of ornamentals: current status and future directions.

Science.gov (United States)

Lütken, Henrik; Clarke, Jihong Liu; Müller, Renate

2012-07-01

Through the last decades, environmentally and health-friendly production methods and conscientious use of resources have become crucial for reaching the goal of a more sustainable plant production. Protection of the environment requires careful consumption of limited resources and reduction of chemicals applied during production of ornamental plants. Numerous chemicals used in modern plant production have negative impacts on human health and are hazardous to the environment. In Europe, several compounds have lost their approval and further legal restrictions can be expected. This review presents the more recent progress of genetic engineering in ornamental breeding, delivers an overview of the biological background of the used technologies and critically evaluates the usefulness of the strategies to obtain improved ornamental plants. First, genetic engineering is addressed as alternative to growth retardants, comprising recombinant DNA approaches targeting relevant hormone pathways, e.g. the gibberellic acid (GA) pathway. A reduced content of active GAs causes compact growth and can be facilitated by either decreased anabolism, increased catabolism or altered perception. Moreover, compactness can be accomplished by using a natural transformation approach without recombinant DNA technology. Secondly, metabolic engineering approaches targeting elements of the ethylene signal transduction pathway are summarized as a possible alternative to avoid the use of chemical ethylene inhibitors. In conclusion, molecular breeding approaches are dealt with in a way allowing a critical biological assessment and enabling the scientific community and public to put genetic engineering of ornamental plants into a perspective regarding their usefulness in plant breeding.

Genes and Alcohol Consumption: Studies with Mutant Mice

Science.gov (United States)

Mayfield, Jody; Arends, Michael A.; Harris, R. Adron; Blednov, Yuri A.

2017-01-01

In this chapter, we review the effects of global null mutant and overexpressing transgenic mouse lines on voluntary self-administration of alcohol. We examine approximately 200 publications pertaining to the effects of 155 mouse genes on alcohol consumption in different drinking models. The targeted genes vary in function and include neurotransmitter, ion channel, neuroimmune, and neuropeptide signaling systems. The alcohol self-administration models include operant conditioning, two- and four-bottle choice continuous and intermittent access, drinking in the dark limited access, chronic intermittent ethanol, and scheduled high alcohol consumption tests. Comparisons of different drinking models using the same mutant mice are potentially the most informative, and we will highlight those examples. More mutants have been tested for continuous two-bottle choice consumption than any other test; of the 137 mouse genes examined using this model, 97 (72%) altered drinking in at least one sex. Overall, the effects of genetic manipulations on alcohol drinking often depend on the sex of the mice, alcohol concentration and time of access, genetic background, as well as the drinking test. PMID:27055617

Commodifying animals: ethical issues in genetic engineering of animals.

Science.gov (United States)

Almond, B

2000-03-01

The genetic modification of living beings raises special ethical concerns which go beyond general discussion of animal rights or welfare. Although the goals may be similar, biotechnology has accelerated the process of modification of types traditionally carried out by cross-breeding. These changes are discussed in relation to two areas: biomedicine, and animal husbandry. Alternative ethical approaches are reviewed, and it is argued that the teleological thesis underlying virtue ethics has special relevance here. The case for and the case against genetic engineering and patenting of life-forms are examined, and conclusions are drawn which favour regulation, caution and respect for animals and animal species.

Engineering Plant Architecture via CRISPR/Cas9-mediated Alteration of Strigolactone Biosynthesis

KAUST Repository

Butt, Haroon

2018-01-28

Precision plant genome engineering holds much promise for targeted improvement of crop traits via unprecedented single-base level control over the genetic material. Strigolactones (SLs) are a key determinant of plant architecture, known for their role in inhibiting shoot branching (tillering). Here, we used CRISPR/Cas9 in rice (Oryza sativa) for targeted disruption of CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7), which controls a key step in SL biosynthesis. The ccd7 mutants exhibited a striking increase in tillering, combined with a dwarf phenotype, which could be rescued by application of the synthetic SL analog GR24. Striga germination assays and liquid chromatography mass spectrometry analysis showed that root exudates of ccd7 mutants were also SL deficient. Taken together, our results show the power of CRISPR/Cas9 for targeted engineering of plant architecture and for elucidating the molecular underpinnings of architecture-related traits.

Engineering Plant Architecture via CRISPR/Cas9-mediated Alteration of Strigolactone Biosynthesis

KAUST Repository

Butt, Haroon; Jamil, Muhammad; Wang, Jian You; Al-Babili, Salim; Mahfouz, Magdy M.

2018-01-01

Precision plant genome engineering holds much promise for targeted improvement of crop traits via unprecedented single-base level control over the genetic material. Strigolactones (SLs) are a key determinant of plant architecture, known for their role in inhibiting shoot branching (tillering). Here, we used CRISPR/Cas9 in rice (Oryza sativa) for targeted disruption of CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7), which controls a key step in SL biosynthesis. The ccd7 mutants exhibited a striking increase in tillering, combined with a dwarf phenotype, which could be rescued by application of the synthetic SL analog GR24. Striga germination assays and liquid chromatography mass spectrometry analysis showed that root exudates of ccd7 mutants were also SL deficient. Taken together, our results show the power of CRISPR/Cas9 for targeted engineering of plant architecture and for elucidating the molecular underpinnings of architecture-related traits.

Variability, heritability and genetic advance in F2 populations of aromatic rice involving induced mutants and Basmati varieties

International Nuclear Information System (INIS)

Hasib, K.M.; Ganguli, P.K.; Kole, P.C.

2000-01-01

The F 2 generation of five cross-combinations of aromatic rice involving two induced mutants 124-17-4 and 21-6-1 of aromatic tall Indica cultivar Gobindabhog and three basmati varieties was studied for mean performance, variability, heritability and genetic advance. The cross 21-6-1/Pakistan Basmati showed higher mean values for grain yield plant, and several yield components. Wide variability was observed for panicle number plant, filled grains panicle, test weight, dry matter production plant, harvest index and grain yield plant. Among the traits, filled grains panicle and test weight in all the crosses, grain yield plant, in five crosses and harvest index in two crosses had high heritability coupled with high genetic advance indicating predominant role of additive gene action. The crosses 21-6-1/Pakistan Basmati and 124-17-4/Pusa Basmati I could be exploited for isolation of promising aromatic recombinants. (author)

Genetics and physiology of the nuclearly inherited yellow foliar mutants in soybean

Science.gov (United States)

Plant photosynthetic pigments are important in harvesting the light energy and transfer of energy during photosynthesis. There are several yellow foliar mutants discovered in soybean and chromosomal locations for about half of them have been deduced. Viable-yellow mutants are capable of surviving wi...

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

Induced mutants for cereal grain protein improvement

International Nuclear Information System (INIS)

1982-01-01

Out of 17 papers and one summary presented, six dealing with the genetic improvement of seed protein using ionizing radiations fall within the INIS subject scope. Other topics discussed were non-radiation induced mutants used for cereal grain protein improvement

Reusable rocket engine preventive maintenance scheduling using genetic algorithm

International Nuclear Information System (INIS)

Chen, Tao; Li, Jiawen; Jin, Ping; Cai, Guobiao

2013-01-01

This paper deals with the preventive maintenance (PM) scheduling problem of reusable rocket engine (RRE), which is different from the ordinary repairable systems, by genetic algorithm. Three types of PM activities for RRE are considered and modeled by introducing the concept of effective age. The impacts of PM on all subsystems' aging processes are evaluated based on improvement factor model. Then the reliability of engine is formulated by considering the accumulated time effect. After that, optimization model subjected to reliability constraint is developed for RRE PM scheduling at fixed interval. The optimal PM combination is obtained by minimizing the total cost in the whole life cycle for a supposed engine. Numerical investigations indicate that the subsystem's intrinsic reliability characteristic and the improvement factor of maintain operations are the most important parameters in RRE's PM scheduling management

Isolation of New Gravitropic Mutants under Hypergravity Conditions

OpenAIRE

Mori, Akiko; Toyota, Masatsugu; Shimada, Masayoshi; Mekata, Mika; Kurata, Tetsuya; Tasaka, Masao; Morita, Miyo T.

2016-01-01

Forward genetics is a powerful approach used to link genotypes and phenotypes, and mutant screening/analysis has provided deep insights into many aspects of plant physiology. Gravitropism is a tropistic response in plants, in which hypocotyls and stems sense the direction of gravity and grow upward. Previous studies of gravitropic mutants have suggested that shoot endodermal cells in Arabidopsis stems and hypocotyls are capable of sensing gravity (i.e., statocytes). In the present study, we r...

De-Problematizing 'GMOs': Suggestions for Communicating about Genetic Engineering.

Science.gov (United States)

Blancke, Stefaan; Grunewald, Wim; De Jaeger, Geert

2017-03-01

The public debates concerning genetic engineering (GE) involve many non-scientific issues. The ensuing complexity is one reason why biotechnologists are reluctant to become involved. By sharing our personal experiences in science communication and suggesting ways to de-problematize GE, we aim to inspire our colleagues to engage with the public. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites

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Jing Niu

2016-01-01

Full Text Available The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric acid and oxalic acid, thus explaining the nonacidifying phenotype. As traditional complementation approaches to characterize the mutant genotype were unsuccessful, we used bulk segregant analysis in combination with high-throughput genome sequencing to identify the mutation responsible for the nonacidifying phenotype. Since A. niger has no sexual cycle, parasexual genetics was used to generate haploid segregants derived from diploids by loss of whole chromosomes. We found that the nonacidifying phenotype was caused by a point mutation in the laeA gene. LaeA encodes a putative methyltransferase-domain protein, which we show here to be required for citric acid production in an A. niger lab strain (N402 and in other citric acid production strains. The unexpected link between LaeA and citric acid production could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also involved in regulating the production of secondary metabolites. Finally, we show that our systems genetics approach is a powerful tool to identify trait mutations.

Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites.

Science.gov (United States)

Niu, Jing; Arentshorst, Mark; Nair, P Deepa S; Dai, Ziyu; Baker, Scott E; Frisvad, Jens C; Nielsen, Kristian F; Punt, Peter J; Ram, Arthur F J

2015-11-13

The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric acid and oxalic acid, thus explaining the nonacidifying phenotype. As traditional complementation approaches to characterize the mutant genotype were unsuccessful, we used bulk segregant analysis in combination with high-throughput genome sequencing to identify the mutation responsible for the nonacidifying phenotype. Since A. niger has no sexual cycle, parasexual genetics was used to generate haploid segregants derived from diploids by loss of whole chromosomes. We found that the nonacidifying phenotype was caused by a point mutation in the laeA gene. LaeA encodes a putative methyltransferase-domain protein, which we show here to be required for citric acid production in an A. niger lab strain (N402) and in other citric acid production strains. The unexpected link between LaeA and citric acid production could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also involved in regulating the production of secondary metabolites. Finally, we show that our systems genetics approach is a powerful tool to identify trait mutations. Copyright © 2016 Niu et al.

Mutant number distribution in an exponentially growing population

Science.gov (United States)

Keller, Peter; Antal, Tibor

2015-01-01

We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück (1943 Genetics 28 491-511) 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mutants that grow stochastically according to a supercritical birth and death process. We give an exact expression for the generating function of the total number of mutants at a given wild-type population size. We present a simple expression for the probability of finding no mutants, and a recursion formula for the probability of finding a given number of mutants. In the ‘large population-small mutation’ limit we recover recent results of Kessler and Levine (2014 J. Stat. Phys. doi:10.1007/s10955-014-1143-3) for a fully stochastic version of the process.

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.

Field cage studies and progressive evaluation of genetically-engineered mosquitoes.

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Luca Facchinelli

Full Text Available A genetically-engineered strain of the dengue mosquito vector Aedes aegypti, designated OX3604C, was evaluated in large outdoor cage trials for its potential to improve dengue prevention efforts by inducing population suppression. OX3604C is engineered with a repressible genetic construct that causes a female-specific flightless phenotype. Wild-type females that mate with homozygous OX3604C males will not produce reproductive female offspring. Weekly introductions of OX3604C males eliminated all three targeted Ae. aegypti populations after 10-20 weeks in a previous laboratory cage experiment. As part of the phased, progressive evaluation of this technology, we carried out an assessment in large outdoor field enclosures in dengue endemic southern Mexico.OX3604C males were introduced weekly into field cages containing stable target populations, initially at 10:1 ratios. Statistically significant target population decreases were detected in 4 of 5 treatment cages after 17 weeks, but none of the treatment populations were eliminated. Mating competitiveness experiments, carried out to explore the discrepancy between lab and field cage results revealed a maximum mating disadvantage of up 59.1% for OX3604C males, which accounted for a significant part of the 97% fitness cost predicted by a mathematical model to be necessary to produce the field cage results.Our results indicate that OX3604C may not be effective in large-scale releases. A strain with the same transgene that is not encumbered by a large mating disadvantage, however, could have improved prospects for dengue prevention. Insights from large outdoor cage experiments may provide an important part of the progressive, stepwise evaluation of genetically-engineered mosquitoes.

Genetically engineering adenoviral vectors for gene therapy.

Science.gov (United States)

Coughlan, Lynda

2014-01-01

Adenoviral (Ad) vectors are commonly used for various gene therapy applications. Significant advances in the genetic engineering of Ad vectors in recent years has highlighted their potential for the treatment of metastatic disease. There are several methods to genetically modify the Ad genome to incorporate retargeting peptides which will redirect the natural tropism of the viruses, including homologous recombination in bacteria or yeast. However, homologous recombination in yeast is highly efficient and can be achieved without the need for extensive cloning strategies. In addition, the method does not rely on the presence of unique restriction sites within the Ad genome and the reagents required for this method are widely available and inexpensive. Large plasmids containing the entire adenoviral genome (~36 kbp) can be modified within Saccharomyces cerevisiae yeast and genomes easily rescued in Escherichia coli hosts for analysis or amplification. A method for two-step homologous recombination in yeast is described in this chapter.

Isolation and characterization of Tn917lac-generated competence mutants of Bacillus subtilis

International Nuclear Information System (INIS)

Hahn, J.; Albano, M.; Dubnau, D.

1987-01-01

The authors isolated 28 mutants of Bacillus subtilis deficient in the development of competence by using the transposon Tn917lacZ as a mutagen. The mutant strains were poorly transformable with plasmid and chromosomal DNAs but were normally transducible and exhibited wild-type resistance to DNA-damaging agents. The mutations were genetically mapped, and the mutants were characterized with respect to their abilities to bind and take up radiolabeled DNA. All were defective in uptake, and some failed to bind significantly amounts of DNA. The abilities of the mutant strains to resolve into two buoyant density classes on Renografin gradients were studied. Most resolved normally, but several banded in Renografin only at the buoyant density of noncompetent cells. The genetic mapping studies and the other analyses suggested that the mutations define a minimum of seven distinct com genes

Engineering Values into Genetic Engineering: A Proposed Analytic Framework for Scientific Social Responsibility

OpenAIRE

Sankar, Pamela L.; Cho, Mildred K.

2015-01-01

Recent experiments have been used to “edit” genomes of various plant, animal and other species, including humans, with unprecedented precision. Furthermore, editing Cas9 endonuclease gene with a gene encoding the desired guide RNA into an organism, adjacent to an altered gene, could create a “gene drive” that could spread a trait through an entire population of organisms. These experiments represent advances along a spectrum of technological abilities that genetic engineers have been working ...

Field Performance of Five Soybean Mutants Under Drought Stress Conditions and Molecular Analysis Using SSR Markers

Directory of Open Access Journals (Sweden)

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

Open field release of genetically engineered sterile male Aedes aegypti in Malaysia.

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Renaud Lacroix

Full Text Available BACKGROUND: Dengue is the most important mosquito-borne viral disease. In the absence of specific drugs or vaccines, control focuses on suppressing the principal mosquito vector, Aedes aegypti, yet current methods have not proven adequate to control the disease. New methods are therefore urgently needed, for example genetics-based sterile-male-release methods. However, this requires that lab-reared, modified mosquitoes be able to survive and disperse adequately in the field. METHODOLOGY/PRINCIPAL FINDINGS: Adult male mosquitoes were released into an uninhabited forested area of Pahang, Malaysia. Their survival and dispersal was assessed by use of a network of traps. Two strains were used, an engineered 'genetically sterile' (OX513A and a wild-type laboratory strain, to give both absolute and relative data about the performance of the modified mosquitoes. The two strains had similar maximum dispersal distances (220 m, but mean distance travelled of the OX513A strain was lower (52 vs. 100 m. Life expectancy was similar (2.0 vs. 2.2 days. Recapture rates were high for both strains, possibly because of the uninhabited nature of the site. CONCLUSIONS/SIGNIFICANCE: After extensive contained studies and regulatory scrutiny, a field release of engineered mosquitoes was safely and successfully conducted in Malaysia. The engineered strain showed similar field longevity to an unmodified counterpart, though in this setting dispersal was reduced relative to the unmodified strain. These data are encouraging for the future testing and implementation of genetic control strategies and will help guide future field use of this and other engineered strains.

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

Natural genetic engineering: intelligence & design in evolution?

DEFF Research Database (Denmark)

Ussery, David

2011-01-01

There are many things that I like about James Shapiro's new book "Evolution: A View from the 21st Century" (FT Press Science, 2011). He begins the book by saying that it is the creation of novelty, and not selection, that is important in the history of life. In the presence of heritable traits...... function. Shapiro argues that what we see in genomes is 'Natural Genetic Engineering', or designed evolution: "Thinking about genomes from an informatics perspective, it is apparent that systems engineering is a better metaphor for the evolutionary process than the conventional view of evolution...... as a select-biased random walk through limitless space of possible DNA configurations" (page 6). In this review, I will have a look at four topics: 1.) why I think genomics is not the whole story; 2.) my own perspective of E. coli genomics, and how I think it relates to this book; 3.) a brief discussion...

Study on biofortification of rice by targeted genetic engineering

Directory of Open Access Journals (Sweden)

Sumon M. Hossain

2012-12-01

Full Text Available Micronutrient malnutrition is a major health problem in Bangladesh and also in many other developing countries, where a diversified diet is not affordable for the majority. In the present world- one, out of seven people suffers from hunger. Yet, there is a stealthier form of hunger than lack of food: micronutrient malnutrition or hidden hunger. While often providing enough calories, monotonous diets (of rural poor frequently fail to deliver sufficient quantities of essential minerals and vitamins. Due to micronutrient deficiencies different characteristic features have been observed to the victims. Various estimates indicate that over two-thirds of the world population, for the most part women and children specially, pre-school children are deficient in at least one micronutrient. This can have devastating consequences for the life, health and well being of the individuals concerned (like premature death, blindness, weakened immune systems etc. Genetic engineering approach is the upcoming strategy to solve this problem. Genetically engineered biofortified staple crops specially, rice that are high in essential micronutrients (Fe, Zn, vitamin A and adapted to local growing environments have the potential to significantly reduce the prevalence of micronutrient deficiencies specially to the rural poor.

Genetic engineering in nonhuman primates for human disease modeling.

Science.gov (United States)

Sato, Kenya; Sasaki, Erika

2018-02-01

Nonhuman primate (NHP) experimental models have contributed greatly to human health research by assessing the safety and efficacy of newly developed drugs, due to their physiological and anatomical similarities to humans. To generate NHP disease models, drug-inducible methods, and surgical treatment methods have been employed. Recent developments in genetic and developmental engineering in NHPs offer new options for producing genetically modified disease models. Moreover, in recent years, genome-editing technology has emerged to further promote this trend and the generation of disease model NHPs has entered a new era. In this review, we summarize the generation of conventional disease model NHPs and discuss new solutions to the problem of mosaicism in genome-editing technology.

A markerless protocol for genetic analysis of Aggregatibacter actinomycetemcomitans

Science.gov (United States)

Cheng, Ya-An; Jee, Jason; Hsu, Genie; Huang, Yanyan; Chen, Casey; Lin, Chun-Pin

2015-01-01

Background/Purpose The genomes of different Aggregatibacter actinomycetemcomitans strains contain many strain-specific genes and genomic islands (defined as DNA found in some but not all strains) of unknown functions. Genetic analysis for the functions of these islands will be constrained by the limited availability of genetic markers and vectors for A. actinomycetemcomitans. In this study we tested a novel genetic approach of gene deletion and restoration in a naturally competent A. actinomycetemcomitans strain D7S-1. Methods Specific genes’ deletion mutants and mutants restored with the deleted genes were constructed by a markerless loxP/Cre system. In mutants with sequential deletion of multiple genes loxP with different spacer regions were used to avoid unwanted recombinations between loxP sites. Results Eight single-gene deletion mutants, four multiple-gene deletion mutants, and two mutants with restored genes were constructed. No unintended non-specific deletion mutants were generated by this protocol. The protocol did not negatively affect the growth and biofilm formation of A. actinomycetemcomitans. Conclusion The protocol described in this study is efficient and specific for genetic manipulation of A. actinomycetemcomitans, and will be amenable for functional analysis of multiple genes in A. actinomycetemcomitans. PMID:24530245

Engineering genetic circuit interactions within and between synthetic minimal cells

Science.gov (United States)

Adamala, Katarzyna P.; Martin-Alarcon, Daniel A.; Guthrie-Honea, Katriona R.; Boyden, Edward S.

2017-05-01

Genetic circuits and reaction cascades are of great importance for synthetic biology, biochemistry and bioengineering. An open question is how to maximize the modularity of their design to enable the integration of different reaction networks and to optimize their scalability and flexibility. One option is encapsulation within liposomes, which enables chemical reactions to proceed in well-isolated environments. Here we adapt liposome encapsulation to enable the modular, controlled compartmentalization of genetic circuits and cascades. We demonstrate that it is possible to engineer genetic circuit-containing synthetic minimal cells (synells) to contain multiple-part genetic cascades, and that these cascades can be controlled by external signals as well as inter-liposomal communication without crosstalk. We also show that liposomes that contain different cascades can be fused in a controlled way so that the products of incompatible reactions can be brought together. Synells thus enable a more modular creation of synthetic biology cascades, an essential step towards their ultimate programmability.

Genetic engineering microbes for bioremediation/ biorecovery of uranium

International Nuclear Information System (INIS)

Apte, S.K.; Rao, A.S.; Appukuttan, D.; Nilgiriwala, K.S.; Acharya, C.

2005-01-01

Bioremediation (both bioremoval and biorecovery) of metals is considered a feasible, economic and eco-friendly alternative to chemical methods of metal extraction, particularly when the metal concentration is very low. Scanty distribution along with poor ore quality makes biomining of uranium an attractive preposition. Biosorption, bioprecipitation or bioaccumulation of uranium, aided by recombinant DNA technology, offer a promising technology for recovery of uranium from acidic or alkaline nuclear waste, tailings or from sea-water. Genetic engineering of bacteria, with a gene encoding an acid phosphatase, has yielded strains that can bioprecipitate uranium from very low concentrations at acidic-neutral pH, in a relatively short time. Organisms overproducing alkaline phosphatase have been selected for uranium precipitation from alkaline waste. Such abilities have now been transferred to the radioresistant microbe Deinococcus radiodurans to facilitate in situ bioremediation of nuclear waste, with some success. Sulfate-reducing bacteria are being characterized for bioremediation of uranium in tailings with the dual objective of uranium precipitation and reduction of sulfate to sulphide. Certain marine cyanobacteria have shown promise for uranium biosorption to extracellular polysaccharides, and intracellular accumulation involving metal sequestering metallothionin proteins. Future work is aimed at understanding the genetic basis of these abilities and to engineer them into suitable organisms subsequently. As photosynthetic, nitrogen-fixing microbes, which are considerably resistant to ionizing radiations, cyanobacteria hold considerable potential for bioremediation of nuclear waste. (author)

Mapping DNA damage-dependent genetic interactions in yeast via party mating and barcode fusion genetics.

Science.gov (United States)

Díaz-Mejía, J Javier; Celaj, Albi; Mellor, Joseph C; Coté, Atina; Balint, Attila; Ho, Brandon; Bansal, Pritpal; Shaeri, Fatemeh; Gebbia, Marinella; Weile, Jochen; Verby, Marta; Karkhanina, Anna; Zhang, YiFan; Wong, Cassandra; Rich, Justin; Prendergast, D'Arcy; Gupta, Gaurav; Öztürk, Sedide; Durocher, Daniel; Brown, Grant W; Roth, Frederick P

2018-05-28

Condition-dependent genetic interactions can reveal functional relationships between genes that are not evident under standard culture conditions. State-of-the-art yeast genetic interaction mapping, which relies on robotic manipulation of arrays of double-mutant strains, does not scale readily to multi-condition studies. Here, we describe barcode fusion genetics to map genetic interactions (BFG-GI), by which double-mutant strains generated via en masse "party" mating can also be monitored en masse for growth to detect genetic interactions. By using site-specific recombination to fuse two DNA barcodes, each representing a specific gene deletion, BFG-GI enables multiplexed quantitative tracking of double mutants via next-generation sequencing. We applied BFG-GI to a matrix of DNA repair genes under nine different conditions, including methyl methanesulfonate (MMS), 4-nitroquinoline 1-oxide (4NQO), bleomycin, zeocin, and three other DNA-damaging environments. BFG-GI recapitulated known genetic interactions and yielded new condition-dependent genetic interactions. We validated and further explored a subnetwork of condition-dependent genetic interactions involving MAG1 , SLX4, and genes encoding the Shu complex, and inferred that loss of the Shu complex leads to an increase in the activation of the checkpoint protein kinase Rad53. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Nonselective enrichment for yeast adenine mutants by flow cytometry

Science.gov (United States)

Bruschi, C. V.; Chuba, P. J.

1988-01-01

The expression of certain adenine biosynthetic mutations in the yeast Saccharomyces cerevisiae results in a red colony color. This phenomenon has historically provided an ideal genetic marker for the study of mutation, recombination, and aneuploidy in lower eukaryotes by classical genetic analysis. In this paper, it is reported that cells carrying ade1 and/or ade2 mutations exhibit primary fluorescence. Based on this observation, the nonselective enrichment of yeast cultures for viable adenine mutants by using the fluorescence-activated cell sorter has been achieved. The advantages of this approach over conventional genetic analysis of mutation, recombination, and mitotic chromosomal stability include speed and accuracy in acquiring data for large numbers of clones. By using appropriate strains, the cell sorter has been used for the isolation of both forward mutations and chromosomal loss events in S. cerevisiae. The resolving power of this system and its noninvasiveness can easily be extended to more complex organisms, including mammalian cells, in which analogous metabolic mutants are available.

Genetic engineering of crops: a ray of hope for enhanced food security.

Science.gov (United States)

Gill, Sarvajeet Singh; Gill, Ritu; Tuteja, Renu; Tuteja, Narendra

2014-01-01

Crop improvement has been a basic and essential chase since organized cultivation of crops began thousands of years ago. Abiotic stresses as a whole are regarded as the crucial factors restricting the plant species to reach their full genetic potential to deliver desired productivity. The changing global climatic conditions are making them worse and pointing toward food insecurity. Agriculture biotechnology or genetic engineering has allowed us to look into and understand the complex nature of abiotic stresses and measures to improve the crop productivity under adverse conditions. Various candidate genes have been identified and transformed in model plants as well as agriculturally important crop plants to develop abiotic stress-tolerant plants for crop improvement. The views presented here are an attempt toward realizing the potential of genetic engineering for improving crops to better tolerate abiotic stresses in the era of climate change, which is now essential for global food security. There is great urgency in speeding up crop improvement programs that can use modern biotechnological tools in addition to current breeding practices for providing enhanced food security.

Grain product of 34 soya mutant lines;Rendimiento de grano de 34 lineas mutantes de soya

Energy Technology Data Exchange (ETDEWEB)

Salmeron E, J.; Mastache L, A. A.; Valencia E, F.; Diaz V, G. E. [Colegio Superior Agropecuario del Estado de Guerrero, Vicente Guerrero No. 81, Col. Centro, 40000 Iguala, Guerrero (Mexico); Cervantes S, T. [Instituto de Recursos Geneticos y Productividad, Colegio de Posgraduados, Carretera Mexico-Texcoco Km. 36.5, Montecillo, 56230 Texcoco, Estado de Mexico (Mexico); De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.; Gatica T, M. A. [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2009-07-01

This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R{sub 4}M{sub 18}) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co{sup 60} gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L{sub 25} and L{sub 32} produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

[Progress of research on genetic engineering antibody and its application in prevention and control of parasitic diseases].

Science.gov (United States)

Yao, Yuan; Yu, Chuan-xin

2013-08-01

Antibody has extensive application prospects in the biomedical field. The inherent disadvantages of traditional polyclonal antibody and monoclonal antibody limit their application values. The humanized and fragmented antibody remodeling has given a rise to a series of genetic engineered antibody variant. This paper reviews the progress of research on genetic engineering antibody and its application in prevention and control of parasitic diseases.

Identification of some Rice Mutants using Morphological and Molecular Methods

International Nuclear Information System (INIS)

Sobieh, S.E.S.

2006-01-01

This investigation was conducted at the experimental farm of plant research department, nuclear research center, atomic energy authority, abu zaabal in order to verify four rice genotypes i.e sakha 102, giza 178, high yielding mutant (Ms 6) and high yielding mutant (MG 16). the (UPOV) rice descriptor was used to identify the germplasm morphologically .Molecular RAPD-PCR was used to identify genetic variability on the molecular level for the tested genotypes. 1- the results indicated that according to (UPOV) rice descriptor eight morphological traits were completely different between mutant Ms 6 in comparison with the parent sakha 102 and mut. MG 16 in comparison parent giza 178, the traits were ; stem thickness, stem length, panicle length, 1000-grain weight, grain length, grain width decorticated grain length and decorticated grain width. 2- using 10 arbitrary primers, through four rice genotypes on the molecular level using RAPD markers. the size of the amplified fragments were ranged from 0.201 to 2.036 k bp. two primers OPB-13 and OPB-16 showed no polymorphism among genotypes tested. 3- the total number of amplicons produced by the 8 polymorphic RAPD profiels was 66. the total number of monomorphic amplicons was 32. however, the total number of polymorphic amplicons was 34. 4- the percentage of polymorphism ranged from (22.22%) for primer OPA-18 to (90%) for primer OPB-11. 5-the highest genetic similarity (90.3%) was between sakha 102 and high yielding mut. (Ms 6). the genetic similarity (75.5%) was between giza 178 and high yielding mut.(MG 16). 6- one positive unique marker amplified by OPA-18 Primer identified the high yielding mutant Ms 6 but three positive unique markers amplified by OPB-17 primer and OPA-18 primer identified the high yielding mutant MG 16

Yield of two mutant lines of soybean for human consumption

International Nuclear Information System (INIS)

Salmeron E, J.; Mastache L, A. A.; Diaz V, G. E.; Valencia E, F.; Ranfla C, R.; Melendez P, M.; Cervantes S, T.; De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.

2009-01-01

The present work has the objective of to evaluate the yield and the agronomic behavior of 2 mutant lines of soybean for human consumption, obtained by means of a process of recurrent irradiation of soybean seed ISAAEG-BM 2 with gammas of Co 60 and selection in the generation R 4 M 18 . For the variable yield significant statistical differences were not observed, but considering the rest of the evaluated agronomic characteristics the mutant lines L 6 and Bombona they were excellent with values of 3,934.6 and 3,806.8 Kg ha- 1 to 15% of grain humidity, they also possess excellent genetic characteristics result of the irradiations and selections of these new genetic materials. (Author)

Genetic identification of a dwarf mutant in cucumber ( Cucumis ...

African Journals Online (AJOL)

The dwarf (compact) plant architecture is an important trait in cucumber (Cucumis sativus L.) breeding. A dwarf type mutant was selected from the cucumbers. The morphological and reproductive characteristics of the dwarf were compared with the vine plants. The dwarf type of cucumbers is characterized by its short ...

IMPROVING PLANT GENETIC ENGINEERING BY MANIPULATING THE HOST. (R829479C001)

Science.gov (United States)

Agrobacterium-mediated transformation is a major technique for the genetic engineering of plants. However, there are many economically important crop and tree species that remain highly recalcitrant to Agrobacterium infection. Although attempts have been made to ...

Mutant number distribution in an exponentially growing population

International Nuclear Information System (INIS)

Keller, Peter; Antal, Tibor

2015-01-01

We present an explicit solution to a classic model of cell-population growth introduced by Luria and Delbrück (1943 Genetics 28 491–511) 70 years ago to study the emergence of mutations in bacterial populations. In this model a wild-type population is assumed to grow exponentially in a deterministic fashion. Proportional to the wild-type population size, mutants arrive randomly and initiate new sub-populations of mutants that grow stochastically according to a supercritical birth and death process. We give an exact expression for the generating function of the total number of mutants at a given wild-type population size. We present a simple expression for the probability of finding no mutants, and a recursion formula for the probability of finding a given number of mutants. In the ‘large population-small mutation’ limit we recover recent results of Kessler and Levine (2014 J. Stat. Phys. doi:10.1007/s10955-014-1143-3) for a fully stochastic version of the process. (paper)

Genetic-evolution-based optimization methods for engineering design

Science.gov (United States)

Rao, S. S.; Pan, T. S.; Dhingra, A. K.; Venkayya, V. B.; Kumar, V.

1990-01-01

This paper presents the applicability of a biological model, based on genetic evolution, for engineering design optimization. Algorithms embodying the ideas of reproduction, crossover, and mutation are developed and applied to solve different types of structural optimization problems. Both continuous and discrete variable optimization problems are solved. A two-bay truss for maximum fundamental frequency is considered to demonstrate the continuous variable case. The selection of locations of actuators in an actively controlled structure, for minimum energy dissipation, is considered to illustrate the discrete variable case.

Characterization of Boerhavia diffusa L. mutant lines by RAPD and isozyme, selected for agronomically valuable traits

International Nuclear Information System (INIS)

Shukla, N.; Sangwan, N.S.; Misra, H.O.; Sangwan, R.S.

2004-01-01

Boerhavia diffusa is a medicinally important plant and finds extensive uses in traditional herbal drug preparations. For the development of improved varieties in terms of superior yield and quality of herb/root of B. diffusa, mutation breeding was attempted. Mutants generated by physical and chemical mutagenic treatments were screened for yield and quality parameters of the root/herb up to three consecutive generations. The selected-screened lines generated by physical and chemical mutagenic treatments on two selected genotypes I and II were molecularly analyzed using eight isozymes and eleven RAPD primers producing good amplification. Mutants from BD10 (selected genotype I) were distinct, while, in case of BD22 (selected genotype II), only one mutant BDMu7 was recorded distinct by isozyme analysis. The wild mutant (BDMu16, with maximum height and mouve coloured flower) was distinct in RAPD banding pattern. Isozymes differentiated the mutants from their respective controls, whereas RAPD differentiated the mutants and controls and also distinguished the mutants. The RAPD analysis was found to be better suited than isozymes for detecting genetic differences among controls and their mutants. However, both RAPD and isozyme analyses gave similar patterns of genetic relationships [it

Telos, conservation of welfare, and ethical issues in genetic engineering of animals.

Science.gov (United States)

Rollin, Bernard E

2015-01-01

The most long-lived metaphysics or view of reality in the history of Western thought is Aristotle's teleology, which reigned for almost 2,000 years. Biology was expressed in terms of function or telos, and accorded perfectly with common sense. The rise of mechanistic, Newtonian science vanquished teleological explanations. Understanding and accommodating animal telos was essential to success in animal husbandry, which involved respect for telos, and was presuppositional to our "ancient contract" with domestic animals. Telos was further abandoned with the rise of industrial agriculture, which utilized "technological fixes" to force animal into environments they were unsuited for, while continuing to be productive. Loss of husbandry and respect for telos created major issues for farm animal welfare, and forced the creation of a new ethic demanding respect for telos. As genetic engineering developed, the notion arose of modifying animals to fit their environment in order to avoid animal suffering, rather than fitting them into congenial environments. Most people do not favor changing the animals, rather than changing the conditions under which they are reared. Aesthetic appreciation of husbandry and virtue ethics militate in favor of restoring husbandry, rather than radically changing animal teloi. One, however, does not morally wrong teloi by changing them-one can only wrong individuals. In biomedical research, we do indeed inflict major pain, suffering and disease on animals. And genetic engineering seems to augment our ability to create animals to model diseases, particularly more than 3,000 known human genetic diseases. The disease, known as Lesch-Nyhan's syndrome or HPRT deficiency, which causes self-mutilation and mental retardation, provides us with a real possibility for genetically creating "animal models" of this disease, animals doomed to a life of great and unalleviable suffering. This of course creates a major moral dilemma. Perhaps one can use the very

Directed genetic modification of African horse sickness virus by reverse genetics

Directory of Open Access Journals (Sweden)

Elaine Vermaak

2015-07-01

Full Text Available African horse sickness virus (AHSV, a member of the Orbivirus genus in the family Reoviridae, is an arthropod-transmitted pathogen that causes a devastating disease in horses with a mortality rate greater than 90%. Fundamental research on AHSV and the development of safe, efficacious vaccines could benefit greatly from an uncomplicated genetic modification method to generate recombinant AHSV. We demonstrate that infectious AHSV can be recovered by transfection of permissive mammalian cells with transcripts derived in vitro from purified AHSV core particles. These findings were expanded to establish a genetic modification system for AHSV that is based on transfection of the cells with a mixture of purified core transcripts and a synthetic T7 transcript. This approach was applied successfully to recover a directed cross-serotype reassortant AHSV and to introduce a marker sequence into the viral genome. The ability to manipulate the AHSV genome and engineer specific mutants will increase understanding of AHSV replication and pathogenicity, as well as provide a tool for generating designer vaccine strains.

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

showed the highest polymorphic fragments, that's mean this primer is specific for pleurotus ostreatus. The highest similarity value (0.875) was found between 22 cont, and its mutant PO 22-l and the lowest value (0.625) was found between strain 22 and strain PO 21. The radiation sensitivity of mycelium in pleurotus ostreatus make the genetic similarities decreased to 73.3⁒, 74.3⁒ of control for strain 66 and strain 21, and for strain 22 it was 100⁒ just (4) polymorphic bands between control and mutant.

The Significance of Content Knowledge for Informal Reasoning regarding Socioscientific Issues: Applying Genetics Knowledge to Genetic Engineering Issues

Science.gov (United States)

Sadler, Troy D.; Zeidler, Dana L.

2005-01-01

This study focused on informal reasoning regarding socioscientific issues. It sought to explore how content knowledge influenced the negotiation and resolution of contentious and complex scenarios based on genetic engineering. Two hundred and sixty-nine students drawn from undergraduate natural science and nonnatural science courses completed a…

Natural variation, an underexploited resource of genetic variation for plant genetics

NARCIS (Netherlands)

Alonso-Blanco, C.; Koornneef, M.

2000-01-01

The definition of gene functions requires the phenotypic characterization of genetic variants. Currently, such functional analysis of Arabidopsis genes is based largely on laboratory-induced mutants that are selected in forward and reverse genetic studies. An alternative complementary source of

A Genetics Laboratory Module Involving Selection and Identification of Lysine Synthesis Mutants in the Yeast Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Jill B. Keeney

2009-12-01

Full Text Available We have developed a laboratory exercise, currently being used with college sophomores, which uses the yeast Saccharomyces cerevisiae to convey the concepts of amino acid biosynthesis, mutation, and gene complementation. In brief, selective medium is used to isolate yeast cells carrying a mutation in the lysine biosynthesis pathway. A spontaneous mutation in any one of three separate genetic loci will allow for growth on selective media; however, the frequency of mutations isolated from each locus differs. Following isolation of a mutated strain, students use complementation analysis to identify which gene contains the mutation. Since the yeast genome has been mapped and sequenced, students with access to the Internet can then research and develop hypotheses to explain the differences in frequencies of mutant genes obtained.

Genetic engineering: Rifkin strikes at corn this time.

Science.gov (United States)

Budiansky, S

As a result of a threatened suit by Jeremy Rifkin, Stanford University has postponed an experiment involving a test plot of genetically-engineered corn. At issue is an injunction forbidding the Recombinant DNA Advisory Committee of the National Institutes of Health from approving federal funding of experiments entailing the release of recombinant DNA into the environment. Rifkin's legal argument is that an environmnental impact statement must be filed for both commercially- and federally-funded research. It is expected that Rifkin's demand for equal treatment regardless of funding source will be agreed to by NIH.

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

Prevention of Lysosomal Storage Diseases and Derivation of Mutant Stem Cell Lines by Preimplantation Genetic Diagnosis

Science.gov (United States)

Altarescu, Gheona; Beeri, Rachel; Eiges, Rachel; Epsztejn-Litman, Silvina; Eldar-Geva, Talia; Elstein, Deborah; Zimran, Ari; Margalioth, Ehud J.; Levy-Lahad, Ephrat; Renbaum, Paul

2012-01-01

Preimplantation genetic diagnosis (PGD) allows birth of unaffected children for couples at risk for a genetic disorder. We present the strategy and outcome of PGD for four lysosomal storage disorders (LSD): Tay-Sachs disease (TSD), Gaucher disease (GD), Fabry disease (FD), and Hunter syndrome (HS), and subsequent development of stem cell lines. For each disease, we developed a family-specific fluorescent multiplex single-cell PCR protocol that included the familial mutation and informative markers surrounding the mutation. Embryo biopsy and PGD analysis were performed on either oocytes (polar bodies one and two) or on single blastomeres from a six-cell embryo. We treated twenty families carrying mutations in these lysosomal storage disorders, including 3 couples requiring simultaneous analysis for two disorders (TSD/GD, TSD/balanced Robertsonian translocation 45XYder(21;14), and HS/oculocutaneus albinism). These analyses led to an overall pregnancy rate/embryo transfer of 38% and the birth of 20 unaffected children from 17 families. We have found that PGD for lysosomal disorders is a safe and effective method to prevent birth of affected children. In addition, by using mutant embryos for the derivation of stem cell lines, we have successfully established GD and HS hESC lines for use as valuable models in LSD research. PMID:23320174

Evolutionary programming as a platform for in silico metabolic engineering

Directory of Open Access Journals (Sweden)

Förster Jochen

2005-12-01

Full Text Available Abstract Background Through genetic engineering it is possible to introduce targeted genetic changes and hereby engineer the metabolism of microbial cells with the objective to obtain desirable phenotypes. However, owing to the complexity of metabolic networks, both in terms of structure and regulation, it is often difficult to predict the effects of genetic modifications on the resulting phenotype. Recently genome-scale metabolic models have been compiled for several different microorganisms where structural and stoichiometric complexity is inherently accounted for. New algorithms are being developed by using genome-scale metabolic models that enable identification of gene knockout strategies for obtaining improved phenotypes. However, the problem of finding optimal gene deletion strategy is combinatorial and consequently the computational time increases exponentially with the size of the problem, and it is therefore interesting to develop new faster algorithms. Results In this study we report an evolutionary programming based method to rapidly identify gene deletion strategies for optimization of a desired phenotypic objective function. We illustrate the proposed method for two important design parameters in industrial fermentations, one linear and other non-linear, by using a genome-scale model of the yeast Saccharomyces cerevisiae. Potential metabolic engineering targets for improved production of succinic acid, glycerol and vanillin are identified and underlying flux changes for the predicted mutants are discussed. Conclusion We show that evolutionary programming enables solving large gene knockout problems in relatively short computational time. The proposed algorithm also allows the optimization of non-linear objective functions or incorporation of non-linear constraints and additionally provides a family of close to optimal solutions. The identified metabolic engineering strategies suggest that non-intuitive genetic modifications span

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.

TOMATOMA Update: Phenotypic and Metabolite Information in the Micro-Tom Mutant Resource.

Science.gov (United States)

Shikata, Masahito; Hoshikawa, Ken; Ariizumi, Tohru; Fukuda, Naoya; Yamazaki, Yukiko; Ezura, Hiroshi

2016-01-01

TOMATOMA (http://tomatoma.nbrp.jp/) is a tomato mutant database providing visible phenotypic data of tomato mutant lines generated by ethylmethane sulfonate (EMS) treatment or γ-ray irradiation in the genetic background of Micro-Tom, a small and rapidly growing variety. To increase mutation efficiency further, mutagenized M3 seeds were subjected to a second round of EMS treatment; M3M1 populations were generated. These plants were self-pollinated, and 4,952 lines of M3M2 mutagenized seeds were generated. We checked for visible phenotypes in the M3M2 plants, and 618 mutant lines with 1,194 phenotypic categories were identified. In addition to the phenotypic information, we investigated Brix values and carotenoid contents in the fruits of individual mutants. Of 466 samples from 171 mutant lines, Brix values and carotenoid contents were between 3.2% and 11.6% and 6.9 and 37.3 µg g(-1) FW, respectively. This metabolite information concerning the mutant fruits would be useful in breeding programs as well as for the elucidation of metabolic regulation. Researchers are able to browse and search this phenotypic and metabolite information and order seeds of individual mutants via TOMATOMA. Our new Micro-Tom double-mutagenized populations and the metabolic information could provide a valuable genetic toolkit to accelerate tomato research and potential breeding programs. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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

Science.gov (United States)

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.

Cloning a T-DNA-Linked Phosphate Gene that mediates Salt Tolerance on Mutant of Arabidopsis thaliana

International Nuclear Information System (INIS)

Njoroge, N.C; Tremblay, L.; Lefebvre, D.D.

2006-01-01

T-DNA insertionally mutagenized seeds of Arabidopsis thaliana were used to unravel genetic mechanisms underlying salt tolerance in plants. Over a period of two weeks, kanamycin homozygous (KK) seeds of the mutant NN143 attain germination levels of 65% and 77% on 175mM Nacl and 300mM mannitol respectively. Under these conditions of osmotic stress, the wild type seeds were incapable of germination. The mutant was also capable of germination on a medium containing 2μM abscisic acid (ABA). After two weeks on 2μM ABA, it attained 100% germination and the wild type did not germinate. The ABA level in the mutant was 40% higher than the wild type. Segregation analysis indicated that salt tolerance in the mutant is T-DNA linked. Genetic analysis of the F1 and F2 generations indicated that the salt tolerance trait in the mutant is dominant. The putative salt tolerance gene of mutant NN143 was cloned by plasmid rescue and sequence data indicated involvement of a protein phosphatase. The possible mechanism underlying salt tolerance in the mutant is discussed.(author)

Collection of rice mutants and application studies of their agronomic characters

International Nuclear Information System (INIS)

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

Nature of mutants induced by ionizing radiation in cultured hamster cells. II. Antigenic response and reverse mutation of HPRT-deficient mutants induced by. gamma. -rays or ethyl methanesulphonate

Energy Technology Data Exchange (ETDEWEB)

Brown, R; Stretch, A; Thacker, J

1986-04-01

A large series of independent mutants deficient in HPRT enzyme activity, isolated from V79-4 hamster cells, were assessed for properties which reflect the nature of the genetic changes induced. A total of 88 mutants were screened, 43 isolated from ..gamma..-ray-treated cultures and 45 induced by ethyl methanesulphonate (EMS). Firstly, each mutant was assayed for the presence of protein with the antigenic response of HPRT. In a competitive inhibition assay, 31% of EMS-induced mutants were CRM-positive compared to 7% of the ..gamma..-ray series. Secondly, each mutant was tested for ability to revert to HPRT proficiency. All except 2 of the EMS-induced mutants reverted with ethyl nitrosourea ENU, and many reverted spontaneously, under the given conditions. However reversion was not detected in about 80% of ..gamma..-ray-induced mutants, suggesting that the types of forward mutation caused by ionizing radiation differ qualitatively from those caused by EMS. (Auth.). 30 refs.; 6 figs.; 2 tabs.

Application of Genetic Engineering for Chromium Removal from Industrial Wastewater

OpenAIRE

N. K. Srivastava; M. K. Jha; I. D. Mall; Davinder Singh

2010-01-01

The treatment of the industrial wastewater can be particularly difficult in the presence of toxic compounds. Excessive concentration of Chromium in soluble form is toxic to a wide variety of living organisms. Biological removal of heavy metals using natural and genetically engineered microorganisms has aroused great interest because of its lower impact on the environment. Ralston metallidurans, formerly known as Alcaligenes eutrophus is a LProteobacterium colonizing indus...

Notification: Evaluation of Office of Pesticide Programs’ Genetically Engineered Corn Insect Resistance Management

Science.gov (United States)

Project #OPE-FY15-0055, July 09, 2015. The EPA OIG plans to begin preliminary research on the EPA's ability to manage and prevent increased insect resistance to genetically engineered Bacillus thuringiensis (Bt) corn.

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)

Behavioral Actions of Alcohol: Phenotypic Relations from Multivariate Analysis of Mutant Mouse Data

Science.gov (United States)

Blednov, Yuri A.; Mayfield, R. Dayne; Belknap, John; Harris, R. Adron

2012-01-01

Behavioral studies of genetically diverse mice have proven powerful for determining relationships between phenotypes and have been widely used in alcohol research. Most of these studies rely on naturally occurring genetic polymorphisms among inbred strains and selected lines. Another approach is to introduce variation by engineering single gene mutations in mice. We have tested 37 different mutant mice and their wild type controls for a variety (31) of behaviors and have mined this dataset by K-means clustering and analysis of correlations. We found a correlation between a stress-related response (activity in a novel environment) and alcohol consumption and preference for saccharin. We confirmed several relationships detected in earlier genetic studies including positive correlation of alcohol consumption with saccharin consumption, and negative correlations with conditioned taste aversion and alcohol withdrawal severity. Introduction of single gene mutations either eliminated or greatly diminished these correlations. The three tests of alcohol consumption used (continuous two bottle choice, and two limited access tests: Drinking In the Dark and Sustained High Alcohol Consumption) share a relationship with saccharin consumption, but differ from each other in their correlation networks. We suggest that alcohol consumption is controlled by multiple physiological systems where single gene mutations can disrupt the networks of such systems. PMID:22405477

Genetic engineering and chemical conjugation of potato virus X.

Science.gov (United States)

Lee, Karin L; Uhde-Holzem, Kerstin; Fischer, Rainer; Commandeur, Ulrich; Steinmetz, Nicole F

2014-01-01

Here we report the genetic engineering and chemical modification of potato virus X (PVX) for the presentation of various peptides, proteins, and fluorescent dyes, or other chemical modifiers. Three different ways of genetic engineering are described and by these means, peptides are successfully expressed not only when the foot and mouth disease virus (FMDV) 2A sequence or a flexible glycine-serine linker is included, but also when the peptide is fused directly to the PVX coat protein. When larger proteins or unfavorable peptide sequences are presented, a partial fusion via the FMDV 2A sequence is preferable. When these PVX chimeras retain the ability to assemble into viral particles and are thus able to infect plants systemically, they can be utilized to inoculate susceptible plants for isolation of sufficient amounts of virus particles for subsequent chemical modification. Chemical modification is required for the display of nonbiological ligands such as fluorophores, polymers, and small drug compounds. We present three methods of chemical bioconjugation. For direct conjugation of small chemical modifiers to solvent exposed lysines, N-hydroxysuccinimide chemistry can be applied. Bio-orthogonal reactions such as copper-catalyzed azide-alkyne cycloaddition or hydrazone ligation are alternatives to achieve more efficient conjugation (e.g., when working with high molecular weight or insoluble ligands). Furthermore, hydrazone ligation offers an attractive route for the introduction of pH-cleavable cargos (e.g., therapeutic molecules).

Genetic Engineering and Sustainable Crop Disease Management: Opportunities for Case-by-Case Decision-Making

Directory of Open Access Journals (Sweden)

Paul Vincelli

2016-05-01

Full Text Available Genetic engineering (GE offers an expanding array of strategies for enhancing disease resistance of crop plants in sustainable ways, including the potential for reduced pesticide usage. Certain GE applications involve transgenesis, in some cases creating a metabolic pathway novel to the GE crop. In other cases, only cisgenessis is employed. In yet other cases, engineered genetic changes can be so minimal as to be indistinguishable from natural mutations. Thus, GE crops vary substantially and should be evaluated for risks, benefits, and social considerations on a case-by-case basis. Deployment of GE traits should be with an eye towards long-term sustainability; several options are discussed. Selected risks and concerns of GE are also considered, along with genome editing, a technology that greatly expands the capacity of molecular biologists to make more precise and targeted genetic edits. While GE is merely a suite of tools to supplement other breeding techniques, if wisely used, certain GE tools and applications can contribute to sustainability goals.

Genetic analysis of DNA repair in Aspergillus: evidence for different types of MMS-sensitive hyperrec mutants

International Nuclear Information System (INIS)

Kaefer, E.; Mayor, O.

1986-01-01

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 γ-rays. 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. (Auth.)

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

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.

Combined MEK and ERK inhibition overcomes therapy-mediated pathway reactivation in RAS mutant tumors.

Directory of Open Access Journals (Sweden)

Mark Merchant

Full Text Available Mitogen-activated protein kinase (MAPK pathway dysregulation is implicated in >30% of all cancers, rationalizing the development of RAF, MEK and ERK inhibitors. While BRAF and MEK inhibitors improve BRAF mutant melanoma patient outcomes, these inhibitors had limited success in other MAPK dysregulated tumors, with insufficient pathway suppression and likely pathway reactivation. In this study we show that inhibition of either MEK or ERK alone only transiently inhibits the MAPK pathway due to feedback reactivation. Simultaneous targeting of both MEK and ERK nodes results in deeper and more durable suppression of MAPK signaling that is not achievable with any dose of single agent, in tumors where feedback reactivation occurs. Strikingly, combined MEK and ERK inhibition is synergistic in RAS mutant models but only additive in BRAF mutant models where the RAF complex is dissociated from RAS and thus feedback productivity is disabled. We discovered that pathway reactivation in RAS mutant models occurs at the level of CRAF with combination treatment resulting in a markedly more active pool of CRAF. However, distinct from single node targeting, combining MEK and ERK inhibitor treatment effectively blocks the downstream signaling as assessed by transcriptional signatures and phospho-p90RSK. Importantly, these data reveal that MAPK pathway inhibitors whose activity is attenuated due to feedback reactivation can be rescued with sufficient inhibition by using a combination of MEK and ERK inhibitors. The MEK and ERK combination significantly suppresses MAPK pathway output and tumor growth in vivo to a greater extent than the maximum tolerated doses of single agents, and results in improved anti-tumor activity in multiple xenografts as well as in two Kras mutant genetically engineered mouse (GEM models. Collectively, these data demonstrate that combined MEK and ERK inhibition is functionally unique, yielding greater than additive anti-tumor effects and

In silico screening of 393 mutants facilitates enzyme engineering of amidase activity in CalB

DEFF Research Database (Denmark)

Hediger, Martin Robert; De Vico, Luca; Rannes, Julie Bille

2013-01-01

Our previously presented method for high throughput computational screening of mutant activity (Hediger et al., 2012) is benchmarked against experimentally measured amidase activity for 22 mutants of Candida antarctica lipase B (CalB). Using an appropriate cutoff criterion for the computed barriers......, the qualitative activity of 15 out of 22 mutants is correctly predicted. The method identifies four of the six most active mutants with ≥3-fold wild type activity and seven out of the eight least active mutants with ≤0.5-fold wild type activity. The method is further used to screen all sterically possible (386......) double-, triple- and quadruple-mutants constructed from the most active single mutants. Based on the benchmark test at least 20 new promising mutants are identified....

Characterization of a Thermo-Inducible Chlorophyll-Deficient Mutant in Barley

Directory of Open Access Journals (Sweden)

Rong Wang

2017-11-01

Full Text Available Leaf color is an important trait for not only controlling crop yield but also monitoring plant status under temperature stress. In this study, a thermo-inducible chlorophyll-deficient mutant, named V-V-Y, was identified from a gamma-radiated population of the barley variety Vlamingh. The leaves of the mutant were green under normal growing temperature but turned yellowish under high temperature in the glasshouse experiment. The ratio of chlorophyll a and chlorophyll b in the mutant declined much faster in the first 7–9 days under heat treatment. The leaves of V-V-Y turned yellowish but took longer to senesce under heat stress in the field experiment. Genetic analysis indicated that a single nuclear gene controlled the mutant trait. The mutant gene (vvy was mapped to the long arm of chromosome 4H between SNP markers 1_0269 and 1_1531 with a genetic distance of 2.2 cM and a physical interval of 9.85 Mb. A QTL for grain yield was mapped to the same interval and explained 10.4% of the yield variation with a LOD score of 4. This QTL is coincident with the vvy gene interval that is responsible for the thermo-inducible chlorophyll-deficient trait. Fine mapping, based on the barley reference genome sequence, further narrowed the vvy gene to a physical interval of 0.428 Mb with 11 annotated genes. This is the first report of fine mapping a thermo-inducible chlorophyll-deficient gene in barley.

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)

Semi-dwarf mutant lines of hexaploid triticale

International Nuclear Information System (INIS)

Pidra, M.

1989-01-01

A spring form of hexaploid secondary triticale ADD 143/71, bred by MOGILEVA at the Plant Breeding Station at Uhretice was used for the mutagen treatment. The mutation experiment started in 1979. Seeds were treated with a 0.8 mM water solution of N-methyl-N-nitrosourea (MNH) (CETL and RELICHOVA, unpublished). From 180 M 1 plants, one spike was harvested per plant. A random sample of these seeds was sown as M 2 in 1980 and several plants with shorter main culm were selected. Selfed progenies of eight mutant plants designated ADD 143-m1, ADD 143-m2, ADD 143-m3 etc. were further tested in M 3 and M 4 . There were significant differences in culm length and in some other characters between the original line and the mutant lines. Especially the line m8 looks like a promising source of semi-dwarfness for breeding programmes of hexaploid triticale. During 1985-1987 genetic analysis was performed on the ADD 143/71 and the mutant lines m2, m6, m7 and m8, which suggest that their mutant genes are allelic and recessive

Grain product of 34 soya mutant lines

International Nuclear Information System (INIS)

Salmeron E, J.; Mastache L, A. A.; Valencia E, F.; Diaz V, G. E.; Cervantes S, T.; De la Cruz T, E.; Garcia A, J. M.; Falcon B, T.; Gatica T, M. A.

2009-01-01

This work was development with the objective of obtaining information of the agronomic behavior of 34 soya mutant lines (R 4 M 18 ) for human consumption and this way to select the 2 better lines. The genetic materials were obtained starting from the variety ISAAEG-B M2 by means of the application of recurrent radiation with Co 60 gammas, to a dose of 350 Gray for the first two generations and both later to 200 Gray and selection during 17 cycles, being obtained the 34 better lines mutants with agronomic characteristic wanted and good flavor. The obtained results were that the mutant lines L 25 and L 32 produced the major quantity in branches/plant number with 7.5 and 7.25, pods/plant number with 171.25 and 167, grains/plant number with 350.89 and 333.07 and grain product (ton/ha) to 15% of humidity 5.15 and 4.68 ton/ha, respectively. (Author)

The use of mutant stock for semi-dwarf plant type and early maturity as cross-breeding materials in rice (coordinated programme on semi-dwarf mutants for rice improvement in Asia and the Pacific Region - RCA)

International Nuclear Information System (INIS)

Pookamana, P.

1985-11-01

Development of semi-dwarf type varieties has led to a substantial yield increase in Thailand, where rice is cultivated on areas of about 8 million hectars. Of 19 recommended Thai rice varieties, 10 possess the DGWG gene which determines semi-dwarf character. This situation can create some problems in terms of genetic vulnerability towards pests, diseases and other adverse stresses. The authors found that susceptibility to disease and insect pests as well as poor grain quality are major drawbacks associated with the DGWG gene. With this background, the major project goal was to obtain, by mutation techniques, a new genetic source of semi-dwarfness. For this purpose 3 tall local Thai varieties (Leaung Awn 29, Niaw Sanpah Tawng and Khao Dawk Mali) with very good grain quality, were chosen as parent material. Using radiation techniques 2 glutinous and 7 non-glutinous semi-dwarf mutants were obtained. Results of agronomic trials indicated that the mutants from local varieties were more promising and higher yielding in comparison to introduced varieties from IRRI, Taiwan, China, France and the USA. The preliminary genetics analysis of these mutants indicated an allelic relationship to the DGWG gene. This result is very important for the rice breeding programme because it made available the semi-dwarf gene in a new genetic background - with desirable characteristics for cultivation in Thailand. These positive results stimulated efforts to obtain new semi-dwarf mutants from other local, lowland rice varieties such as Leaung Tawang and Leb Mue Nahng 111. 49 and 35 semi-dwarf mutants were already selected after irradiation and are now under agronomic evaluation

Isolation and characterization of Candida albicans morphological mutants derepressed for the formation of filamentous hypha-type structures

International Nuclear Information System (INIS)

Gil, C.; Pomes, R.; Nombela, C.

1990-01-01

Several Candida albicans morphological mutants were obtained by a procedure based on a combined treatment with nitrous acid plus UV irradiation and a double-enrichment step to increase the proportion of mutants growing as long filamentous structures. Altered cell morphogenesis in these mutants correlated with an altered colonial phenotype. Two of these mutants, C. albicans NEL102 and NEL103, were selected and characterized. Mutant blastoconidia initiated budding but eventually gave rise to filamentous hypha-type formations. These filaments were long and septate, and they branched very regularly at positions near septa. Calcofluor white (which is known to bind chitin-rich areas) stained septa, branching zones, and filament tips very intensely, as observed under the fluorescence microscope. Wild-type hybrids were obtained by fusing protoplasts of strain NEL102 with B14, another morphological mutant previously described as being permanently pseudomycelial, indicating that genetic determinants responsible for the two altered phenotypes are different. The mutants characterized in this work seemed to sequentially express the morphogenic characteristics of C. albicans, from blastoconidia to hyphae, in the absence of any inducer. Further characterization of these strains could be relevant to gain understanding of the genetic control of dimorphism in this species

Forward and reverse genetics: The LORE1 retrotransposon insertion mutants

DEFF Research Database (Denmark)

Fukai, Eigo; Malolepszy, Anna; Sandal, Niels Nørgaard

2014-01-01

The endogenous Lotus retrotransposon 1 (LORE1) transposes in the germ line of Lotus japonicus plants that carry an active element. This feature of LORE1 has been exploited for generation of a large non-transgenic insertion mutant population, where insertions have been annotated using next-generat...

Agronomic performance of rape seed (brassica napus L.) mutant lines under drought conditions

International Nuclear Information System (INIS)

Shah, S.A.; Ali, I.; Shah, S.J.A.; Rehman, K.; Rashid, A.

1995-01-01

Oil seed forms of Brassica napus are not well adapted to drought and the warner environments of Pakistan. Induced mutations were, therefore, utilized for improving drought tolerance efficiency of two napus cultivars. Induction of genetic variability, selection of desirable mutants and stabilization of mutants in acceptable agronomic background were carried out during 1988-1991. Fourteen promising mutants each of cv. Pak-cheen and Tower were evaluated for different agronomic characters in separate yield trials, under extremely drought conditions. The results demonstrated that yield potential of some mutants was very high and 9 mutants of cv. Pak-cheen and 8 mutants of cv. Tower significantly (P<0.05) out yield the local commercial cultivar. Eleven mutants in both the trials matured significantly earlier than the check. Nevertheless, more extensive testing of the drought tolerant lines under diversified environs of the country will help confirm these findings. (author)

Analysis on the DNA Fingerprinting of Aspergillus Oryzae Mutant Induced by High Hydrostatic Pressure

International Nuclear Information System (INIS)

Wang Hua; Zhang Jian; Wang Kai; Liu Bing-Bing; Zou Bo; Zou Guang-Tian; Yang Fan; Shen Si-Le

2011-01-01

The mutant strains of aspergillus oryzae (HP300a) are screened under 300 MPa for 20 min. Compared with the control strains, the screened mutant strains have unique properties such as genetic stability, rapid growth, lots of spores, and high protease activity. Random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) are used to analyze the DNA fingerprinting of HP300a and the control strains. There are 67.9% and 51.3% polymorphic bands obtained by these two markers, respectively, indicating significant genetic variations between HP300a and the control strains. In addition, comparison of HP300a and the control strains, the genetic distances of random sequence and simple sequence repeat of DNA are 0.51 and 0.34, respectively. (general)

Analysis on the DNA Fingerprinting of Aspergillus Oryzae Mutant Induced by High Hydrostatic Pressure

Science.gov (United States)

Wang, Hua; Zhang, Jian; Yang, Fan; Wang, Kai; Shen, Si-Le; Liu, Bing-Bing; Zou, Bo; Zou, Guang-Tian

2011-01-01

The mutant strains of aspergillus oryzae (HP300a) are screened under 300 MPa for 20 min. Compared with the control strains, the screened mutant strains have unique properties such as genetic stability, rapid growth, lots of spores, and high protease activity. Random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) are used to analyze the DNA fingerprinting of HP300a and the control strains. There are 67.9% and 51.3% polymorphic bands obtained by these two markers, respectively, indicating significant genetic variations between HP300a and the control strains. In addition, comparison of HP300a and the control strains, the genetic distances of random sequence and simple sequence repeat of DNA are 0.51 and 0.34, respectively.

Assessment of Genetic diversity in mutant cowpea lines using ...

African Journals Online (AJOL)

FKOLADE

2016-11-09

Nov 9, 2016 ... DNA extraction. The seeds of the mutants and their parents were planted out in pots in the screen house, and young leaves were harvested from them ... The PCR was done using a modified touch down progam as follows: 94°C for 2 min, 12 cycles of 2 min at 94°C, one min at 65°C. (-0.7°C per cycle) and 1 ...

Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis

International Nuclear Information System (INIS)

Shirley, B.W.; Kubasek, W.L.; Storz, G.; Bruggemann, E.; Koornneef, M.; Ausubel, F.M.; Goodman, H.M.

1995-01-01

Eleven loci that play a role in the synthesis of flavonoids in Arabidopsis are described. Mutations at these loci, collectively named transparent testa (tt), disrupt the synthesis of brown pigments in the seed coat (testa). Several of these loci (tt3, tt4, tt5 and ttg) are also required for the accumulation of purple anthocyanins in leaves and stems and one locus (ttg) plays additional roles in trichome and root hair development. Specific functions were previously assigned to tt1-7 and ttg. Here, the results of additional genetic, biochemical and molecular analyses of these mutants are described. Genetic map positions were determined for tt8, tt9 and tt10. Thin-layer chromatography identified tissue- and locus-specific differences in the flavonols and anthocyanidins synthesized by mutant and wild-type plants. It was found that UV light reveals distinct differences in the floral tissues of tt3, tt4, tt5, tt6 and ttg, even though these tissues are indistinguishable under visible light. Evidence was also uncovered that tt8 and ttg specifically affect dihydroflavonol reductase gene expression. A summary of these and previously published results are incorporated into an overview of the genetics of flavonoid biosynthesis in Arabidopsis

Consumer attitudes and decision-making with regard to genetically engineered food products: A review of the literature and a presentation of models for future research

DEFF Research Database (Denmark)

Bredahl, Lone; Grunert, Klaus G.; Frewer, Lynn

Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard t...... Likelihood Model and Social Judgment Theory. The model specifically takes into account the impact of credibility and various informational factors, such as persuasive content of the information provided, on attitudes.......Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard...... engineering in food production in general as additional determinants of behavioural intentions. 5. How consumers' attitudes towards genetically engineered food products are affected by various information strategies is explained in an attitude change model, which integrates aspects of the Elaboration...

Consumer attitudes and decision-making with regard to genetically engineered food products: A review of the literature and a presentation of models for future research

DEFF Research Database (Denmark)

Bredahl, Lone; Grunert, Klaus G.; Frewer, Lynn

1998-01-01

Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard t...... Likelihood Model and Social Judgment Theory. The model specifically takes into account the impact of credibility and various informational factors, such as persuasive content of the information provided, on attitudes.......Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard...... engineering in food production in general as additional determinants of behavioural intentions. 5. How consumers' attitudes towards genetically engineered food products are affected by various information strategies is explained in an attitude change model, which integrates aspects of the Elaboration...

[Engineering of a System for the Production of Mutant Human Alpha-Fetoprotein in the Methylotrophic Yeast Pichia pastoris].

Science.gov (United States)

Morozkina, E V; Vavilova, E A; Zatsepin, S S; Klyachko, E V; Yagudin, T A; Chulkin, A M; Dudich, I V; Semenkova, L N; Churilova, I V; Benevolenskii, S V

2016-01-01

A system for the production of mutant recombinant human alpha-fetoprotein (rhAFPO) lacking the glycosylation site has been engineered in the yeast Pichia pastoris. A strain of the methylotrophic yeast Pichia pastoris GS 115/pPICZ?A/rhAFP0, which produces unglycosylated rhAFPO and secretes it to the culture medium, has been constructed. Optimization and scale-up of the fermentation technology have resulted in an increase in the rhAFP0 yield to 20 mg/L. A scheme of isolation and purification of biologically active rhAFP0 has been developed. The synthesized protein has the antitumor activity, which is analogous to the activity of natural human embryonic alpha-fetoprotein.

Genetic engineering of stem cells for enhanced therapy.

Science.gov (United States)

Nowakowski, Adam; Andrzejewska, Anna; Janowski, Miroslaw; Walczak, Piotr; Lukomska, Barbara

2013-01-01

Stem cell therapy is a promising strategy for overcoming the limitations of current treatment methods. The modification of stem cell properties may be necessary to fully exploit their potential. Genetic engineering, with an abundance of methodology to induce gene expression in a precise and well-controllable manner, is particularly attractive for this purpose. There are virus-based and non-viral methods of genetic manipulation. Genome-integrating viral vectors are usually characterized by highly efficient and long-term transgene expression, at a cost of safety. Non-integrating viruses are also highly efficient in transduction, and, while safer, offer only a limited duration of transgene expression. There is a great diversity of transfectable forms of nucleic acids; however, for efficient shuttling across cell membranes, additional manipulation is required. Both physical and chemical methods have been employed for this purpose. Stem cell engineering for clinical applications is still in its infancy and requires further research. There are two main strategies for inducing transgene expression in therapeutic cells: transient and permanent expression. In many cases, including stem cell trafficking and using cell therapy for the treatment of rapid-onset disease with a short healing process, transient transgene expression may be a sufficient and optimal approach. For that purpose, mRNA-based methods seem ideally suited, as they are characterized by a rapid, highly efficient transfection, with outstanding safety. Permanent transgene expression is primarily based on the application of viral vectors, and, due to safety concerns, these methods are more challenging. There is active, ongoing research toward the development of non-viral methods that would induce permanent expression, such as transposons and mammalian artificial chromosomes.

Science, law, and politics in the Food and Drug Administration's genetically engineered foods policy: FDA's 1992 policy statement.

Science.gov (United States)

Pelletier, David L

2005-05-01

The US Food and Drug Administration's (FDA's) 1992 policy statement was developed in the context of critical gaps in scientific knowledge concerning the compositional effects of genetic transformation and severe limitations in methods for safety testing. FDA acknowledged that pleiotropy and insertional mutagenesis may cause unintended changes, but it was unknown whether this happens to a greater extent in genetic engineering compared with traditional breeding. Moreover, the agency was not able to identify methods by which producers could screen for unintended allergens and toxicants. Despite these uncertainties, FDA granted genetically engineered foods the presumption of GRAS (Generally Recognized As Safe) and recommended that producers use voluntary consultations before marketing them.

Genetic analysis of the induced mutants of rice resistant to bacterial leaf blight

International Nuclear Information System (INIS)

Nakai, H.

1990-01-01

Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M 3 or M 4 lines derived from selected resistant M 2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

Respiratory-deficient mutants of the unicellular green alga Chlamydomonas: a review.

Science.gov (United States)

Salinas, Thalia; Larosa, Véronique; Cardol, Pierre; Maréchal-Drouard, Laurence; Remacle, Claire

2014-05-01

Genetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. This, combined with a screen that easily allows discriminating respiratory-deficient mutants, makes Chlamydomonas a model system of choice to study mitochondria biology in photosynthetic organisms. Since the first description of Chlamydomonas respiratory-deficient mutants in 1977 by random mutagenesis, many other mutants affected in mitochondrial components have been characterized. These respiratory-deficient mutants increased our knowledge on function and assembly of the respiratory enzyme complexes. More recently some of these mutants allowed the study of mitochondrial gene expression processes poorly understood in Chlamydomonas. In this review, we update the data concerning the respiratory components with a special focus on the assembly factors identified on other organisms. In addition, we make an inventory of different mitochondrial respiratory mutants that are inactivated either on mitochondrial or nuclear genes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

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)

Regioselective alkane hydroxylation with a mutant AlkB enzyme

Science.gov (United States)

Koch, Daniel J.; Arnold, Frances H.

2012-11-13

AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

HSP90 Shapes the Consequences of Human Genetic Variation.

Science.gov (United States)

Karras, Georgios I; Yi, Song; Sahni, Nidhi; Fischer, Máté; Xie, Jenny; Vidal, Marc; D'Andrea, Alan D; Whitesell, Luke; Lindquist, Susan

2017-02-23

HSP90 acts as a protein-folding buffer that shapes the manifestations of genetic variation in model organisms. Whether HSP90 influences the consequences of mutations in humans, potentially modifying the clinical course of genetic diseases, remains unknown. By mining data for >1,500 disease-causing mutants, we found a strong correlation between reduced phenotypic severity and a dominant (HSP90 ≥ HSP70) increase in mutant engagement by HSP90. Examining the cancer predisposition syndrome Fanconi anemia in depth revealed that mutant FANCA proteins engaged predominantly by HSP70 had severely compromised function. In contrast, the function of less severe mutants was preserved by a dominant increase in HSP90 binding. Reducing HSP90's buffering capacity with inhibitors or febrile temperatures destabilized HSP90-buffered mutants, exacerbating FA-related chemosensitivities. Strikingly, a compensatory FANCA somatic mutation from an "experiment of nature" in monozygotic twins both prevented anemia and reduced HSP90 binding. These findings provide one plausible mechanism for the variable expressivity and environmental sensitivity of genetic diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

DNA Misfolding Found to Cause Cancer in IDH-mutant Gliomas

Science.gov (United States)

Researchers studying IDH-mutant brain tumors have identified a previously unknown genetic mechanism that may contribute to cancer. A change in how DNA is arranged, or packaged, in the cell nucleus may inappropriately activate a gene associated with brain cancer.

Improving itaconic acid production through genetic engineering of an industrial Aspergillus terreus strain.

Science.gov (United States)

Huang, Xuenian; Lu, Xuefeng; Li, Yueming; Li, Xia; Li, Jian-Jun

2014-08-11

Itaconic acid, which has been declared to be one of the most promising and flexible building blocks, is currently used as monomer or co-monomer in the polymer industry, and produced commercially by Aspergillus terreus. However, the production level of itaconic acid hasn't been improved in the past 40 years, and mutagenesis is still the main strategy to improve itaconate productivity. The genetic engineering approach hasn't been applied in industrial A. terreus strains to increase itaconic acid production. In this study, the genes closely related to itaconic acid production, including cadA, mfsA, mttA, ATEG_09969, gpdA, ATEG_01954, acoA, mt-pfkA and citA, were identified and overexpressed in an industrial A. terreus strain respectively. Overexpression of the genes cadA (cis-aconitate decarboxylase) and mfsA (Major Facilitator Superfamily Transporter) enhanced the itaconate production level by 9.4% and 5.1% in shake flasks respectively. Overexpression of other genes showed varied effects on itaconate production. The titers of other organic acids were affected by the introduced genes to different extent. Itaconic acid production could be improved through genetic engineering of the industrially used A. terreus strain. We have identified some important genes such as cadA and mfsA, whose overexpression led to the increased itaconate productivity, and successfully developed a strategy to establish a highly efficient microbial cell factory for itaconate protuction. Our results will provide a guide for further enhancement of the itaconic acid production level through genetic engineering in future.

A chilling sensitive mutant of Arabidopsis with altered steryl-ester metabolism

International Nuclear Information System (INIS)

Hugly, S.; McCourt, P.; Somerville, C.; Browse, J.; Patterson, G.W.

1990-01-01

A chilling-sensitive mutant of Arabidopsis thaliana was isolated and subjected to genetic, physiological, and biochemical analysis. The chilling-sensitive nature of the mutant line is due to a single recessive nuclear mutation at a locus designated chs1. In contrast to wild-type plants, which are not adversely affected by low temperatures, the chs1 mutant is killed by several days of exposure to temperatures below 18 degree C. Following exposure to chilling temperatures, the mutant displays two common symptoms of chilling injury - leaf chlorosis and electrolyte leakage. In these respects, the physiological response of the mutant to low temperatures mimics the response observed in some naturally occurring chilling sensitive species. The biochemical basis of chilling sensitivity was explored by examining the pattern of incorporation of 14 CO 2 into soluble metabolites and lipids in wild-type and mutant plants. The only difference observed between the mutant and wild type was that following low temperature treatment, the mutant accumulated 10-fold more radioactivity in a specific class of neutral lipids which were identified by a variety of criteria to be steryl-esters. The accumulation of radioactivity in the steryl-ester fraction occurs 24 hours before there is any visible evidence of chilling injury

Genetic architecture promotes the evolution and maintenance of cooperation.

Directory of Open Access Journals (Sweden)

Antoine Frénoy

Full Text Available When cooperation has a direct cost and an indirect benefit, a selfish behavior is more likely to be selected for than an altruistic one. Kin and group selection do provide evolutionary explanations for the stability of cooperation in nature, but we still lack the full understanding of the genomic mechanisms that can prevent cheater invasion. In our study we used Aevol, an agent-based, in silico genomic platform to evolve populations of digital organisms that compete, reproduce, and cooperate by secreting a public good for tens of thousands of generations. We found that cooperating individuals may share a phenotype, defined as the amount of public good produced, but have very different abilities to resist cheater invasion. To understand the underlying genetic differences between cooperator types, we performed bio-inspired genomics analyses of our digital organisms by recording and comparing the locations of metabolic and secretion genes, as well as the relevant promoters and terminators. Association between metabolic and secretion genes (promoter sharing, overlap via frame shift or sense-antisense encoding was characteristic for populations with robust cooperation and was more likely to evolve when secretion was costly. In mutational analysis experiments, we demonstrated the potential evolutionary consequences of the genetic association by performing a large number of mutations and measuring their phenotypic and fitness effects. The non-cooperating mutants arising from the individuals with genetic association were more likely to have metabolic deleterious mutations that eventually lead to selection eliminating such mutants from the population due to the accompanying fitness decrease. Effectively, cooperation evolved to be protected and robust to mutations through entangled genetic architecture. Our results confirm the importance of second-order selection on evolutionary outcomes, uncover an important genetic mechanism for the evolution and

Pertussis toxins, other antigens become likely targets for genetic engineering

Energy Technology Data Exchange (ETDEWEB)

Marwick, C.

1990-11-14

Genetically engineered pertussis vaccines have yet to be fully tested clinically. But early human, animal, and in vitro studies indicate effectiveness in reducing toxic effects due to Bordetella pertussis. The licensed pertussis vaccines consists of inactivated whole cells of the organism. Although highly effective, they have been associated with neurologic complications. While the evidence continues to mount that these complications are extremely rare, if they occur at all, it has affected the public's acceptance of pertussis immunization.

Induction and isolation of DNA transformation mutants in the yeast Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Hegerich, P.A.; Bruschi, C.V.

1987-01-01

The objective of this research was to induce and isolate mutants of the yeast Saccharomyces cerevisiae which have become transformable by purified plasmid DNA. Non-transformable yeast cells were mutagenized by ultraviolet light using a 65% lethal dose (480 ergs/mm 2 ). After a period of overnight liquid holding recovery, the irradiated cells were subjected to DNA transformation using our CaCl 2 protocol with the multi-marker shuttle plasmid pBB carrying the LEU 2 leucine gene. Following transformation the colonies that grew on selective leucineless medium were identified and subjected to further genetic analysis. From a total of 1 x 10 9 cells the authors have isolated 7 colonies deriving from putative mutants that have acquired the capability to uptake plasmid DNA. The transformants were cured from the plasmid by its mitotic loss on non-selective medium, then re-transformed to verify their genetic competence to give rise to a number of transformants comparable to transformable strains. We have identified and isolated one mutant, coded trs-1, which is able to reproduce a frequency of transformation comparable with the tranformable control. They, therefore, conclude that this mutant is specific for plasmid DNA transformation and that the mutation is mitotically stable

Development of Plant Mutant Resources with an useful characters by Radiation Fusion Technology

International Nuclear Information System (INIS)

Kang, Si Yong; Kim, Dong Sub; Lee, Geung Joo

2009-02-01

A mutation breeding is to use physical or chemical mutagens to induce mutagenesis, followed by individual selections with favorable traits. The mutation breeding has many advantages over other breeding methods, which include the usefulness for improving one or two inferior characteristics, applications to broad species with different reproductive systems or to diverse plant materials, native or plant introduction with narrow genetic background, time and cost-effectiveness, and valuable mutant resources for genomics researches. Recent applications of the radiation breeding techniques to developments of flowering plants or food crops with improved functional constituents heightened the public's interests in agriculture and in our genetic resources and seed industries. The goals of this project, therefore, include achieving advances in domestic seed industries and agricultural productivities by developing and using new radiation mutants with favored traits, protecting an intellectual property right of domestic seeds or germplasms, and sharing the valuable mutants and mutated gene information for the genomics and biotech researches that eventually leads to economic benefits

Molecular Cloning Designer Simulator (MCDS: All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects

Directory of Open Access Journals (Sweden)

Zhenyu Shi

2016-12-01

Full Text Available Molecular Cloning Designer Simulator (MCDS is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1 it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2 it can perform a user-defined workflow of cloning steps in a single execution of the software; (3 it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4 it includes experimental information to conveniently guide wet lab work; and (5 it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com. Keywords: BioCAD, Genetic engineering software, Molecular cloning software, Synthetic biology, Workflow simulation and management

Crop Resources Ethic in Plant Genetic Engineering and Fortune Transfer Between Generations

Institute of Scientific and Technical Information of China (English)

WANG Xiaowei; DING Guangzhou; LIANG Xueqing

2006-01-01

The relation between human and crop resources belongs to the ethic of resources exploitation. The purposes of discussing the ethic of crop resources are to protect the ecology and safety of crops, to gain sustainable development, furthermore, to choose and form the production structure that is favorable to saving crop resources and protecting the ecology of crops. Plant genetic engineering is the technology of molecule breeding of rearrangement of inheritance materials at the level of molecule directionally, of improving plant properties and of breeding high quality and yield varieties of crops. The prominent effects of the technology on the crop ecological system are human subjective factors increasing as well as violating the nature and intensifying the conflict between human being and nature.Therefore, in plant genetic engineering, crop resources exploitation should follow certain ethic principles. Under the theory of ethics of natural resources, by the means of biologioal statistics, the author systematically analyzed the possible model of crop resources transfer between generations as well as the transfer mode of magnitude of real materials and magnitude of value.

The morality of socioscientific issues: Construal and resolution of genetic engineering dilemmas

Science.gov (United States)

Sadler, Troy D.; Zeidler, Dana L.

2004-01-01

The ability to negotiate and resolve socioscientific issues has been posited as integral components of scientific literacy. Although philosophers and science educators have argued that socioscientific issues inherently involve moral and ethical considerations, the ultimate arbiters of morality are individual decision-makers. This study explored the extent to which college students construe genetic engineering issues as moral problems. Twenty college students participated in interviews designed to elicit their ideas, reactions, and feelings regarding a series of gene therapy and cloning scenarios. Qualitative analyses revealed that moral considerations were significant influences on decision-making, indicating a tendency for students to construe genetic engineering issues as moral problems. Students engaged in moral reasoning based on utilitarian analyses of consequences as well as the application of principles. Issue construal was also influenced by affective features such as emotion and intuition. In addition to moral considerations, a series of other factors emerged as important dimensions of socioscientific decision-making. These factors included personal experiences, family biases, background knowledge, and the impact of popular culture. The implications for classroom science instruction and future research are discussed.

Genetic Engineering and the Amelioration of Genetic Defect

Science.gov (United States)

Lederberg, Joshua

1970-01-01

Discusses the claims for a brave new world of genetic manipulation" and concludes that if we could agree upon applying genetic (or any other effective) remedies to global problems we probably would need no rescourse to them. Suggests that effective methods of preventing genetic disease are prevention of mutations and detection and…

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

Rubisco mutants of Chlamydomonas reinhardtii enhance photosynthetic hydrogen production.

Science.gov (United States)

Pinto, T S; Malcata, F X; Arrabaça, J D; Silva, J M; Spreitzer, R J; Esquível, M G

2013-06-01

Molecular hydrogen (H2) is an ideal fuel characterized by high enthalpy change and lack of greenhouse effects. This biofuel can be released by microalgae via reduction of protons to molecular hydrogen catalyzed by hydrogenases. The main competitor for the reducing power required by the hydrogenases is the Calvin cycle, and rubisco plays a key role therein. Engineered Chlamydomonas with reduced rubisco levels, activity and stability was used as the basis of this research effort aimed at increasing hydrogen production. Biochemical monitoring in such metabolically engineered mutant cells proceeded in Tris/acetate/phosphate culture medium with S-depletion or repletion, both under hypoxia. Photosynthetic activity, maximum photochemical efficiency, chlorophyll and protein levels were all measured. In addition, expression of rubisco, hydrogenase, D1 and Lhcb were investigated, and H2 was quantified. At the beginning of the experiments, rubisco increased followed by intense degradation. Lhcb proteins exhibited monomeric isoforms during the first 24 to 48 h, and D1 displayed sensitivity under S-depletion. Rubisco mutants exhibited a significant decrease in O2 evolution compared with the control. Although the S-depleted medium was much more suitable than its complete counterpart for H2 production, hydrogen release was observed also in sealed S-repleted cultures of rubisco mutated cells under low-moderate light conditions. In particular, the rubisco mutant Y67A accounted for 10-15-fold higher hydrogen production than the wild type under the same conditions and also displayed divergent metabolic parameters. These results indicate that rubisco is a promising target for improving hydrogen production rates in engineered microalgae.

Projecting potential adoption of genetically engineered freeze-tolerant Eucalyptus in the United States

Science.gov (United States)

David N. Wear; Ernest Dixon IV; Robert C. Abt; Navinder Singh

2015-01-01

Development of commercial Eucalyptus plantations has been limited in the United States because of the species’ sensitivity to freezing temperatures. Recently developed genetically engineered clones of a Eucalyptus hybrid, which confer freeze tolerance, could expand the range of commercial plantations. This study explores how...

Enhanced proteolysis of thiopurine S-methyltransferase (TPMT) encoded by mutant alleles in humans (TPMT∗3A, TPMT∗2): Mechanisms for the genetic polymorphism of TPMT activity

OpenAIRE

Tai, Hung-Liang; Krynetski, Eugene Y.; Schuetz, Erin G.; Yanishevski, Yuri; Evans, William E.

1997-01-01

TPMT is a cytosolic enzyme that catalyzes the S-methylation of aromatic and heterocyclic sulfhydryl compounds, including medications such as mercaptopurine and thioguanine. TPMT activity exhibits autosomal codominant genetic polymorphism, and patients inheriting TPMT deficiency are at high risk of potentially fatal hematopoietic toxicity. The most prevalent mutant alleles associated with TPMT deficiency in humans have been cloned and characterized (TPMT∗2 and TPMT∗3A), but the mechanisms for ...

EGG transformation through the use of irradiated pollen: 'Poor man's genetic engineering'

International Nuclear Information System (INIS)

Pandey, K.K.

1981-01-01

There is no way that the 'fertilization cummutation hypothesis' can be considered to be an alternative to transformation. 'Poor man's genetic engineering' as a tool for plant breeders should be the development and application of the knowledge about growth-promothing genes which are thought to occur in self-compatible as well as in self-incompatible species. (AJ)

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.

Genome-wide analytical approaches for reverse metabolic engineering of industrially relevant phenotypes in yeast

Science.gov (United States)

Oud, Bart; Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T

2012-01-01

Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages. PMID:22152095

Genome-wide analytical approaches for reverse metabolic engineering of industrially relevant phenotypes in yeast.

Science.gov (United States)

Oud, Bart; van Maris, Antonius J A; Daran, Jean-Marc; Pronk, Jack T

2012-03-01

Successful reverse engineering of mutants that have been obtained by nontargeted strain improvement has long presented a major challenge in yeast biotechnology. This paper reviews the use of genome-wide approaches for analysis of Saccharomyces cerevisiae strains originating from evolutionary engineering or random mutagenesis. On the basis of an evaluation of the strengths and weaknesses of different methods, we conclude that for the initial identification of relevant genetic changes, whole genome sequencing is superior to other analytical techniques, such as transcriptome, metabolome, proteome, or array-based genome analysis. Key advantages of this technique over gene expression analysis include the independency of genome sequences on experimental context and the possibility to directly and precisely reproduce the identified changes in naive strains. The predictive value of genome-wide analysis of strains with industrially relevant characteristics can be further improved by classical genetics or simultaneous analysis of strains derived from parallel, independent strain improvement lineages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Optimization of Aero Engine Acceleration Control in Combat State Based on Genetic Algorithms

Science.gov (United States)

Li, Jie; Fan, Ding; Sreeram, Victor

2012-03-01

In order to drastically exploit the potential of the aero engine and improve acceleration performance in the combat state, an on-line optimized controller based on genetic algorithms is designed for an aero engine. For testing the validity of the presented control method, detailed joint simulation tests of the designed controller and the aero engine model are performed in the whole flight envelope. Simulation test results show that the presented control algorithm has characteristics of rapid convergence speed, high efficiency and can fully exploit the acceleration performance potential of the aero engine. Compared with the former controller, the designed on-line optimized controller (DOOC) can improve the security of the acceleration process and greatly enhance the aero engine thrust in the whole range of the flight envelope, the thrust increases an average of 8.1% in the randomly selected working states. The plane which adopts DOOC can acquire better fighting advantage in the combat state.

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

DECOMPOSTION OF GENETICALLY ENGINEERED TOBACCO UNDER FIELD CONDITIONS: PERSISTENCE OF THE PROTEINASE INHIBITOR I PRODUCT AND EFFECTS OF SOIL MICROBIAL RESPIRATION AND PROTOZOA, NEMATODE AND MICROARTHR

Science.gov (United States)

1. To evaluate the potential effects of genetically engineered (transgenic) plants on soil ecosystems, litterbags containing leaves of non-engineered (parental) and transgenic tobacco plants were buried in field plots. The transgenic tobacco plants were genetically engineered to ...

Defective glycinergic synaptic transmission in zebrafish motility mutants

Directory of Open Access Journals (Sweden)

Hiromi Hirata

2010-01-01

Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

Science.gov (United States)

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2009-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

Genetic analysis of sunflower chlorophyll mutants

International Nuclear Information System (INIS)

Mashkina, E.V.; Guskov, E.P.

2001-01-01

The method of getting the chlorophyll mutations in sunflower was developed by Y.D. Beletskii in 1969 with the use of N-nitroso-N-methylurea (NMH). Certain concentrations of NMH are known to induce plastid mutations in growing seeds, and their yield depends on the duration of the exposure. The given work presented studies on the influence of rifampicin (R) and 2,4-dinitrophenol (DNP) on the genetic activity NMH, as an inductor of plastid and nuclear mutations

Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

Directory of Open Access Journals (Sweden)

Mardani Gashtasb

2016-01-01

Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

'HoneySweet' plum - a valuable genetically engineered fruit-tree cultivar and germplasm resource

Science.gov (United States)

‘HoneySweet’ is a plum variety developed through genetic engineering to be highly resistant to plum pox potyvirus (PPV), the causal agent of sharka disease, that threatens stone-fruit industries world-wide and most specifically, in Europe. Field testing for over 15 years in Europe has demonstrated ...

Genetic study on salt tolerance involving mutants of barley

International Nuclear Information System (INIS)

Patil, S.S.; Sharma, R.P.

1990-01-01

Full text: Cultivar 'R-16' was subjected to mutagenesis through gamma irradiation, EMS and their combination treatments. M 6 lines differing in salt tolerance were utilised along with untreated control to generate 8x3 diallel crosses. The magnitude of combining ability variances indicated a relatively prominent role of SCA variance (non additive). The values of GCA effects indicate high breeding value of the mutant M-3 for salt tolerance based on measuring shoot length and root length of 10 day old seedlings. (author)

Signature pathway expression of xylose utilization in the genetically engineered industrial yeast Saccharomyces cerevisiae

Science.gov (United States)

Background: The limited xylose utilizing ability of native Saccharomyces cerevisiae has been a major obstacle for efficient cellulosic ethanol production from lignocellulosic materials. Haploid laboratory strains of S. cerevisiae are commonly used for genetic engineering to enable its xylose utiliza...

Characteristic, inheritance and breeding application of rice mutants with greenable albino leaf

International Nuclear Information System (INIS)

Fang Xiantao; Ma Hongli; Zhao Fuyuan; Zhang Qingqi; Zhang Shubiao

2009-01-01

Inheritance and main agronomic traits of photo-thermo-sensitive genic male sterile line with green-revertible albino leaf were investigated. The results indicated that the mutants might be divided into three types: albino regreening type (W2, W3, W4 and W10), albino to kelly type (W9) and abino-regreening-albino-regreening type (W1 and W7). Genetic study indicated that green-revertible albino leaf color trait of the mutants as controlled by a single recessive gene. These mutants had similar agronomic traits and fertility characteristics to the corresponding male sterile line 'Peiai 64S'. The hybrids of these mutants had similar characteristics with original-hybrids in plant type, developing of tillers and plant height. The yield components of the mutant hybrids were different depending on different mutants. The yield potential of hybrids of W1, W2 and W3 were similar to the original-hybrid. The results also indicated that W1, W2 and W3 had breeding application value. (authors)

Plant breeding and genetics newsletter. No. 7

International Nuclear Information System (INIS)

2001-07-01

This year seems to be very promising for the Plant Breeding and Genetic sub-Programme. At the demand of geneticists, plant breeders, and more recently molecular geneticists for information on released mutant varieties of specific crops, the FAO/IAEA Mutant Varieties Database (MVD) was transferred to the web site and is now available through Internet under the following URL: http://www-mvd.iaea.org. The idea to collect and transfer information on crop varieties developed with the use of mutation techniques to plant breeders ws conceived at almost the same time as the establishment of the Plant Breeding and Genetics Section (PBG), Joint FAO/IAEA Division. The first classified list of induced mutant varieties was presented by Sigurbjoernsson at the Pullman Symposium, and published in 1969. Since the first issue of the MBNL (May, 1972) information on newly released mutant varieties was published at the end of each issue under the title 'List of Mutant Varieties'. The full list of 2252 mutant varieties has been published in the Mutation Breeding Review No. 12 (December 2000) to close this period of collecting data on mutant varieties. Such condensed but full information on mutant varieties should help geneticists, molecular biologists and plant breeders to asses the value of mutation techniques in germplasm enhancement, and stimulate the use of induced variation

Genomic diversity among Basmati rice ( Oryza sativa L) mutants ...

African Journals Online (AJOL)

Mutation breeding can be considered successful in obtaining new cultivars and broadening the genetic base of rice crop. In order to obtain new varieties of rice with improved agronomic and grain characteristics, gamma radiation (60Co) has been used to generate novel mutants of the Basmati rice. In this study rice cultivars ...

Genetic analysis of rice semidwarf mutant Tad-M-1

International Nuclear Information System (INIS)

Wang Naiyuan; Yang Rencui

1995-01-01

This paper dealed with the inheritance of the rice semidwarf of Tad-M-,a mutant line bred from traditional indica rice Variety Tadukan by radiation. The results indicated that semidwarf of Tad-M-1 was controlled by one pair of recessive gene, which was nonallelic to sd-1 gene of variety Aijiaonante and sd-g gene of variety Xinguiai and allelic to the semidwarf gene of Yunnan japonica variety Xueheaizao and Sichuan indica variety Yizila.The possible uses of Tad-M-1 in rice breeding was also discussed

Characterization of a microalgal mutant for CO_2 biofixation and biofuel production

International Nuclear Information System (INIS)

Qi, Feng; Pei, Haiyan; Hu, Wenrong; Mu, Ruimin; Zhang, Shuo

2016-01-01

Highlights: • Combination of the isolation using 96-well microplates and traditional UV mutagenesis for screening HCT mutant. • Microalgal mutant Chlorella vulgaris SDEC-3M was screened out by modified UV mutagenesis. • SDEC-3M showed high CO_2 tolerance, high CO_2 requiring and relevant genetic stability. • LCE and carbohydrate content of SDEC-3M were significantly elevated. • SDEC-3M offers a strong candidature as CO_2 biofixation and biofuel production. - Abstract: In the present work, a Chlorella vulgaris mutant, named as SDEC-3M, was screened out through the combination of the isolation using 96-well microplates and traditional UV mutagenesis. Compared with its parent (wild type), the growth of SDEC-3M preferred higher CO_2 (15% v/v) environment to ambient air (0.038% CO_2 (v/v)), indicating that the mutant qualified with good tolerance and growth potential under high level CO_2 (high CO_2 tolerance) but was defective in directly utilizing the low level CO_2 (high CO_2 requiring). The genetic stability under ambient air and high level CO_2 was confirmed by a continuous cultivation for five generations. Higher light conversion efficiency (14.52%) and richer total carbohydrate content (42.48%) demonstrated that both solar energy and CO_2 were more effectively productively fixed into carbohydrates for bioethanol production than the parent strain. The mutant would benefit CO_2 biofixation from industrial exhaust gas to mitigate of global warming and promote biofuel production to relieve energy shortage.

Genetic Recombination

Science.gov (United States)

Whitehouse, H. L. K.

1973-01-01

Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

78 FR 13302 - Syngenta Biotechnology, Inc.; Determination of Nonregulated Status of Corn Genetically Engineered...

Science.gov (United States)

2013-02-27

...] Syngenta Biotechnology, Inc.; Determination of Nonregulated Status of Corn Genetically Engineered for... are advising the public of our determination that a corn line developed by the Syngenta Biotechnology... evaluation of data submitted by Syngenta Biotechnology, Inc., in its petition for a determination of...

Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain

Science.gov (United States)

Florea, Michael; Hagemann, Henrik; Santosa, Gabriella; Micklem, Chris N.; Spencer-Milnes, Xenia; de Arroyo Garcia, Laura; Paschou, Despoina; Lazenbatt, Christopher; Kong, Deze; Chughtai, Haroon; Jensen, Kirsten; Freemont, Paul S.; Kitney, Richard; Reeve, Benjamin; Ellis, Tom

2016-01-01

Bacterial cellulose is a strong and ultrapure form of cellulose produced naturally by several species of the Acetobacteraceae. Its high strength, purity, and biocompatibility make it of great interest to materials science; however, precise control of its biosynthesis has remained a challenge for biotechnology. Here we isolate a strain of Komagataeibacter rhaeticus (K. rhaeticus iGEM) that can produce cellulose at high yields, grow in low-nitrogen conditions, and is highly resistant to toxic chemicals. We achieved external control over its bacterial cellulose production through development of a modular genetic toolkit that enables rational reprogramming of the cell. To further its use as an organism for biotechnology, we sequenced its genome and demonstrate genetic circuits that enable functionalization and patterning of heterologous gene expression within the cellulose matrix. This work lays the foundations for using genetic engineering to produce cellulose-based materials, with numerous applications in basic science, materials engineering, and biotechnology. PMID:27247386

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

Development of useful genetic resources by proton-beam irradiation

International Nuclear Information System (INIS)

Kim, In Gyu; Kim, Kug Chan; Park, Hyi Gook; Jung, Il Lae; Seo, Yong Won; Chang, Chul Seong; Kim, Jae Yoon; Ham, Jae Woong

2005-08-01

The aim of this study is to develop new, useful and high-valuable genetic resources through the overproduction of biodegradable plastics and the propagation of wheat using proton-beam irradiation. Useful host strain was isolated through the mutagenization of the Escherichia coli K-12 strain, followed by characterizing the genetic and physiological properties of the E. coli mutant strains. The selected E. coli mutant strain produced above 85g/L of PHB, showed above 99% of PHB intracellular content and spontaneously liberated intracellular PHB granules. Based on the results, the production cost of PHB has been estimated to approximately 2$/kg, leading effective cost-down. Investigated the propagation of wheat and its variation, a selectable criterion of wet pro of was established and genetic analysis of useful mutant was carried out

Phytosequestration: Carbon biosequestration by plants and the prospects of genetic engineering

Energy Technology Data Exchange (ETDEWEB)

Jansson, C.; Wullschleger, S.D.; Kalluri, U.C.; Tuskan, G.A.

2010-07-15

Photosynthetic assimilation of atmospheric carbon dioxide by land plants offers the underpinnings for terrestrial carbon (C) sequestration. A proportion of the C captured in plant biomass is partitioned to roots, where it enters the pools of soil organic C and soil inorganic C and can be sequestered for millennia. Bioenergy crops serve the dual role of providing biofuel that offsets fossil-fuel greenhouse gas (GHG) emissions and sequestering C in the soil through extensive root systems. Carbon captured in plant biomass can also contribute to C sequestration through the deliberate addition of biochar to soil, wood burial, or the use of durable plant products. Increasing our understanding of plant, microbial, and soil biology, and harnessing the benefits of traditional genetics and genetic engineering, will help us fully realize the GHG mitigation potential of phytosequestration.

Multiplexed genome engineering and genotyping methods applications for synthetic biology and metabolic engineering.

Science.gov (United States)

Wang, Harris H; Church, George M

2011-01-01

Engineering at the scale of whole genomes requires fundamentally new molecular biology tools. Recent advances in recombineering using synthetic oligonucleotides enable the rapid generation of mutants at high efficiency and specificity and can be implemented at the genome scale. With these techniques, libraries of mutants can be generated, from which individuals with functionally useful phenotypes can be isolated. Furthermore, populations of cells can be evolved in situ by directed evolution using complex pools of oligonucleotides. Here, we discuss ways to utilize these multiplexed genome engineering methods, with special emphasis on experimental design and implementation. Copyright © 2011 Elsevier Inc. All rights reserved.

Photorepair mutants of Arabidopsis

International Nuclear Information System (INIS)

Jiang, C.Z.; Yee, J.; Mitchell, D.L.; Britt, A.B.

1997-01-01

UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyces cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosophila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system

Multi-source and ontology-based retrieval engine for maize mutant phenotypes

Science.gov (United States)

In the midst of this genomics era, major plant genome databases are collecting massive amounts of heterogeneous information, including sequence data, gene product information, images of mutant phenotypes, etc., as well as textual descriptions of many of these entities. While basic browsing and sear...

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

Directory of Open Access Journals (Sweden)

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.

Genetically engineered yeast

DEFF Research Database (Denmark)

2014-01-01

A genetically modified Saccharomyces cerevisiae comprising an active fermentation pathway producing 3-HP expresses an exogenous gene expressing the aminotransferase YhxA from Bacillus cereus AH1272 catalysing a transamination reaction between beta-alanine and pyruvate to produce malonate semialde......A genetically modified Saccharomyces cerevisiae comprising an active fermentation pathway producing 3-HP expresses an exogenous gene expressing the aminotransferase YhxA from Bacillus cereus AH1272 catalysing a transamination reaction between beta-alanine and pyruvate to produce malonate...... semialdehyde. The yeast may also express a 3-hydroxyisobutyrate dehydrogenase (HIBADH) and a 3-hydroxypropanoate dehydrogenase (3-HPDH) and aspartate 1-decarboxylase. Additionally the yeast may express pyruvate carboxylase and aspartate aminotransferase....

Molecular and genetic characterization of OSH6 ( Oryza sativa ...

African Journals Online (AJOL)

Genetic studies of dissociation (Ds) insertion mutant rice plants indicated that ectopic expression of truncated OSH6 (Oryza sativa Homeobox 6) mRNA may be responsible for the mutant phenotype of knotted leaf formation at the peduncle. Additionally, ectopic expression of truncated OSH6 mRNA in the OSH6-Ds mutant ...

Development of a reduced linolenate soy [Glycine max] mutant by re-irradiation and its genetic analysis

International Nuclear Information System (INIS)

Takagi, Y.; Rahman, S.M.; Anai, T.; Wasala, S.K.; Kinoshita, T.; Khalekuzzaman, M.

1999-01-01

A high content of linolenic acid leads to reduction of keeping quality and frying stability of cooking oil. The present study was conducted to obtain a further reduction of linolenic acid in soybean [Glycine max (L.) Merr.] oil by re-irradiation of M-5 and determine its genetic system. M-5 is a mutant with 4.5% linolenic acid content, derived from the cultivar Bay (8.0% linolenic acid). A seed lot from line M-5 was treated with X-ray irradiation and M2 plants were obtained from randomly selected seeds of M1 plants. The M-2 plants were screened for reduced linolenic acid. One plant was found with 3.0% linolenic acid content and was named MS382. The M3 and M1 generations of this line proved that the character was fixed and significantly lower than the M-5 control. For inheritance studies, MS382 was reciprocally crossed with M-5 (fan) and LOLL [fanfanx-a, a recombinant of M-5 (fan) x M24 (fanx-a)]. The F2 segregation ratio and the segregation of F3 seeds from F2 plants of MS382 x M-5 indicated that reduced linolenic acid in MS382 was conbindly controlled by fan (M-5) and an additional gene. To determine if this additional gene was similar with the fanx-a gene in LOLL, F2 seeds and F3 seeds from each F2 plant of MS382 x LOLL were evaluated. No transgressive segregation for linolenic acid was found in this cross, indicating the genes for reduced linolenic acid content in MS382 and LOLL were identical. However, the mutant MS382 was developed by re-irradiation which indicates the practicability of this technique to develop new gene for further reduction of linolenic acid in soybean oil

Masked rat: an x-ray-induced mutant with chronic blepharitis, alopecia, and pasteurellosis

International Nuclear Information System (INIS)

Kent, R.L.; Lutzner, M.A.; Hansen, C.T.

1976-01-01

An autosomal recessive mutation had been previously x-ray-induced in the rat and named the masked rat (genotype mk/mk). This study describes the mutant's appearance, histology, and microflora. The rat's eyelids were swollen, often to the point of closure, and its face was partially covered by a brownish crust, giving the mutant a mask-like appearance. The chronic blepharitis was also accompanied by alopecia that appeared as bare patches across the mutant's back. Pasteurella pneumotropica was found in eyelids and on skin from all masked rats. The normal rat demonstrated a resistance to Pasteurella pneumotropica infection, or, conversely, the masked rat appeared to be genetically predisposed to pasteurellosis

Isolation of two independent allyl alcohol resistant Adh-1 null mutants following selection of pollen and seeds.

NARCIS (Netherlands)

Wisman, E.; Ramanna, M.S.; Zabel, P.

1993-01-01

The Adh-1 null mutant (B15-1-8) isolated previously was used to establish conditions that allow the selection of ADH-deficient pollen grains and seeds of tomato. New Adh-1 null mutants were then selected among the progenies derived from crosses between the genetically unstable tomato lines Yvms,

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)

A novel mouse Fgfr2 mutant, hobbyhorse (hob, exhibits complete XY gonadal sex reversal.

Directory of Open Access Journals (Sweden)

Pam Siggers

Full Text Available The secreted molecule fibroblast growth factor 9 (FGF9 plays a critical role in testis determination in the mouse. In embryonic gonadal somatic cells it is required for maintenance of SOX9 expression, a key determinant of Sertoli cell fate. Conditional gene targeting studies have identified FGFR2 as the main gonadal receptor for FGF9 during sex determination. However, such studies can be complicated by inefficient and variable deletion of floxed alleles, depending on the choice of Cre deleter strain. Here, we report a novel, constitutive allele of Fgfr2, hobbyhorse (hob, which was identified in an ENU-based forward genetic screen for novel testis-determining loci. Fgr2hob is caused by a C to T mutation in the invariant exon 7, resulting in a polypeptide with a mis-sense mutation at position 263 (Pro263Ser in the third extracellular immunoglobulin-like domain of FGFR2. Mutant homozygous embryos show severe limb and lung defects and, when on the sensitised C57BL/6J (B6 genetic background, undergo complete XY gonadal sex reversal associated with failure to maintain expression of Sox9. Genetic crosses employing a null mutant of Fgfr2 suggest that Fgr2hob is a hypomorphic allele, affecting both the FGFR2b and FGFR2c splice isoforms of the receptor. We exploited the consistent phenotype of this constitutive mutant by analysing MAPK signalling at the sex-determining stage of gonad development, but no significant abnormalities in mutant embryos were detected.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Genetic interaction and mapping studies on the leaflet development (lld) mutant in Pisum ... Genetic features of thyroid hormone receptors ... DREB1/CBF transcription factors: their structure, function and role in abiotic stress tolerance in plants.

Development of enzymes and enzyme systems by genetic engineering to convert biomass to sugars

Science.gov (United States)

TITLE Development of Enzymes and Enzyme Systems by Genetic Engineering to Convert Biomass to Sugars ABSTRACT Plant cellulosic material is one of the most viable renewable resources for the world’s fuel and chemical feedstock needs. Currently ethanol derived from corn starch is the most common li...

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

Fission yeast 26S proteasome mutants are multi-drug resistant due to stabilization of the Pap1transcription factor

DEFF Research Database (Denmark)

Penney, Mary; Samejima, Itaru; Wilkinson, Caroline

2012-01-01

Here we report the result of a genetic screen for mutants resistant to the microtubule poison methyl benzimidazol-2-yl carbamate (MBC) that were also temperature sensitive for growth. In total the isolated mutants were distributed in ten complementation groups. Cloning experiments revealed...

Association of methionine requirement with methyl mercury resistant mutants of yeast

Energy Technology Data Exchange (ETDEWEB)

Singh, A.; Sherman, F.

1974-01-25

It has been known for several years that strains resistant to mercury can be obtained in several bacterial species. Soon after the correlation between resistance to antibiotics and to mercury was recognized, it was established that genetic elements conferring resistance to antibiotics, mercury and other heavy metals in Escherichia coli and Samonella typhimurium and Staphylococcus aureus reside on extrachromosomal resistance transfer factors or plasmids. Among fungi, mercury resistant strains of Botrytis cinerea, Penicillium notatum, Sclerotinia fructicola, Stemphylium sarcinaeforme, and Saccharomyces cerevisiae have been reported. In most cases, this was accomplished by training the normal strains for growth on media supplemented with successively increasing concentrations of mercury compounds, and in some cases the resistance was lost when subcultured on mercury-free media. It is noteworthy that in none of the mercury-adapted strains of fungi has the genetic basis of resistance been determined. In this report we describe a method of isolation and characterization of methyl mercury resistant mutants of S. cerevisiae. This study was undertaken with the view that the examination of physiological changes associated with genetically defined resistant mutants will be useful in studying the mechanisms of cellular detoxification of organic mercurials.

Genetic analysis

NARCIS (Netherlands)

Koornneef, M.; Alonso-Blanco, C.; Stam, P.

2006-01-01

The Mendelian analysis of genetic variation, available as induced mutants or as natural variation, requires a number of steps that are described in this chapter. These include the determination of the number of genes involved in the observed trait's variation, the determination of dominance

Nonbehavioral Selection for Pawns, Mutants of PARAMECIUM AURELIA with Decreased Excitability

Science.gov (United States)

Schein, Stanley J.

1976-01-01

The reversal response in Paramecium aurelia is mediated by calcium which carries the inward current during excitation. Electrophysiological studies indicate that strontium and barium can also carry the inward current. Exposure to high concentrations of barium rapidly paralyzes and later kills wild-type paramecia. Following mutagenesis with nitrosoguanidine, seven mutants which continued to swim in the `high-barium' solution were selected. All of the mutants show decreased reversal behavior, with phenotypes ranging from extremely non-reversing (`extreme' pawns) to nearly wild-type reversal behavior (`partial' pawns). The mutations fall into three complementation groups, identical to the pwA, pwB, and pwC genes of Kung et al. (1975). All of the pwA and pwB mutants withstand longer exposure to barium, the pwB mutants surviving longer than the pwA mutants. Among mutants of each gene, survival is correlated with loss of reversal behavior. Double mutants (A–B, A–C, B–C), identified in the exautogamous progeny of crosses between `partial' mutants, exhibited a more extreme non-reversing phenotype than either of their single-mutant (`partial' pawn) parents.———Inability to reverse could be expected from an alteration in the calcium-activated reversal mechanism or in excitation. A normal calcium-activated structure was demonstrated in all pawns by chlorpromazine treatment. In a separate report (Schein, Bennett and Katz 1976) the results of electrophysiological investigations directly demonstrate decreased excitability in all of the mutants, a decrease due to an altered calcium activation. The studies of the genetics, the survival in barium and the electro-physiology of the pawns demonstrate that the pwA and pwB genes have different effects on calcium activation. PMID:1001878

Breeding L(+)-lactic acid high productive mutant from xylose by nitrogen ions

International Nuclear Information System (INIS)

Yang Yingge; Li Wen; Liu Dan; Fan Yonghong; Wang Dongmei; Zheng Zhiming; Yu Zengliang

2007-01-01

In order to obtain higher L(+)-lactic acid yield strain fermentating from xylose, the original strain Rhizopus oryzae RLC41-6 was mutated by 10keV N + ion implantation. A mutant strain RQ4012 was obtained. After 72h shake-flask cultivation, the concentration of L(+)-lactic acid reached 74.37g/L, and the productivity was 1.03g/(L.h). Its lactic acid yield was 160% higher than that of the original one, and the mutant strain has high genetic stability. (authors)

Oncogenic Signaling by Leukemia-Associated Mutant Cbl Proteins

Science.gov (United States)

Nadeau, Scott; An, Wei; Palermo, Nick; Feng, Dan; Ahmad, Gulzar; Dong, Lin; Borgstahl, Gloria E. O.; Natarajan, Amarnath; Naramura, Mayumi; Band, Vimla; Band, Hamid

2013-01-01

Members of the Cbl protein family (Cbl, Cbl-b, and Cbl-c) are E3 ubiquitin ligases that have emerged as critical negative regulators of protein tyrosine kinase (PTK) signaling. This function reflects their ability to directly interact with activated PTKs and to target them as well as their associated signaling components for ubiquitination. Given the critical roles of PTK signaling in driving oncogenesis, recent studies in animal models and genetic analyses in human cancer have firmly established that Cbl proteins function as tumor suppressors. Missense mutations or small in-frame deletions within the regions of Cbl protein that are essential for its E3 activity have been identified in nearly 5% of leukemia patients with myelodysplastic/myeloproliferative disorders. Based on evidence from cell culture studies, in vivo models and clinical data, we discuss the potential signaling mechanisms of mutant Cbl-driven oncogenesis. Mechanistic insights into oncogenic Cbl mutants and associated animal models are likely to enhance our understanding of normal hematopoietic stem cell homeostasis and provide avenues for targeted therapy of mutant Cbl-driven cancers. PMID:23997989

Rapid identification of lettuce seed germination mutants by bulked segregant analysis and whole genome sequencing.

Science.gov (United States)

Huo, Heqiang; Henry, Isabelle M; Coppoolse, Eric R; Verhoef-Post, Miriam; Schut, Johan W; de Rooij, Han; Vogelaar, Aat; Joosen, Ronny V L; Woudenberg, Leo; Comai, Luca; Bradford, Kent J

2016-11-01

Lettuce (Lactuca sativa) seeds exhibit thermoinhibition, or failure to complete germination when imbibed at warm temperatures. Chemical mutagenesis was employed to develop lettuce lines that exhibit germination thermotolerance. Two independent thermotolerant lettuce seed mutant lines, TG01 and TG10, were generated through ethyl methanesulfonate mutagenesis. Genetic and physiological analyses indicated that these two mutations were allelic and recessive. To identify the causal gene(s), we applied bulked segregant analysis by whole genome sequencing. For each mutant, bulked DNA samples of segregating thermotolerant (mutant) seeds were sequenced and analyzed for homozygous single-nucleotide polymorphisms. Two independent candidate mutations were identified at different physical positions in the zeaxanthin epoxidase gene (ABSCISIC ACID DEFICIENT 1/ZEAXANTHIN EPOXIDASE, or ABA1/ZEP) in TG01 and TG10. The mutation in TG01 caused an amino acid replacement, whereas the mutation in TG10 resulted in alternative mRNA splicing. Endogenous abscisic acid contents were reduced in both mutants, and expression of the ABA1 gene from wild-type lettuce under its own promoter fully complemented the TG01 mutant. Conventional genetic mapping confirmed that the causal mutations were located near the ZEP/ABA1 gene, but the bulked segregant whole genome sequencing approach more efficiently identified the specific gene responsible for the phenotype. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

Directory of Open Access Journals (Sweden)

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.

Nuclear technique for inducing new genetical sources of powdery mildew resistant mutants of wheat

International Nuclear Information System (INIS)

Shi Jinguo; Hu Xiaoyuan; Fan Qingxia; Wang Linqing; Hong Jisong

1996-01-01

Three varieties of winter wheat were treated with γ-rays, electron-beams, NaN 3 , EMS with various doses and intermittent irradiation of γ-rays respectively. 16 pure varieties and 12 hybrids were irradiated by γ-rays with appropriate doses (250∼300 Gy) for inducing mutation resistant to powdery mildew in winter wheat. γ-rays, electron-beams, NaN 3 and EMS were effective mutagens for inducing powdery mildew resistant mutants. The latter two were more effective than the former. It showed that the appropriate doses were as follows: γ-rays 300∼350 Gy, electron-beams 100∼200 Gy, NaN 3 1∼3 mmol/L, EMS about 0.3%. It also showed that the intermittent irradiation of γ-rays was more effective than the continuous irradiation for inducing powdery mildew resistant mutants. Irradiating hybrids were more effective materials than pure varieties for this purpose. 86 mutants with resistance to powdery mildew were obtained

Reanalysis of parabiosis of obesity mutants in the age of leptin.

Science.gov (United States)

Zeng, Wenwen; Lu, Yi-Hsueh; Lee, Jonah; Friedman, Jeffrey M

2015-07-21

In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not posttranslationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin(-/-) double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure.

Radiation mutagenesis in development of genetic fundamentals of cotton selection

International Nuclear Information System (INIS)

Musaev, D.A.; Almatov, A.S.

1987-01-01

Some results of investigations on preparation and genetic analysis of mutants in inbreeding lines of genetic collections of cotton plants, as well as problems on mutant application in practical selection are covered. The results show that the scientific authenticity and efficiency of fundamental and applied investigations in the field of experimental mutagenesis of cotton plants,being a facultative self-polinator, depend on keeping necessary methodical requirements. Application of inbreeding lines of genetic collection with marker features as the initial material, isolation of plants usinng self-polination of flowers on all stages of investigation are related to these requirements. Several methodical recommendations on genetic-selective investigations are developed

An improved ARS2-derived nuclear reporter enhances the efficiency and ease of genetic engineering in Chlamydomonas

DEFF Research Database (Denmark)

Specht, Elizabeth A; Nour-Eldin, Hussam Hassan; Hoang, Kevin T D

2015-01-01

The model alga Chlamydomonas reinhardtii has been used to pioneer genetic engineering techniques for high-value protein and biofuel production from algae. To date, most studies of transgenic Chlamydomonas have utilized the chloroplast genome due to its ease of engineering, with a sizeable suite o...

Genetic engineering of plant volatile terpenoids: effects on a herbivore, a predator and a parasitoid

NARCIS (Netherlands)

Kos, M.; Houshyani, B.; Overeem, A.J.; Bouwmeester, H.J.; Weldegergis, B.T.; van Loon, J.J.A.; Dicke, M.; Vet, L.E.M.

2013-01-01

BACKGROUND: Most insect-resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be

Genetic Engineering of Crypthecodinium cohnii to Increase Growth and Lipid Accumulation

Directory of Open Access Journals (Sweden)

Jinjin Diao

2018-03-01

Full Text Available In this study, we evaluated suitable selected markers and optimized transformation protocols to develop a new genetic transformation methodology for DHA-producing Crypthecodinium cohnii. Additionally, ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO, potentially involved in CO2 fixation under autotrophic conditions, was selected as the target for construction of a gene knockdown mutant. Our results show that the constructs were successfully inserted into the C. cohnii chromosome by homologous recombination. Comparative analysis showed that deletion of the RuBisCO gene promoted cell growth and increased the lipid content of C. cohnii under heterotrophic conditions compared with those of the wild-type. The liquid chromatography-mass spectrometry (LC-MS based metabolomic analysis showed that the metabolites involved in energy metabolism were upregulated, suggesting that the deletion of the RuBisCO gene may contribute to the re-direction of more carbon or energy toward growth and lipid accumulation under heterotrophic conditions.

Production of nutritionally-deficient mutants of the axenic blue-green alga Anabaena flos-aquae NRC-44-1 by ultraviolet irradiation

Energy Technology Data Exchange (ETDEWEB)

Kumar, H D; Gorham, P R

1975-01-01

Anabaena flos-aquae NRC-44-1 is a freshwater nitrogen fixing blue-green alga of some ecological significance because of its toxicity. In axenic culture and possibly also in nature, the alga is highly susceptible to lysis at certain stages of its growth. Nothing is known about genetic phenomena governing toxin production, nitrogen fixation or other characteristics of this organism, mainly because of unavailability of mutant strains that could be utilized in genetic experiments. With the object of overcoming this obstacle to the eventual study of genetics of Anabaena flos-aquae, attempts were made to produce and isolate nutritionally-deficient mutants of this species.

Identification of auxotrophic mutants of the yeast Kluyveromyces marxianus by non-homologous end joining-mediated integrative transformation with genes from Saccharomyces cerevisiae.

Science.gov (United States)

Yarimizu, Tohru; Nonklang, Sanom; Nakamura, Junpei; Tokuda, Shuya; Nakagawa, Takaaki; Lorreungsil, Sasithorn; Sutthikhumpha, Surasit; Pukahuta, Charida; Kitagawa, Takao; Nakamura, Mikiko; Cha-Aim, Kamonchai; Limtong, Savitree; Hoshida, Hisashi; Akada, Rinji

2013-12-01

The isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. For the development of these genetic methods in the thermotolerant fermentative yeast Kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. To identify the mutated genes, linear DNA fragments of nutrient biosynthetic pathway genes were amplified from Saccharomyces cerevisiae chromosomal DNA and used to directly transform the K. marxianus auxotrophic mutants by random integration into chromosomes through non-homologous end joining (NHEJ). The appearance of transformant colonies indicated that the specific S. cerevisiae gene complemented the K. marxianus mutant. Using this interspecific complementation approach with linear PCR-amplified DNA, we identified auxotrophic mutations of ADE2, ADE5,7, ADE6, HIS2, HIS3, HIS4, HIS5, HIS6, HIS7, LYS1, LYS2, LYS4, LYS9, LEU1, LEU2, MET2, MET6, MET17, TRP3, TRP4 and TRP5 without the labour-intensive requirement of plasmid construction. Mating, sporulation and tetrad analysis techniques for K. marxianus were also established. With the identified auxotrophic mutant strains and S. cerevisiae genes as selective markers, NHEJ-mediated integrative transformation with PCR-amplified DNA is an attractive system for facilitating genetic analyses in the yeast K. marxianus. Copyright © 2013 John Wiley & Sons, Ltd.

Genetically engineered plants in the product development pipeline in India.

Science.gov (United States)

Warrier, Ranjini; Pande, Hem

2016-01-02

In order to proactively identify emerging issues that may impact the risk assessment and risk management functions of the Indian biosafety regulatory system, the Ministry of Environment, Forests and Climate Change sought to understand the nature and diversity of genetically engineered crops that may move to product commercialization within the next 10 y. This paper describes the findings from a questionnaire designed to solicit information about public and private sector research and development (R&D) activities in plant biotechnology. It is the first comprehensive overview of the R&D pipeline for GE crops in India.

The use of RAPD fingerprinting to detect genetic variation of a selected signal grass mutant

International Nuclear Information System (INIS)

Affrida Abu Hassan; Ghazali HAzhar Mohamad; Abdul Rahim Harun

2002-01-01

Signal grass (Brachiaria decumbens) has been used for many years as grazing pasture for ruminants but it may know to be toxic to small ruminants. Mutagenesis provides an alternative approach to create phenotypic variability in the grass that might be free from toxicity and allow greater selection potential for desired characteristics. The mutant of Brachiara decumbens, which was obtained through induced mutation by gamma irradiation at dose 900 Gh showed phenotypic changes in term of tiller number, leaf to stem ratio and internode length. The variations caused by irradiation were detected by Random Amplified Polymorphic DNA (RAPD) analysis. Decamer oligonucleotide primers were used to generate DNA profiles. 575 bp polymorphic DNA band was observed between control and the mutant. RAPD has been proven to be useful to detect polymorphism between mutants and the control. (Author)

Isolation and genetic analysis of Aspergillus niger mutants with reduced extracellular glucoamylase

International Nuclear Information System (INIS)

Valent, G.U.; Calil, M.R.; Bonatelli Junior, R.

1992-01-01

Mutants with impaired production of extracellular glucoamylase were isolated at a high frequency (2% of survivors) from an Aspergillus niger strain treated with UV light. These were designated as low glucoamylase producers (lgp, up to 30% of the parental yield) and medium producers (mgp, a 35 to 50% decrease in enzyme level). All the mutants were shown to be recessive; one strain segregated two unlinked genes. Complementation tests, and segregation from heterozygous diploid, suggested at least three to four unlinked genes, each able to impair glucoamylase production. There is evidence of a single structural gene for glucoamylase in A. niger. Therefore, as production of extracellular enzymes is normally the final result of several steps at intracellular and membrane levels, including regulation of enzyme synthesis, we suggest intergenic interaction that controls extracellular enzyme accumulation and that mutation in any of these genes would result in impaired production. (author)

Genetic and biochemical studies of the lipid-containing bacteriophage PR4

International Nuclear Information System (INIS)

Vanden Boom, T.J.

1989-01-01

Bacteriophage PR4 is a lipid-containing bacterial virus able to infect Escherichia coli and Salmonella typhimurium. The icosahedral virion consists of an external protein capsid layer which surrounds a membrane vesicle enclosed ds DNA genome. The author has analyzed the time course of phage PR4 protein synthesis and have identified at least 34 proteins present in phage infected cells not detected in uninfected control cultures. In addition, he has isolated a more extensive set of conditional-lethal nonsense mutants of this virus. This collection of mutants permitted the identification of seven additional phage PR4 gene products, including the terminal genome protein and an accessory lytic factor. The present collection of phage PR4 mutants has been assigned to 19 distinct genetic groups on the basis of genetic complementation tests and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the proteins produced in mutant-infected UV-irradiated cells. A restriction endonuclease map of the phage PR4 genome was constructed which includes 59 sites for ten restriction endonucleases. In addition, he has constructed a collection of recombinant plasmids containing subgenomic DNA fragments of bacteriophage PR4. He has used this collection of plasmids to generate a physical-genetic map of the PR4 genome. The physical-genetic map localizes mutations in 13 phage PR4 genetic groups on the viral DNA molecule. To investigate the role of phosphatidylglycerol (PG) in phage assembly and infectivity, he propagated PR4 on an E. coli mutant defective in PG synthesis. The PG content of phage PR4 grown on the mutant host accounted for 0.4% of the total viral phospholipids, representing a 90-fold decrease in PG relative to the PG content of phage grown on a wild type host

Activation of DAF-16/FOXO by reactive oxygen species contributes to longevity in long-lived mitochondrial mutants in Caenorhabditis elegans.

Science.gov (United States)

Senchuk, Megan M; Dues, Dylan J; Schaar, Claire E; Johnson, Benjamin K; Madaj, Zachary B; Bowman, Megan J; Winn, Mary E; Van Raamsdonk, Jeremy M

2018-03-01

Mild deficits in mitochondrial function have been shown to increase lifespan in multiple species including worms, flies and mice. Here, we study three C. elegans mitochondrial mutants (clk-1, isp-1 and nuo-6) to identify overlapping genetic pathways that contribute to their longevity. We find that genes regulated by the FOXO transcription factor DAF-16 are upregulated in all three strains, and that the transcriptional changes present in these worms overlap significantly with the long-lived insulin-IGF1 signaling pathway mutant daf-2. We show that DAF-16 and multiple DAF-16 interacting proteins (MATH-33, IMB-2, CST-1/2, BAR-1) are required for the full longevity of all three mitochondrial mutants. Our results suggest that the activation of DAF-16 in these mutants results from elevated levels of reactive oxygen species. Overall, this work reveals an overlapping genetic pathway required for longevity in three mitochondrial mutants, and, combined with previous work, demonstrates that DAF-16 is a downstream mediator of lifespan extension in multiple pathways of longevity.

Genetic monitoring of agrocoenosis

International Nuclear Information System (INIS)

Lukin, V.D.

2005-01-01

Mutants with high frequency of revertants appearance can be used as biological indicator of genetic monitoring of agrocoenosis. It differs from the initial form in dwarf-size of the shrub, the changed plate of leaf and sterility. The low limit of the mutant sensitiveness on the test of visible reverse mutations to the doses of gamma-irradiation is 0,2 Gy and to the rate of soil contamination by lead is 50 mg per 1 kg of soil. (authors)

DNA repair in Haemophilus influenzae: isolation and characterization of an ultraviolet sensitive mutator mutant

International Nuclear Information System (INIS)

Walter, R.B.

1985-01-01

DNA repair in Haemophilus influenzae appears to be quite different from that seen in Escherichia coli in that H. influenzae shows neither SOS nor adaptation phenomena. Repair of DNA lesions in H. influenzae has been seen to occur via recombinational, excision, and mismatch repair pathways acting independently of one another. The author has isolated an ultraviolet (UV)-sensitive mutator mutant (mutB1) of H. influenzae Rd which shows deficiencies in both recombinational and mismatch repair pathways. This mutant is sensitive to a variety of DNA damaging agents as well as being hypermutable by alkylating agents and base analogues. MutB1 cells do not show post-UV DNA breakdown but do begin excision after UV irradiation. Genetic transformation with UV-irradiated DNA on mut B1 recipients shows that high (HE) and low (LE) efficiency markers are transformed at a ratio of 1.0 as in the mismatch repair deficient hex 1 mutant; however, kinetics of UV-inactivation experiments indicate that HE markers are sensitized and act as LE markers do on wild type recipients. Thus, the mutB gene product appears to play a role in both DNA repair and genetic transformation. A model is outlined which presents a role for a DNA helicase in both DNA repair and genetic transformation of H. influenzae

Genetic and Biochemical Analysis of Intragenic Complementation Events among Nitrate Reductase Apoenzyme-Deficient Mutants of Nicotiana Plumbaginifolia

OpenAIRE

Pelsy, F.; Gonneau, M.

1991-01-01

Intragenic complementation has been observed between apoenzyme nitrate reductase-deficient mutants (nia) of Nicotiana plumbaginifolia. In vivo as in vitro, the NADH-nitrate reductase (NR) activity in plants heterozygous for two different nia alleles was lower than in the wild type plant, but the plants were able to grow on nitrate as a sole nitrogen source. NR activity, absent in extracts of homozygous nia mutants was restored by mixing extracts from two complementing nia mutants. These obser...

Bioactive compounds of fourth generation gamma-irradiated Typhoniumflagelliforme Lodd. mutants based on gas chromatography-mass spectrometry

Science.gov (United States)

Sianipar, N. F.; Purnamaningsih, R.; Rosaria

2016-08-01

Rodent tuber (Typhonium flagelliforme Lodd.) is an Indonesian anticancer medicinal plant. The natural genetic diversity of rodent tuber is low due to vegetative propagation. Plant's genetic diversity has to be increased for obtaining clones which contain a high amount of anticancer compounds. In vitro calli were irradiated with 6 Gy of gamma ray to produce in vitro mutant plantlets. Mutant plantlets were acclimated and propagated in a greenhouse. This research was aimed to identify the chemical compounds in the leaves and tubers ofthe fourth generation of rodent tuber's vegetative mutant clones (MV4) and control plantsby using GC- MS method. Leaves and tubers of MV4 each contained 2 and 5 anticancer compounds which quantities were higher compared to control plants. MV4 leaves contained 5 new anticancer compounds while its tubers contained 3 new anticancer compounds which were not found in control. The new anticancer compounds in leaves were hexadecanoic acid, stigmast-5-en-3-ol, ergost-5-en-3-ol, farnesol isomer a, and oleic acid while the new anticancer compounds in tubers were alpha tocopherol, ergost-5-en-3-ol, and beta-elemene. Rodent tuber mutant clones are very potential to be developed into anticancer drugs.

Stakeholder views on the creation and use of genetically-engineered animals in research.

Science.gov (United States)

Ormandy, Elisabeth H

2016-05-01

This interview-based study examined the diversity of views relating to the creation and use of genetically-engineered (GE) animals in biomedical science. Twenty Canadian participants (eight researchers, five research technicians and seven members of the public) took part in the interviews, in which four main themes were discussed: a) how participants felt about the genetic engineering of animals as a practice; b) governance of the creation and use of GE animals in research, and whether current guidelines are sufficient; c) the Three Rs (Replacement, Reduction, Refinement) and how they are applied during the creation and use of GE animals in research; and d) whether public opinion should play a greater role in the creation and use of GE animals. Most of the participants felt that the creation and use of GE animals for biomedical research purposes (as opposed to food purposes) is acceptable, provided that tangible human health benefits are gained. However, obstacles to Three Rs implementation were identified, and the participants agreed that more effort should be placed on engaging the public on the use of GE animals in research. 2016 FRAME.

A new and efficient approach for construction of uridine/uracil auxotrophic mutants in the filamentous fungus Aspergillus oryzae using Agrobacterium tumefaciens-mediated transformation.

Science.gov (United States)

Nguyen, Khuyen Thi; Ho, Quynh Ngoc; Do, Loc Thi Binh Xuan; Mai, Linh Thi Dam; Pham, Duc-Ngoc; Tran, Huyen Thi Thanh; Le, Diep Hong; Nguyen, Huy Quang; Tran, Van-Tuan

2017-06-01