WorldWideScience

Sample records for left-hand t-dna genes

  1. The Left-Handed Writer.

    Science.gov (United States)

    Bloodsworth, James Gaston

    Contrary to the beliefs of many, right-handedness is not a single factor existing in almost all people, with a few exceptions termed left-handed: neither extreme exists independently of the other. During the first 4 years of life there is a period of fluctuation between right and left-handed dominance. Statistics and findings vary in determining…

  2. ARE LEFT HANDED SURGEONS LEFT OUT?

    OpenAIRE

    SriKamkshi Kothandaraman; Balasubramanian Thiagarajan

    2012-01-01

    Being a left-handed surgeon, more specifically a left-handed ENT surgeon, presents a unique pattern of difficulties.This article is an overview of left-handedness and a personal account of the specific difficulties a left-handed ENT surgeon faces.

  3. Left-handed Children in Singapore.

    Science.gov (United States)

    Gan, Linda

    1998-01-01

    Used teacher questionnaires to examine incidence of left-handedness in nearly 2,800 Singaporean children, racial differences in this left-handed population, and educational provisions in preschool and primary school. Findings indicated that 7.5% of preschoolers and 6.3% of primary children were left-handed, with a higher proportion being Chinese…

  4. The Left-Handed: "Their Sinister" History.

    Science.gov (United States)

    Costas, Elaine Fowler

    The history of left-handedness can provide teachers and parents a better understanding of left-handed children and give those children more pride in their difference. No child should be made to feel that he or she is abnormal because of using the left hand, although some specific instruction for these students is necessary in handwriting. Many…

  5. Magnetization of left-handed metamaterials

    International Nuclear Information System (INIS)

    Kourakis, I; Shukla, P K

    2006-01-01

    We propose a possible mechanism for the generation of magnetic fields in negative refraction index composite metamaterials. Considering the propagation of a high-frequency modulated amplitude electric field in a left-handed material (LHM), we show that the ponderomotive interaction between the field and low-frequency potential distributions leads to spontaneous generation of magnetic fields, whose form and properties are discussed

  6. Hand Preference and Skill in 115 Children of Two Left-Handed Parents.

    Science.gov (United States)

    Annett, Marian

    1983-01-01

    Studied hand skill and performance in children (N=115) of left-handed parents using peg moving tasks and soccer kicks. Concluded that being raised by two left-handed parents does little to hinder the expression of the rs plus gene. Correlations for handedness in families depend more on genetics than experience. (Author/JAC)

  7. Agrobacterium tumefaciens T-DNA Integration and Gene Targeting in Arabidopsis thaliana Non-Homologous End-Joining Mutants

    Directory of Open Access Journals (Sweden)

    Qi Jia

    2012-01-01

    Full Text Available In order to study the role of AtKu70 and AtKu80 in Agrobacterium-mediated transformation and gene targeting, plant lines with a T-DNA insertion in AtKu80 or AtKu70 genes were functionally characterized. Such plant lines lacked both subunits, indicating that heterodimer formation between AtKu70 and AtKu80 is needed for the stability of the proteins. Homozygous mutants were phenotypically indistinguishable from wild-type plants and were fertile. However, they were hypersensitive to the genotoxic agent bleomycin, resulting in more DSBs as quantified in comet assays. They had lower end-joining efficiency, suggesting that NHEJ is a critical pathway for DSB repair in plants. Both Atku mutants and a previously isolated Atmre11 mutant were impaired in Agrobacterium T-DNA integration via floral dip transformation, indicating that AtKu70, AtKu80, and AtMre11 play an important role in T-DNA integration in Arabidopsis. The frequency of gene targeting was not significantly increased in the Atku80 and Atku70 mutants, but it was increased at least 10-fold in the Atmre11 mutant compared with the wild type.

  8. Vergisson 4: a left-handed Neandertal.

    Science.gov (United States)

    Condemi, Silvana; Monge, Janet; Quertelet, Sylvain; Frayer, David W; Combier, Jean

    2017-01-01

    Handedness is an important marker for lateralization of humans in the modern and fossil record. For the most part, Neandertals and their ancestors are strongly right-handed. We describe a single tooth from a Neandertal level at Vergisson 4 (Vg 4-83). This left upper central incisor shows all the features typical of Neandertal incisors. It also exhibits a predominance of left-handed striations. Striations on the incisor's labial surface were mapped at 20x magnification using Photoshop. Angulations of the striations were determined from their deviation from the maximum mesio-distal line and were analyzed using NIH's freeware, Image J. Of the 60 labial surface striations, Vg 4-83 shows a strong predominance of left-handed striations (46; 76.7%), which are statistically significantly different (p handed striations. The identification of another left-handed Neandertal adds to our understanding about handedness variation in this fossil hominin. Given the high frequency of right-handed Neandertals, the 90: 10 modern ratio is still preserved in this group. © 2016 Wiley Periodicals, Inc.

  9. Nonlinear left-handed transmission line metamaterials

    International Nuclear Information System (INIS)

    Kozyrev, A B; Weide, D W van der

    2008-01-01

    Metamaterials, exhibiting simultaneously negative permittivity ε and permeability μ, more commonly referred to as left-handed metamaterials (LHMs) and also known as negative-index materials, have received substantial attention in the scientific and engineering communities [1]. Most studies of LHMs (and electromagnetic metamaterials in general) have been in the linear regime of wave propagation and have already inspired new types of microwave circuits and devices. The results of these studies have already been the subject of numerous reviews and books. This review covers a less explored but rapidly developing area of investigation involving media that combine nonlinearity (dependence of the permittivity and permeability on the magnitude of the propagating field) with the anomalous dispersion exhibited by LHM. The nonlinear phenomena in such media will be considered on the example of a model system: the nonlinear left-handed transmission line. These nonlinear phenomena include parametric generation and amplification, harmonic and subharmonic generation as well as modulational instabilities and envelope solitons. (topical review)

  10. Spatial Deficit in Familial Left-Handed Children.

    Science.gov (United States)

    And Others; Eme, Robert

    1978-01-01

    The study evaluated the hypothesis that familial left-handed children, who presumably have bilateral representation of language ability, should show an impairment in spatial abiblity on 44 children (22 right handed, 11 familial left handed, and 11 nonfamilial left handed) whose average age was 8 years old. (Author/PHR)

  11. 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)

  12. Detection of transformed cells in crown gall tumors using the GUS reporter gene and correlation of GUS stained cells with T-DNA gene activity

    International Nuclear Information System (INIS)

    Black, R.C.; Labriola, J.; Binns, A.N.

    1990-01-01

    Crown gall tumors are a mixture of transformed hormone producing cells and normal cells. Until now it has not been possible to directly visualize these cell types in situ. We have constructed strains of Agrobacterium tumefaciens that carry the 35S-β-glucuronidase (GUS) reporter gene in either wild type or mutant Ti plasmids. Using histochemical staining for GUS activity, blue (GUS positive) sectors are observed in tumor sections. In order to demonstrate that the blue sectors actually represent cells expressing other T-DNA genes, we have looked for T-DNA gene encoded enzyme activity in the stained and unstained sectors. The blue sectors accumulate octopine (a product of the octopine synthase gene on the T-DNA) while the white (GUS negative) sectors do not. We conclude that the use of the GUS reporter gene provides a sensitive and reliable method for visualizing transformation events in plant tissues. A comparison of the proportion of transformed and nontransformed cells in wild type tumors vs. tumors deficient in auxin or cytokinin encoding genes will be discussed

  13. Challenges training left-handed surgeons.

    Science.gov (United States)

    Anderson, Maia; Carballo, Erica; Hughes, David; Behrer, Christopher; Reddy, Rishindra M

    2017-09-01

    Being left-handed (LH) is considered a disadvantage in surgical training. We sought to understand the perspectives of LH trainees and surgical educators on the challenges and modifications in training LH surgeons. A survey was distributed to surgeons, surgical residents, and medical students about challenges teaching and learning surgical technique. 25 LH surgeons, 65 right-handed (RH) surgeons, and 39 LH trainees completed the survey. Compared to LH surgeons, RH surgeons reported more difficulty (46% vs 16%, p = 0.003) and less comfort teaching LH trainees (28% vs 4%, p = 0.002), and 10 (15%) reported that LH trainees have less technical ability. RH surgeons identified challenges translating technique to LH trainees and physical limitations of an environment optimized for right-handed mechanics. The disadvantage LH surgical trainees face is due to barriers in training rather than inherent lesser ability. Nonetheless, minimal modifications are made to overcome these barriers. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Enantioselective targeting left-handed Z-G-quadruplex.

    Science.gov (United States)

    Zhao, Andong; Zhao, Chuanqi; Ren, Jinsong; Qu, Xiaogang

    2016-01-25

    Herein, we report the first example where an M-enantiomer of a chiral metal complex can selectively stabilize a left-handed G-quadruplex, but its P-enantiomer cannot. The interactions between the chiral metal complexes and the left-handed G-quadruplex were evaluated by UV melting, circular dichroism, isothermal titration calorimetry, gel electrophoresis and NMR titrations.

  15. Left-Handed Students: A Forgotten Minority. Fastback 399.

    Science.gov (United States)

    Kelly, Evelyn B.

    This fastback, a booklet bound "left-handed," is designed to help educators become aware of the problems faced by left-handed students in school and to suggest ways that many of the problems might be solved. Following an introduction discussing a personal experience with left-handedness, the booklet continues with a brief history of the treatment…

  16. Left-Handed Children--Are They Losing Out?

    Science.gov (United States)

    Milsom, Lauren

    1995-01-01

    Discusses difficulties faced by left-handed children in everyday schoolwork. Highlights include right-handed bias of toys, clothing, and tools; the need for guidance in handwriting; problem areas including domestic science, arts and crafts, and metal and woodwork; left-hand advantages in sports and creative arts; and the European Left-Handers Club…

  17. Left-Handed Preschool Children with Orthopedic Disabilities.

    Science.gov (United States)

    Banham, Katharine M.

    1983-01-01

    The mental development of 332 preschool-age children with orthopedic disabilities was assessed at a children's hospital over a 10-year period, and comparisons were made for right-handed and left-handed. The left-handed children were slower than right-handed children in learning speech and language skills (Author/SEW)

  18. Gene expression profile of zeitlupe/lov kelch protein1 T-DNA insertion mutants in Arabidopsis thaliana: Downregulation of auxin-inducible genes in hypocotyls.

    Science.gov (United States)

    Saitoh, Aya; Takase, Tomoyuki; Kitaki, Hiroyuki; Miyazaki, Yuji; Kiyosue, Tomohiro

    2015-01-01

    Elongation of hypocotyl cells has been studied as a model for elucidating the contribution of cellular expansion to plant organ growth. ZEITLUPE (ZTL) or LOV KELCH PROTEIN1 (LKP1) is a positive regulator of warmth-induced hypocotyl elongation under white light in Arabidopsis, although the molecular mechanisms by which it promotes hypocotyl cell elongation remain unknown. Microarray analysis showed that 134 genes were upregulated and 204 genes including 15 auxin-inducible genes were downregulated in the seedlings of 2 ztl T-DNA insertion mutants grown under warm conditions with continuous white light. Application of a polar auxin transport inhibitor, an auxin antagonist or an auxin biosynthesis inhibitor inhibited hypocotyl elongation of control seedlings to the level observed with the ztl mutant. Our data suggest the involvement of auxin and auxin-inducible genes in ZTL-mediated hypocotyl elongation.

  19. Left-handed materials in metallic magnetic granular composites

    International Nuclear Information System (INIS)

    Chui, S.T.; Lin, Z.F.; Hu, L.-B.

    2003-01-01

    There is recently interests in the 'left-handed' materials. In these materials the direction of the wave vector of electromagnetic radiation is opposite to the direction of the energy flow. We present simple arguments that suggests that magnetic composites can also be left-handed materials. However, the physics involved seems to be different from the original argument. In our argument, the imaginary part of the dielectric constant is much larger than the real part, opposite to the original argument

  20. Isotropic three-dimensional left-handed meta-materials

    OpenAIRE

    Koschny, Th.; Zhang, L.; Soukoulis, C. M.

    2005-01-01

    We investigate three-dimensional left-handed and related meta-materials based on a fully symmetric multi-gap single-ring SRR design and crossing continuous wires. We demonstrate isotropic transmission properties of a SRR-only meta-material and the corresponding left-handed material which possesses a negative effective index of refraction due to simultaneously negative effective permeability and permittivity. Minor deviations from complete isotropy are due to the finite thickness of the meta-m...

  1. Scattering Forces within a Left-Handed Photonic Crystal.

    Science.gov (United States)

    Ang, Angeleene S; Sukhov, Sergey V; Dogariu, Aristide; Shalin, Alexander S

    2017-01-23

    Electromagnetic waves are known to exert optical forces on particles through radiation pressure. It was hypothesized previously that electromagnetic waves inside left-handed metamaterials produce negative radiation pressure. Here we numerically examine optical forces inside left-handed photonic crystals demonstrating negative refraction and reversed phase propagation. We demonstrate that even though the direction of force might not follow the flow of energy, the positive radiation pressure is maintained inside photonic crystals.

  2. Left-handed surgical instruments - a guide for cardiac surgeons.

    Science.gov (United States)

    Burdett, Clare; Theakston, Maureen; Dunning, Joel; Goodwin, Andrew; Kendall, Simon William Henry

    2016-08-19

    For ease of use and to aid precision, left-handed instruments are invaluable to the left-handed surgeon. Although they exist, they are not available in many surgical centres. As a result, most operating theatre staff (including many left-handers) have little knowledge of their value or even application. With specific reference to cardiac surgery, this article addresses the ways in which they differ, why they are needed and what is required - with tips on use.

  3. Infrared metasurface with tunable composite right/left-handed dispersion

    Science.gov (United States)

    Ma, Jie; Luo, Yi; Wu, Xuefei; Xu, Hongyan; Jing, Hongwei; Wu, Zhiming; Jiang, Yadong; Liu, Zhijun

    2017-11-01

    The distinctive dispersion of composite right/left-handed transmission-line metamaterial offers a unique way of manipulating electromagnetic waves across a wide spectral range from microwave to the infrared. In this paper, we present a tunable mid-infrared composite right/left-handed metasurface based on the phase-change material of vanadium dioxide. The metasurface consists of an array of ‘H’-shaped gold pads separated from a metallic ground plane by a film of vanadium dioxide. As the insulator-to-metal phase transition is thermally triggered, both right-handed and left-handed metasurface modes redshift with reduced absorbance before they are eventually switched off. The tunabilities of right-handed mode frequency and left-handed mode frequency are measured to be approximately 3.6% and 2.7%, respectively. Our demonstrated metasurface with tunable composite right/left-handed dispersion could be useful for beam scanning for a fixed frequency in mid-infrared applications.

  4. Inducible Expression of Agrobacterium Virulence Gene VirE2 for Stringent Regulation of T-DNA Transfer in Plant Transient Expression Systems.

    Science.gov (United States)

    Denkovskienė, Erna; Paškevičius, Šarūnas; Werner, Stefan; Gleba, Yuri; Ražanskienė, Aušra

    2015-11-01

    Agrotransfection with viral vectors is an effective solution for the transient production of valuable proteins in plants grown in contained facilities. Transfection methods suitable for field applications are desirable for the production of high-volume products and for the transient molecular reprogramming of plants. The use of genetically modified (GM) Agrobacterium strains for plant transfections faces substantial biosafety issues. The environmental biosafety of GM Agrobacterium strains could be improved by regulating their T-DNA transfer via chemically inducible expression of virE2, one of the essential Agrobacterium virulence genes. In order to identify strong and stringently regulated promoters in Agrobacterium strains, we evaluated isopropyl-β-d-thiogalactoside-inducible promoters Plac, Ptac, PT7/lacO, and PT5/lacOlacO and cumic acid-inducible promoters PlacUV5/CuO, Ptac/CuO, PT5/CuO, and PvirE/CuO. Nicotiana benthamiana plants were transfected with a virE2-deficient A. tumefaciens strain containing transient expression vectors harboring inducible virE2 expression cassettes and containing a marker green fluorescent protein (GFP) gene in their T-DNA region. Evaluation of T-DNA transfer was achieved by counting GFP expression foci on plant leaves. The virE2 expression from cumic acid-induced promoters resulted in 47 to 72% of wild-type T-DNA transfer. Here, we present efficient and tightly regulated promoters for gene expression in A. tumefaciens and a novel approach to address environmental biosafety concerns in agrobiotechnology.

  5. DNA repair genes RAD52 and SRS2, a cell wall synthesis regulator gene SMI1, and the membrane sterol synthesis scaffold gene ERG28 are important in efficient Agrobacterium-mediated yeast transformation with chromosomal T-DNA.

    Science.gov (United States)

    Ohmine, Yuta; Satoh, Yukari; Kiyokawa, Kazuya; Yamamoto, Shinji; Moriguchi, Kazuki; Suzuki, Katsunori

    2016-04-02

    Plant pathogenic Agrobacterium strains can transfer T-DNA regions of their Ti plasmids to a broad range of eukaryotic hosts, including fungi, in vitro. In the recent decade, the yeast Saccharomyces cerevisiae is used as a model host to reveal important host proteins for the Agrobacterium-mediated transformation (AMT). Further investigation is required to understand the fundamental mechanism of AMT, including interaction at the cell surface, to expand the host range, and to develop new tools. In this study, we screened a yeast mutant library for low AMT mutant strains by advantage of a chromosome type T-DNA, which transfer is efficient and independent on integration into host chromosome. By the mutant screening, we identified four mutant strains (srs2Δ, rad52Δ, smi1Δ and erg28Δ), which showed considerably low AMT efficiency. Structural analysis of T-DNA product replicons in AMT colonies of mutants lacking each of the two DNA repair genes, SRS2 and RAD52, suggested that the genes act soon after T-DNA entry for modification of the chromosomal T-DNA to stably maintain them as linear replicons and to circularize certain T-DNA simultaneously. The cell wall synthesis regulator SMI1 might have a role in the cell surface interaction between the donor and recipient cells, but the smi1Δ mutant exhibited pleiotropic effect, i.e. low effector protein transport as well as low AMT for the chromosomal T-DNA, but relatively high AMT for integrative T-DNAs. The ergosterol synthesis regulator/enzyme-scaffold gene ERG28 probably contributes by sensing a congested environment, because growth of erg28Δ strain was unaffected by the presence of donor bacterial cells, while the growth of the wild-type and other mutant yeast strains was suppressed by their presence. RAD52 and the DNA helicase/anti-recombinase gene SRS2 are necessary to form and maintain artificial chromosomes through the AMT of chromosomal T-DNA. A sterol synthesis scaffold gene ERG28 is important in the high

  6. Wide-scale screening of T-DNA lines for transcription factor genes affecting male gametophyte development in Arabidopsis

    Czech Academy of Sciences Publication Activity Database

    Reňák, David; Dupľáková, Nikoleta; Honys, David

    2012-01-01

    Roč. 25, č. 1 (2012), s. 39-60 ISSN 0934-0882 R&D Projects: GA AV ČR KJB600380701; GA ČR GA522/09/0858; GA MŠk(CZ) OC10054 Institutional research plan: CEZ:AV0Z50380511 Keywords : Male gametophyte * Transcription factor * T-DNA insertion line Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.070, year: 2012

  7. Molecular analysis of T-DNA insertion mutants identified putative regulatory elements in the atTERT gene

    Czech Academy of Sciences Publication Activity Database

    Fojtová, Miloslava; Peška, Vratislav; Dobšáková, Zuzana; Mozgová, I.; Fajkus, Jiří; Sýkorová, Eva

    2011-01-01

    Roč. 62, č. 15 (2011), s. 5531-5545 ISSN 0022-0957 R&D Projects: GA AV ČR(CZ) IAA500040801; GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Arabidopsis thaliana * T-DNA insertion * telomerase Subject RIV: BO - Biophysics Impact factor: 5.364, year: 2011

  8. Magnetotunable left-handed FeSiB ferromagnetic microwires

    Czech Academy of Sciences Publication Activity Database

    Labrador, A.; Gómez-Polo, C.; Pérez-Landazábal, J.I.; Zablotskyy, Vitaliy A.; Ederra, I.; Gonzalo, R.; Badini-Confalonieri, G.; Vazquez, M.

    2010-01-01

    Roč. 35, č. 13 (2010), s. 2161-2163 ISSN 0146-9592 Institutional research plan: CEZ:AV0Z10100522 Keywords : ferromagnetic microwires * left - handed materials * ferromagnetic resonance Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.316, year: 2010 http://www.opticsinfobase.org/abstract.cfm?uri=ol-35-13-2161

  9. Challenges left-handed students face in Kenyan girls' secondary ...

    African Journals Online (AJOL)

    The conclusion of this study provide evidence that there is need for Kenya government to rethink her initial and in-service special education needs' teacher training to include a module in left-handedness in order to equip all teachers to be able to identify and assist left-handed students to learn with least difficult.

  10. Design and analysis of doped left-handed materials

    International Nuclear Information System (INIS)

    Zhang Hongxin; Bao Yongfang; Chen Tianming; Lü Yinghua; Wang Haixia

    2008-01-01

    We devise three sorts of doped left-handed materials (DLHMs) by introducing inductors and capacitors into the traditional left-handed material (LHM) as heterogeneous elements. Some new properties are presented through finite-difference time-domain (FDTD) simulations. On the one hand, the resonance in the traditional LHM is weakened and the original pass band is narrowed by introducing inductors. On the other hand, the original pass band of the LHM can be shifted and a new pass band can be generated by introducing capacitors. When capacitors and inductors are introduced simultaneously, the resonance of traditional LHM is somewhat weakened and the number of original pass bands as well as its bandwidth can be changed

  11. Position-Dependent Methylation and Transcriptional Silencing of Transgenes in Inverted T-DNA Repeats: Implications for Posttranscriptional Silencing of Homologous Host Genes in Plants

    Science.gov (United States)

    Stam, Maike; Viterbo, Ada; Mol, Joseph N. M.; Kooter, Jan M.

    1998-01-01

    Posttranscriptional silencing of chalcone synthase (Chs) genes in petunia transformants occurs by introducing T-DNAs that contain a promoter-driven or promoterless Chs transgene. With the constructs we used, silencing occurs only by T-DNA loci which are composed of two or more T-DNA copies that are arranged as inverted repeats (IRs). Since we are interested in the mechanism by which these IR loci induce silencing, we have analyzed different IR loci and nonsilencing single-copy (S) T-DNA loci with respect to the expression and methylation of the transgenes residing in these loci. We show that in an IR locus, the transgenes located proximal to the IR center are much more highly methylated than are the distal genes. A strong silencing locus composed of three inverted T-DNAs bearing promoterless Chs transgenes was methylated across the entire locus. The host Chs genes in untransformed plants were moderately methylated, and no change in methylation was detected when the genes were silenced. Run-on transcription assays showed that promoter-driven transgenes located proximal to the center of a particular IR are transcriptionally more repressed than are the distal genes of the same IR locus. Transcription of the promoterless Chs transgenes could not be detected. In the primary transformant, some of the IR loci were detected together with an unlinked S locus. We observed that the methylation and expression characteristics of the transgenes of these S loci were comparable to those of the partner IR loci, suggesting that there has been cross talk between the two types of loci. Despite the similar features, S loci are unable to induce silencing, indicating that the palindromic arrangement of the Chs transgenes in the IR loci is critical for silencing. Since transcriptionally silenced transgenes in IRs can trigger posttranscriptional silencing of the host genes, our data are most consistent with a model of silencing in which the transgenes physically interact with the

  12. Atypical white matter microstructure in left-handed individuals.

    Science.gov (United States)

    McKay, Nicole S; Iwabuchi, Sarina J; Häberling, Isabelle S; Corballis, Michael C; Kirk, Ian J

    2017-05-01

    Information regarding anatomical connectivity in the human brain can be gathered using diffusion tensor imaging (DTI). Fractional anisotropy (FA) is the most commonly derived value, and reflects how strongly directional are the underlying tracts. Differences in FA are thus associated with differences in the underlying microstructure of the brain. The relationships between these differences in microstructure and functional differences in corresponding regions have also been examined. Previous studies have found an effect of handedness on functional lateralization in the brain and corresponding microstructural differences. Here, using tract-based spatial statistics to analyse DTI-derived FA values, we further investigated the structural white matter architecture in the brains of right- and left-handed males. We found significantly higher FA values for left-handed, relatively to right-handed, individuals, in all major lobes, and in the corpus callosum. In support of previous suggestions, we find that there is a difference in the microstructure of white matter in left- and right-handed males that could underpin reduced lateralization of function in left-handed individuals.

  13. Frequency Bandwidth Optimization of Left-Handed Metamaterial

    Science.gov (United States)

    Chevalier, Christine T.; Wilson, Jeffrey D.

    2004-01-01

    Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.

  14. Structure of a left-handed DNA G-quadruplex.

    Science.gov (United States)

    Chung, Wan Jun; Heddi, Brahim; Schmitt, Emmanuelle; Lim, Kah Wai; Mechulam, Yves; Phan, Anh Tuân

    2015-03-03

    Aside from the well-known double helix, DNA can also adopt an alternative four-stranded structure known as G-quadruplex. Implications of such a structure in cellular processes, as well as its therapeutic and diagnostic applications, have been reported. The G-quadruplex structure is highly polymorphic, but so far, only right-handed helical forms have been observed. Here we present the NMR solution and X-ray crystal structures of a left-handed DNA G-quadruplex. The structure displays unprecedented features that can be exploited as unique recognition elements.

  15. Controllable optical black hole in left-handed materials.

    Science.gov (United States)

    Bai, Qiang; Chen, Jing; Shen, Nian-Hai; Cheng, Chen; Wang, Hui-Tian

    2010-02-01

    Halting and storing light by infinitely decelerating its speed, in the absence of any form of external control, is extremely di+/-cult to imagine. Here we present a theoretical prediction of a controllable optical black hole composed of a planar left-handed material slab. We reveal a criterion that the effective round-trip propagation length in one zigzag path is zero, which brings light to a complete standstill. Both theory and ab initio simulation demonstrate that this optical black hole has degrees flexible controllability for the speed of light. Surprisingly, the ab initio simulations reveal that our scheme has degrees flexible controllability for swallowing, holding, and releasing light.

  16. A Novel Tunable Triple-Band Left-Handed Metamaterial

    Directory of Open Access Journals (Sweden)

    Si Li

    2017-01-01

    Full Text Available A novel tunable triple-band left-handed metamaterial (LHM composed of a single-loop resonator (SLR and a variable capacitor-loaded short wire pair (CL-SWP printed on both sides of a substrate is presented in this paper. The CL-SWP-based metamaterial (MTM is a novel single-sided LHM. It is theoretically analyzed capable of extracting tunable negative permeability and a wide-band negative permittivity. We ran simulations for the CL-SWP-based MTM, the SLR-based MTM, and the proposed LHM. Together with the measured results, it is identified that this novel LHM exhibits a tunable triple-band left-handed (LH property. With the increase of the loaded capacitance, one LH band is relatively stable, while the other two are moving towards lower frequencies with their bandwidth getting wider and narrower, respectively. The surface current density distributions indicate that the first LH band is mainly decided by the SLR, one of the rest 2 LH bands is mainly decided by the CL-SWP, and the other one is decided by the SLR and CL-SWP together.

  17. Garner-Interference in left-handed awkward grasping.

    Science.gov (United States)

    Eloka, Owino; Feuerhake, Felix; Janczyk, Markus; Franz, Volker H

    2015-07-01

    The Perception-Action Model (PAM) claims to provide a coherent interpretation of data from all areas of the visual neurosciences, most notably data from neuropsychological patients and from behavioral experiments in healthy people. Here, we tested two claims that are part of the core version of the PAM: (a) certain actions (natural, highly practiced, and right-handed) are controlled by the dorsal vision for action pathway, while other actions (awkward, unpracticed, or left-handed) are controlled by the ventral vision for perception pathway. (b) Only the dorsal pathway operates in an analytical fashion, being able to selectively focus on the task-relevant dimension of an object (Ganel and Goodale, Nature 426(6967):664-667, 2003). We show that one of these claims must be wrong: using the same test for analytical processing as Ganel and Goodale (2003), we found that even an action that should clearly be ventral (left-handed awkward grasping) shows analytical processing just as a dorsal task does (right-handed natural precision grasping). These results are at odds with the PAM and point to an inconsistency of the model.

  18. Left Hand Dominance Affects Supra-Second Time Processing

    Science.gov (United States)

    Vicario, Carmelo Mario; Bonní, Sonia; Koch, Giacomo

    2011-01-01

    Previous studies exploring specific brain functions of left- and right-handed subjects have shown variances in spatial and motor abilities that might be explained according to consistent structural and functional differences. Given the role of both spatial and motor information in the processing of temporal intervals, we designed a study aimed at investigating timing abilities in left-handed subjects. To this purpose both left- and right-handed subjects were asked to perform a time reproduction of sub-second vs. supra-second time intervals with their left and right hand. Our results show that during processing of the supra-second intervals left-handed participants sub-estimated the duration of the intervals, independently of the hand used to perform the task, while no differences were reported for the sub-second intervals. These results are discussed on the basis of recent findings on supra-second motor timing, as well as emerging evidence that suggests a linear representation of time with a left-to-right displacement. PMID:22028685

  19. Left Handed Materials: A New Paradigm in Structured Electromagnetics

    International Nuclear Information System (INIS)

    Johri, Manoj; Paudyal, Harihar

    2010-05-01

    A new paradigm has emerged exhibiting reverse electromagnetic properties. Novel composite and micro-structured materials (metamaterials) have been designed to control electromagnetic radiation. Such substances have been called as Left Handed Material (LHM) with simultaneous negative permittivity and negative permeability and negative refractive index as well. Left handed materials are of importance because of their ability to influence the behavior of electromagnetic radiation and to display properties beyond those available in naturally occurring materials. Typically these are sub-wavelength artificial structures where the dimensions are very small compared to the working wavelength. These dimensions are normally of the order of λ/10 where λ is the wavelength of electromagnetic wave propagating in the material. Emergence of this new paradigm leads to some very interesting consequences, such as, to create lenses that are not diffraction limited, cloaking, sensors (chemical, biological and individual molecule), optical and radio communication. This new development in structured electromagnetic materials has had a dramatic impact on the physics, optics and engineering communities. (author)

  20. Surface polaritons in grating composed of left-handed materials

    Science.gov (United States)

    Tiwari, D. C.; Premlal, P. L.; Chaturvedi, Vandana

    2018-01-01

    In this work, we developed a unique mathematical model to solve dispersion relation for surface polaritons (SPs) in artificial composite materials grating. Here, we have taken two types of materials for analysis. In the first case, the grating composed of epsilon-negative (ENG) material and air interface. In second case, grating composed of left-handed materials (LHMs) and ENG medium interface is considered. The dispersion curves of both p and s polarized SPs modes are obtained analytically. In the case of ENG grating and air interface, polaritons dispersion curves exist for p-polarization only, whereas for LHM grating and ENG medium interface, the polaritons dispersion curves for both p and s polarization are observed.

  1. Bright breathers in nonlinear left-handed metamaterial lattices

    Science.gov (United States)

    Koukouloyannis, V.; Kevrekidis, P. G.; Veldes, G. P.; Frantzeskakis, D. J.; DiMarzio, D.; Lan, X.; Radisic, V.

    2018-02-01

    In the present work, we examine a prototypical model for the formation of bright breathers in nonlinear left-handed metamaterial lattices. Utilizing the paradigm of nonlinear transmission lines, we build a relevant lattice and develop a quasi-continuum multiscale approximation that enables us to appreciate both the underlying linear dispersion relation and the potential for bifurcation of nonlinear states. We focus here, more specifically, on bright discrete breathers which bifurcate from the lower edge of the linear dispersion relation at wavenumber k=π . Guided by the multiscale analysis, we calculate numerically both the stable inter-site centered and the unstable site-centered members of the relevant family. We quantify the associated stability via Floquet analysis and the Peierls-Nabarro barrier of the energy difference between these branches. Finally, we explore the dynamical implications of these findings towards the potential mobility or lack thereof (pinning) of such breather solutions.

  2. Left-handed sperm removal by male Calopteryx damselflies (Odonata).

    Science.gov (United States)

    Tsuchiya, Kaori; Hayashi, Fumio

    2014-01-01

    Male genitalia in several insect species are asymmetry in right and left shape. However, the function of such asymmetric male genitalia is still unclear. We found that the male genitalia of the damselfly Calopteryx cornelia (Odonata: Calopterygidae) are morphologically symmetric just after emergence but asymmetric after reproductive maturation. Males remove rival sperm stored in the female bursa copulatrix (single spherical sac) and the following spermatheca (Y-shaped tubular sac) prior to their own ejaculation to prevent sperm competition. Males possess the aedeagus with a recurved head to remove bursal sperm and a pair of spiny lateral processes to remove spermathecal sperm. The right lateral process is less developed than the left, and sperm stored in the right spermathecal tube are rarely removed. Experiments involving surgical cutting of each lateral process demonstrated that only the left process functions in spermathecal sperm removal. Thus, males of C. cornelia are left-handed in their sperm removal behaviour at copulation.

  3. A planar left-handed metamaterial based on electric resonators

    International Nuclear Information System (INIS)

    Chen Chun-Hui; Qu Shao-Bo; Wang Jia-Fu; Ma Hua; Wang Xin-Hua; Xu Zhuo

    2011-01-01

    A planar left-handed metamaterial(LHM) composed of electric resonator pairs is presented in this paper. Theoretical analysis, an equivalent circuit model and simulated results of a wedge sample show that this material exhibits a negative refraction pass-band around 9.6GHz under normal-incidence and is insensitive to a change in incidence angle. Furthermore, as the angle between the arm of the electric resonators and the strip connecting the arms increases, the frequency range of the pass-band shifts downwards. Consequently, this LHM guarantees a relatively stable torlerence of errors when it is practically fabricated. Moreover, it is a candidate for designing multi-band LHM through combining the resonator pairs with different angles. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  4. Raman spectroscopic study of left-handed Z-RNA

    International Nuclear Information System (INIS)

    Trulson, M.O.; Cruz, P.; Puglisi, J.D.; Tinoco, I. Jr.; Mathies, R.A.

    1987-01-01

    The solvent conditions that induce the formation of a left-handed Z form of poly[r(G-C)] have been extended to include 6.5 M NaBr at 35 0 C and 3.8 M MgCl 2 at room temperature. The analysis of the A → Z transition in RNA by circular dichroism (CD), 1 H and 31 P NMR, and Raman spectroscopy shows that two distinct forms of left-handed RNA exist. The Z/sub R/-RNA structure forms in high concentrations of NaBr and NaClO 4 and exhibits a unique CD signature. Z/sub D/-RNA is found in concentrated MgCl 2 and has a CD signature similar to the Z form of poly[d(G-C)]. Significant differences in the glycosyl angle and sugar pucker between Z-DNA and Z-RNA are suggested by the 16-cm -1 difference in the position of this band. The Raman evidence for structural difference between Z/sub D/- and Z/sub R/-RNA comes from two groups of bands: First, Raman intensities between 1180 and 1600 cm -1 of Z/sub D/-RNA differ from those for Z/sub R/-RNA, corroborating the CD evidence for differences in base-stacking geometry. Second, the phosphodiester stretching bands near 815 cm -1 provide evidence of differences in backbone geometry between Z/sub D-/ and Z/sub R/-RNA

  5. Raman spectroscopic study of left-handed Z-RNA.

    Science.gov (United States)

    Trulson, M O; Cruz, P; Puglisi, J D; Tinoco, I; Mathies, R A

    1987-12-29

    The solvent conditions that induce the formation of a left-handed Z form of poly[r(G-C)] have been extended to include 6.5 M NaBr at 35 degrees C and 3.8 M MgCl2 at room temperature. The analysis of the A----Z transition in RNA by circular dichroism (CD), 1H and 31P NMR, and Raman spectroscopy shows that two distinct forms of left-handed RNA exist. The ZR-RNA structure forms in high concentrations of NaBr and NaClO4 and exhibits a unique CD signature. ZD-RNA is found in concentrated MgCl2 and has a CD signature similar to the Z form of poly[d(G-C)]. The loss of Raman intensity of the 813-cm-1 A-form marker band in both the A----ZR-RNA and A----ZD-RNA transitions parallels the loss of intensity at 835 cm-1 in the B----Z transition of DNA. A guanine vibration that is sensitive to the glycosyl torsion angle shifts from 671 cm-1 in A-RNA to 641 cm-1 in both ZD- and ZR-RNA, similar to the B----Z transition in DNA in which this band shifts from 682 to 625 cm-1. Significant differences in the glycosyl angle and sugar pucker between Z-DNA and Z-RNA are suggested by the 16-cm-1 difference in the position of this band. The Raman evidence for structural difference between ZD- and ZR-RNA comes from two groups of bands: First, Raman intensities between 1180 and 1600 cm-1 of ZD-RNA differ from those for ZR-RNA, corroborating the CD evidence for differences in base-stacking geometry. Second, the phosphodiester stretching bands near 815 cm-1 provide evidence of differences in backbone geometry between ZD- and ZR-RNA.

  6. Sequence and functional analysis of the left-hand part of the T-region from the nopaline-type Ti plasmid, pTiC58.

    Science.gov (United States)

    Otten, L; Salomone, J Y; Helfer, A; Schmidt, J; Hammann, P; De Ruffray, P

    1999-12-01

    The Agrobacterium tumefaciens nopaline strain C58 transfers a large, 29 kb T-DNA into plant cells during infection. Part of this DNA (the 'common DNA') is also found on the T-DNA of octopine strains, the remaining DNA is nopaline strain-specific. Up to now, only parts of the C58 T-DNA and related T37 T-DNA have been sequenced. We have sequenced the remainder of the nopaline-specific T-DNA (containing genes a to d) and acs to iaaM. Gene c codes for a new unknown T-DNA protein. Gene a is homologous to the agrocinopine synthase gene. Genes b, c', d and e are part of a larger family: they are related to the T-DNA genes 5, rolB, lso and 3'. Genes 5, rolB and lso induce or modify plant growth and have been called T-DNA oncogenes. Our studies show that gene 3' (located on the TR-DNA of octopine strains) is also oncogenic. Although the b-e T-DNA fragment from C58 and its individual genes lack growth-inducing activity, an a-acs deletion mutant was distinctly less virulent on Kalanchoe daigremontiana and showed reduced shoot formation on Kalanchoe tubiflora. Shoot formation could be restored by genes c and c' in co-infection experiments. Contrary to an earlier report, a C58 e gene deletion mutant was fully virulent on all plants tested.

  7. Flat Lens Focusing Demonstrated With Left-Handed Metamaterial

    Science.gov (United States)

    Wilson, Jeffrey D.; Schwartz, Zachary D.; Chevalier, Christine T.; Downey, Alan N.; Vaden, Karl R.

    2004-01-01

    Left-handed metamaterials (LHM's) are a new media engineered to possess an effective negative index of refraction over a selected frequency range. This characteristic enables LHM's to exhibit physical properties never before observed. In particular, a negative index of refraction should cause electromagnetic radiation to refract or bend at a negative angle when entering an LHM, as shown in the figure above on the left. The figure on the right shows that this property could be used to bring radiation to a focus with a flat LHM lens. The advantage of a flat lens in comparison to a conventional curved lens is that the focal length could be varied simply by adjusting the distance between the lens and the electromagnetic wave source. In this in-house work, researchers at the NASA Glenn Research Center developed a computational model for LHM's with the three-dimensional electromagnetic commercial code Microwave Studio, constructed an LHM flat lens, and used it to experimentally demonstrate the reversed refraction and flat lens focusing of microwave radiation.

  8. Why are some people left-handed? An evolutionary perspective

    Science.gov (United States)

    Llaurens, V.; Raymond, M.; Faurie, C.

    2008-01-01

    Since prehistoric times, left-handed individuals have been ubiquitous in human populations, exhibiting geographical frequency variations. Evolutionary explanations have been proposed for the persistence of the handedness polymorphism. Left-handedness could be favoured by negative frequency-dependent selection. Data have suggested that left-handedness, as the rare hand preference, could represent an important strategic advantage in fighting interactions. However, the fact that left-handedness occurs at a low frequency indicates that some evolutionary costs could be associated with left-handedness. Overall, the evolutionary dynamics of this polymorphism are not fully understood. Here, we review the abundant literature available regarding the possible mechanisms and consequences of left-handedness. We point out that hand preference is heritable, and report how hand preference is influenced by genetic, hormonal, developmental and cultural factors. We review the available information on potential fitness costs and benefits acting as selective forces on the proportion of left-handers. Thus, evolutionary perspectives on the persistence of this polymorphism in humans are gathered for the first time, highlighting the necessity for an assessment of fitness differences between right- and left-handers. PMID:19064347

  9. Technical modifications for laparoscopic cholecystectomy by the left-handed surgeon.

    Science.gov (United States)

    Herrero-Segura, Antonio; López-Tomassetti Fernández, Eudaldo M; Medina-Arana, Vicente

    2007-10-01

    There is a complete paucity of literature for left-handed surgeons. Some studies revealed that left-handed surgical residents have lesser operating skills and some surgeons have considered leaving surgery at some point in their career owing to laterality-related frustrations. Most important, whereas minimally invasive surgical techniques have had a profound impact on the treatment of diseased gallbladder, these procedures do not eliminate laterality related to the discomfort of left-handed surgeons. Usually, left-handed surgeons must teach themselves a procedure. They must make modifications and learn some technical tips to make a more comfortable, convenient, and safe intervention. The aim of this study was to describe some modifications made by a left-handed surgeon to perform 52 safe laparoscopic cholecystectomies with standard right-handed instruments in our hospital. These surgical steps could be used in a reproducible way to minimize the recurring difficulties of left-handed learners in a surgical residency program.

  10. Drilling simulated temporal bones with left-handed tools: a left-hander's right?

    Science.gov (United States)

    Torgerson, Cory S; Brydges, Ryan; Chen, Joseph M; Dubrowski, Adam

    2007-11-01

    Left-handed trainees can be at a disadvantage in the surgical environment because of a right-handed bias. The effectiveness of teaching left-handed trainees to use an otologic drill designed for their dominant hand versus the conventional right-handed drill was examined. Novice medical students were recruited from the university community. Twenty-four subjects were left-handed, and 12 were right-handed. Eight left-handed surgeons also participated. A randomized controlled trial was conducted to compare the performance of left-handed trainees using novel left-handed drills to that of left-handed trainees using right-handed tools and to that of right-handed trainees using right-handed tools. The evaluation consisted of 3 phases: pretest, skill acquisition, and 2 post-tests. The measurement tools included expert assessment of performance, and subjective and objective final product analyses. An initial construct validity phase was conducted in which validity of the assessment tools was ensured. Both the left-handers using left-handed tools and the right-handers using right-handed tools significantly outperformed the left-handers using right-handed tools at pretest, immediate posttest, and delayed posttest. All participants improved their performance as a function of practice. The left-handed trainees learned bone drilling better with tools designed for the left hand. These tools may be incorporated into residency training programs for the development of surgical technical skills. Future studies should assess skill transfer between the left-handed and right-handed drills.

  11. The Aspergillus nidulans amdS gene as a marker for the identification of multicopy T-DNA integration events in Agrobacterium-mediated transformation of Aspergillus awamori

    NARCIS (Netherlands)

    Michielse, C.B.; Ram, A.F.J.; Hondel, C.A.M.J.J. van den

    2004-01-01

    The Aspergillus nidulans amdS selection marker was used for the identification of multicopy T-DNA insertions in Agrobacterium-mediated transformation of Asp. awamori. The selection of transformants on agar plates containing acetamide as sole nitrogen source and hygromycin resulted in a six-fold

  12. Functioning of medial olivocochlear bundle in right- and left-handed individuals.

    Science.gov (United States)

    Kaipa, Ramesh; Kumar, U Ajith

    2017-07-01

    Functional symmetry of medial olivocochlear bundle (MOCB) as a function of handedness remains to be well investigated. The current study aimed to assess the functional symmetry of MOCB through contralateral inhibition of otoacoustic emissions (OAEs) in right- and left-handed individuals. Thirteen left-handed and 13 right-handed individuals in the age range of 19-25 years participated. Behavioural experiment involved measuring speech perception in noise and vocal reaction time. Physiological experiment involved measuring the contralateral inhibition of OAEs in both the ears of participants. Findings of the current study revealed lack of functional asymmetry in right- as well as left-handed individuals. Results of the current study suggest that right- as well as left-handed individuals do not demonstrate functional asymmetry at the level of descending auditory pathways unlike the higher cortical centres.

  13. Assessment of speed of writing among left-handed and righthanded ...

    African Journals Online (AJOL)

    -handed undergraduates at University of Benin. One hundred (100) undergraduate students irrespective of gender were used. Fifty of the students were males while the remaining fifty were females. Fifty (50) were left-handed and fifty (50) were ...

  14. Superior Temporal Gyrus Volume Abnormalities and Thought Disorder in Left-Handed Schizophrenic Men

    Science.gov (United States)

    Holinger, Dorothy P.; Shenton, Martha E.; Wible, Cynthia G.; Donnino, Robert; Kikinis, Ron; Jolesz, Ferenc A.; McCarley, Robert W.

    2010-01-01

    Objective Studies of schizophrenia have not clearly defined handedness as a differentiating variable. Moreover, the relationship between thought disorder and anatomical anomalies has not been studied extensively in left-handed schizophrenic men. The twofold purpose of this study was to investigate gray matter volumes in the superior temporal gyrus of the temporal lobe (left and right hemispheres) in left-handed schizophrenic men and left-handed comparison men, in order to determine whether thought disorder in the left-handed schizophrenic men correlated with tissue volume abnormalities. Method Left-handed male patients (N=8) with DSM-III-R diagnoses of schizophrenia were compared with left-handed comparison men (N=10) matched for age, socioeconomic status, and IQ. Magnetic resonance imaging (MRI) with a 1.5-T magnet was used to obtain scans, which consisted of contiguous 1.5-mm slices of the whole brain. MRI analyses (as previously defined by the authors) included the anterior, posterior, and total superior temporal gyrus in both the left and right hemispheres. Results There were three significant findings regarding the left-handed schizophrenic men: 1) bilaterally smaller gray matter volumes in the posterior superior temporal gyrus (16% smaller on the right, 15% smaller on the left); 2) a smaller volume on the right side of the total superior temporal gyrus; and 3) a positive correlation between thought disorder and tissue volume in the right anterior superior temporal gyrus. Conclusions These results suggest that expression of brain pathology differs between left-handed and right-handed schizophrenic men and that the pathology is related to cognitive disturbance. PMID:10553736

  15. A Qualitative assessment of the impact of handedness among left-handed surgeons in Saudi Arabia.

    Science.gov (United States)

    Zaghloul, Mohamed S; Saquib, Juliann; Al-Mazrou, AbdulRahman; Saquib, Nazmus

    2018-01-01

    Among Muslims, the use of the left hand in daily activities is discouraged; many people believe that left-handed physicians lack the competency for surgery. The study aim was to document the experience of left-handed surgeons in Saudi Arabia and the impact of handedness on their training, job performance, collegial relationships, and career progression. This qualitative study included 9 left-handed physicians in various surgical specialties from 4 major hospitals in Al-Qassim, Saudi Arabia. Face-to-face interviews using a semi-structured questionnaire were conducted. Interview transcripts were analysed with Qualitative Content Analysis Method. Of the participants, 78% were male and the mean age was 40 years. Twenty-two per cent were consultants, 67% were specialists, and 11% were resident physicians. Participants reported the following: (a) a lack of training programmes specific to handedness in undergraduate and postgraduate medical training, (b) inconvenience while being assisted by a right-handed colleague, (c) stress, fatigue, and physical pain due to the use of right-handed instruments, and (d) training of the right hand being the most common adaptation technique for a left-handed surgeon. It was concluded that left-handed surgeons experience difficulty with right-handed instruments and right-handed colleagues during surgery. It is recommended that clinical curriculum incorporate hand-specific training in surgery.

  16. Bimanual proprioceptive performance differs for right- and left-handed individuals.

    Science.gov (United States)

    Han, Jia; Waddington, Gordon; Adams, Roger; Anson, Judith

    2013-05-10

    It has been proposed that asymmetry between the upper limbs in the utilization of proprioceptive feedback arises from functional differences in the roles of the preferred and non-preferred hands during bimanual tasks. The present study investigated unimanual and bimanual proprioceptive performance in right- and left-handed young adults with an active finger pinch movement discrimination task. With visual information removed, participants were required to make absolute judgments about the extent of pinch movements made to physical stops, either by one hand, or by both hands concurrently, with the sequence of presented movement extents varied randomly. Discrimination accuracy scores were derived from participants' responses using non-parametric signal detection analysis. Consistent with previous findings, a non-dominant hand/hemisphere superiority effect was observed, where the non-dominant hands of right- and left-handed individuals performed overall significantly better than their dominant hands. For all participants, bimanual movement discrimination scores were significantly lower than scores obtained in the unimanual task. However, the magnitude of the performance reduction, from the unimanual to the bimanual task, was significantly greater for left-handed individuals. The effect whereby bimanual proprioception was disproportionately affected in left-handed individuals could be due to enhanced neural communication between hemispheres in left-handed individuals leading to less distinctive separation of information obtained from the two hands in the cerebral cortex. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Are there excitability changes in the hand motor cortex during speech in left-handed subjects?

    Science.gov (United States)

    Tokimura, Hiroshi; Tokimura, Yoshika; Arita, Kazunori

    2012-01-01

    Hemispheric dominance was investigated in left-handed subjects using single transcranial magnetic stimulation to assess the possible effect of forced change in the dominant hand. Single transcranial magnetic stimuli were delivered randomly over the hand area of the left or right motor cortex of 8 Japanese self-declared left-handed adult volunteers. Electromyographic responses were recorded in the relaxed first dorsal interosseous muscle while the subjects read aloud. Laterality quotient calculated by the Edinburgh Inventory ranged from -100 to -5.26 and laterality index calculated from motor evoked potentials ranged from -86.2 to 38.8. There was no significant correlation between laterality quotient and laterality index. Mean data values across all 8 subjects indicated significant increases only in the left hand. Our ratio analysis of facilitation of the hand motor potentials showed that 2 each of the 8 self-declared left-handers were right- and left-hand dominant and the other 4 were bilateral-hand dominant. Speech dominancy was localized primarily in the right cerebral hemisphere in left-handed subjects, but some individuals exhibited bilateral or left dominance, possibly attributable to the forced change of hand preference for writing in childhood. Our findings suggest changes in the connections between the speech and hand motor areas.

  18. Left-handed properties dependence versus the interwire distance in Fe-based microwires metastructures

    Directory of Open Access Journals (Sweden)

    Gabriel Ababei

    2016-05-01

    Full Text Available Experimental and theoretical investigations on the left-handed properties dependence versus the interwire distance of three new proposed Fe77.5Si7.5B15 glass coated microwires-based metastructures are presented. The left-handed characteristics of the metastructures were determined in the frequency range 8.2 ÷ 12 GHz and external d.c. magnetic fields ranging from 0 to 32 kA/m. The experimental results show that the electromagnetic losses of the metastructures increase with the decreasing of the interwire distance due to the increasing of the long-range dynamic dipole-dipole interaction within inter-wires in the presence of the microwave field. The numerical calculations using Nicolson–Weiss–Ross algorithm are in agreement with the experimental results. The variation of the interwire distance proves to be a useful tool to obtain metastructures with controlled left-handed characteristics.

  19. Neural Model for Left-Handed CPW Bandpass Filter Loaded Split Ring Resonator

    Science.gov (United States)

    Liu, Haiwen; Wang, Shuxin; Tan, Mingtao; Zhang, Qijun

    2010-02-01

    Compact left-handed coplanar waveguide (CPW) bandpass filter loaded split ring resonator (SRR) is presented in this paper. The proposed filter exhibits a quasi-elliptic function response and its circuit size occupies only 12 × 11.8 mm2 (≈0.21 λg × 0.20 λg). Also, a simple circuit model is given and the parametric study of this filter is discussed. Then, with the aid of NeuroModeler software, a five-layer feed-forward perceptron neural networks model is built up to optimize the proposed filter design fast and accurately. Finally, this newly left-handed CPW bandpass filter was fabricated and measured. A good agreement between simulations and measurement verifies the proposed left-handed filter and the validity of design methodology.

  20. Dark localized structures in a cavity filled with a left-handed material

    International Nuclear Information System (INIS)

    Tlidi, Mustapha; Kockaert, Pascal; Gelens, Lendert

    2011-01-01

    We consider a nonlinear passive optical cavity filled with left-handed and right-handed materials and driven by a coherent injected beam. We assume that both left-handed and right-handed materials possess a Kerr focusing type of nonlinearity. We show that close to the zero-diffraction regime, high-order diffraction allows us to stabilize dark localized structures in this device. These structures consist of dips in the transverse profile of the intracavity field and do not exist without high-order diffraction. We analyze the snaking bifurcation diagram associated with these structures. Finally, a realistic estimation of the model parameters is provided.

  1. Dark localized structures in a cavity filled with a left-handed material

    Energy Technology Data Exchange (ETDEWEB)

    Tlidi, Mustapha [Optique non lineaire theorique, Universite Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Bruxelles (Belgium); Kockaert, Pascal [OPERA-photonique, Universite Libre de Bruxelles, CP 194/5, 50, Av. F. D. Roosevelt, B-1050 Bruxelles (Belgium); Gelens, Lendert [Applied Physics Research Group (APHY), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel (Belgium)

    2011-07-15

    We consider a nonlinear passive optical cavity filled with left-handed and right-handed materials and driven by a coherent injected beam. We assume that both left-handed and right-handed materials possess a Kerr focusing type of nonlinearity. We show that close to the zero-diffraction regime, high-order diffraction allows us to stabilize dark localized structures in this device. These structures consist of dips in the transverse profile of the intracavity field and do not exist without high-order diffraction. We analyze the snaking bifurcation diagram associated with these structures. Finally, a realistic estimation of the model parameters is provided.

  2. Programming of left hand exploits task set but that of right hand depends on recent history.

    Science.gov (United States)

    Tang, Rixin; Zhu, Hong

    2017-07-01

    There are many differences between the left hand and the right hand. But it is not clear if there is a difference in programming between left hand and right hand when the hands perform the same movement. In current study, we carried out two experiments to investigate whether the programming of two hands was equivalent or they exploited different strategies. In the first experiment, participants were required to use one hand to grasp an object with visual feedback or to point to the center of one object without visual feedback on alternate trials, or to grasp an object without visual feedback and to point the center of one object with visual feedback on alternating trials. They then performed the tasks with the other hand. The result was that previous pointing task affected current grasping when it was performed by the left hand, but not the right hand. In experiment 2, we studied if the programming of the left (or right) hand would be affected by the pointing task performed on the previous trial not only by the same hand, but also by the right (or left) hand. Participants pointed and grasped the objects alternately with two hands. The result was similar with Experiment 1, i.e., left-hand grasping was affected by right-hand pointing, whereas right-hand grasping was immune from the interference from left hand. Taken together, the results suggest that when open- and closed-loop trials are interleaved, motor programming of grasping with the right hand was affected by the nature of the online feedback on the previous trial only if it was a grasping trial, suggesting that the trial-to-trial transfer depends on sensorimotor memory and not on task set. In contrast, motor programming of grasping with the left hand can use information about the nature of the online feedback on the previous trial to specify the parameters of the movement, even when the type of movement that occurred was quite different (i.e., pointing) and was performed with the right hand. This suggests that

  3. Artificial magnetism and left-handed media from dielectric rings and rods

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, L [Department of Electromagnetic Field, Czech Technical University in Prague, 166 27-Prague (Czech Republic); Marques, R, E-mail: l_jelinek@us.e [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla, 41012-Sevilla (Spain)

    2010-01-20

    It is shown that artificial magnetism with relatively large frequency bandwidth can be obtained from periodic arrangements of dielectric rings. Combined with dielectric rods, dielectric rings can provide 3D isotropic left-handed metamaterials which are an advantageous alternative to metallic split ring resonators (SRRs) and/or metallic wires when undetectability by low frequency external magnetic fields is desired. Furthermore it is shown that, unlike conventional SRRs, dielectric rings can also be combined with natural plasma-like media to obtain a left-handed metamaterial.

  4. Enhanced localization of Dyakonov-like surface waves in left-handed materials

    DEFF Research Database (Denmark)

    Crasovan, L. C.; Takayama, O.; Artigas, D.

    2006-01-01

    We address the existence and properties of hybrid surface waves forming at interfaces between left-handed materials and dielectric birefringent media. The existence conditions of such waves are found to be highly relaxed in comparison to Dyakonov waves existing in right-handed media. We show...... that left-handed materials cause the coexistence of several surface solutions, which feature an enhanced degree of localization. Remarkably, we find that the hybrid surface modes appear for large areas in the parameter space, a key property in view of their experimental observation....

  5. Induction of RNAi Responses by Short Left-Handed Hairpin RNAi Triggers.

    Science.gov (United States)

    Hagopian, Jonathan C; Hamil, Alexander S; van den Berg, Arjen; Meade, Bryan R; Eguchi, Akiko; Palm-Apergi, Caroline; Dowdy, Steven F

    2017-10-01

    Small double-stranded, left-handed hairpin (LHP) RNAs containing a 5'-guide-loop-passenger-3' structure induce RNAi responses by a poorly understood mechanism. To explore LHPs, we synthesized fully 2'-modified LHP RNAs targeting multiple genes and found all to induce robust RNAi responses. Deletion of the loop and nucleotides at the 5'-end of the equivalent passenger strand resulted in a smaller LHP that still induced strong RNAi responses. Surprisingly, progressive deletion of up to 10 nucleotides from the 3'-end of the guide strand resulted in a 32mer LHP capable of inducing robust RNAi responses. However, further guide strand deletion inhibited LHP activity, thereby defining the minimal length guide targeting length to 13 nucleotides. To dissect LHP processing, we examined LHP species that coimmunoprecipitated with Argonaute 2 (Ago2), the catalytic core of RNA-induced silencing complex, and found that the Ago2-associated processed LHP species was of a length that correlated with Ago2 cleavage of the passenger strand. Placement of a blocking 2'-OMe blocking modification at the LHP predicted Ago2 cleavage site resulted in an intact LHP loaded into Ago2 and no RNAi response. Taken together, these data argue that in the absence of a substantial loop, this novel class of small LHP RNAs enters the RNAi pathway by a Dicer-independent mechanism that involves Ago2 cleavage and results in an extended guide strand. This work establishes LHPs as an alternative RNAi trigger that can be produced from a single synthesis for potential use as an RNAi therapeutic.

  6. Cued Dichotic Listening with Right-Handed, Left-Handed, Bilingual and Learning-Disabled Children.

    Science.gov (United States)

    Obrzut, John E.; And Others

    This study used cued dichotic listening to investigate differences in language lateralization among right-handed (control), left handed, bilingual, and learning disabled children. Subjects (N=60) ranging in age from 7-13 years were administered a consonant-vowel-consonant dichotic paradigm with three experimental conditions (free recall, directed…

  7. Aortic root and proximal aortic arch replacement (performed by a left-handed surgeon).

    Science.gov (United States)

    Carrel, Thierry

    2017-01-01

    We present our standard technique of composite graft replacement performed by a left-handed surgeon. This procedure is performed with a 30-day mortality comparable to that of elective isolated aortic valve replacement. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  8. The study of radiosensitivity in left handed compared to right handed healthy women.

    Science.gov (United States)

    Khosravifarsani, Meysam; Monfared, Ali Shabestani; Akhavan-Niaki, Haleh; Moslemi, Dariush; Hajian-Tilaki, Karimollah; Elahimanesh, Farideh; Borzoueisileh, Sajad; Seyfizadeh, Nayer; Amiri, Mehrangiz

    2012-08-24

    Radiosensitivity is an inheriting trait that mainly depends on genetic factors. it is well known in similar dose of ionizing radiation and identical biological characteristics 9-10 percent of normal population have higher radiation response. Some reports indicate that distribution of breast cancer, immune diseases including autoimmune diseases as example lupus, Myasthenia Gravies and even the rate of allergy are more frequent in left handed individuals compared to right handed individuals. The main goal of the present study is determination of radiosensitivity in left handed compared to right handed in healthy women by cytokinesis blocked micronuclei [CBMN] assay.5 ml peripheral fresh blood sample was taken from 100 healthy women including 60 right handed and 40 left handed. The age of participants was between 20-25 old years and they had been matched by sex. After blood sampling, blood samples were divided to 2 groups including irradiated and non-irradiated lymphocytes that irradiated lymphocytes were exposed to 2 Gy CO-60 Gama rays source then chromosomal aberrations was analyzed by CBMN [Cytokinesis Blocked Micronuclei Assay]. Our results have shown radiosensitivity index [RI] in left-handers compared to right-handers is higher. Furthermore, the mean MN frequency is elevated in irradiated lymphocytes of left-handers in comparison with right-handers. Our results from CBMN assay have shown radiosensitivity in the left handed is higher than right handed women but more attempts need to prove this hypothesis.

  9. A Left Handed Compliment: A newly discovered, early nineteenth-century lithograph by John Lewis Marks.

    Science.gov (United States)

    McManus, I C; Snowman, Janet

    2010-01-01

    A newly discovered, early nineteenth-century lithograph by John Lewis Marks (b. ca. 1795-1796, d. ca. 1857-1861), entitled A Left Handed Compliment, is described. In this humorous print a young boy is using his left hand to draw the face of an elderly woman who is his grandmother, and she is shocked at the boy's suggestion that he will, “just see if I can't touch off your old Phizog left handed”. The source of the joke about the left-handed compliment is obscure, but more than likely it is sexual in origin. Glued to the verso of the print are early versions of two prints by Robert Seymour (1798-1836), the illustrator of Dickens' Pickwick Papers, suggesting a possible link between Marks and Seymour. From the hatch patterns on the Seymour engravings, it appears that Seymour may himself have been left-handed and perhaps therefore the butt of the joke. An alternative possibility is that Phizog is a reference to Dickens' later illustrator whose pseudonym was Phiz. It is also just conceivable that the young boy is Marks's own young son, Jacob. The print can be placed in the context of a scatological English vernacular humour that extends from Shakespeare through to Donald McGill and into the present day.

  10. Evidence for right-hand feeding biases in a left-handed population.

    Science.gov (United States)

    Flindall, Jason W; Stone, Kayla D; Gonzalez, Claudia L R

    2015-05-01

    We have recently shown that actions with similar kinematic requirements, but different end-state goals may be supported by distinct neural networks. Specifically, we demonstrated that when right-handed individuals reach-to-grasp food items with intent to eat, they produce smaller maximum grip apertures (MGAs) than when they grasp the same item with intent to place it in a location near the mouth. This effect was restricted to right-handed movements; left-handed movements showed no difference between tasks. The current study investigates whether (and to which side) the effect may be lateralized in left-handed individuals. Twenty-one self-identified left-handed participants grasped food items of three different sizes while grasp kinematics were captured via an Optotrak Certus motion capture array. A main effect of task was identified wherein the grasp-to-eat action generated significantly smaller MGAs than did the grasp-to-place action. Further analysis revealed that similar to the findings in right-handed individuals, this effect was significant only during right-handed movements. Upon further inspection however, we found individual differences in the magnitude and direction of the observed lateralization. These results underscore the evolutionary significance of the grasp-to-eat movement in producing population-level right-handedness in humans as well as highlighting the heterogeneity of the left-handed population.

  11. Operate a 10-Key Adding Machine with My Left Hand? Sure! Student's Manual and Instructor's Handbook.

    Science.gov (United States)

    Wells, Frances

    Supporting performance objective 70 of the V-TECS (Vocational-Technical Education Consortium of States) Paying and Receiving Bankteller Catalog, this module includes both a set of student materials and an instructor's manual on using the 10-key adding machine with the left hand. (This module is the first in a set of eight on banktelling, [CE 019…

  12. A Left-Hand Rule for Faraday's Law

    Science.gov (United States)

    Salu, Yehuda

    2014-01-01

    A left-hand rule for Faraday's law is presented here. This rule provides a simple and quick way of finding directional relationships between variables of Faraday's law without using Lenz's rule.

  13. Left-handed helical polymer resin nanotubes prepared by using N-palmitoyl glucosamine.

    Science.gov (United States)

    Li, Jiangang; Li, Yi; Li, Baozong; Yang, Yonggang

    2017-12-20

    Although the preparation of single-handed helical inorganic and hybrid organic-inorganic nanotubes is well developed, approaches to the formation of single-handed organopolymeric nanotubes are limited. Here, left-handed helical m-phenylenediamine-formaldehyde resin and 3-aminophenol-formaldehyde resin nanotubes were prepared by using N-palmitoyl glucosamine that can self-assemble into left-handed twisted nanoribbons in a mixture of methanol and water. In the reaction mixture, the helical pitch of the nanoribbons decreased with increasing reaction time. The resin nanotubes were obtained after removing the N-palmitoyl glucosamine template, and circular dichroism spectroscopy indicated that the organopolymeric nanotubes had optical activity. Carbonaceous nanotubes were then prepared by carbonization of the 3-aminophenol-formaldehyde resin nanotubes. © 2017 Wiley Periodicals, Inc.

  14. [The comparison of characteristics of smooth pursuit in left-handed and right-handed persons].

    Science.gov (United States)

    Bozhkova, V P; Surovicheva, N S; Nikolaev, D P

    2010-01-01

    The estimation of the smooth pursuit efficiency in healthy young adults by method based on stroboscopic stimulation is given. The influence of manual function asymmetry on smooth pursuit was tested. Subjects were classified as left-handed or right-handed under a well known handedness questionnaire of Annett supplemented by Luria's tests. It was shown that the strong right-handed persons have a high quality of smooth pursuit of stimuli moving horizontally in rightward and leftward directions with the velocities 20 degrees/s and 25 degrees/s. Left-handed persons track similar stimuli, on the average, worse than the strong right-handed ones. It haven't been observed the influence of manual function asymmetry on the dependence of the smooth pursuit efficiency from the moving stimuli direction (left to right or right to left).

  15. Study on an SRR-shaped left-handed material patch antenna

    Science.gov (United States)

    Song, X. H.; Chen, L. L.; Wu, C. H.; Yuan, Y. N.

    2011-03-01

    Left-handed material (LHM) is an artificial material. It has negative permittivity and negative permeability simultaneously and has attracted a great deal of attention in recent years. This paper investigates a patch antenna based on SRR-shaped left-handed material by using the method of finite difference time domain (FDTD). A patch antenna based on SRR and notches is designed by employing the traditional construction method; the results show that there exists a wave resonance state at 7.67 GHz, where its refraction index is close to - 1. The effect has greatly enhanced the electromagnetic wave's resonance intensity, and has improved the localized extent of the electromagnetic energy noticeably in such an LHM structure; besides, it can also enhance the radiation gain, broaden the frequency band, improve the impedance matching condition, and restrain the high harmonics.

  16. Two-Dimensional Simulation of Left-Handed Metamaterial Flat Lens Using Remcon XFDTD

    Science.gov (United States)

    Wilson, Jeffrey D.; Reinert, Jason M.

    2006-01-01

    Remcom's XFDTD software was used to model the properties of a two-dimensional left-handed metamaterial (LHM) flat lens. The focusing capability and attenuation of the material were examined. The results showed strong agreement with experimental results and theoretical predictions of focusing effects and focal length. The inherent attenuation in the model corresponds well with the experimental results and implies that the code does a reasonably accurate job of modeling the actual metamaterial.

  17. Left-handed cardiac surgery: tips from set up to closure for trainees and their trainers.

    Science.gov (United States)

    Burdett, Clare; Dunning, Joel; Goodwin, Andrew; Theakston, Maureen; Kendall, Simon

    2016-09-01

    There are certain obstacles which left-handed surgeons can face when training but these are not necessary and often perpetuated by a lack of knowledge. Most have been encountered and overcome at some point but unless recorded and disseminated they will have to be resolved repeatedly by each trainee and their trainers. This article highlights difficulties that the left-hander may encounter in cardiac surgery and gives practical operative advice for both trainees and their trainers to help overcome them.

  18. A sinister plot? Facts, beliefs, and stereotypes about the left-handed personality.

    Science.gov (United States)

    Grimshaw, Gina M; Wilson, Marc S

    2013-01-01

    Is there a left-handed personality? Is there a left-handed stereotype? Although psychologists have enthusiastically compared left- and right-handers across myriad cognitive, behavioural, and neuropsychological domains, there has been very little empirical investigation of the relationship between handedness and personality. In Study 1 we assessed the Big 5 personality traits (extraversion, agreeableness, conscientiousness, emotionality, and openness to experience) in a sample of 662 young adults in New Zealand. Left- and right-handers did not differ on any factor. However, there was a curvilinear relationship between hand preference and extraversion; mixed-handers were more introverted than either left- or right-handers. This finding is consistent with other research indicating that degree may be of more psychological consequence than direction of handedness. In Study 2 we assessed beliefs and stereotypes about the left-handed personality. Both left- and right-handers shared the belief that left-handers are more introverted and open to experience than right-handers. This stereotype is not negative, and argues against the status of left-handers as a stigmatised group in modern Western culture.

  19. From solitons to rogue waves in nonlinear left-handed metamaterials.

    Science.gov (United States)

    Shen, Yannan; Kevrekidis, P G; Veldes, G P; Frantzeskakis, D J; DiMarzio, D; Lan, X; Radisic, V

    2017-03-01

    In the present work, we explore soliton and roguelike wave solutions in the transmission line analog of a nonlinear left-handed metamaterial. The nonlinearity is expressed through a voltage-dependent, symmetric capacitance motivated by recently developed ferroelectric barium strontium titanate thin-film capacitor designs. We develop both the corresponding nonlinear dynamical lattice and its reduction via a multiple scales expansion to a nonlinear Schrödinger (NLS) model for the envelope of a given carrier wave. The reduced model can feature either a focusing or a defocusing nonlinearity depending on the frequency (wave number) of the carrier. We then consider the robustness of different types of solitary waves of the reduced model within the original nonlinear left-handed medium. We find that both bright and dark solitons persist in a suitable parametric regime, where the reduction to the NLS model is valid. Additionally, for suitable initial conditions, we observe a rogue wave type of behavior that differs significantly from the classic Peregrine rogue wave evolution, including most notably the breakup of a single Peregrine-like pattern into solutions with multiple wave peaks. Finally, we touch upon the behavior of generalized members of the family of the Peregrine solitons, namely, Akhmediev breathers and Kuznetsov-Ma solitons, and explore how these evolve in the left-handed transmission line.

  20. Incidence of intraoperative complications in cataract surgery performed by left-handed residents.

    Science.gov (United States)

    Kim, Jae Yong; Ali, Rasha; Cremers, Sandra Lora; Yun, Sung-Cheol; Henderson, Bonnie An

    2009-06-01

    To compare the incidence of intraoperative complications during cataract surgery performed by left-handed and right-handed residents and to find predictor variables for complications in resident-performed surgery. Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA. This retrospective chart review comprised cataract extractions performed by postgraduate fourth-year residents from July 1, 2001, to June 30, 2006. The incidence of posterior capsule tear and vitreous loss were the main outcomes. Univariate and multivariate logistic analyses incorporated the variables of patient age and sex; laterality of surgical eye; presence of diabetes mellitus, glaucoma, or age-related macular degeneration; history of vitrectomy; axial length; pseudoexfoliation; small pupils; white cataract; posterior polar cataract; handedness of resident; and academic quarter during which surgery occurred. Left-handed residents performed 170 (9.8%) of the 1730 surgeries. The incidence of posterior capsule tear and vitreous loss was significantly lower in surgeries performed by left-handed residents than in those performed by right-handed residents (P = .03 and Pleft-handed residents. Handedness and patient age were significant predictor variables for these complications.

  1. Reduced asymmetry in motor skill learning in left-handed compared to right-handed individuals.

    Science.gov (United States)

    McGrath, Robert L; Kantak, Shailesh S

    2016-02-01

    Hemispheric specialization for motor control influences how individuals perform and adapt to goal-directed movements. In contrast to adaptation, motor skill learning involves a process wherein one learns to synthesize novel movement capabilities in absence of perturbation such that they are performed with greater accuracy, consistency and efficiency. Here, we investigated manual asymmetry in acquisition and retention of a complex motor skill that requires speed and accuracy for optimal performance in right-handed and left-handed individuals. We further determined if degree of handedness influences motor skill learning. Ten right-handed (RH) and 10 left-handed (LH) adults practiced two distinct motor skills with their dominant or nondominant arms during separate sessions two-four weeks apart. Learning was quantified by changes in the speed-accuracy tradeoff function measured at baseline and one-day retention. Manual asymmetry was evident in the RH group but not the LH group. RH group demonstrated significantly greater skill improvement for their dominant-right hand than their nondominant-left hand. In contrast, for the LH group, both dominant and nondominant hands demonstrated comparable learning. Less strongly-LH individuals (lower EHI scores) exhibited more learning of their dominant hand. These results suggest that while hemispheric specialization influences motor skill learning, these effects may be influenced by handedness. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Large-scale modulation of left-handed passband in hybrid graphene/dielectric metasurface

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chuanbao; Bai, Yang; Qiao, Lijie [Key Laboratory of Environmental Fracture (Ministry of Education), University of Science and Technology Beijing (China); Zhou, Ji [State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing (China); Zhao, Qian [State Kay Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing (China)

    2017-08-15

    Large-scale modulation of the left-handed transmission with a high quality factor is greatly desired by high-performance optical devices, but the requirements are hard to be satisfied simultaneously. This paper presents a hybrid graphene/dielectric metasurface to realize a large transmission modulation for the left-handed passband at near-infrared frequencies via tuning the Fermi energy of graphene. By splitting the nanoblocks, i.e. introducing an additional symmetry breaking in the unit cell, the metasurface demonstrates an ultrahigh quality factor (Q ∼ 550) of Fano resonance with near-unity transmission and full 2π phase coverage due to the interference between Mie-type magnetic and electric resonances, which induces the negative refraction property. Besides, the split in the nanoblock greatly enhances the local field by increasing the critical coupling area, so the light-graphene interaction is promoted intensively. When the surface conductivity of graphene is electrically tuned, the hybrid graphene/dielectric metasurface exhibits a deep modulation of 85% for the left-handed passband, which is robust even for the highest loss of graphene. Moreover, the simple configuration remarkably reduces the fabrication requirements to facilitate the widespread applications. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Identification of pathogenicity-related genes in the vascular wilt fungus verticillium dahliae by agrobacterium tumefaciens-mediated t-DNA insertional mutagenesis.

    Science.gov (United States)

    Verticillium dahliae is the causal agent of vascular wilt in many economically important crops worldwide. Identification of genes that underpin pathogenicity or virulence may suggest targets for alternative control methods for this fungus. In this study, Agrobacterium tumefaciens-mediated transform...

  4. Distinct features of post-transcriptional gene silencing by antisense transgenes in single copy and inverted T-DNA repeat loci.

    NARCIS (Netherlands)

    Stam, M.; de Bruin, R.A.M.; van Blokland, H.J.M.; van der Hoorn, R.; Mol, J.N.M.; Kooter, J.M.

    2000-01-01

    The application of antisense transgenes in plants is a powerful tool to inhibit gene expression. The underlying mechanism of this inhibition is still poorly understood. High levels of antisense RNA (as-RNA) are expected to result in strong silencing but often there is no clear correlation between

  5. Confining model with composite left-handed and unconfined right-handed particles

    International Nuclear Information System (INIS)

    Bordi, F.; Gatto, R.; Dominici, D.; Florence Univ.

    1982-01-01

    We present a fermionic composite model in which left-handed quarks and leptons transform as bound states of three elementary fermions confined under a subcolor gauge group whereas their right-handed partners are unconfined singlets. All the elementary fermions, confined or unconfined, are classified into a single spinor representation. A mass-mechanism, originating from the breaking of the spinor representation, gives masses to the quarks and leptons, originally massless from the anomaly conditions. A natural mechanism arises for the neutrino mass matrix. (orig.)

  6. Refraction Characteristics of Cold Plasma Thin Film as a Left-Handed Metamaterial

    International Nuclear Information System (INIS)

    Sabah, Cumali

    2011-01-01

    A methodical analysis of refraction characteristics of a plane wave with any arbitrary polarization by a cold plasma thin film as a left-handed metamaterial (CPTF-LHM) which has simultaneously negative permittivity and permeability is presented. Numerical calculations are performed by the transfer matrix method using an in-house developed simulation program code. The results strongly recommend a possibility of manufacturing anti-reflection and/or total-transmission coatings and filters for a wide frequency range and/or by tuning the fraction of thickness of the CPTF-LHM. (fundamental areas of phenomenology(including applications))

  7. Left-handed and right-handed U(1) gauge symmetry

    Science.gov (United States)

    Nomura, Takaaki; Okada, Hiroshi

    2018-01-01

    We propose a model with the left-handed and right-handed continuous Abelian gauge symmetry; U(1) L × U(1) R . Then three right-handed neutrinos are naturally required to achieve U(1) R anomaly cancellations, while several mirror fermions are also needed to do U(1) L anomaly cancellations. Then we formulate the model, and discuss its testability of the new gauge interactions at collider physics such as the large hadron collider (LHC) and the international linear collider (ILC). In particular, we can investigate chiral structure of the interactions by the analysis of forward-backward asymmetry based on polarized beam at the ILC.

  8. Pure associative tactile agnosia for the left hand: clinical and anatomo-functional correlations.

    Science.gov (United States)

    Veronelli, Laura; Ginex, Valeria; Dinacci, Daria; Cappa, Stefano F; Corbo, Massimo

    2014-09-01

    Associative tactile agnosia (TA) is defined as the inability to associate information about object sensory properties derived through tactile modality with previously acquired knowledge about object identity. The impairment is often described after a lesion involving the parietal cortex (Caselli, 1997; Platz, 1996). We report the case of SA, a right-handed 61-year-old man affected by first ever right hemispheric hemorrhagic stroke. The neurological examination was normal, excluding major somaesthetic and motor impairment; a brain magnetic resonance imaging (MRI) confirmed the presence of a right subacute hemorrhagic lesion limited to the post-central and supra-marginal gyri. A comprehensive neuropsychological evaluation detected a selective inability to name objects when handled with the left hand in the absence of other cognitive deficits. A series of experiments were conducted in order to assess each stage of tactile recognition processing using the same stimulus sets: materials, 3D geometrical shapes, real objects and letters. SA and seven matched controls underwent the same experimental tasks during four sessions in consecutive days. Tactile discrimination, recognition, pantomime, drawing after haptic exploration out of vision and tactile-visual matching abilities were assessed. In addition, we looked for the presence of a supra-modal impairment of spatial perception and of specific difficulties in programming exploratory movements during recognition. Tactile discrimination was intact for all the stimuli tested. In contrast, SA was able neither to recognize nor to pantomime real objects manipulated with the left hand out of vision, while he identified them with the right hand without hesitations. Tactile-visual matching was intact. Furthermore, SA was able to grossly reproduce the global shape in drawings but failed to extract details of objects after left-hand manipulation, and he could not identify objects after looking at his own drawings. This case

  9. Superpositions of Laguerre-Gaussian Beams in Strongly Nonlocal Left-handed Materials

    International Nuclear Information System (INIS)

    Zhong Weiping; Wang Liyang; Belic, Milivoj; Huang Tingwen

    2010-01-01

    We present beam solutions of the strongly nonlocal nonlinear Schroedinger equation in left-handed materials (LHMs). Different Laguerre-Gaussian (LG) necklace beams, such as symmetric and asymmetric single layer and multilayer necklace beams are created by the superposition of two single beams with different topological charges. Such superpositions are then propagated through LHMs, displaying linear diffraction. It is found that the superposition of two LG nm beams with opposite topological charges does not show rotational behavior and that there exists rotation for other topological charge combinations. Our theory predicts that the accessible solitons cannot exist in LHMs. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  10. Left-handed metamaterial using Z-shaped SRR for multiband application by azimuthal angular rotations

    Science.gov (United States)

    Mehedi Hasan, Md; Faruque, Mohammad Rashed Iqbal

    2017-04-01

    In this paper, a left-handed metamaterial is proposed for multiband applications analysed by azimuthal (xy-plane) angular (φ) rotations. The square resonators are split and a metal bar titled in a way that look like a z-shape split ring resonator structure that is angular sensitive. The metamaterial is designed on the epoxy resin fibre substrate material, which shows extended bandwidth approximately 47.5% of the applicable frequency from 2.0 to 14.0 GHz and the quality factor is 77.30. Finite integration technique based electromagnetic simulator computer simulation technology Microwave Studio is used to design, simulation, and analyses purposes. The demonstrate structure rotates from 0° to π /2 and every π /12 degree intervals in the xy-plane for analysing the effects on bandwidths, effective medium ratio and left-handed characteristics. However, the measured data are well complied with the simulated data by rotating the metamaterial at the above mentioned azimuthal angle.

  11. Dual-band left-handed metamaterials fabricated by using tree-shaped fractal

    International Nuclear Information System (INIS)

    Xu He-Xiu; Wang Guang-Ming; Yang Zi-Mu; Wang Jia-Fu

    2012-01-01

    A method of fabricating dual-band left-handed metematerials (LHMs) is investigated numerically and experimentally by single-sided tree-like fractals. The resulting structure features multiband magnetic resonances and two electric resonances. By appropriately adjusting the dimensions, two left-handed (LH) bands with simultaneous negative permittivity and permeability are engineered and are validated by full-wave eigenmode analysis and measurement as well in the microwave frequency range. To study the multi-resonant mechanism in depth, the LHM is analysed from three different perspectives of field distribution analysis, circuit model analysis, and geometrical parameters evaluation. The derived formulae are consistent with all simulated results and resulting electromagnetic phenomena, indicating the effectiveness of the established theory. The method provides an alternative to the design of multi-band LHM and has the advantage of not requiring two individual resonant particles and electrically continuous wires, which in turn facilitates planar design and considerably simplifies the fabrication. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  12. Functional MRI evaluation of supplementary motor area language dominance in right- and left-handed subjects.

    Science.gov (United States)

    Dalacorte, Amauri; Portuguez, Mirna Wetters; Maurer das Neves, Carlos Magno; Anes, Maurício; Dacosta, Jaderson Costa

    2012-01-01

    Functional magnetic resonance imaging (fMRI) is a non-invasive brain imaging technique widely used in the evaluation of the brain function that provides images with high temporal and spatial resolution. Investigation of the supplementary motor area (SMA) function is critical in the pre-surgical evaluation of neurological patients, since marked individual differences and complex overlapping with adjacent cortical areas exist, and it is important to spare the SMA from lesions when adjacent cortical tissue is surgically removed. We used fMRI to assess the activity of SMA in six right-handed and six left-handed healthy volunteers when a task requiring silent repetition of a series of words was given. Brain activation areas in each of the subjects were localized according to the standard Talairach coordinate space, and the individual voxels for each map were compared after 3D sagittal images were created and SMA was delimited. Quantitative analysis of hemispheric and bilateral SMA activation was described as mean ± standard deviation of hot points/total points. The results show that the language task induced bilateral SMA activation. Left SMA activation was significantly higher than right SMA activation in both right-handed and left-handed subjects.

  13. The respiratory syncytial virus nucleoprotein-RNA complex forms a left-handed helical nucleocapsid.

    Science.gov (United States)

    Bakker, Saskia E; Duquerroy, Stéphane; Galloux, Marie; Loney, Colin; Conner, Edward; Eléouët, Jean-François; Rey, Félix A; Bhella, David

    2013-08-01

    Respiratory syncytial virus (RSV) is an important human pathogen. Its nucleocapsid (NC), which comprises the negative sense RNA viral genome coated by the viral nucleoprotein N, is a critical assembly that serves as template for both mRNA synthesis and genome replication. We have previously described the X-ray structure of an NC-like structure: a decameric ring formed of N-RNA that mimics one turn of the helical NC. In the absence of experimental data we had hypothesized that the NC helix would be right-handed, as the N-N contacts in the ring appeared to more easily adapt to that conformation. We now unambiguously show that the RSV NC is a left-handed helix. We further show that the contacts in the ring can be distorted to maintain key N-N-protein interactions in a left-handed helix, and discuss the implications of the resulting atomic model of the helical NC for viral replication and transcription.

  14. Left-handed skeletally mature baseball players have smaller humeral retroversion in the throwing arm than right-handed players.

    Science.gov (United States)

    Takenaga, Tetsuya; Goto, Hideyuki; Sugimoto, Katsumasa; Tsuchiya, Atsushi; Fukuyoshi, Masaki; Nakagawa, Hiroki; Nozaki, Masahiro; Takeuchi, Satoshi; Otsuka, Takanobu

    2017-12-01

    It is known that the humeral retroversion of baseball players is greater in the throwing arm than in the nonthrowing arm. An investigation measuring dry bone specimens also showed that the right humerus had greater retroversion than the left. Considering these facts, it was hypothesized that humeral retroversion would differ between right- and left-handed players. This study aimed to compare the bilateral humeral retroversion between right- and left-handed skeletally mature baseball players. We investigated 260 (196 right-handed and 64 left-handed) male baseball players who belonged to a college or amateur team. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique (humeral torsion angle [HTA]) as described by previous studies. Analysis of covariance, adjusted for handedness and baseball position, assessed the effect of throwing arm dominance on HTA. In comparison of the throwing arm, HTA was significantly smaller in left-handed (left humerus) than in right-handed (right humerus) players (77° vs. 81°; P left-handed (right humerus) than in right-handed (left humerus) players (73° vs. 69°; P left-handed than in right-handed players (3° vs. 12°; P left-handed skeletally mature baseball players was significantly smaller in the throwing arm, greater in the nonthrowing arm, and smaller in side-to-side differences than that of right-handed players. These findings may be key to understanding some of the biomechanical differences between right- and left-handed baseball players. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  15. Noninvasive brain stimulation for treatment of right- and left-handed poststroke aphasics.

    Science.gov (United States)

    Heiss, Wolf-Dieter; Hartmann, Alexander; Rubi-Fessen, Ilona; Anglade, Carole; Kracht, Lutz; Kessler, Josef; Weiduschat, Nora; Rommel, Thomas; Thiel, Alexander

    2013-01-01

    Accumulating evidence from single case studies, small case series and randomized controlled trials seems to suggest that inhibitory noninvasive brain stimulation (NIBS) over the contralesional inferior frontal gyrus (IFG) of right-handers in conjunction with speech and language therapy (SLT) improves recovery from poststroke aphasia. Application of inhibitory NIBS to improve recovery in left-handed patients has not yet been reported. A total of 29 right-handed subacute poststroke aphasics were randomized to receive either 10 sessions of SLT following 20 min of inhibitory repetitive transcranial magnetic stimulation (rTMS) over the contralesional IFG or 10 sessions of SLT following sham stimulation; 2 left-handers were treated according to the same protocol with real rTMS. Language activation patterns were assessed with positron emission tomography prior to and after the treatment; 95% confidence intervals for changes in language performance scores and the activated brain volumes in both hemispheres were derived from TMS- and sham-treated right-handed patients and compared to the same parameters in left-handers. Right-handed patients treated with rTMS showed better recovery of language function in global aphasia test scores (t test, p left-handed patients also improved, with 1 patient within the confidence limits of TMS-treated right-handers (23 points, 15.9-28.9) and the other patient within the limits of sham-treated subjects (8 points, 2.8-14.5). Both patients exhibited only a very small interhemispheric shift, much less than expected in TMS-treated right-handers, and more or less consolidated initially active networks in both hemispheres. Inhibitory rTMS over the nondominant IFG appears to be a safe and effective treatment for right-handed poststroke aphasics. In the 2 cases of left-handed aphasics no deterioration of language performance was observed with this protocol. However, therapeutic efficiency is less obvious and seems to be more related to the

  16. Left-Handed Metamaterials Studies and their Application to Accelerator Physics

    CERN Document Server

    Antipov, Sergey P; Liu Wan Ming; Power, John G

    2005-01-01

    Recently, there has been a growing interest in applying artificial materials, known as Left-Handed Metamaterials (LHM), to accelerator physics. These materials have both negative permittivity and permeability and therefore possess several unusual properties: the index of refraction is negative and the direction of the group velocity is antiparallel to the direction of the phase velocity (along k). These properties lead to a reverse Cherenkov effect, which has potential beam diagnostic applications, in addition to accelerator applications. Several LHM devices with different configurations are being experimentally and theoretically studied at Argonne. In this paper, we describe permittivity and permeability retrieval techniques that we have developed and applied to these devices. We have also investigated the possibility of building a Cherenkov detector based on LHM and propose an experiment to observe the reverse radiation generated by an electron beam passing through a LHM. The potential advantage of a LHM de...

  17. Tree-shaped fractal meta-surface with left-handed characteristics for absorption application

    Science.gov (United States)

    Faruque, M. R. I.; Hasan, M. M.; Islam, M. T.

    2018-02-01

    A tri-band fractal meta-surface absorber composed of metallic branches of a tree connected with a straight metal strip has been presented in this paper for high absorption application. The proposed tree-shaped structure shows resonance in C-, X-, and Ku-bands and left-handed characteristics in 14.15 GHz. The dimension of the tree-shaped meta-surface single unit cell structure is 9 × 9 mm2 and the effective medium ratio is 5.50. In addition, the designed absorber structure shows absorption above 84%, whereas the absorber structure printed on epoxy resin fiber substrate material. The FIT-based CST-MWS has been utilized for the design, simulation, and analysis purposes. Fabrication is also done for the experimental validation.

  18. Heart rate variability differs between right- and left-handed individuals.

    Science.gov (United States)

    Yüksel, Ramazan; Arslan, Muzeyyen; Dane, Senol

    2014-06-01

    Previous studies reported reduced longevity in left-handers with the suggestion that it may be associated with different heart diseases. Therefore, differences in heart rate variability (HRV), an index of autonomic cardiac activity, were examined for right- and left-handed individuals. 120 healthy young university students (75 women, 45 men; M age = 20.4 yr., SD = 1.5) volunteered. Handedness was assessed with the Edinburgh Handedness Inventory and HRV was measured via electrocardiography. The results suggest that the left-handers' HRV was significantly different from that of right-handers on several parameters. The atypical cerebral organization of left-handers may be related to an imbalanced autonomic system that results in higher frequencies of heart irregularities.

  19. Do Right- and Left-Handed Monkeys Differ on Cognitive Measures?

    Science.gov (United States)

    Hopkins, William D.; Washburn, David A.

    1994-01-01

    Twelve left- and 14 right-handed monkeys were compared on 6 measures of cognitive performance (2 maze-solving tasks, matching-to-sample, delayed matching-to-sample, delayed response using spatial cues, and delayed response using form cues). The dependent variable was trials-to-training criterion for each of the 6 tasks. Significant differences were found between left- and right-handed monkeys on the 2 versions of the delayed response task. Right-handed monkeys reached criterion significantly faster on the form cue version of the task, whereas left-handed monkeys reached criterion significantly faster on delayed response for spatial position (p less than .05). The results suggest that sensitive hand preference measures of laterality can reveal differences in cognitive performance, which in turn may reflect underlying laterality in functional organization of the nervous system.

  20. Kuznetsov-Ma waves train generation in a left-handed material

    Science.gov (United States)

    Atangana, Jacques; Giscard Onana Essama, Bedel; Biya-Motto, Frederick; Mokhtari, Bouchra; Cherkaoui Eddeqaqi, Noureddine; Crépin Kofane, Timoléon

    2015-03-01

    We analyze the behavior of an electromagnetic wave which propagates in a left-handed material. Second-order dispersion and cubic-quintic nonlinearities are considered. This behavior of an electromagnetic wave is modeled by a nonlinear Schrödinger equation which is solved by collective coordinates theory in order to characterize the light pulse intensity profile. More so, a specific frequency range has been outlined where electromagnetic wave behavior will be investigated. The perfect combination of second-order dispersion and cubic nonlinearity leads to a robust soliton. When the quintic nonlinearity comes into play, it provokes strong and long internal perturbations which lead to Benjamin-Feir instability. This phenomenon, also called modulational instability, induces appearance of a Kuznetsov-Ma waves train. We numerically verify the validity of Kuznetsov-Ma theory by presenting physical conditions which lead to Kuznetsov-Ma waves train generation. Thereafter, some properties of such waves train are also verified.

  1. Left-Handed Effect of Composite Rectangular SRRs and Its Application in Patch Antennae

    International Nuclear Information System (INIS)

    Ming, Huang; Yue-Qun, Zhou; Ting-Gen, Shen

    2010-01-01

    We concentrate on describing the important influence and physical law of the split resonant ring (SRR) based left-handed materials on patch antennae. The finite-difference time-domain method, together with the finite element method is used to study the characteristics of patch antennae based on composite rectangular SRRs. A novel composite rectangular SRR system is formed by assembling the conventional patch antennae and SRRs, it is found that electromagnetic wave resonance occurs near f = 3.15 GHz, the equivalent permittivity and permeability are both negative, and the electromagnetic wave's tunnel effect and evanescent waves' enhancing effect are formed, which can improve the localization extent of electromagnetic wave's energy apparently. Such effects can improve the antenna's radiation gain and its matching condition. The phenomenon indicates that such composite rectangular patch antennae are promising in wireless communications such as mobile phones, satellite communication and aviation. (fundamental areas of phenomenology(including applications))

  2. Variant lumbrical musculature of the left hand: Clinico-anatomic elucidation.

    Science.gov (United States)

    Singh, S; Loh, H K; Mehta, V

    2016-12-01

    Human hand is haughtily described in literature as 'revolution in evolution'. Lumbricals form an intricate part of its musculature playing a vital role in complex digital movements. By virtue of their origin from the volar aspect of palm and their insertion onto the dorsal aspect to the extensor digital expansion of the digits, lumbricals display complex actions flexing the metacarpophalangeal joint and extending the interphalangeal joints. Such manoeuvres of the digits are vital for skilful and precision movements. During routine dissection of the teaching program of undergraduate medical students, unusual origin and morphology of all the four lumbrical muscles in the left hand of a male cadaver was observed. Clinicians and hand surgeons should be aware of its variations while designing and dealing with hand surgeries. An attempt has been made to comprehend its clinical, embryological and phylogenetic aspects. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. Reversed Cherenkov-transition radiation in a waveguide partly filled with a left-handed medium

    Science.gov (United States)

    Alekhina, Tatiana Yu.; Tyukhtin, Andrey V.

    2018-04-01

    We analyze the electromagnetic field of a charged particle that moves uniformly in a circular waveguide and crosses a boundary between a vacuum area and an area filled with a left-handed medium exhibiting resonant frequency dispersion. The investigation of the waveguide mode components is performed analytically and numerically. The reversed Cherenkov radiation in the filled area of the waveguide and the reversed Cherenkov-transition radiation (RCTR) in the vacuum area are analyzed. The conditions for the excitation of RCTR are obtained. It is shown that the number of modes of RCTR is always finite; in particular, under certain conditions, the RCTR is composed of the first waveguide mode only. Plots of the typical fields of the excited waveguide mode are presented.

  4. Multiband Slot-Based Dual Composite Right/Left-Handed Transmission Line

    Directory of Open Access Journals (Sweden)

    E. Abdo-Sanchez

    2012-10-01

    Full Text Available A dual Composite Right-/Left-Handed Transmission Line (CRLH TL implementation that presents multiband behaviour is proposed in this contribution. The artificial TL is realized by loading a host microstrip line with alternate rectangular stubs and slots. The required series and shunt immittances are respectively provided by the slot and the stub. Due to the distributed nature of these immittances, the resultant phase response presents theoretically infinite RH and LH alternate bands, thus being appropriate for multiband applications. The design methodology is described with the help of a proposed TLs-based equivalent circuit and highlights the simplicity for balance condition. Full wave simulated results of the dispersion characteristics and frequency response of a unit-cell and a three-cells structure are presented.

  5. Reduced dream-recall frequency in left-handed adolescents: a replication.

    Science.gov (United States)

    Schredl, Michael; Beaton, Alan A; Henley-Einion, Josie; Blagrove, Mark

    2014-01-01

    The ability to recall a dream upon waking up in the morning has been linked to a broad variety of factors such as personality, creativity, sleep behaviour and cognitive function. There have been conflicting findings as to whether dream recall is related more to the right or to the left hemisphere, and conflicting findings regarding the relationship of dream-recall frequency to handedness. We have found previously that right- and mixed-handers report having more dreams than left-handers, a finding more pronounced among adolescents than adults. In the present sample of 3535 participants aged from 6 to 18 years, right-handedness and mixed/inconsistent handedness were associated with higher dream-recall frequency compared to that of left-handed persons, again especially in adolescents compared with children. Further research is required to uncover the reason for the lower frequency of dream recall by left-handers.

  6. Auditory middle latency responses differ in right- and left-handed subjects: an evaluation through topographic brain mapping.

    Science.gov (United States)

    Mohebbi, Mehrnaz; Mahmoudian, Saeid; Alborzi, Marzieh Sharifian; Najafi-Koopaie, Mojtaba; Farahani, Ehsan Darestani; Farhadi, Mohammad

    2014-09-01

    To investigate the association of handedness with auditory middle latency responses (AMLRs) using topographic brain mapping by comparing amplitudes and latencies in frontocentral and hemispheric regions of interest (ROIs). The study included 44 healthy subjects with normal hearing (22 left handed and 22 right handed). AMLRs were recorded from 29 scalp electrodes in response to binaural 4-kHz tone bursts. Frontocentral ROI comparisons revealed that Pa and Pb amplitudes were significantly larger in the left-handed than the right-handed group. Topographic brain maps showed different distributions in AMLR components between the two groups. In hemispheric comparisons, Pa amplitude differed significantly across groups. A left-hemisphere emphasis of Pa was found in the right-handed group but not in the left-handed group. This study provides evidence that handedness is associated with AMLR components in frontocentral and hemispheric ROI. Handedness should be considered an essential factor in the clinical or experimental use of AMLRs.

  7. Foreign bodies of the ear and nose in children and its correlation with right or left handed children.

    Science.gov (United States)

    Peridis, Stamatios; Athanasopoulos, Ioannis; Salamoura, Maria; Parpounas, Konstantinos; Koudoumnakis, Emmanouel; Economides, John

    2009-02-01

    Foreign bodies (FB) of the ear and nose are common findings in the pediatric population. The objective of this project is to present our experience of cases presented to our department and to correlate the insertion of the FB in relation to the child's handedness. This project was carried out at the Department of Otorhinolaryngology Head and Neck Surgery of "Aghia Sophia" Children's Hospital (Athens, Greece), between December 2007 and August 2008. Data collected includes age and sex of the child, time elapsed between the insertion of the FB and its removal, type of FB, site of insertion, description of the child's handedness, conditions of removal and complications. 46 FB were removed from the nasal cavities. On the right nasal cavity, 29/31 (93.55%) children were right handed and 2/31 (6.45%) were left handed. On the left nasal cavity, 11/14 (78.57%) were right handed and 3/14 (21.43%) children were left handed. One right handed child had a FB in both nasal cavities. 44 FB were removed from the ear (external auditory canal: EAC), 30 (68.18%) from the right EAC and 14 (31.82%) from the left. On the right EAC, 28/30 (93.33%) children were right handed and 2/30 (6.67%) were left handed. Children with FB of the left EAC were 9/14 (64.29%) right handed and 5/14 (35.71%) left handed. Children insert FB into their nasal cavities randomly (P=0.308). As a result, there is no correlation with the child's handedness and right/left nasal cavities FB insertion. On the other hand, children do insert FB into their right/left EAC according whether they are right/left handed (P=0.014). Consequently, right handed children insert FB into their right EAC and left handed children into their left EAC.

  8. Left-handed polyproline-II helix revisited: proteins causing proteopathies.

    Science.gov (United States)

    Adzhubei, Alexei A; Anashkina, Anastasia A; Makarov, Alexander A

    2017-09-01

    Left-handed polyproline-II type helix is a regular conformation of polypeptide chain not only of fibrous, but also of folded and natively unfolded proteins and peptides. It is the only class of regular secondary structure substantially represented in non-fibrous proteins and peptides on a par with right-handed alpha-helix and beta-structure. In this study, we have shown that polyproline-II helix is abundant in several peptides and proteins involved in proteopathies, the amyloid-beta peptides, protein tau and prion protein. Polyproline-II helices form two interaction sites in the amyloid-beta peptides, which are pivotal for pathogenesis of Alzheimer's disease (AD). It also with high probability is the structure of the majority of tau phosphorylation sites, important for tau hyperphosphorylation and formation of neurofibrillary tangles, a hallmark of AD. Polyproline-II helices form large parts of the structure of the folded domain of prion protein. They can undergo conversion to beta-structure as a result of relatively small change of one torsional angle of polypeptide chain. We hypothesize that in prions and amyloids, in general polyproline-II helices can serve as structural elements of the normal structure as well as dormant nuclei of structure conversion, and thus play important role in structure changes leading to the formation of fibrils.

  9. Illusory movements induced by tendon vibration in right- and left-handed people.

    Science.gov (United States)

    Tidoni, Emmanuele; Fusco, Gabriele; Leonardis, Daniele; Frisoli, Antonio; Bergamasco, Massimo; Aglioti, Salvatore Maria

    2015-02-01

    Frequency-specific vibratory stimulation of peripheral tendons induces an illusion of limb movement that may be useful for restoring proprioceptive information in people with sensorimotor disability. This potential application may be limited by inter- and intra-subject variability in the susceptibility to such an illusion, which may depend on a variety of factors. To explore the influence of stimulation parameters and participants' handedness on the movement illusion, we vibrated the right and left tendon of the biceps brachii in a group of right- and left-handed people with five stimulation frequencies (from 40 to 120 Hz in step of 20 Hz). We found that all participants reported the expected illusion of elbow extension, especially after 40 and 60 Hz. Left-handers exhibited less variability in reporting the illusion compared to right-handers across the different stimulation frequencies. Moreover, the stimulation of the non-dominant arm elicited a more vivid illusion with faster onset relative to the stimulation of the dominant arm, an effect that was independent from participants' handedness. Overall, our data show that stimulation frequency, handedness and arm dominance influence the tendon vibration movement illusion. The results are discussed in reference to their relevance in linking motor awareness, improving current devices for motor ability recovery after brain or spinal damage and developing prosthetics and virtual embodiment systems.

  10. Zeroth-order resonance phenomenon in an acoustic composite right/left-handed metamaterial resonator.

    Science.gov (United States)

    Kim, Wan-Gu; Kang, Hwi Suk; Yoon, Suk Wang; Lee, Kang Il

    2017-10-01

    This study proposes an acoustic theory that describes the resonance phenomena in a resonator made of acoustic composite right/left-handed (CRLH) metamaterials, and verifies it through numerical simulation. The established theory for a microwave CRLH metamaterial resonator is adapted to explain the resonance phenomena in an acoustic CRLH metamaterial resonator. In particular, attention is focused on the zeroth-order resonance phenomenon which has several interesting properties. When a resonator is composed of a CRLH metamaterial, a resonance with a flat acoustic field distribution may occur at one of the frequencies where the wavenumber becomes zero. This resonance is called zeroth-order resonance. Through numerical simulation, such unusual resonance phenomenon in acoustics is observed in more detail and the proposed theory is verified. The results of the theory and the numerical simulation clearly show that zeroth-order resonance can exist at those frequencies where the acoustic field distribution is flat due to infinite wavelength. It is also shown that the resonance frequency and the Q factor of this resonance depend on the boundary condition at both ends of the resonator, and they basically do not change even when the number of units is reduced or increased.

  11. The Right Way to Teach Left-Handed Residents: Strategies for Training by Right Handers.

    Science.gov (United States)

    Prasad, Nikhil K; Kvasnovsky, Charlotte; Wise, Eric S; Kavic, Stephen M

    Left-handed (LH) residents remain underrepresented among surgical trainees, and there are few available data on how best to train them. The challenge is amplified when pairing a LH resident with a right-handed (RH) mentor. This report provides recommendations on how to improve the training of LH surgeons in a safe and effective manner. A comprehensive literature review was performed using different databases and search engines to identify all articles relevant to the training of LH residents. A total of 40 articles highlighted the challenges for LH surgical residents and RH mentors. Our recommendations are based on the following 4 themes: identifying inherent differences in left vs. RH residents, providing guidance to RH mentors training LH residents, adapting the RH environment to the LH surgeon, and maximizing safety during training. An organized approach needs to be taken in training the LH resident. Changes should be instituted at program-wide and national levels to ensure that the training experience of the sinistral surgical resident is optimized. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  12. Diastereomeric Right- and Left-Handed Helical Structures with Fourteen (R)-Chiral Centers.

    Science.gov (United States)

    Eto, Ryo; Oba, Makoto; Ueda, Atsushi; Uku, Tsubasa; Doi, Mitsunobu; Matsuo, Yosuke; Tanaka, Takashi; Demizu, Yosuke; Kurihara, Masaaki; Tanaka, Masakazu

    2017-12-22

    The relationship between chiral centers and the helical-screw control of their peptides has already been reported, but it has yet to be elucidated in detail. A chiral four-membered ring α,α-disubstituted α-amino acid with a (R,R)-butane-2,3-diol acetal moiety at the γ-position, but no α-chiral carbon, was synthesized. X-ray crystallographic analysis unambiguously revealed that its homo-chiral heptapeptide formed right-handed (P) and left-handed (M) 3 10 -helical structures at a ratio of 1:1. They appeared to be enantiomeric at the peptide backbone, but diastereomeric with fourteen (R)-configuration chiral centers. Conformational analyses of homopeptides in solution also indicated that diastereomeric (P) and (M) helices existed at approximately equal amounts, with a slight preference toward right-handedness, and they quickly interchanged at room temperature. The circumstances of chiral centers are important for the control of their helical-screw direction. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Practice Perspectives of Left-Handed Clinical Dental Students in India.

    Science.gov (United States)

    Kapoor, Shivam; Puranik, Manjunath P; Uma, S R

    2016-10-01

    Handedness becomes important for students during their training period. Limited literature is available regarding the same. The purpose of this study was to assess the dental practice perspectives and determine the hand preference and discomfort level among the Left-Handed (LH) clinical dental students. A 30-item survey tool was used to conduct a cross-sectional survey among four successive LH cohorts (third and final year undergraduates, dental interns and postgraduates) in all the dental colleges of Bengaluru, Karnataka, India, during the year 2014. A total of 84 students completed the survey, response rate being 100%. About one-third (37%) reported that their institution was not properly equipped to accommodate LH students. Majority felt that LH dentists were at a higher risk of developing musculoskeletal complications. Mouth mirror handling showed equal distribution for handedness as compared to the other dental activities, whereas discomfort levels were negligible ("without any difficulty"). Dental practice perspective scores significantly correlated with the difficulty levels (r=-0.333, pleft-handers had a right dental practice perspective and their responses indicate a need to address their issues empathetically.

  14. Accommodating Discontinuities in Dimeric Left-Handed Coiled Coils in ATP Synthase External Stalks

    Science.gov (United States)

    Wise, John G.; Vogel, Pia D.

    2009-01-01

    ATP synthases from coupling membranes are complex rotary motors that convert the energy of proton gradients across coupling membranes into the chemical potential of the β-γ anhydride bond of ATP. Proton movement within the ring of c subunits localized in the F0-sector drives γ and ɛ rotation within the F1α3β3 catalytic core where substrates are bound and products are released. An external stalk composed of homodimeric subunits b2 in Escherichia coli or heterodimeric bb′ in photosynthetic synthases connects F0 subunit a with F1 subunits δ and most likely α. The external stalk resists rotation, and is of interest both functionally and structurally. Hypotheses that the external stalk contributes to the overall efficiency of the reaction through elastic coupling of rotational substeps, and that stalks form staggered, right-handed coiled coils, are investigated here. We report on different structures that accommodate heptad discontinuities with either local or global underwinding. Analyses of the knob-and-hole packing of the E. coli b2 and Synechocystis bb′ stalks strongly support the possibility that these proteins can adopt conventional left-handed coiled coils. PMID:19348765

  15. A Printed Xi-Shaped Left-Handed Metamaterial on Low-Cost Flexible Photo Paper.

    Science.gov (United States)

    Ashraf, Farhad Bin; Alam, Touhidul; Islam, Mohammad Tariqul

    2017-07-05

    A Xi-shaped meta structure, has been introduced in this paper. A modified split-ring resonator (MSRR) and a capacitive loaded strip (CLS) were used to achieve the left-handed property of the metamaterial. The structure was printed using silver metallic nanoparticle ink, using a very low-cost photo paper as a substrate material. Resonators were inkjet-printed using silver nanoparticle metallic ink on paper to make this metamaterial flexible. It is also free from any kind of chemical waste, which makes it eco-friendly. A double negative region from 8.72 GHz to 10.91 GHz (bandwidth of 2.19 GHz) in the X-band microwave spectra was been found. Figure of merit was also obtained to measure any loss in the double negative region. The simulated result was verified by the performance of the fabricated prototype. The total dimensions of the proposed structure were 0.29 λ × 0.29 λ × 0.007 λ . It is a promising unit cell because of its simplicity, cost-effectiveness, and easy fabrication process.

  16. Science in the Making: Right Hand, Left Hand. I: A BBC television programme broadcast in 1953.

    Science.gov (United States)

    McManus, I C; Rawles, Richard; Moore, James; Freegard, Matthew

    2010-01-01

    In August 1953, the BBC broadcast a television science programme entitled Science in the Making: Right Hand, Left Hand. The programme was broadcast live, being presented by Dr Jacob Bronowski in collaboration with Dr Kenneth Smith, and produced by George Noordhof. It not only presented a popular account of current ideas about right- and left-handedness, by using a group of celebrities (and a chimpanzee) in the studio, but also asked viewers to complete a brief questionnaire on handedness, which was printed in the Radio Times. Recently 6,336 of the returned questionnaires, which were said to have been analysed by Sir Cyril Burt and a colleague, were found in the archive of the Psychology Department of University College London. The present paper describes what we have discovered about the programme from various sources, including the producer and the son of Dr Kenneth Smith, and also presents basic descriptions of the postcards and the response to the programme. In two subsequent papers we will describe our analysis of the data from the postcards, which represents an unusual, large-scale survey of handedness in the mid-twentieth century.

  17. Science in the Making: Right Hand, Left Hand. II: The duck-rabbit figure.

    Science.gov (United States)

    McManus, I C; Freegard, Matthew; Moore, James; Rawles, Richard

    2010-01-01

    The BBC television programme Right Hand, Left Hand, broadcast in August 1953, showed a version of the duck-rabbit figure and asked viewers to say what they could see in the “puzzle picture”. Nearly 4,000 viewers described the image, and the answers to those questions have recently been found and analysed. The programme probably used the same version of the figure as appeared in Wittgenstein's Philosophical Investigations, which had been published a month or two previously. Although Dr Jacob Bronowski, the presenter of the programme, had suspected that left- and right-handers might differ in their perception of the figure, since they might scan it from different sides, in fact there is no relationship in the data between six measures of lateralisation and a propensity for seeing a duck or a rabbit. However the large data set does show separate effects of both age and sex on viewing the figure, female and older viewers being more likely to report seeing a rabbit (although a clear majority of viewers reported seeing a duck). There was also a very significant tendency for female viewers to use more typical descriptions of the duck, whereas males used a wider variety of types.

  18. On the Relation between Composite Right-/Left-Handed Transmission Lines and Chebyshev Filters

    Directory of Open Access Journals (Sweden)

    Changjun Liu

    2009-01-01

    Full Text Available Composite right-/left-handed (CRLH transmission lines have gained great interest in the microwave community. In practical applications, such CRLH sections realized by series and shunt resonators have a finite length. Starting from the observation that a high-order Chebyshev filter also exhibits a periodic central section of very similar structure, the relations between finite length CRHL transmission lines and Chebyshev filters are discussed in this paper. It is shown that a finite length CRLH transmission line in the balanced case is equivalent to the central part of a low-ripple high-order Chebyshev band-pass filter, and a dual-CRLH transmission line in the balanced case is equivalent to a low-ripple high-order Chebyshev band-stop filter. The nonperiodic end sections of a Chebyshev filter can be regarded as matching sections, thus leading to an even better amplitude and phase response. It is also shown that, equally to a CRHL transmission line, a Chebyshev filter exhibits negative phase velocity in part of its passband. As a consequence, an improved behavior of finite length CRLH transmission lines may be achieved adding matching sections based on filter theory; this is demonstrated by a simulation example.

  19. Time-domain electromagnetic energy in a frequency-dispersive left-handed medium

    International Nuclear Information System (INIS)

    Cui Tiejun; Kong Jinau

    2004-01-01

    From Maxwell's equations and the Poynting theorem, the time-domain electric and magnetic energy densities are generally defined in the frequency-dispersive media based on the conservation of energy. As a consequence, a general definition of electric and magnetic energy is proposed. Comparing with existing formulations of electric and magnetic energy in frequency-dispersive media, the new definition is more reasonable and is valid in any case. Using the new definition and staring from the equation of motion, we have shown rigorously that the total energy density and the individual electric and magnetic energy densities are always positive in a realistic artificial left-handed medium (LHM) [R. A. Shelby, D. R. Smith, and S. Schultz, Science 292, 77 (2001)], which obeys actually the Lorentz medium model, although such a LHM has negative permittivity and negative permeability simultaneously in a certain frequency range. We have also shown that the conservation of energy is not violated in LHM. The earlier conclusions can be easily extended to the Drude medium model and the cold plasma medium model. Through an exact analysis of a one-dimensional transient current source radiating in LHM, numerical results are given to demonstrate that the work done by source, the power flowing outwards a surface, and the electric and magnetic energy stored in a volume are all positive in the time domain

  20. Lighting up left-handed Z-DNA: photoluminescent carbon dots induce DNA B to Z transition and perform DNA logic operations.

    Science.gov (United States)

    Feng, Lingyan; Zhao, Andong; Ren, Jinsong; Qu, Xiaogang

    2013-09-01

    Left-handed Z-DNA has been identified as a transient structure occurred during transcription. DNA B-Z transition has attracted much attention because of not only Z-DNA biological importance but also their relation to disease and DNA nanotechnology. Recently, photoluminescent carbon dots, especially highly luminescent nitrogen-doped carbon dots, have attracted much attention on their applications to bioimaging and gene/drug delivery because of carbon dots with low toxicity, highly stable photoluminescence and controllable surface function. However, it is still unknown whether carbon dots can influence DNA conformation or structural transition, such as B-Z transition. Herein, based on our previous series work on DNA interactions with carbon nanotubes, we report the first example that photoluminescent carbon dots can induce right-handed B-DNA to left-handed Z-DNA under physiological salt conditions with sequence and conformation selectivity. Further studies indicate that carbon dots would bind to DNA major groove with GC preference. Inspired by carbon dots lighting up Z-DNA and DNA nanotechnology, several types of DNA logic gates have been designed and constructed based on fluorescence resonance energy transfer between photoluminescent carbon dots and DNA intercalators.

  1. Broadband Butler Matrices with the Use of High-Pass LC Sections as Left-Handed Transmission Lines

    Directory of Open Access Journals (Sweden)

    K. Staszek

    2014-04-01

    Full Text Available An application of left-handed transmission line sections in Butler matrices has been investigated. It has been shown, for the first time, that the utilization of both left-handed and right-handed transmission lines allows for broadband differential phase shifters’ realization, required in the Butler matrices. A complete theoretical analysis is given, for Butler matrices incorporating ideal transmission lines of both right- and left handed types and expressions for the achievable bandwidth and differential phase deviation are derived. The presented idea has been verified by the design of a 4 x 4 Butler matrix operating in a frequency range of 2.5 – 3.5 GHz. As an artificial left-handed transmission line, an equivalent high-pass LC circuit realized in a quasi-lumped element technique, has been considered, and the resulting phase shift of such a circuit is given analytically. The obtained measurement results fully confirm the validity of the proposed idea of broadband Butler matrices’ realization.

  2. The laterality of stop and go processes of the motor response in left-handed and right-handed individuals.

    Science.gov (United States)

    Hiraoka, Koichi; Igawa, Kyudo; Kashiwagi, Mina; Nakahara, Chisato; Oshima, Yuki; Takakura, Yu

    2018-01-01

    The objective of the present study was to investigate whether the stop and go processes of the motor response are asymmetrical and whether the asymmetries are dependent on handedness and the response selection process that is engaged. Both right-handed and left-handed participants abducted either the left or right index finger in response to an imperative cue in the choice reaction time (choice RT) or the simple RT task. A stop cue was presented after the imperative cue with a probability of .25. When the stop cue was presented, the participants withheld the prepared response. On the choice RT task, left-handed participants had significantly shorter RT and stop signal reaction time (SSRT) with the left versus the right hand, whereas right-handers showed no difference between hands on either measure. In the simple RT task, the RT and SSRT were not significantly different between the groups or the response sides. These results indicate that both the stop and go processes of the prepared left-hand response are completed earlier than those of the right-hand response in left-handed individuals when the stimulus-response process involves a response selection process.

  3. Time- and Cost-Efficient Identification of T-DNA Insertion Sites through Targeted Genomic Sequencing

    Science.gov (United States)

    Lepage, Étienne; Zampini, Éric; Boyle, Brian; Brisson, Normand

    2013-01-01

    Forward genetic screens enable the unbiased identification of genes involved in biological processes. In Arabidopsis, several mutant collections are publicly available, which greatly facilitates such practice. Most of these collections were generated by agrotransformation of a T-DNA at random sites in the plant genome. However, precise mapping of T-DNA insertion sites in mutants isolated from such screens is a laborious and time-consuming task. Here we report a simple, low-cost and time efficient approach to precisely map T-DNA insertions simultaneously in many different mutants. By combining sequence capture, next-generation sequencing and 2D-PCR pooling, we developed a new method that allowed the rapid localization of T-DNA insertion sites in 55 out of 64 mutant plants isolated in a screen for gyrase inhibition hypersensitivity. PMID:23951038

  4. Right- and left-handed three-helix proteins. I. Experimental and simulation analysis of differences in folding and structure.

    Science.gov (United States)

    Glyakina, Anna V; Pereyaslavets, Leonid B; Galzitskaya, Oxana V

    2013-09-01

    Despite the large number of publications on three-helix protein folding, there is no study devoted to the influence of handedness on the rate of three-helix protein folding. From the experimental studies, we make a conclusion that the left-handed three-helix proteins fold faster than the right-handed ones. What may explain this difference? An important question arising in this paper is whether the modeling of protein folding can catch the difference between the protein folding rates of proteins with similar structures but with different folding mechanisms. To answer this question, the folding of eight three-helix proteins (four right-handed and four left-handed), which are similar in size, was modeled using the Monte Carlo and dynamic programming methods. The studies allowed us to determine the orders of folding of the secondary-structure elements in these domains and amino acid residues which are important for the folding. The obtained data are in good correlation with each other and with the experimental data. Structural analysis of these proteins demonstrated that the left-handed domains have a lesser number of contacts per residue and a smaller radius of cross section than the right-handed domains. This may be one of the explanations of the observed fact. The same tendency is observed for the large dataset consisting of 332 three-helix proteins (238 right- and 94 left-handed). From our analysis, we found that the left-handed three-helix proteins have some less-dense packing that should result in faster folding for some proteins as compared to the case of right-handed proteins. Copyright © 2013 Wiley Periodicals, Inc.

  5. Modeling of a Variable Focal Length Flat Lens Using Left Handed Metamaterials

    Science.gov (United States)

    Reinert, Jason

    2004-01-01

    Left Handed Metamaterials (LHM) were originally purposed by Victor Veselago in1968. These substances would allow a flat structure to focus electromagnetic (EM) waves because they have a negative index of refraction. A similar structure made from conventional materials, those with a positive index of refraction, would disperse the waves. But until recently, these structures have been purely theoretical because substances with both a negative permittivity and negative permeability, material properties necessary for a negative index of refraction, do not naturally exist, Recent developments have produced a structure composed of an array of thin wires and split ring resonators that shows a negative index of refraction. area smaller than a square wavelength. How small the area is can be determined by how perfectly the lens is polished and how pure the substance is that composes the lens. These lenses must also be curved for focusing to occur. The focal length is determined by the curvature of the lens and the material. On the other hand, a flat structure made from LHM would focus light because of the effect of a negative index of refraction in Snell s law. The focal length could also be varied by simply adjusting the distance of the lens from the source of radiation. This could create many devices that are adjustable to different situations in fields such as biomedical imaging and communication. the software package XFDTD which solves Maxwell s equations in the frequency domain as well as the time domain. The program used Drude models of materials to simulate the effect of negative permittivity and negative permeability. Because of this, a LHM can be simulated as a solid block of material instead of an array of wires and split ring resonators. After a flat lens is formed, I am to examine the focusing effect of the lens and determine if a higher resolution flat lens can be developed. Traditional lenses made from conventional materials cannot focus an EM wave onto an My

  6. Science in the Making: Right Hand, Left Hand. III: Estimating historical rates of left-handedness.

    Science.gov (United States)

    McManus, I C; Moore, James; Freegard, Matthew; Rawles, Richard

    2010-01-01

    The BBC television programme Right Hand, Left Hand, broadcast in August 1953, used a postal questionnaire to ask viewers about their handedness. Respondents were born between 1864 and 1948, and in principle therefore the study provides information on rates of left-handedness in those born in the nineteenth century, a group for which few data are otherwise available. A total of 6,549 responses were received, with an overall rate of left-handedness of 15.2%, which is substantially above that expected for a cohort born in the nineteenth and early twentieth centuries. Left-handers are likely to respond preferentially to surveys about handedness, and the extent of over-response can be estimated in modern control data obtained from a handedness website, from the 1953 BBC data, and from Crichton-Browne's 1907 survey, in which there was also a response bias. Response bias appears to have been growing, being relatively greater in the most modern studies. In the 1953 data there is also evidence that left-handers were more common among later rather than early responders, suggesting that left-handers may have been specifically recruited into the study, perhaps by other left-handers who had responded earlier. In the present study the estimated rate of bias was used to correct the nineteenth-century BBC data, which was then combined with other available data as a mixture of two constrained Weibull functions, to obtain an overall estimate of handedness rates in the nineteenth century. The best estimates are that left-handedness was at its nadir of about 3% for those born between about 1880 and 1900. Extrapolating backwards, the rate of left-handedness in the eighteenth century was probably about 10%, with the decline beginning in about 1780, and reaching around 7% in about 1830, although inevitably there are many uncertainties in those estimates. What does seem indisputable is that rates of left-handedness fell during most of the nineteenth century, only subsequently to rise in

  7. Characterization Of Laccase T-DNA Mutants In Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Andersen, Jeppe R; Asp, Torben; Mansfield, Shawn

    Laccases (P-diphenol:O2 oxidoreductase; EC 1.10.3.2), also termed laccase-like multicopper oxidases, are blue copper-containing oxidases which comprise multigene families in plants. In the Arabidopsis thaliana genome, 17 laccase genes (LAC1 to LAC17) have been annotated. To identify laccases...... involved in cell wall biosynthesis in Arabidopsis primary stems we have developed homozygous T-DNA mutants for 14 individual laccases. Six laccases are highly expressed in the wild type primary stem, four of which (LAC2, LAC4, LAC12, and LAC17) show correlated gene expression with one to several genes (e...... different and distinct biochemical pathways and that laccases might be involved in polymerization of both polysaccharides and monolignols in the Arabidopsis cell wall....

  8. Cherenkov radiation by an electron bunch that moves in a vacuum above a left-handed material

    International Nuclear Information System (INIS)

    Averkov, Yu.O.; Yakovenko, V.M.

    2005-01-01

    Cherenkov radiation by a nonrelativistic electron bunch that moves above an interface of a vacuum-left-handed material has been investigated theoretically. The electron density of the bunch is described by a Gauss distribution. Cherenkov radiation for the frequency range where the refractive index is negative is shown to lead to simultaneous excitation of both bulk and surface electromagnetic waves over one and the same frequency range. In this case the wave vector magnitude in the plane of the interface of surface electromagnetic waves is larger than the corresponding wave vector magnitude of bulk electromagnetic waves. The energy flows in a left-handed material have been calculated. The spectral density and the radiation pattern have been investigated

  9. A compact very wideband amplifying filter based on RTD loaded composite right/left-handed transmission lines.

    Science.gov (United States)

    Abu-Marasa, Mahmoud O Mahmoud; El-Khozondar, Hala Jarallah

    2015-01-01

    The composite right/left-handed (CRLH) transmission line (TL) is presented as a general TL possessing both left-handed (LH) and right-handed (RH) natures. RH materials have both positive permittivity and positive permeability, and LH materials have both negative permittivity and negative permeability. This paper aims to design and analyze nonlinear CRLH-TL transmission line loaded with resonant tunneling diode (RTD). The main application of this design is a very wideband and compact filter that amplifies the travelling signal. We used OrCAD and ADS software to analyze the proposed circuit. CRLH-TL consists of a microstrip line which is loaded with complementary split-rings resonators (CSRRs), series gaps, and shunt inductor connected parallel to the RTD. The designed structure possess a wide band that ranges from 5 to 10.5 GHz and amplifies signal up to 50 %. The proposed design is of interest to microwave compact component designers.

  10. Effective Medium Ratio Obeying Wideband Left-Handed Miniaturized Meta-atoms for Multi-band Applications

    Science.gov (United States)

    Hossain, Mohammad Jakir; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2018-03-01

    In this paper, a miniaturized wideband left-handed (LH) meta-atom based on planar modified multiple hexagonal split ring resonators was designed, simulated, fabricated and tested that can maintain a left-handed property. An analysis and comparison of the different array structures were performed that obtained better effective medium ratio (EMR) and wideband (5.54 GHz) for multi band operations in the microwave regime. Finite-difference time-domain (FDTD) method based Computer Simulation Technology was implemented to design the meta-atom. The meta-atom showed multi-band response in conjunction with wideband and LH property over the certain frequency bands in the microwave spectra. The EMR was considerably improved compared to previously reported meta-atoms. The measured results showed good agreement with the simulated results. The dimensions, S-parameters and EMR parameters of the proposed miniaturized LH meta-atom are appropriate for L-, S-, C-, X-, and Ku-band applications.

  11. Right- and left-handed rules on the transverse spin angular momentum of a surface wave of photonic crystal.

    Science.gov (United States)

    Hu, Jinbing; Xia, Tongnan; Cai, Xiaoshu; Tian, Shengnan; Guo, Hanming; Zhuang, Songlin

    2017-07-01

    By investigating the surface wave of photonic crystal, we put forward two sets of rules: the right-handed screw rule, judging the transverse spin angular momentum (SAM) directions according to the propagation direction of the surface wave; and the left-handed rule, judging the excitation direction of the surface wave in accordance to the SAM direction of incident circularly polarized light and the relative position of the dipole-like scatterer with respect to the interface where the surface wave propagates. Both right- and left-handed rules apply to the interface consisting of opposite-sign-permittivity materials. With the help of these two sets of rules, it is convenient to judge the direction of the transverse SAM and the excited surface wave, which facilitate the application involving transverse SAM of the surface wave.

  12. Surgical skills acquisition among left-handed trainees-true inferiority or unfair assessment: a preliminary study.

    Science.gov (United States)

    Lee, Jason Y; Mucksavage, Phillip; McDougall, Elspeth M

    2013-01-01

    Studies involving the formal assessment of surgical skills have often reported inferior abilities among left-handed surgical trainees (LHT). Most surgical training curricula and assessment methods, however, are inherently geared toward right-handed trainees (RHT); potentially placing LHT at both a training and assessment disadvantage. We evaluated the effect of a hand dominance-based curriculum for acquisition of basic suturing and knot tying skills among medical students. After Institutional Review Board approval, first- and second-year medical students from the University of California, Irvine School of Medicine were recruited to participate in a basic suturing and knot tying skills course. Consenting students were randomized to either a left-handed curriculum or a right-handed curriculum consisting of (1) a 30-minute introductory video and (2) a 2-hour instructor-led, hands-on training session on basic suturing and knot tying. All instructional methods, instruments, and instructors were exclusively right-handed or left-handed for the right-handed curriculum or left-handed curriculum, respectively. Students were assessed on the performance of 2 suturing tasks, continuous running suturing and instrument knot tying, and performance assessments were conducted both immediately and 2 weeks posttraining. A total of 19 students completed the training course and both assessments (8 LHT, 11 RHT). Students randomized to a curriculum "concordant" with their hand dominance performed significantly better than those randomized to a "discordant" curriculum on both tasks (p hand dominance might have inferior acquisition of basic suturing and knot tying skills. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  13. Mirrors in the PDB: left-handed α-turns guide design with D-amino acids

    Science.gov (United States)

    Annavarapu, Srinivas; Nanda, Vikas

    2009-01-01

    Background Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Results Propensities for amino acids to occur in contiguous αL helices correlate with published thermodynamic scales for incorporation of D-amino acids into αR helices. Two backbone rules for terminating a left-handed helix are found: an αR conformation is disfavored at the amino terminus, and a βR conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to αL helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. Conclusion By examining left-handed α-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed α-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds. PMID:19772623

  14. Mirrors in the PDB: left-handed alpha-turns guide design with D-amino acids.

    Science.gov (United States)

    Annavarapu, Srinivas; Nanda, Vikas

    2009-09-22

    Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Propensities for amino acids to occur in contiguous alpha(L) helices correlate with published thermodynamic scales for incorporation of D-amino acids into alpha(R) helices. Two backbone rules for terminating a left-handed helix are found: an alpha(R) conformation is disfavored at the amino terminus, and a beta(R) conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to alpha(L) helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. By examining left-handed alpha-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed alpha-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds.

  15. Sites That Can Produce Left-Handed Amino Acids in the Supernova Neutrino Amino Acid Processing Model

    OpenAIRE

    Boyd, Richard N.; Famiano, Michael A.; Onaka, Takashi; Kajino, Toshitaka

    2018-01-01

    The Supernova Neutrino Amino Acid Processing model, which uses electron anti-neutrinos and the magnetic field from a source object such as a supernova to selectively destroy one amino acid chirality, is studied for possible sites that would produce meteoroids having partially left-handed amino acids. Several sites appear to provide the requisite magnetic field intensities and electron anti-neutrino fluxes. These results have obvious implications for the origin of life on Earth.

  16. Mirrors in the PDB: left-handed α-turns guide design with D-amino acids

    Directory of Open Access Journals (Sweden)

    Nanda Vikas

    2009-09-01

    Full Text Available Abstract Background Incorporating variable amino acid stereochemistry in molecular design has the potential to improve existing protein stability and create new topologies inaccessible to homochiral molecules. The Protein Data Bank has been a reliable, rich source of information on molecular interactions and their role in protein stability and structure. D-amino acids rarely occur naturally, making it difficult to infer general rules for how they would be tolerated in proteins through an analysis of existing protein structures. However, protein elements containing short left-handed turns and helices turn out to contain useful information. Molecular mechanisms used in proteins to stabilize left-handed elements by L-amino acids are structurally enantiomeric to potential synthetic strategies for stabilizing right-handed elements with D-amino acids. Results Propensities for amino acids to occur in contiguous αL helices correlate with published thermodynamic scales for incorporation of D-amino acids into αR helices. Two backbone rules for terminating a left-handed helix are found: an αR conformation is disfavored at the amino terminus, and a βR conformation is disfavored at the carboxy terminus. Helix capping sidechain-backbone interactions are found which are unique to αL helices including an elevated propensity for L-Asn, and L-Thr at the amino terminus and L-Gln, L-Thr and L-Ser at the carboxy terminus. Conclusion By examining left-handed α-turns containing L-amino acids, new interaction motifs for incorporating D-amino acids into right-handed α-helices are identified. These will provide a basis for de novo design of novel heterochiral protein folds.

  17. Sites that Can Produce Left-handed Amino Acids in the Supernova Neutrino Amino Acid Processing Model

    Science.gov (United States)

    Boyd, Richard N.; Famiano, Michael A.; Onaka, Takashi; Kajino, Toshitaka

    2018-03-01

    The Supernova Neutrino Amino Acid Processing model, which uses electron anti-neutrinos and the magnetic field from a source object such as a supernova to selectively destroy one amino acid chirality, is studied for possible sites that would produce meteoroids with partially left-handed amino acids. Several sites appear to provide the requisite magnetic field intensities and electron anti-neutrino fluxes. These results have obvious implications for the origin of life on Earth.

  18. Allograph errors and impaired access to graphic motor codes in a case of unilateral agraphia of the dominant left hand.

    Science.gov (United States)

    Hanley, J R; Peters, S

    2001-06-01

    This paper describes the case of a unilateral agraphic patient (GG) who makes letter substitutions only when writing letters and words with his dominant left hand. Accuracy is significantly greater when he is writing with his right hand and when he is asked to spell words orally. GG also makes case errors when writing letters, and will sometimes write words in mixed case. However, these allograph errors occur regardless of which hand he is using to write. In terms of cognitive models of peripheral dysgraphia (e.g., Ellis, 1988), it appears that he has an allograph level impairment that affects writing with both hands, and a separate problem in accessing graphic motor patterns that disrupts writing with the left hand only. In previous studies of left-handed patients with unilateral agraphia (Zesiger & Mayer, 1992; Zesiger, Pegna, & Rilliet, 1994), it has been suggested that allographic knowledge used for writing with both hands is stored exclusively in the left hemisphere, but that graphic motor patterns are represented separately in each hemisphere. The pattern of performance demonstrated by GG strongly supports such a conclusion.

  19. Automated processes in tennis: do left-handed players benefit from the tactical preferences of their opponents?

    Science.gov (United States)

    Loffing, Florian; Hagemann, Norbert; Strauss, Bernd

    2010-02-01

    Previous research on laterality in sport suggests an over-representation of left-handers in interactive sports such as tennis and cricket. These findings potentially reflect left-handers' advantage over their right-handed competitors in those sports. Although considered crucial for successful performance, the tactical component of their superiority has yet to be analysed. Two studies were conducted to test for a side bias in tennis players' tactical preferences. In the first study, 108 right- and left-handed players of varying skill watched rallies on a computer screen and had to indicate where they would place the ball in the opposing half. The results showed the tactical preference of players to place more balls on a left-handed opponent's mostly stronger forehand side compared with when faced with a right-hander. In the second study, 54 professional tennis matches involving right- and left-handers were analysed with respect to ball placement frequencies on the opponent's backhand side. Significantly fewer balls were hit to the backhand side of a left-handed opponent, thus replicating the findings of Study 1 in on-court situations. Both studies indicate players' preference to place shots to their right irrespective of their opponent's handedness. Findings support the assumption that left-handers might enjoy a strategic advantage in tennis.

  20. On the advantage of being left-handed in volleyball: further evidence of the specificity of skilled visual perception.

    Science.gov (United States)

    Loffing, Florian; Schorer, Jörg; Hagemann, Norbert; Baker, Joseph

    2012-02-01

    High ball speeds and close distances between competitors require athletes in interactive sports to correctly anticipate an opponent's intentions in order to render appropriate reactions. Although it is considered crucial for successful performance, such skill appears impaired when athletes are confronted with a left-handed opponent, possibly because of athletes' reduced perceptual familiarity with rarely encountered left-handed actions. To test this negative perceptual frequency effect hypothesis, we invited 18 skilled and 18 novice volleyball players to predict shot directions of left- and right-handed attacks in a video-based visual anticipation task. In accordance with our predictions, and with recent reports on laterality differences in visual perception, the outcome of left-handed actions was significantly less accurately predicted than the outcome of right-handed attacks. In addition, this left-right bias was most distinct when predictions had to be based on preimpact (i.e., before hand-ball contact) kinematic cues, and skilled players were generally more affected by the opponents' handedness than were novices. The study's findings corroborate the assumption that skilled visual perception is attuned to more frequently encountered actions.

  1. Subunit b-Dimer of the Escherichia coli ATP Synthase Can Form Left-Handed Coiled-Coils

    Science.gov (United States)

    Wise, John G.; Vogel, Pia D.

    2008-01-01

    One remaining challenge to our understanding of the ATP synthase concerns the dimeric coiled-coil stator subunit b of bacterial synthases. The subunit b-dimer has been implicated in important protein interactions that appear necessary for energy conservation and that may be instrumental in energy conservation during rotary catalysis by the synthase. Understanding the stator structure and its interactions with the rest of the enzyme is crucial to the understanding of the overall catalytic mechanism. Controversy exists on whether subunit b adopts a classic left-handed or a presumed right-handed dimeric coiled-coil and whether or not staggered pairing between nonhomologous residues in the homodimer is required for intersubunit packing. In this study we generated molecular models of the Escherichia coli subunit b-dimer that were based on the well-established heptad-repeat packing exhibited by left-handed, dimeric coiled-coils by employing simulated annealing protocols with structural restraints collected from known structures. In addition, we attempted to create hypothetical right-handed coiled-coil models and left- and right-handed models with staggered packing in the coiled-coil domains. Our analyses suggest that the available structural and biochemical evidence for subunit b can be accommodated by classic left-handed, dimeric coiled-coil quaternary structures. PMID:18326648

  2. Transferability of different classical force fields for right and left handed α-helices constructed from enantiomeric amino acids.

    Science.gov (United States)

    Biswas, Santu; Sarkar, Sujit; Pandey, Prithvi Raj; Roy, Sudip

    2016-02-21

    Amino acids can form d and l enantiomers, of which the l enantiomer is abundant in nature. The naturally occurring l enantiomer has a greater preference for a right handed helical conformation, and the d enantiomer for a left handed helical conformation. The other conformations, that is, left handed helical conformations of the l enantiomers and right handed helical conformations of the d enantiomers, are not common. The energetic differences between left and right handed alpha helical peptide chains constructed from enantiomeric amino acids are investigated using quantum chemical calculations (using the M06/6-311g(d,p) level of theory). Further, the performances of commonly used biomolecular force fields (OPLS/AA, CHARMM27/CMAP and AMBER) to represent the different helical conformations (left and right handed) constructed from enantiomeric (D and L) amino acids are evaluated. 5- and 10-mer chains from d and l enantiomers of alanine, leucine, lysine, and glutamic acid, in right and left handed helical conformations, are considered in the study. Thus, in total, 32 α-helical polypeptides (4 amino acids × 4 conformations of 5-mer and 10-mer) are studied. Conclusions, with regards to the performance of the force fields, are derived keeping the quantum optimized geometry as the benchmark, and on the basis of phi and psi angle calculations, hydrogen bond analysis, and different long range helical order parameters.

  3. Right- and left-handed three-helix proteins. II. Similarity and differences in mechanical unfolding of proteins.

    Science.gov (United States)

    Glyakina, Anna V; Likhachev, Ilya V; Balabaev, Nikolay K; Galzitskaya, Oxana V

    2014-01-01

    Here, we study mechanical properties of eight 3-helix proteins (four right-handed and four left-handed ones), which are similar in size under stretching at a constant speed and at a constant force on the atomic level using molecular dynamics simulations. The analysis of 256 trajectories from molecular dynamics simulations with explicit water showed that the right-handed three-helix domains are more mechanically resistant than the left-handed domains. Such results are observed at different extension velocities studied (192 trajectories obtained at the following conditions: v = 0.1, 0.05, and 0.01 Å ps(-1) , T = 300 K) and under constant stretching force (64 trajectories, F = 800 pN, T = 300 K). We can explain this by the fact, at least in part, that the right-handed domains have a larger number of contacts per residue and the radius of cross section than the left-handed domains. Copyright © 2013 Wiley Periodicals, Inc.

  4. Cisplatin GG-crosslinks within single-stranded DNA: origin of the preference for left-handed helicity.

    Science.gov (United States)

    Monnet, Jordan; Kozelka, Jiří

    2012-10-01

    Molecular dynamics (MD) simulations of the single-stranded DNA trinucleotide TG*G*, with the G* guanines crosslinked by the antitumor drug cisplatin, were performed with explicit representation of the water as solvent. The purpose of the simulations was to explain previous NMR observations indicating that in single-stranded cisplatin-DNA adducts, the crosslinked guanines adopt a left-handed helical orientation, whereas in duplexes, the orientation is right-handed. The analysis of the MD trajectory of TG*G* has ascribed a crucial role to hydrogen-bonding (direct or through-water) interactions of the 5'-oriented NH(3) ligand of platinum with acceptor groups at the 5'-side of the crosslink, namely the TpG* phosphate and the terminal 5'-OH group. These interactions bring about some strain into the trinucleotide which is slightly but significantly (1-1.5 kcal.mol(-1)) higher for the right-handed orientation than for the left-handed one. During the unconstrained, 3 ns long MD simulation, left-handed conformations were ~15 times more abundant than the right-handed ones. This sampling difference agrees roughly with the calculated energy difference in strain energy. Overall, these results show that the Pt-GG crosslink within single-stranded DNA is malleable and can access different conformations at a moderate energy cost. This malleability could be of importance in interactions between the platinated DNA and cellular proteins, in which the DNA is locally unwound. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Darwin's left hand. Analysis of chiroptical properties of unirradiated and irradiated L- and D-amino acids

    International Nuclear Information System (INIS)

    Durchschlag, H.; Seidl, C.; Tiefenbach, K.J.

    2011-01-01

    Complete text of publication follows. Although normal chemical reactions roughly produce equal mixtures of left-handed and right-handed types, life used some specialized machinery to produce only left-handed forms of amino acids. Origin of life theories must explain how nature could produce the proper mirrored building blocks. There appear, however, to be no established reasons why left-handed amino acids should be favoured in biological systems, and the possible emergence of chiral uniqueness in living processes is still an unresolved riddle. In a multitude of experiments, we have tested the sensitivity of all L- and D- amino acids against X-irradiation and UV light exposure, with special emphasis on any differences in degradation, (thermal) stability and ability to act as substrates. Among the techniques tested, the spectroscopic techniques (UV absorption, fluorescence, and in particular far-UV circular dichroism) turned out to be most effective, in addition to crystallisation experiments. In this context, a variety of experimental conditions (pH, gassing conditions etc.) were chosen. For analysing the data of aromatic and non-aromatic amino acids, respectively, appropriate precautions have to be taken. As a result of our investigations, indeed, several significant dissimilarities between different types of amino acids and different enantiomers were established. For example, among the aromatic representatives, L and D forms of tyrosines turned out to show a quite different behaviour, while among the non-aromatics, L and D enantiomers of asparagines and glutamines established distinctly different characteristics. Overall, under definite conditions, D-isomers tend to be more sensitive to radiation than their L-counterparts. If this experimentally observed radiosensitivity of L and D enantiomers is indeed the reason for amino acid homochirality and the 'handedness of life' has to be elucidated in future experiments on earth and in space.

  6. The thermal effect on the left-handedness of the mesoscopic composite right-Left handed transmission line

    Science.gov (United States)

    Wei, Xiao-Jing; Zhao, Shun-Cai; Guo, Hong-Wei

    2017-10-01

    Starting from the quantum fluctuation of current in the mesoscopic composite right-left handed transmission line (CRLH-TL) in the thermal Fock state, we investigate the left-handedness dependent of the frequencies, intensity and quantum fluctuations of the current field in the CRLH-TL under different thermal environment. The results show that the intensity and quantum fluctuations of current field in lower frequency bands affect the left-handedness distinctly under different thermal environment. The thermal effect on the left-handedness in the mesoscopic CRLH-TL deserves further experimental investigation in its miniaturization application.

  7. Clinical psychomotor skills among left and right handed medical students: are the left-handed medical students left out?

    Science.gov (United States)

    Alnassar, Sami; Alrashoudi, Aljoharah Nasser; Alaqeel, Mody; Alotaibi, Hala; Alkahel, Alanoud; Hajjar, Waseem; Al-Shaikh, Ghadeer; Alsaif, Abdulaziz; Haque, Shafiul; Meo, Sultan Ayoub

    2016-03-22

    There is a growing perception that the left handed (LH) medical students are facing difficulties while performing the clinical tasks that involve psychomotor skill, although the evidence is very limited and diverse. The present study aimed to evaluate the clinical psychomotor skills among Right-handed (RH) and left-handed (LH) medical students. For this study, 54 (27 left handed and 27 right handed) first year medical students were selected. They were trained for different clinical psychomotor skills including suturing, laparoscopy, intravenous cannulation and urinary catheterization under the supervision of certified instructors. All students were evaluated for psychomotor skills by different instructors. The comparative performance of the students was measured by using a global rating scale, each selected criteria was allotted 5-points score with the total score of 25. There were no significant differences in the performance of psychomotor skills among LH and RH medical students. The global rating score obtained by medical students in suturing techniques was: LH 15.89 ± 2.88, RH 16.15 ± 2.75 (p = 0.737), cannulation techniques LH 20.44 ± 2.81, RH 20.70 ± 2.56 (p = 0.725), urinary catheterization LH 4.33 ± 0.96 RH 4.11 ± 1.05 (p = 0.421). For laparoscopic skills total peg transfer time was shorter among LH medical students compared to RH medical students (LH 129.85 ± 80.87 s vs RH 135.52 ± 104.81 s) (p = 0.825). However, both RH and LH students completed their procedure within the stipulated time. Among LH and RH medical students no significant difference was observed in performing the common surgical psychomotor skills. Surgical skills for LH or RH might not be a result of innate dexterity but rather the academic environment in which they are trained and assessed. Early laterality-related mentoring in medical schools as well as during the clinical residency might reduce the inconveniences faced by the left-handed

  8. The Genomic Pattern of tDNA Operon Expression in E. coli.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available In fast-growing microorganisms, a tRNA concentration profile enriched in major isoacceptors selects for the biased usage of cognate codons. This optimizes translational rate for the least mass invested in the translational apparatus. Such translational streamlining is thought to be growth-regulated, but its genetic basis is poorly understood. First, we found in reanalysis of the E. coli tRNA profile that the degree to which it is translationally streamlined is nearly invariant with growth rate. Then, using least squares multiple regression, we partitioned tRNA isoacceptor pools to predicted tDNA operons from the E. coli K12 genome. Co-expression of tDNAs in operons explains the tRNA profile significantly better than tDNA gene dosage alone. Also, operon expression increases significantly with proximity to the origin of replication, oriC, at all growth rates. Genome location explains about 15% of expression variation in a form, at a given growth rate, that is consistent with replication-dependent gene concentration effects. Yet the change in the tRNA profile with growth rate is less than would be expected from such effects. We estimated per-copy expression rates for all tDNA operons that were consistent with independent estimates for rDNA operons. We also found that tDNA operon location, and the location dependence of expression, were significantly different in the leading and lagging strands. The operonic organization and genomic location of tDNA operons are significant factors influencing their expression. Nonrandom patterns of location and strandedness shown by tDNA operons in E. coli suggest that their genomic architecture may be under selection to satisfy physiological demand for tRNA expression at high growth rates.

  9. ILQINS hexapeptide, identified in lysozyme left-handed helical ribbons and nanotubes, forms right-handed helical ribbons and crystals.

    Science.gov (United States)

    Lara, Cecile; Reynolds, Nicholas P; Berryman, Joshua T; Xu, Anqiu; Zhang, Afang; Mezzenga, Raffaele

    2014-03-26

    Amyloid fibrils are implicated in over 20 neurodegenerative diseases. The mechanisms of fibril structuring and formation are not only of medical and biological importance but are also relevant for material science and nanotechnologies due to the unique structural and physical properties of amyloids. We previously found that hen egg white lysozyme, homologous to the disease-related human lysozyme, can form left-handed giant ribbons, closing into nanotubes. By using matrix-assisted laser desorption ionization mass spectrometry analysis, we here identify a key component of such structures: the ILQINS hexapeptide. By combining atomic force microscopy and circular dichorism, we find that this fragment, synthesized by solid-phase peptide synthesis, also forms fibrillar structures in water at pH 2. However, all fibrillar structures formed possess an unexpected right-handed twist, a rare chirality within the corpus of amyloid experimental observations. We confirm by small- and wide-angle X-ray scattering and molecular dynamics simulations that these fibrils are composed of conventional left-handed β-sheets, but that packing stresses between adjacent sheets create this twist of unusual handedness. We also show that the right-handed fibrils represent a metastable state toward β-sheet-based microcrystals formation.

  10. Reconfigurable/tunable dual band/dual mode ferrite composite right/left-handed CPW coupled-line coupler

    Science.gov (United States)

    Abdalla, M. A.; Hu, Z.

    2017-09-01

    This paper presents the design, modeling and experimental verification of a novel reconfigurable/tunable dual band/dual mode ferrite composite right/left handed CPW coupled-line coupler. The composite right/left handed configuration has been realized by loading coupled CPW transmission lines with series inter-digital capacitors and shunt segment inductors. The coupler performance has been verified using the equivalent circuit model, electromagnetic full wave simulations and experimental measurements. The coupler operates on dual mode in that it has dual bands of operation with two different propagation mechanisms. The first band has only a reciprocal backward coupling whereas the second band has only nonreciprocal through propagation. The non-reciprocity isolation in the second band is better than average of 15 dB. Compared to conventional single band single mode coupled line coupler of length = 0.25 λg, the proposed novel dual band dual mode coupler length is almost the same (0.265 λg) at 4.5 GHz. Furthermore, the dual mode/dual band coupler can have tunable functionality.

  11. Analysis of EEG signal by flicker-noise spectroscopy: identification of right-/left-hand movement imagination.

    Science.gov (United States)

    Broniec, A

    2016-12-01

    Flicker-noise spectroscopy (FNS) is a general phenomenological approach to analyzing dynamics of complex nonlinear systems by extracting information contained in chaotic signals. The main idea of FNS is to describe an information hidden in correlation links, which are present in the chaotic component of the signal, by a set of parameters. In the paper, FNS is used for the analysis of electroencephalography signal related to the hand movement imagination. The signal has been parametrized in accordance with the FNS method, and significant changes in the FNS parameters have been observed, at the time when the subject imagines the movement. For the right-hand movement imagination, abrupt changes (visible as a peak) of the parameters, calculated for the data recorded from the left hemisphere, appear at the time corresponding to the initial moment of the imagination. In contrary, for the left-hand movement imagination, the meaningful changes in the parameters are observed for the data recorded from the right hemisphere. As the motor cortex is activated mainly contralaterally to the hand, the analysis of the FNS parameters allows to distinguish between the imagination of the right- and left-hand movement. This opens its potential application in the brain-computer interface.

  12. Correction: Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on β-glucocerebrosidase activity.

    Science.gov (United States)

    Stauffert, Fabien; Serra-Vinardell, Jenny; Gómez-Grau, Marta; Michelakakis, Helen; Mavridou, Irene; Grinberg, Daniel; Vilageliu, Lluïsa; Casas, Josefina; Bodlenner, Anne; Delgado, Antonio; Compain, Philippe

    2017-09-26

    Correction for 'Stereodivergent synthesis of right- and left-handed iminoxylitol heterodimers and monomers. Study of their impact on β-glucocerebrosidase activity' by Fabien Stauffert et al., Org. Biomol. Chem., 2017, 15, 3681-3705.

  13. [Transposition errors during learning to reproduce a sequence by the right- and the left-hand movements: simulation of positional and movement coding].

    Science.gov (United States)

    Liakhovetskiĭ, V A; Bobrova, E V; Skopin, G N

    2012-01-01

    Transposition errors during the reproduction of a hand movement sequence make it possible to receive important information on the internal representation of this sequence in the motor working memory. Analysis of such errors showed that learning to reproduce sequences of the left-hand movements improves the system of positional coding (coding ofpositions), while learning of the right-hand movements improves the system of vector coding (coding of movements). Learning of the right-hand movements after the left-hand performance involved the system of positional coding "imposed" by the left hand. Learning of the left-hand movements after the right-hand performance activated the system of vector coding. Transposition errors during learning to reproduce movement sequences can be explained by neural network using either vector coding or both vector and positional coding.

  14. Bacterial transposons are co-transferred with T-DNA to rice chromosomes during Agrobacterium-mediated transformation.

    Science.gov (United States)

    Kim, Sung-Ryul; An, Gynheung

    2012-06-01

    Agrobacterium tumefaciens is widely utilized for delivering a foreign gene into a plant's genome. We found the bacterial transposon Tn5393 in transgenic rice plants. Analysis of the flanking sequences of the transferred-DNA (T-DNA) identified that a portion of the Tn5393 sequence was present immediately next to the end of the T-DNA. Because this transposon was present in A. tumefaciens strain LBA4404, but not in EHA105 and GV3101, our findings indicated that Tn5393 was transferred from LBA4404 into the rice genome during the transformation process. We also noted that another bacterial transposon, Tn5563, is present in transgenic plants. Analyses of 331 transgenic lines revealed that 26.0% carried Tn5393 and 2.1% contained Tn5563. In most of the lines, an intact transposon was integrated into the T-DNA and transferred to the rice chromosome. More than one copy of T-DNA was introduced into the plants, often at a single locus. This resulted in T-DNA repeats of normal and transposon-carrying TDNA that generated deletions of a portion of the T-DNA, joining the T-DNA end to the bacterial transposon. Based on these data, we suggest that one should carefully select the appropriate Agrobacterium strain to avoid undesirable transformation of such sequences.

  15. Generation and characterization of the Western Regional Research Center Brachypodium T-DNA insertional mutant collection.

    Directory of Open Access Journals (Sweden)

    Jennifer N Bragg

    Full Text Available The model grass Brachypodium distachyon (Brachypodium is an excellent system for studying the basic biology underlying traits relevant to the use of grasses as food, forage and energy crops. To add to the growing collection of Brachypodium resources available to plant scientists, we further optimized our Agrobacterium tumefaciens-mediated high-efficiency transformation method and generated 8,491 Brachypodium T-DNA lines. We used inverse PCR to sequence the DNA flanking the insertion sites in the mutants. Using these flanking sequence tags (FSTs we were able to assign 7,389 FSTs from 4,402 T-DNA mutants to 5,285 specific insertion sites (ISs in the Brachypodium genome. More than 29% of the assigned ISs are supported by multiple FSTs. T-DNA insertions span the entire genome with an average of 19.3 insertions/Mb. The distribution of T-DNA insertions is non-uniform with a larger number of insertions at the distal ends compared to the centromeric regions of the chromosomes. Insertions are correlated with genic regions, but are biased toward UTRs and non-coding regions within 1 kb of genes over exons and intron regions. More than 1,300 unique genes have been tagged in this population. Information about the Western Regional Research Center Brachypodium insertional mutant population is available on a searchable website (http://brachypodium.pw.usda.gov designed to provide researchers with a means to order T-DNA lines with mutations in genes of interest.

  16. Resonance Frequency and Bandwidth of the Negative/Positive n Mode of a Composite Right-/Left-Handed Transmission Line

    Directory of Open Access Journals (Sweden)

    Seong-Jung Kim

    2018-01-01

    Full Text Available In this study, the analytic expression for the positive/negative nth-mode resonance frequency of an N unit cell composite right-/left-handed (CRLH transmission line is derived. To explain the resonance mechanism of the nth mode, especially for the negative mode, the current distribution of the N unit cell CRLH transmission line is investigated with a circuit simulation. Results show that both positive and negative nth resonance modes have n times current variations, but their phase difference is 180° as expected. Moreover, the positive nth resonance occurs at a high frequency, whereas the negative nth resonance transpires at a low frequency, thus indicating that the negative resonance mode can be utilized for a small resonator. The correlation between the slope of the dispersion curve and the bandwidth is also observed. In sum, the balanced condition of the CRLH transmission line provides a broader bandwidth than the unbalanced condition.

  17. Theoretical investigation of five-layer waveguide structure including two left-handed material layers for refractometric applications

    Science.gov (United States)

    Alkanoo, Anas A.; Taya, Sofyan A.

    2018-03-01

    A slab waveguide structure consisting of five layers is studied for optical sensing applications. The five-layer waveguide structure has a guiding dielectric film, two left-handed material (LHM) layers and two dielectric layers as a substrate and a cladding. The dispersion relation and the sensitivity to any change in the index of the analyte layer are derived. The sensitivity is explored with different parameters of the structure. It is found that the sensitivity of the proposed structure can be significantly improved with the increase of the index of the guiding layer and the decrease of the permittivity of the LHM layers. Moreover, it can be also improved with the increase of the thickness of the LHM layers.

  18. Extracellular VirB5 enhances T-DNA transfer from Agrobacterium to the host plant.

    Directory of Open Access Journals (Sweden)

    Benoît Lacroix

    Full Text Available VirB5 is a type 4 secretion system protein of Agrobacterium located on the surface of the bacterial cell. This localization pattern suggests a function for VirB5 which is beyond its known role in biogenesis and/or stabilization of the T-pilus and which may involve early interactions between Agrobacterium and the host cell. Here, we identify VirB5 as the first Agrobacterium virulence protein that can enhance infectivity extracellularly. Specifically, we show that elevating the amounts of the extracellular VirB5--by exogenous addition of the purified protein, its overexpression in the bacterium, or transgenic expression in and secretion out of the host cell--enhances the efficiency the Agrobacterium-mediated T-DNA transfer, as measured by transient expression of genes contained on the transferred T-DNA molecule. Importantly, the exogenous VirB5 enhanced transient T-DNA expression in sugar beet, a major crop recalcitrant to genetic manipulation. Increasing the pool of the extracellular VirB5 did not complement an Agrobacterium virB5 mutant, suggesting a dual function for VirB5: in the bacterium and at the bacterium-host cell interface. Consistent with this idea, VirB5 expressed in the host cell, but not secreted, had no effect on the transformation efficiency. That the increase in T-DNA expression promoted by the exogenous VirB5 was not due to its effects on bacterial growth, virulence gene induction, bacterial attachment to plant tissue, or host cell defense response suggests that VirB5 participates in the early steps of the T-DNA transfer to the plant cell.

  19. Extracellular VirB5 enhances T-DNA transfer from Agrobacterium to the host plant.

    Science.gov (United States)

    Lacroix, Benoît; Citovsky, Vitaly

    2011-01-01

    VirB5 is a type 4 secretion system protein of Agrobacterium located on the surface of the bacterial cell. This localization pattern suggests a function for VirB5 which is beyond its known role in biogenesis and/or stabilization of the T-pilus and which may involve early interactions between Agrobacterium and the host cell. Here, we identify VirB5 as the first Agrobacterium virulence protein that can enhance infectivity extracellularly. Specifically, we show that elevating the amounts of the extracellular VirB5--by exogenous addition of the purified protein, its overexpression in the bacterium, or transgenic expression in and secretion out of the host cell--enhances the efficiency the Agrobacterium-mediated T-DNA transfer, as measured by transient expression of genes contained on the transferred T-DNA molecule. Importantly, the exogenous VirB5 enhanced transient T-DNA expression in sugar beet, a major crop recalcitrant to genetic manipulation. Increasing the pool of the extracellular VirB5 did not complement an Agrobacterium virB5 mutant, suggesting a dual function for VirB5: in the bacterium and at the bacterium-host cell interface. Consistent with this idea, VirB5 expressed in the host cell, but not secreted, had no effect on the transformation efficiency. That the increase in T-DNA expression promoted by the exogenous VirB5 was not due to its effects on bacterial growth, virulence gene induction, bacterial attachment to plant tissue, or host cell defense response suggests that VirB5 participates in the early steps of the T-DNA transfer to the plant cell.

  20. Analysis of T-DNA integration and generative segregation in transgenic winter triticale (x Triticosecale Wittmack

    Directory of Open Access Journals (Sweden)

    Hensel Goetz

    2012-09-01

    Full Text Available Abstract Background While the genetic transformation of the major cereal crops has become relatively routine, to date only a few reports were published on transgenic triticale, and robust data on T-DNA integration and segregation have not been available in this species. Results Here, we present a comprehensive analysis of stable transgenic winter triticale cv. Bogo carrying the selectable marker gene HYGROMYCIN PHOSPHOTRANSFERASE (HPT and a synthetic green fluorescent protein gene (gfp. Progeny of four independent transgenic plants were comprehensively investigated with regard to the number of integrated T-DNA copies, the number of plant genomic integration loci, the integrity and functionality of individual T-DNA copies, as well as the segregation of transgenes in T1 and T2 generations, which also enabled us to identify homozygous transgenic lines. The truncation of some integrated T-DNAs at their left end along with the occurrence of independent segregation of multiple T-DNAs unintendedly resulted in a single-copy segregant that is selectable marker-free and homozygous for the gfp gene. The heritable expression of gfp driven by the maize UBI-1 promoter was demonstrated by confocal laser scanning microscopy. Conclusions The used transformation method is a valuable tool for the genetic engineering of triticale. Here we show that comprehensive molecular analyses are required for the correct interpretation of phenotypic data collected from the transgenic plants.

  1. Memorization of Sequences of Movements of the Right or the Left Hand by Right- and Left-Handers: Vector Coding.

    Science.gov (United States)

    Bobrova, E V; Bogacheva, I N; Lyakhovetskii, V A; Fabinskaja, A A; Fomina, E V

    2017-01-01

    In order to test the hypothesis of hemisphere specialization for different types of information coding (the right hemisphere, for positional coding; the left one, for vector coding), we analyzed the errors of right and left-handers during a task involving the memorization of sequences of movements by the left or the right hand, which activates vector coding by changing the order of movements in memorized sequences. The task was first performed by the right or the left hand, then by the opposite hand. It was found that both'right- and left-handers use the information about the previous movements of the dominant hand, but not of the non-dom" inant one. After changing the hand, right-handers use the information about previous movements of the second hand, while left-handers do not. We compared our results with the data of previous experiments, in which positional coding was activated, and concluded that both right- and left-handers use vector coding for memorizing the sequences of their dominant hands and positional coding for memorizing the sequences of non-dominant hand. No similar patterns of errors were found between right- and left-handers after changing the hand, which suggests that in right- and left-handersthe skills are transferred in different ways depending on the type of coding.

  2. Unraveling mysteries of personal performance style; biomechanics of left-hand position changes (shifting) in violin performance.

    Science.gov (United States)

    Visentin, Peter; Li, Shiming; Tardif, Guillaume; Shan, Gongbing

    2015-01-01

    Instrumental music performance ranks among the most complex of learned human behaviors, requiring development of highly nuanced powers of sensory and neural discrimination, intricate motor skills, and adaptive abilities in a temporal activity. Teaching, learning and performing on the violin generally occur within musico-cultural parameters most often transmitted through aural traditions that include both verbal instruction and performance modeling. In most parts of the world, violin is taught in a manner virtually indistinguishable from that used 200 years ago. The current study uses methods from movement science to examine the "how" and "what" of left-hand position changes (shifting), a movement skill essential during violin performance. In doing so, it begins a discussion of artistic individualization in terms of anthropometry, the performer-instrument interface, and the strategic use of motor behaviors. Results based on 540 shifting samples, a case series of 6 professional-level violinists, showed that some elements of the skill were individualized in surprising ways while others were explainable by anthropometry, ergonomics and entrainment. Remarkably, results demonstrated each violinist to have developed an individualized pacing for shifts, a feature that should influence timing effects and prove foundational to aesthetic outcomes during performance. Such results underpin the potential for scientific methodologies to unravel mysteries of performance that are associated with a performer's personal artistic style.

  3. Unraveling mysteries of personal performance style; biomechanics of left-hand position changes (shifting in violin performance

    Directory of Open Access Journals (Sweden)

    Peter Visentin

    2015-10-01

    Full Text Available Instrumental music performance ranks among the most complex of learned human behaviors, requiring development of highly nuanced powers of sensory and neural discrimination, intricate motor skills, and adaptive abilities in a temporal activity. Teaching, learning and performing on the violin generally occur within musico-cultural parameters most often transmitted through aural traditions that include both verbal instruction and performance modeling. In most parts of the world, violin is taught in a manner virtually indistinguishable from that used 200 years ago. The current study uses methods from movement science to examine the “how” and “what” of left-hand position changes (shifting, a movement skill essential during violin performance. In doing so, it begins a discussion of artistic individualization in terms of anthropometry, the performer-instrument interface, and the strategic use of motor behaviors. Results based on 540 shifting samples, a case series of 6 professional-level violinists, showed that some elements of the skill were individualized in surprising ways while others were explainable by anthropometry, ergonomics and entrainment. Remarkably, results demonstrated each violinist to have developed an individualized pacing for shifts, a feature that should influence timing effects and prove foundational to aesthetic outcomes during performance. Such results underpin the potential for scientific methodologies to unravel mysteries of performance that are associated with a performer’s personal artistic style.

  4. A Compact Via-free Composite Right/Left Handed Low-pass Filter with Improved Selectivity

    Science.gov (United States)

    Kumar, Ashish; Choudhary, Dilip Kumar; Chaudhary, Raghvendra Kumar

    2017-07-01

    In this paper, a compact via-free low pass filter is designed based on composite right/left handed (CRLH) concept. The structure uses open ended concept. Rectangular slots are etched on signal transmission line (TL) to suppress the spurious band without altering the performance and size of filter. The filter is designed for low pass frequency band with cut-off frequency of 3.5 GHz. The proposed metamaterial structure has several prominent advantages in term of selectivity up to 34 dB/GHz and compactness with average insertion loss less than 0.4 dB. It has multiple applications in wireless communication (such as GSM900, global navigation satellite system (1.559-1.610 GHz), GSM1800, WLAN/WiFi (2.4-2.49 GHz) and WiMAX (2.5-2.69 GHz)). The design parameters have been measured and compared with the simulated results and found excellent agreement. The electrical size of proposed filter is 0.14λ0× 0.11λ0 (where λ0 is free space wavelength at zeroth order resonance (ZOR) frequency 2.7 GHz).

  5. Origin of Both Right- and Left-Handed Helicities in a Supramolecular Gel with and without Ni2+at the Supramolecular Level.

    Science.gov (United States)

    Go, Misun; Choi, Heekyoung; Moon, Cheol Joo; Park, Jaehyeon; Choi, Yeonweon; Lee, Shim Sung; Choi, Myong Yong; Jung, Jong Hwa

    2018-01-02

    We demonstrate the different origins of helical directions in polymeric gels derived from a hydrazone reaction in the absence and presence of Ni 2+ . The right-handed helicity of polymeric gels without Ni 2+ originates from the enantiomeric d-form alanine moiety embedded in the building block. However, the right-handed helicity is inverted to a left-handed helicity upon the addition of Ni 2+ , indicating that added Ni 2+ greatly affects the conformation of the polymeric gel by overcoming the influence of the enantiomer embedded in the building block on the helicity at the supramolecular level. More interestingly, the ratio of the right-toleft-handed helical fibers varies with the concentration of Ni 2+ , which converts from 100% right-handed helical fiber to 90% left-handed helical fiber. In the presence of Ni 2+ , both right- and left-handed helical fibers coexist at the supramolecular level. Some fibers also exhibit both right- and left-handed helicities in a single fiber.

  6. The formation of right-handed and left-handed chiral nanopores within a single domain during amino acid self-assembly on Au(111).

    Science.gov (United States)

    Yang, Sena; Jeon, Aram; Driver, Russell W; Kim, Yeonwoo; Jeon, Eun Hee; Kim, Sehun; Lee, Hee-Seung; Lee, Hangil

    2016-05-25

    We report the formation of both right- and left-handed chiral nanopores within a single domain during the self-assembly of an amino acid derivative on an inert Au(111) surface using STM. DFT calculations employed to rationalize this unusual result identified that intermolecular interactions between chiral, windmill-shaped tetramers are crucial for self-assembly.

  7. Right-handed and left-handed G-quadruplexes have the same DNA sequence: distinct conformations induced by an organic small molecule and potassium.

    Science.gov (United States)

    Fu, Boshi; Huang, Jinguo; Chen, Yuqi; Wang, Yafen; Xue, Tianrui; Xu, GuoHua; Wang, Shaoru; Zhou, Xiang

    2016-08-21

    Herein, we report two distinct G-quadruplex conformations of the same G-rich oligonucleotide, regulated by a small molecule. This is the first report in which both right- and left-handed G-quadruplex conformations have been obtained from the same sequence. We discriminated these two distinct conformations and investigated their kinetics and thermodynamics.

  8. Motor unit activity in biceps brachii of left-handed humans during sustained contractions with two load types.

    Science.gov (United States)

    Gould, Jeffrey R; Cleland, Brice T; Mani, Diba; Amiridis, Ioannis G; Enoka, Roger M

    2016-09-01

    The purpose of the study was to compare the discharge characteristics of single motor units during sustained isometric contractions that required either force or position control in left-handed individuals. The target force for the two sustained contractions (24.9 ± 10.5% maximal force) was identical for each biceps brachii motor unit (n = 32) and set at 4.7 ± 2.0% of maximal voluntary contraction (MVC) force above its recruitment threshold (range: 0.5-41.2% MVC force). The contractions were not sustained to task failure, but the duration (range: 60-330 s) was identical for each motor unit and the decline in MVC force immediately after the sustained contractions was similar for the two tasks (force: 11.1% ± 13.7%; position: 11.6% ± 9.9%). Despite a greater increase in the rating of perceived exertion during the position task (task × time interaction, P < 0.006), the amplitude of the surface-recorded electromyogram for the agonist and antagonist muscles increased similarly during the two tasks. Nonetheless, mean discharge rate of the biceps brachii motor units declined more during the position task (task × time interaction, P < 0.01) and the variability in discharge times (coefficient of variation for interspike interval) increased only during the position task (task × time interaction, P < 0.008). When combined with the results of an identical study on right-handers (Mottram CJ, Jakobi JM, Semmler JG, Enoka RM. J Neurophysiol 93: 1381-1392, 2005), the findings indicate that handedness does not influence the adjustments in biceps brachii motor unit activity during sustained submaximal contractions requiring either force or position control. Copyright © 2016 the American Physiological Society.

  9. Right- and Left-Handed Helices, What is in between? Interconversion of Helical Structures of Alternating Pyridinedicarboxamide/m-(phenylazo)azobenzene Oligomers.

    Science.gov (United States)

    Tao, Peng; Parquette, Jon R; Hadad, Christopher M

    2012-12-11

    Some unnatural polymers/oligomers have been designed to adopt a well-defined, compact, three-dimensional folding capability. Azobenzene units are common linkages in these oligomer designs. Two alternating pyridinedicarboxamide/m-(phenylazo)azobenzene oligomers that can fold into both right- and left-handed helices were studied computationally in order to understand their dynamical properties. Helical structures were shown to be the global minima among the many different conformations generated from the Monte Carlo simulations, and extended conformations have higher potential energies than compact ones. To understand the interconversion process between right- and left-handed helices, replica-exchange molecular dynamic (REMD) simulations were performed on both oligomers, and with this method, both right- and left-handed helices were successfully sampled during the simulations. REMD trajectories revealed twisted conformations as intermediate structures in the interconversion pathway between the two helical forms of these azobenzene oligomers. This mechanism was observed in both oligomers in current study and occurred locally in the larger oligomer. This discovery indicates that the interconversion between helical structures with different handedness goes through a compact and partially folded structure instead of globally unfold and extended structure. This is also verified by the nudged elastic band (NEB) calculations. The temperature weighted histogram analysis method (T-WHAM) was applied on the REMD results to generate contour maps of the potential of mean force (PMF). Analysis showed that right- and left-handed helices are equally sampled in these REMD simulations. In large oligomers, both right- and left-handed helices can be adopted by different parts of the molecule simultaneously. The interconversion between two helical forms can occur in the middle of the helical structure and not necessarily at the termini of the oligomer.

  10. Deviating T-DNA transfer from Agrobacterium tumefaciens to plants

    DEFF Research Database (Denmark)

    van der Graaff, Eric; den Dulk-Ras, A; Hooykaas, P J

    1996-01-01

    We analyzed 29 T-DNA inserts in transgenic Arabidopsis thaliana plants for the junction of the right border sequences and the flanking plant DNA. DNA sequencing showed that in most lines the right border sequences transferred had been preserved during integration, corroborating literature data. S...

  11. Deviating T-DNA transfer from Agrobacterium tumefaciens to plants

    DEFF Research Database (Denmark)

    van der Graaff, Eric; den Dulk-Ras, A; Hooykaas, P J

    1996-01-01

    We analyzed 29 T-DNA inserts in transgenic Arabidopsis thaliana plants for the junction of the right border sequences and the flanking plant DNA. DNA sequencing showed that in most lines the right border sequences transferred had been preserved during integration, corroborating literature data...

  12. Hemispheric prevalence during chewing in normal right-handed and left-handed subjects: a functional magnetic resonance imaging preliminary study.

    Science.gov (United States)

    Bracco, Pietro; Anastasi, Giuseppe; Piancino, Maria Grazia; Frongia, Gianluigi; Milardi, Demetrio; Favaloro, Angelo; Bramanti, Placido

    2010-04-01

    This study evaluated the activation of different cortical areas during nondeliberate chewing of soft and hard boluses in five right-handed and five left-handed subjects with normal occlusion, to determine different hemispheric prevalences. The study was conducted with a functional Magnetic Resonance Imaging (1.5 T Magnetom Vision - Siemens Medical, Germany) using a head coil. The results showed that the most frequently activated areas were Brodmann's areas four and six in the primary motor and premotor cortex, the insula and Broca's area and, overall, showed greater activity of the cortical mastication area (CMA) in the right hemisphere for right-handed and in the left hemisphere for left-handed subjects.

  13. [Influence of "prehistory" of sequential movements of the right and the left hand on reproduction: coding of positions, movements and sequence structure].

    Science.gov (United States)

    Bobrova, E V; Liakhovetskiĭ, V A; Borshchevskaia, E R

    2011-01-01

    The dependence of errors during reproduction of a sequence of hand movements without visual feedback on the previous right- and left-hand performance ("prehistory") and on positions in space of sequence elements (random or ordered by the explicit rule) was analyzed. It was shown that the preceding information about the ordered positions of the sequence elements was used during right-hand movements, whereas left-hand movements were performed with involvement of the information about the random sequence. The data testify to a central mechanism of the analysis of spatial structure of sequence elements. This mechanism activates movement coding specific for the left hemisphere (vector coding) in case of an ordered sequence structure and positional coding specific for the right hemisphere in case of a random sequence structure.

  14. Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material.

    Science.gov (United States)

    Dalarsson, Mariana; Tassin, Philippe

    2009-04-13

    We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results obtained by accurate numerical simulations. Our model straightforwardly allows for arbitrary spectral dispersion.

  15. Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material

    OpenAIRE

    Dalarsson, Mariana; Tassin, Philippe

    2012-01-01

    We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results o...

  16. Negative refraction index of the quantum lossy left-handed transmission lines affected by the displaced squeezed Fock state and dissipation

    Science.gov (United States)

    Zhao, Shun-Cai; Wei, Xiao-Jing; Wu, Qi-Xuan

    2017-05-01

    Quantum lossy left-handed transmission lines (LHTLs) are central to the miniaturized application in microwave band. This work discusses the NRI of the quantized lossy LHTLs in the presence of the resistance and the conductance in a displaced squeezed Fock state (DSFS). And the results show some novel specific quantum characteristics of NRI caused by the DSFS and dissipation, which may be significant for its miniaturized application in a suit of novel microwave devices.

  17. Recognition and one-pot extraction of right- and left-handed semiconducting single-walled carbon nanotube enantiomers using fluorene-binaphthol chiral copolymers.

    Science.gov (United States)

    Akazaki, Kojiro; Toshimitsu, Fumiyuki; Ozawa, Hiroaki; Fujigaya, Tsuyohiko; Nakashima, Naotoshi

    2012-08-01

    Synthesized single-walled carbon nanotubes (SWNTs) are mixtures of right- and left-handed helicity and their separation is an essential topic in nanocarbon science. In this paper, we describe the separation of right- and left-handed semiconducting SWNTs from as-produced SWNTs. Our strategy for this goal is simple: we designed copolymers composed of polyfluorene and chiral bulky moieties because polyfluorenes with long alkyl-chains are known to dissolve only semiconducting SWNTs and chiral binaphthol is a so-called BINAP family that possesses a powerful enantiomer sorting capability. In this study, we synthesized 12 copolymers, (9,9-dioctylfluorene-2,7-diyl)x((R)- or (S)-2,2'-dimethoxy-1,1'-binaphthalen-6,6-diyl)y, where x and y are copolymer composition ratios. It was found that, by a simple one-pot sonication method, the copolymers are able to extract either right- or left-handed semiconducting SWNT enantiomers with (6,5)- and (7,5)-enriched chirality. The separated materials were confirmed by circular dichroism, vis-near IR and photoluminescence spectroscopies. Interestingly, the copolymer showed inversion of SWNT enantiomer recognition at higher contents of the chiral binaphthol moiety. Molecular mechanics simulations reveal a cooperative effect between the degree of chirality and copolymer conformation to be responsible for these distinct characteristics of the extractions. This is the first example describing the rational design and synthesis of novel compounds for the recognition and simple sorting of right- and left-handed semiconducting SWNTs with a specific chirality.

  18. Tendon and ligament fibrillar crimps give rise to left-handed helices of collagen fibrils in both planar and helical crimps.

    Science.gov (United States)

    Franchi, Marco; Ottani, Vittoria; Stagni, Rita; Ruggeri, Alessandro

    2010-03-01

    Collagen fibres in tendons and ligaments run straight but in some regions they show crimps which disappear or appear more flattened during the initial elongation of tissues. Each crimp is formed of collagen fibrils showing knots or fibrillar crimps at the crimp top angle. The present study analyzes by polarized light microscopy, scanning electron microscopy, transmission electron microscopy the 3D morphology of fibrillar crimp in tendons and ligaments of rat demonstrating that each fibril in the fibrillar region always twists leftwards changing the plane of running and sharply bends modifying the course on a new plane. The morphology of fibrillar crimp in stretched tendons fulfills the mechanical role of the fibrillar crimp acting as a particular knot/biological hinge in absorbing tension forces during fibril strengthening and recoiling collagen fibres when stretching is removed. The left-handed path of fibrils in the fibrillar crimp region gives rise to left-handed fibril helices observed both in isolated fibrils and sections of different tendons and ligaments (flexor digitorum profundus muscle tendon, Achilles tendon, tail tendon, patellar ligament and medial collateral ligament of the knee). The left-handed path of fibrils represents a new final suprafibrillar level of the alternating handedness which was previously described only from the molecular to the microfibrillar level. When the width of the twisting angle in the fibrillar crimp is nearly 180 degrees the fibrils appear as left-handed flattened helices forming crimped collagen fibres previously described as planar crimps. When fibrils twist with different subsequent rotational angles (left-helical course but, running in many different nonplanar planes, they form wider helical crimped fibres.

  19. Bidirectional promoter trapping T-DNA for insertional mutagenesis in Verticillium dahliae.

    Science.gov (United States)

    Deng, Sheng; Wang, Cai-yue; Zhang, Xin; Lin, Ling

    2014-07-01

    Transfer DNA (T-DNA)-based random insertional mutagenesis is a universal forward genetic approach for gene identification and cloning in many phytopathogenic fungi. In a large number of randomly selected transformants, screening for mutants with a specific phenotype is laborious, especially for pathogenicity-defective mutants. To accelerate mutant screening and gene identification, a bidirectional promoter-trapping Ti binary vector, 1300-bisGFP-hyg, was constructed and deployed in this study. More than 6000 Verticillium dahliae transformants were obtained by the mediation of Agrobacterium tumefaciens carrying the vector. One thousand randomly selected transformants were cultured on Czapek-Dox and on Czapek-Dox plus cotton root extract media plates. The cultured transformants with green fluorescent protein (GFP) expression or changes in phenotype were selected and used in virulence or promoter-trapping assays. Based on the virulence assay of 60 transformants, the pathogenicity of 17 of these mutants was compromised. Ten pathogenicity-defective mutants were found with GFP expression, and 6 with expression in Czapek-Dox plus cotton root extract media specifically. Using TAIL-PCR (thermal asymmetric interlaced polymerase chain reaction), the T-DNA insertion sites were identified in 8 GFP-expressing transformants, including 5 pathogenicity-defective mutants and 3 unaffected transformants. Promoters of 6 genes were successfully trapped using the T-DNA method in this study. The nonpathogenic transformant 24C9 was the subject of additional investigation. It displayed strong GFP expression on water agar medium supplemented with cotton root extracts and on cotton seedling stems. The results obtained by Southern blot and quantitative real-time PCR confirmed that the transcription level of VdUGPU (encoding UTP-glucose-1-phosphate uridylyltransferase) was significantly reduced owing to T-DNA insertion in the gene promoter region. These results indicate that the bidirectional

  20. [Case of callosal disconnection syndrome with a chief complaint of right-hand disability, despite presence of left-hand diagonistic dyspraxia].

    Science.gov (United States)

    Okamoto, Yoko; Saida, Hisako; Yamamoto, Toru

    2009-04-01

    e report the case of 48-year-old right-handed male patient with an infarction affecting most part of the body and the splenium of the left half of the corpus callosum. Neuropsychological examination revealed typical signs of callosal disconnection including left-sided apraxia, diagonistic dyspraxia, left-sided agraphia, left-hand tactile anomia, left hemialexia, and right-sided constructional disability. Moreover, he complained of impairment in activities involving the right hand disability and agraphia. He could not stop behaving with his right hand when he had a vague idea. For example, he involuntarily picked up a tea bottle with his right hand when he had a desire to drink, although the action was not appropriate to that occasion. The imitation and utilization behavior did not imply this case, because his right hand behaviors were not exaggerated in response to external stimuli, such as the gestures of the examiner or the subjects in front of the patient. Unexpectedly, he complained about impairment of the activity of his right hand and was unaware of left hand apraxia or diagonistic dyspraxia; this trend continued for 6 months, at the time of this writing. We argue that the patient may have been subconsciouly aware of the symptoms of his left hand but had not verbalized them.

  1. Cascade of chromosomal rearrangements caused by a heterogeneous T-DNA integration supports the double-stranded break repair model for T-DNA integration.

    Science.gov (United States)

    Hu, Yufei; Chen, Zhiyu; Zhuang, Chuxiong; Huang, Jilei

    2017-06-01

    Transferred DNA (T-DNA) from Agrobacterium tumefaciens can be integrated into the plant genome. The double-stranded break repair (DSBR) pathway is a major model for T-DNA integration. From this model, we expect that two ends of a T-DNA molecule would invade into a single DNA double-stranded break (DSB) or independent DSBs in the plant genome. We call the later phenomenon a heterogeneous T-DNA integration, which has never been observed. In this work, we demonstrated it in an Arabidopsis T-DNA insertion mutant seb19. To resolve the chromosomal structural changes caused by T-DNA integration at both the nucleotide and chromosome levels, we performed inverse PCR, genome resequencing, fluorescence in situ hybridization and linkage analysis. We found, in seb19, a single T-DNA connected two different chromosomal loci and caused complex chromosomal rearrangements. The specific break-junction pattern in seb19 is consistent with the result of heterogeneous T-DNA integration but not of recombination between two T-DNA insertions. We demonstrated that, in seb19, heterogeneous T-DNA integration evoked a cascade of incorrect repair of seven DSBs on chromosomes 4 and 5, and then produced translocation, inversion, duplication and deletion. Heterogeneous T-DNA integration supports the DSBR model and suggests that two ends of a T-DNA molecule could be integrated into the plant genome independently. Our results also show a new origin of chromosomal abnormalities. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  2. Electroencephalographic (eeg coherence between visual and motor areas of the left and the right brain hemisphere while performing visuomotor task with the right and the left hand

    Directory of Open Access Journals (Sweden)

    Simon Brežan

    2007-09-01

    Full Text Available Background: Unilateral limb movements are based on the activation of contralateral primary motor cortex and the bilateral activation of premotor cortices. Performance of a visuomotor task requires a visuomotor integration between motor and visual cortical areas. The functional integration (»binding« of different brain areas, is probably mediated by the synchronous neuronal oscillatory activity, which can be determined by electroencephalographic (EEG coherence analysis. We introduced a new method of coherence analysis and compared coherence and power spectra in the left and right hemisphere for the right vs. left hand visuomotor task, hypothesizing that the increase in coherence and decrease in power spectra while performing the task would be greater in the contralateral hemisphere.Methods: We analyzed 6 healthy subjects and recorded their electroencephalogram during visuomotor task with the right or the left hand. For data analysis, a special Matlab computer programme was designed. The results were statistically analysed by a two-way analysis of variance, one-way analysis of variance and post-hoc t-tests with Bonferroni correction.Results: We demonstrated a significant increase in coherence (p < 0.05 for the visuomotor task compared to control tasks in alpha (8–13 Hz in beta 1 (13–20 Hz frequency bands between visual and motor electrodes. There were no significant differences in coherence nor power spectra depending on the hand used. The changes of coherence and power spectra between both hemispheres were symmetrical.Conclusions: In previous studies, a specific increase of coherence and decrease of power spectra for the visuomotor task was found, but we found no conclusive asymmetries when performing the task with right vs. left hand. This could be explained in a way that increases in coherence and decreases of power spectra reflect symmetrical activation and cooperation between more complex visual and motor brain areas.

  3. Simultaneous formation of right- and left-handed anti-parallel coiled-coil interfaces by a coil2 fragment of human lamin A.

    Science.gov (United States)

    Kapinos, Larisa E; Burkhard, Peter; Herrmann, Harald; Aebi, Ueli; Strelkov, Sergei V

    2011-04-22

    The elementary building block of all intermediate filaments (IFs) is a dimer featuring a central α-helical rod domain flanked by the N- and C-terminal end domains. In nuclear IF proteins (lamins), the rod domain consists of two coiled-coil segments, coil1 and coil2, that are connected by a short non-helical linker. Coil1 and the C-terminal part of coil2 contain the two highly conserved IF consensus motifs involved in the longitudinal assembly of dimers. The previously solved crystal structure of a lamin A fragment (residues 305-387) corresponding to the second half of coil2 has yielded a parallel left-handed coiled coil. Here, we present the crystal structure and solution properties of another human lamin A fragment (residues 328-398), which is largely overlapping with fragment 305-387 but harbors a short segment of the tail domain. Unexpectedly, no parallel coiled coil forms within the crystal. Instead, the α-helices are arranged such that two anti-parallel coiled-coil interfaces are formed. The most significant interface has a right-handed geometry, which is accounted for by a characteristic 15-residue repeat pattern that overlays with the canonical heptad repeat pattern. The second interface is a left-handed anti-parallel coiled coil based on the predicted heptad repeat pattern. In solution, the fragment reveals only a weak dimerization propensity. We speculate that the C-terminus of coil2 might unzip, thereby allowing for a right-handed coiled-coil interface to form between two laterally aligned dimers. Such an interface might co-exist with a heterotetrameric left-handed coiled-coil assembly, which is expected to be responsible for the longitudinal A(CN) contact. Copyright © 2011. Published by Elsevier Ltd.

  4. A simplified analytical approach to calculation of the electromagnetic behavior of left-handed metamaterials with a graded refractive index profile

    Directory of Open Access Journals (Sweden)

    Dalarsson N.

    2007-01-01

    Full Text Available We investigated the spectral properties of a new class of nanostructured artificial composite materials with tailored electromagnetic response, i.e. negative refractive index materials, also known as "left-handed" metamaterials. We analyzed structures incorporating both ordinary positive index media and negative refractive index metamaterials where the interface may be graded to an arbitrary degree. Utilizing a modified version of the Rosen-Morse function, we derived analytical expressions for the field intensity and spectral reflection and transmission through a graded interface between positive and negative index materials. We compared our results to numerical solutions obtained using the transfer matrix technique. .

  5. Left-handed helical preference in an achiral peptide chain is induced by an L-amino acid in an N-terminal type II β-turn.

    Science.gov (United States)

    De Poli, Matteo; De Zotti, Marta; Raftery, James; Aguilar, Juan A; Morris, Gareth A; Clayden, Jonathan

    2013-03-15

    Oligomers of the achiral amino acid Aib adopt helical conformations in which the screw-sense may be controlled by a single N-terminal residue. Using crystallographic and NMR techniques, we show that the left- or right-handed sense of helical induction arises from the nature of the β-turn at the N terminus: the tertiary amino acid L-Val induces a left-handed type II β-turn in both the solid state and in solution, while the corresponding quaternary amino acid L-α-methylvaline induces a right-handed type III β-turn.

  6. Suicidal single gunshot injury to the head: differences in site of entrance wound and direction of the bullet path between right- and left-handed--an autopsy study.

    Science.gov (United States)

    Nikolić, Slobodan; Zivković, Vladimir; Babić, Dragan; Juković, Fehim

    2012-03-01

    The aim of this study was to determine the differences in the anatomical site of a gunshot entrance wound and the direction of the bullet path between right- and left-handed subjects who committed a suicide by a single gunshot injury to the head. The retrospective autopsy study was performed for a 10-year period, and it included selected cases of single suicidal gunshot head injury, committed by handguns. We considered only contact or near-contact wounds. The sample included 479 deceased, with average age 47.1 ± 19.1 years (range, 12-89 years): 432 males and 47 females, with 317 right-handed, 25 left-handed, and 137 subjects with unknown dominant hand. In our observed sample, most cases involved the right temple as the site of entrance gunshot wound (about 67%), followed by the mouth (16%), forehead (7%), left temple (6%), submental (2%), and parietal region (1%). The left temple, right temple, and forehead were the sites of the gunshot entrance wounds, which were the best predictors of the handedness of the deceased (Spearman ρ = 0.149, P = 0.006). Our study showed that the direction of the bullet intracranial path in cases of suicide was even a more potent predictor of the handedness of the deceased (Spearman ρ = 0.263, P = 0.000; Wald = 149.503, P = 0.000).

  7. Left-hand somatosensory stimulation combined with visual scanning training in rehabilitation for post-stroke hemineglect: a randomised, double-blind study.

    Science.gov (United States)

    Polanowska, Katarzyna; Seniów, Joanna; Paprot, Ewa; Leśniak, Marcin; Członkowska, Anna

    2009-06-01

    The aim of this randomised, double-blind study was to investigate the therapeutic effectiveness of left-hand electrical stimulation for patients with post-stroke left visuo-spatial neglect. This approach was hypothesised to enhance activation of the right hemisphere attention system and to improve visual exploration of extrapersonal space. Participants (n = 40) in the study were in a relatively early stage of recovery from their first right hemisphere stroke, and were randomly assigned to the experimental (E) or control (C) group. Group E received conventional visual scanning training combined with electrostimulation of the left hand, while Group C received scanning training with sham stimulation. Their visuo-spatial neglect was assessed twice, prior to the rehabilitation programme and on its completion, using cancellation tests and a letter-reading task. The effect of electrostimulation on hemineglect was assessed following a single administration and after a month-long rehabilitation programme. Although the immediate effect of stimulation was poor, after a month-long rehabilitation period we found significantly greater improvement in Group E patients than in Group C patients. Interestingly, the presence of hemisensory loss did not weaken the observed effect. Therefore, we claim that contralesional hand stimulation combined with visual scanning was a more effective treatment for hemineglect rehabilitation than scanning training alone.

  8. [A case of combined sensation disturbance and clumsiness of the left hand caused by an infarction localized to brodmann areas 1 and 2].

    Science.gov (United States)

    Kutoku, Yumiko; Hagiwara, Hiroki; Ichikawa, Yaeko; Takeda, Katsuhiko; Sunada, Yoshihide

    2007-04-01

    A 70-year-old woman was admitted to our hospital with a complaint of numbness and clumsiness of the left hand. On physical examination 23 days after the onset of cerebral infarction, she showed no apparent muscle weakness. Although her elementary somatosensory function was mostly intact with a minimal joint position sensation disturbance, she showed disturbances in tactile recognition, two-point discrimination, and weight perception. She also had difficulty in discrete finger movement of her left hand, especially when her eyes were closed. Brain MRI disclosed a small infarction localized to Brodmann areas 1 and 2 in the right postcentral gyrus. In the left median nerve short-latency somatosensory evoked potentials (s-SEPs), the N20 potential was normally evoked. This finding also indicated that the area 3b was preserved. The sensory symptoms observed in this patient were compatible with the hierarchical somatosensory processing model in the postcentral gyrus proposed by Iwamura et al, in which the elementary sensation recognized in area 3 is transferred to areas 1 and 2, and then processed to discriminative sensation. The disturbed discrete finger movement in this patient probably resulted from impaired tactile recognition which could be compensated for by visual information.

  9. Agrobacterium T-DNA-encoded protein Atu6002 interferes with the host auxin response

    Science.gov (United States)

    Lacroix, Benoît; Gizatullina, Diana I.; Babst, Benjamin A.; Gifford, Andrew N.; Citovsky, Vitaly

    2013-01-01

    Summary Several genes in the Agrobacterium tumefaciens transferred (T) DNA encode proteins that are involved in developmental alterations leading to the formation of tumors in infected plants. We investigated the role of the protein encoded by the Atu6002 gene, the function of which is completely unknown. The Atu6002 expression occurs in Agrobacterium-induced tumors, and is also activated upon activation of plant cell division by growth hormones. Within the expressing plant cells, the Atu6002 protein is targeted to the plasma membrane. Interestingly, constitutive ectopic expression of Atu6002 in transgenic tobacco plants lead to a severe developmental phenotype characterized by stunted growth, shorter internodes, lanceolate leaves, increased branching, and modified flower morphology. These Atu6002-expressing plants also displayed impaired response to auxin. However, auxin cellular uptake and polar transport were not significantly inhibited in these plants, suggesting that Atu6002 interferes with auxin perception or signaling pathways. PMID:24128370

  10. The left hand second to fourth digit ratio (2D:4D does not discriminate world-class female gymnasts from age matched sedentary girls.

    Directory of Open Access Journals (Sweden)

    Maarten W Peeters

    Full Text Available INTRODUCTION: The second to fourth-digit-ratio (2D:4D, a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with sports performance, although results are not univocal. If this relation exists, it is most likely to be detected by comparing extreme groups on the continuum of sports performance. METHODS: In this study the 2D:4D ratio of world-class elite female artistic gymnasts (n = 129, competing at the 1987 Rotterdam World-Championships was compared to the 2D:4D ratio of sedentary age-matched sedentary girls (n = 129, alongside with other anthropometric characteristics including other sexually dimorphic traits such as an androgyny index (Bayer & Bayley and Heath-Carter somatotype components (endomorphy, mesomorphy, ectomorphy using AN(COVA. 2D:4D was measured on X-rays of the left hand. RESULTS: Left hand 2D:4D digit ratio in world class elite female gymnasts (0.921±0.020 did not differ significantly from 2D:4D in age-matched sedentary girls (0.924±0.018, either with or without inclusion of potentially confounding covariates such as skeletal age, height, weight, somatotype components or androgyny index. Height (161.9±6.4 cm vs 155.4±6.6 cm p0.01, somatotype components (4.0/3.0/2.9 vs 1.7/3.7/3.2 for endomorphy (p<0.01, mesomorphy (p<0.01 and ectomorphy (p<0.05 respectively all differed significantly between sedentary girls and elite gymnasts. As expressed by the androgyny index, gymnasts have, on average, broader shoulders relative to their hips, compared to the reference sample. Correlations between the 2D:4D ratio and chronological age, skeletal age, and the anthropometric characteristics are low and not significant. CONCLUSION: Although other anthropometric characteristics of sexual dimorphism were significantly different between the two samples, the present study cannot discriminate sedentary girls from world-class female gymnasts by means of the left hand 2D:4D ratio.

  11. Chiroptical properties of anionic and cationic porphyrins and metalloporphyrins in complex with left-handed Z-DNA and right-handed B-DNA.

    Science.gov (United States)

    Choi, Jung Kyu; D'Urso, Alessandro; Balaz, Milan

    2013-10-01

    We report the chiroptical signature and binding interactions of cationic (meso-tetrakis(4-N-methylptridyl)porphyrin, 2HT4) and anionic (meso-tetrakis(4-sulfonatophenyl)porphyrin, 2HTPPS) porphyrins and their zinc(II) and nickel(II) derivatives (ZnT4, ZnTPPS, NiT4, and NiTPPS) with right-handed B-form and two forms of left-handed Z-form of alternating guanine-cytosine polydeoxynucleotide poly(dG-dC)2. NiTPPS is able to spectroscopically discriminate between spermine-induced Z-DNA and Co(III)-induced Z-DNA via new induced circular dichroism signal in the visible region of the electromagnetic spectrum. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Propagation properties of right-hand circularly polarized Airy-Gaussian beams through slabs of right-handed materials and left-handed materials.

    Science.gov (United States)

    Huang, Jiayao; Liang, Zijie; Deng, Fu; Yu, Weihao; Zhao, Ruihuang; Chen, Bo; Yang, Xiangbo; Deng, Dongmei

    2015-11-01

    The propagation of right-hand circularly polarized Airy-Gaussian beams (RHCPAiGBs) through slabs of right-handed materials (RHMs) and left-handed materials (LHMs) is investigated analytically and numerically with the transfer matrix method. An approximate analytical expression for the RHCPAiGBs passing through a paraxial ABCD optical system is derived on the basis of the Huygens diffraction integral formula. The intensity and the phase distributions of the RHCPAiGBs through RHMs and LHMs are demonstrated. The influence of the parameter χ0 on the propagation of RHCPAiGBs through RHM and LHM slabs is investigated. The RHCPAiGBs possess transverse-momentum currents, which shows that the physics underlying this intriguing accelerating effect is that of the combined contributions of the transverse spin and transverse orbital currents. Additionally, we go a step further to explore the radiation force including the gradient force and scattering force of the RHCPAiGBs.

  13. Relative effectiveness of dominant versus non-dominant hand position for rescuer's side of approach during chest compressions between right-handed and left-handed novice rescuers.

    Science.gov (United States)

    You, Je Sung; Kim, Hoon; Park, Jung Soo; Baek, Kyung Min; Jang, Mun Sun; Lee, Hye Sun; Chung, Sung Phil; Kim, SeungWhan

    2015-03-01

    The major components affecting high quality cardiopulmonary resuscitation (CPR) have been defined as the ability of the rescuer, hand position, position of the rescuer and victim, depth and rate of chest compressions, and fatigue. Until now, there have been no studies on dominant versus non-dominant hand position and the rescuer's side of approach. This study was designed to evaluate the effectiveness of hand position and approach side on the quality of CPR between right-handed (RH) and left-handed (LH) novice rescuers. 44 health science university students with no previous experience of basic life support (BLS) volunteered for the study. We divided volunteers into two groups by handedness. Adult BLS was performed on a manikin for 2 min in each session. The sequences were randomly performed on the manikin's left side of approach (Lap) with the rescuer's left hand in contact with the sternum (Lst), Lap/Rst, Rap/Lst and Rap/Rst. We compared the quality of chest compressions between the RH and LH groups according to predetermined positions. A significant decrease in mean compression depth between the two groups was only observed when rescuers performed in the Rap/Lst scenario, regardless of hand dominance. The frequency of correct hand placement also significantly decreased in the Lap/Rst position for the LH group. The performance of novice rescuers during chest compressions is influenced by the position of the dominant hand and the rescuer's side of approach. In CPR training and real world situations, a novice rescuer, regardless of handedness, should consider hand positions for contacting the sternum identical to the side of approach after approaching from the nearest and most accessible side, for optimal CPR performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. The left hand second to fourth digit ratio (2D:4D is not related to any physical fitness component in adolescent girls.

    Directory of Open Access Journals (Sweden)

    Maarten W Peeters

    Full Text Available INTRODUCTION: The second to fourth-digit-ratio (2D:4D, a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with fitness and sports performance, although results are not univocal. Most studies however focus on a single aspect of physical fitness or one sports discipline. METHODS: In this study the 2D:4D ratio of 178 adolescent girls (age 13.5-18 y was measured on X-rays of the left hand. The relation between 2D:4D digit ratio and multiple aspects of physical fitness (balance, speed of limb movement, flexibility, explosive strength, static strength, trunk strength, functional strength, running speed/agility, and endurance was studied by correlation analyses and stepwise multiple regression. For comparison the relation between these physical fitness components and a selected number of objectively measured anthropometric traits (stature, mass, BMI, somatotype components and the Bayer & Bailey androgyny index are presented alongside the results of 2D:4D digit ratio. RESULTS: Left hand 2D:4D digit ratio (0.925±0.019 was not significantly correlated with any of the physical fitness components nor any of the anthropometric variables included in the present study. 2D:4D did not enter the multiple stepwise regression for any of the physical fitness components in which other anthropometric traits explained between 9.2% (flexibility and 33.9% (static strength of variance. CONCLUSION: Unlike other anthropometric traits the 2D:4D digit ratio does not seem to be related to any physical fitness component in adolescent girls and therefore most likely should not be considered in talent detection programs for sporting ability in girls.

  15. A 3D chiral metal-organic framework based on left-handed helices containing 3-amino-1 H-1,2,4-triazole ligand

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing, E-mail: bliu_1203@163.com [College of Chemistry and Chemical Engineering, Shaanxi University of Sciences and Technology, Xi’an, 710021 Shaanxi (China); Yang, Tian-Yi [The High School Affricated to Shaanxi Normal University, Xi’an, 710061 Shaanxi (China); Feng, Hui-Jun; Zhang, Zong-Hui [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an, 710062 Shaanxi (China); Xu, Ling, E-mail: xuling@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi’an, 710062 Shaanxi (China)

    2015-10-15

    A chiral metal-organic framework, [Cu(atr)(OH)]·0.5H{sub 2}O·0.5en (1) (Hatr=3-amino-1 H-1,2,4-triazole, en=ethylenediamine), was constructed via diffusion reaction of the achiral Hatr ligand and CuSO{sub 4} as starting materials. Compound 1 crystallizes in the chiral space group P3{sub 2}21 and features a porous metal-organic framework with 44.1% solvent-accessible volume fabricated by left-handed helices with a pitch height of l{sub p}=10.442 Å. Six helices gather around in a cycle forming a large honeycomb channel with a 6.58 Å inner diameter. Cu(II) center and atr{sup ‒} ligand regarded as 3-connected nodes, compound 1 can be simplified to a 3-c uninodal (4.12{sup 2}) (qtz-h) topological network. A gradual decreasing in the magnetic moment depending on temperature decreasing indicates an antiferromagnetic interaction in 1. The powder XRD confirms the bulk sample is a single crystal pure phase, and the thermogravimetric analysis shows the thermal stability of 1 is up to ca. 240 °C. - Highlights: • The present 3D chiral MOF is built from achiral Hatr ligand. • Six left-handed helices gather into a honeycomb channel in chiral sp P3{sub 2}21. • Compound 1 shows a 3-c uninodal (4.12{sup 2}) or qtz-h topological network. • Compound 1 indicates an antiferromagnetic interaction.

  16. High-Throughput Analysis of T-DNA Location and Structure Using Sequence Capture.

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    Soichi Inagaki

    Full Text Available Agrobacterium-mediated transformation of plants with T-DNA is used both to introduce transgenes and for mutagenesis. Conventional approaches used to identify the genomic location and the structure of the inserted T-DNA are laborious and high-throughput methods using next-generation sequencing are being developed to address these problems. Here, we present a cost-effective approach that uses sequence capture targeted to the T-DNA borders to select genomic DNA fragments containing T-DNA-genome junctions, followed by Illumina sequencing to determine the location and junction structure of T-DNA insertions. Multiple probes can be mixed so that transgenic lines transformed with different T-DNA types can be processed simultaneously, using a simple, index-based pooling approach. We also developed a simple bioinformatic tool to find sequence read pairs that span the junction between the genome and T-DNA or any foreign DNA. We analyzed 29 transgenic lines of Arabidopsis thaliana, each containing inserts from 4 different T-DNA vectors. We determined the location of T-DNA insertions in 22 lines, 4 of which carried multiple insertion sites. Additionally, our analysis uncovered a high frequency of unconventional and complex T-DNA insertions, highlighting the needs for high-throughput methods for T-DNA localization and structural characterization. Transgene insertion events have to be fully characterized prior to use as commercial products. Our method greatly facilitates the first step of this characterization of transgenic plants by providing an efficient screen for the selection of promising lines.

  17. T-DNA integration patterns in transgenic maize lines mediated by ...

    African Journals Online (AJOL)

    To explore transfer deoxyribonucleic acid (T-DNA) integration patterns in the maize genome, we improved the protocol of thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR), and amplified the flanking sequences around T-DNA integration sites from 70 independent transgenic maize lines mediated by ...

  18. Synthesis, structure, and electrochemistry and magnetic properties of a novel 1D homochiral MnIII(5-Brsalen) coordination polymer with left-handed helical character

    Science.gov (United States)

    Dong, Dapeng; Yu, Naisen; Zhao, Haiyan; Liu, Dedi; Liu, Jia; Li, Zhenghua; Liu, Dongping

    2016-01-01

    A novel homochiral manganese (III) Mn(5-Brsalen) coordination polymer with left-handed helical character by spontaneous resolution on crystallization by using Mn(5-Brsalen) and 4,4-bipyridine, [MnIII(5-Brsalen)(4,4-bipy)]·ClO4·CH3OH (1) (4,4-bipy = 4,4-bipyridine) has been synthesized and structurally characterized by X-ray single-crystal diffraction, elemental analysis and infrared spectroscopy. In compound 1, each manganese(III) anion is six-coordinate octahedral being bonded to four atoms of 5-Brsalen ligand in an equatorial plane and two nitrogen atoms from a 4,4-bipyridine ligand in axial positions. The structure of compound 1 can be described a supramolecular 2D-like structure which was formed by the intermolecular π-stacking interactions between the neighboring chains of the aromatic rings of 4,4-bipyridine and 5-Brsalen molecules. UV-vis absorption spectrum, electrochemistry and magnetic properties of the compound 1 have also been studied.

  19. Practice makes perfect, but only with the right hand: sensitivity to perceptual illusions with awkward grasps decreases with practice in the right but not the left hand.

    Science.gov (United States)

    Gonzalez, C L R; Ganel, T; Whitwell, R L; Morrissey, B; Goodale, M A

    2008-01-31

    It has been proposed that the visual mechanisms that control well-calibrated actions, such as picking up a small object with a precision grip, are neurally distinct from those that mediate our perception of the object. Thus, grip aperture in such situations has been shown to be remarkably insensitive to many size-contrast illusions. But most of us have practiced such movements hundreds, if not thousands of times. What about less familiar and unpracticed movements? Perhaps they would be less likely to be controlled by specialized visuomotor mechanisms and would therefore be more sensitive to size-contrast illusions. To test this idea, we asked right-handed subjects to pick up small objects using either a normal precision grasp (thumb and index finger) or an awkward grasp (thumb and ring finger), in the context of the Ponzo illusion. Even though this size-contrast illusion had no effect on the scaling of the precision grasp, it did have a significant effect on the scaling of the awkward grasp. Nevertheless, after three consecutive days of practice, even the awkward grasp became resistant to the illusion. In a follow-up experiment, we found that awkward grasps with the left hand (in right handers) did not benefit from practice and remained sensitive to the illusion. We conclude that the skilled target-directed movements are controlled by visual mechanisms that are quite distinct from those controlling unskilled movements, and that these specialized visuomotor mechanisms may be lateralized to the left hemisphere.

  20. Chiroptical properties, binding affinity, and photostability of a conjugated zinc porphyrin dimer complexed with left-handed Z-DNA and right-handed B-DNA.

    Science.gov (United States)

    Choi, Jung Kyu; Reed, Aisha; Balaz, Milan

    2014-01-14

    We have studied the UV-vis absorption and chiroptical properties, binding affinity and photostability of a conjugated positively charged butadiyne-linked Zn(ii) porphyrin dimer bound to DNA sequence poly(dG-dC)2. Right-handed B-DNA, spermine-induced Z-DNA and Co(iii)-induced Z-DNA have been explored. Resonance light scattering (RLS) spectra showed formation of porphyrin aggregates in the presence of all DNA forms with the largest aggregates formed with B-DNA. The porphyrin dimer gave rise to induced bisignate circular dichroism (CD) signals in the presence of the left-handed Z-DNA conformations. On the other hand, the dimer stayed nearly chiroptically silent when complexed with the B-form of poly(dG-dC)2. Our results indicated that the conjugated Zn(ii) porphyrin dimer can be used as a sensor for the chiroptical detection of Z-DNA in the visible (400-500 nm) and near-infrared region of the electromagnetic spectrum (700-800 nm). The helicity of DNA had little effect on the dimer binding affinities. The photostability of the porphyrin dimer complexed with any form of DNA was higher than that of the free molecule. The porphyrin dimer bound to Z-DNA exhibited slower photobleaching than the B-DNA dimer complex.

  1. 12/10-Helical β-Peptide with Dynamic Folding Propensity: Coexistence of Right- and Left-Handed Helices in an Enantiomeric Foldamer.

    Science.gov (United States)

    Shin, Seonho; Lee, Mihye; Guzei, Ilia A; Kang, Young Kee; Choi, Soo Hyuk

    2016-10-12

    We present the first examples of atomic-resolution crystal data for the β-peptide 12/10-helix from oligomers of cis-2-aminocyclohexane carboxylic acid (cis-ACHC) with alternating chirality. The local conformations of two enantiomeric cis-ACHC dimer units suggested that a chiral β-peptide may adopt both right-handed and left-handed helical conformations in solution. To probe the conformational behavior of 12/10-helical β-peptides, the two reference helices with a single handedness were synthesized with a more rigidified cis-ACHC derivative. Comparison with these reference helices at low temperature revealed that a chiral cis-ACHC oligomer with alternating chirality indeed displays 12/10-helical conformations with both handedness that equilibrate rapidly in solution. This is a very rare example of chiral oligomers with helix inversion ability. The 12/10-helical backbone should be a valuable addition to potential scaffolds for applications involving helices with dynamic folding propensity.

  2. Solvent-Directed Switch of a Left-Handed 10/12-Helix into a Right-Handed 12/10-Helix in Mixed β-Peptides.

    Science.gov (United States)

    Thodupunuri, Prashanth; Katukuri, Sirisha; Ramakrishna, Kallaganti V S; Sharma, Gangavaram V M; Kunwar, Ajit C; Sarma, Akella V S; Hofmann, Hans-Jörg

    2017-02-17

    Present study describes the synthesis and conformational analysis of β-peptides from C-linked carbo-β-amino acids [β-Caa (l) ] with a d-lyxo furanoside side chain and β-hGly in 1:1 alternation. NMR and CD investigations on peptides with an (S)-β-Caa (l) monomer at the N-terminus revealed a right-handed 10/12-mixed helix. An unprecedented solvent-directed "switch" both in helical pattern and handedness was observed when the sequence begins with a β-hGly residue instead of a (S)-β-Caa (l) constituent. NMR studies on these peptides in chloroform indicated a left-handed 10/12-helix, while the CD spectrum in methanol inferred a right-handed secondary structure. The NMR data for these peptides in CD 3 OH showed the presence of a right-handed 12/10-helix. NMR investigations in acetonitrile indicated the coexistence of both helix types. Quantum chemical studies predicted a small energy difference of 0.3 kcal/mol between the two helix types, which may explain the possibility of solvent influence. Examples for a solvent-directed switch of both the H-bonding pattern and the handedness of foldamer helices are rare so far. A comparable solvent effect was not found in the corresponding peptides with (R)-β-Caa (l) residues, where right-handed 12/10-helices are predominating.

  3. A New Definition of Fractional Derivatives Based on Truncated Left-Handed Grünwald-Letnikov Formula with 0<α<1 and Median Correction

    Directory of Open Access Journals (Sweden)

    Zhiwu Liao

    2014-01-01

    Full Text Available We propose a new definition of fractional derivatives based on truncated left-handed Grünwald-Letnikov formula with 0<α<1 and median correction. Analyzing the difficulties to choose the fractional orders and unsatisfied processing results in signal processing using fractional-order partial differential equations and related methods; we think that the nonzero values of the truncated fractional order derivatives in the smooth regions are major causes for these situations. In order to resolve the problem, the absolute values of truncated parts of the G-L formula are estimated by the median of signal values of the remainder parts, and then the truncated G-L formula is modified by replacing each of the original signal value to the differences of the signal value and the median. Since the sum of the coefficients of the G-L formula is zero, the median correction can reduce the truncated errors greatly to proximate G-L formula better. We also present some simulation results and experiments to support our theory analysis.

  4. Right-handed double-helix ultrashort DNA yields chiral nematic phases with both right- and left-handed director twist.

    Science.gov (United States)

    Zanchetta, Giuliano; Giavazzi, Fabio; Nakata, Michi; Buscaglia, Marco; Cerbino, Roberto; Clark, Noel A; Bellini, Tommaso

    2010-10-12

    Concentrated solutions of duplex-forming DNA oligomers organize into various mesophases among which is the nematic (N(∗)), which exhibits a macroscopic chiral helical precession of molecular orientation because of the chirality of the DNA molecule. Using a quantitative analysis of the transmission spectra in polarized optical microscopy, we have determined the handedness and pitch of this chiral nematic helix for a large number of sequences ranging from 8 to 20 bases. The B-DNA molecule exhibits a right-handed molecular double-helix structure that, for long molecules, always yields N(∗) phases with left-handed pitch in the μm range. We report here that ultrashort oligomeric duplexes show an extremely diverse behavior, with both left- and right-handed N(∗) helices and pitches ranging from macroscopic down to 0.3 μm. The behavior depends on the length and the sequence of the oligomers, and on the nature of the end-to-end interactions between helices. In particular, the N(∗) handedness strongly correlates with the oligomer length and concentration. Right-handed phases are found only for oligomers shorter than 14 base pairs, and for the sequences having the transition to the N(∗) phase at concentration larger than 620 mg/mL. Our findings indicate that in short DNA, the intermolecular double-helical interactions switch the preferred liquid crystal handedness when the columns of stacked duplexes are forced at high concentrations to separations comparable to the DNA double-helix pitch, a regime still to be theoretically described.

  5. A simple connection of the (electroweak) anapole moment with the (electroweak) charge radius of a massless left-handed Dirac neutrino

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, A. [Universidad Autonoma de Puebla, Puebla (Mexico)

    2001-04-01

    Assuming that the neutrino is a massless left-handed Dirac particle, we show that the neutrino anapole moment and the neutrino charge radius satisfy the simple relation a{sub v} =(r{sup 2}{sub v}) /6, in the context of the Standard Model of the electroweak interactions. We also show that the neutrino electroweak anapole moment a{sub v}l{sup E}W and the neutrino electroweak charge radius (r{sup 2}{sub v}){sup E}W, which have been defined through the v{sub l}l' scattering at the one-loop level and are physical quantities, also obey the relation a{sub v}l{sup E}W =(r{sup 2}{sub v}){sup E}W/6. [Spanish] Suponiendo que el neutrino es una particula de Dirac, sin masa y con helicidad izquierda, mostramos que el momento anapolar a{sub v} y el radio de carga (r{sub v}{sup 2}) del neutrino satisfacen la relacion simple a{sub v} =(r{sup 2}{sub v}) /6, en el contexto del Modelo Estandar de las interacciones electrodebiles. Ademas, mostramos que el momento anapolar electrodebil a{sub v}l{sup E}W y el radio de carga electrodebil (r{sup 2}{sub v}){sup E}W del neutrino, los cuales han sido definidos a traves de la dispersion v{sub l}l' a nivel de un lazo y que son cantidades fisicas, tambien obedecen la relacion a{sub v}l{sup E}W =(r{sup 2}{sub v}){sup E}W/6.

  6. Negotiating Left-Hand and Right-Hand Bends: A Motorcycle Simulator Study to Investigate Experiential and Behaviour Differences Across Rider Groups

    Science.gov (United States)

    Crundall, Elizabeth; Crundall, David; Stedmon, Alex W.

    2012-01-01

    Why do motorcyclists crash on bends? To address this question we examined the riding styles of three groups of motorcyclists on a motorcycle simulator. Novice, experienced and advanced motorcyclists navigated a series of combined left and right bends while their speed and lane position were recorded. Each rider encountered an unexpected hazard on both a left- and right-hand bend section. Upon seeing the hazards, all riders decreased their speed before steering to avoid the hazard. Experienced riders tended to follow more of a racing line through the bends, which resulted in them having to make the most severe changes to their position to avoid a collision. Advanced riders adopted the safest road positions, choosing a position which offered greater visibility through the bends. As a result, they did not need to alter their road position in response to the hazard. Novice riders adopted similar road positions to experienced riders on the left-hand bends, but their road positions were more similar to advanced riders on right-hand bends, suggesting that they were more aware of the risks associated with right bends. Novice riders also adopted a safer position on post-hazard bends whilst the experienced riders failed to alter their behaviour even though they had performed the greatest evasive manoeuvre in response to the hazards. Advanced riders did not need to alter their position as their approach to the bends was already optimal. The results suggest that non-advanced riders were more likely to choose an inappropriate lane position than an inappropriate speed when entering a bend. Furthermore, the findings support the theory that expertise is achieved as a result of relearning, with advanced training overriding ‘bad habits’ gained through experience alone. PMID:22253845

  7. In planta transformation method for T-DNA transfer in orchids

    Science.gov (United States)

    Semiarti, Endang; Purwantoro, Aziz; Mercuriani, Ixora S.; Anggriasari, Anida M.; Jang, Seonghoe; Suhandono, Sony; Machida, Yasunori; Machida, Chiyoko

    2014-03-01

    Transgenic plant technology is an efficient tool to study the function of gene(s) in plant. The most popular and widely used technique is Agrobacterium-mediated transformation in which cocultivation was done by immersing the plant tissues/organ in overnight bacterial cultured for about 30 minutes to one hour under in vitro condition. In this experiment, we developed more easier technique that omitted the in vitro step during cocultivation with Agrobacterium, namely in planta transformation method. Pollinaria (compact pollen mass of orchid) of Phalaenopsis amabilis and Spathoglottis plicata orchids were used as target explants that were immersed into bacterial culture for 30 minutes, then dried up the pollinaria, the transformed pollinaria was used to pollinate orchid flowers. The T-DNA used for this experiments were Ubipro∷PaFT/A. tumefaciens GV3101 for P. amabilis and MeEF1α2 pro∷GUS/ A. tumefaciens LBA 4404 for S.plicata. Seeds that were produced from pollinated flowers were grown onto 10 mg/l hygromicin containing NP (New Phalaenopsis) medium. The existance of transgene in putative transformant protocorm (developing orchid embryo) genome was confirmed using PCR with specific primers of either PaFT or GUS genes. Histochemical GUS assay was also performed to the putative transformants. The result showed that transformation frequencies were 2.1 % in P. amabilis, and 0,53% in S. plicata. These results indicates that in planta transformation method could be used for Agrobacterium-mediated genetic transformation, with advantage easier and more secure work from contaminants than that of the in vitro method.

  8. Using enveloping distribution sampling to compute the free enthalpy difference between right- and left-handed helices of a β-peptide in solution.

    Science.gov (United States)

    Lin, Zhixiong; Timmerscheidt, Tobias A; van Gunsteren, Wilfred F

    2012-08-14

    Recently, the method of enveloping distribution sampling (EDS) to efficiently obtain free enthalpy differences between different molecular systems from a single simulation has been generalized to compute free enthalpy differences between different conformations of a system [Z. X. Lin, H. Y. Liu, S. Riniker, and W. F. van Gunsteren, J. Chem. Theory Comput. 7, 3884 (2011)]. However, the efficiency of EDS in this case is hampered if the parts of the conformational space relevant to the two end states or conformations are far apart and the conformational diffusion from one state to the other is slow. This leads to slow convergence of the EDS parameter values and free enthalpy differences. In the present work, we apply the EDS methodology to a challenging case, i.e., to calculate the free enthalpy difference between a right-handed 2.7(10∕12)-helix and a left-handed 3(14)-helix of a hexa-β-peptide in solution from a single simulation. No transition between the two helices was detected in a standard EDS parameter update simulation, thus enhanced sampling techniques had to be applied, which included adiabatic decoupling (AD) of solute and solvent motions in combination with increasing the solute temperature, and lowering the shear viscosity of the solvent. AD was found to be unsuitable to enhance the sampling of the solute conformations in the EDS parameter update simulations. Lowering the solvent shear viscosity turned out to be useful during EDS parameter update simulations, i.e., it did speed up the conformational diffusion of the solute, more transitions between the two helices were observed. This came at the cost of more CPU time spent due to the shorter time step needed for simulations with the lower solvent shear viscosity. Using an improved EDS parameter update scheme, parameter convergence was five-fold enhanced. The resulting free enthalpy difference between the two helices calculated from EDS agrees well with the result obtained through direct counting from a

  9. Structure of the hypothetical protein Ton1535 from Thermococcus onnurineus NA1 reveals unique structural properties by a left-handed helical turn in normal α-solenoid protein.

    Science.gov (United States)

    Jeong, Jae-Hee; Kim, Yi-Seul; Rojvirija, Catleya; Cha, Hyung Jin; Kim, Yeon-Gil; Ha, Sung Chul

    2014-06-01

    The crystal structure of Ton1535, a hypothetical protein from Thermococcus onnurineus NA1, was determined at 2.3 Å resolution. With two antiparallel α-helices in a helix-turn-helix motif as a repeating unit, Ton1535 consists of right-handed coiled N- and C-terminal regions that are stacked together using helix bundles containing a left-handed helical turn. One left-handed helical turn in the right-handed coiled structure produces two unique structural properties. One is the presence of separated concave grooves rather than one continuous concave groove, and the other is the contribution of α-helices on the convex surfaces of the N-terminal region to the extended surface of the concave groove of the C-terminal region and vice versa. © 2013 Wiley Periodicals, Inc.

  10. Crystal structure of the left-handed archaeal RadA helical filament: identification of a functional motif for controlling quaternary structures and enzymatic functions of RecA family proteins

    Science.gov (United States)

    Chen, Li-Tzu; Ko, Tzu-Ping; Chang, Yuan-Chih; Lin, Kuei-An; Chang, Chia-Seng; Wang, Andrew H.-J.; Wang, Ting-Fang

    2007-01-01

    The RecA family of proteins mediates homologous recombination, an evolutionarily conserved pathway that maintains genomic stability by protecting against DNA double strand breaks. RecA proteins are thought to facilitate DNA strand exchange reactions as closed-rings or as right-handed helical filaments. Here, we report the crystal structure of a left-handed Sulfolobus solfataricus RadA helical filament. Each protomer in this left-handed filament is linked to its neighbour via interactions of a β-strand polymerization motif with the neighbouring ATPase domain. Immediately following the polymerization motif, we identified an evolutionarily conserved hinge region (a subunit rotation motif) in which a 360° clockwise axial rotation accompanies stepwise structural transitions from a closed ring to the AMP–PNP right-handed filament, then to an overwound right-handed filament and finally to the left-handed filament. Additional structural and functional analyses of wild-type and mutant proteins confirmed that the subunit rotation motif is crucial for enzymatic functions of RecA family proteins. These observations support the hypothesis that RecA family protein filaments may function as rotary motors. PMID:17329376

  11. An Insight into T-DNA Integration Events in Medicago sativa

    Science.gov (United States)

    Nicolia, Alessandro; Ferradini, Nicoletta; Veronesi, Fabio

    2017-01-01

    The molecular mechanisms of transferred DNA (T-DNA) integration into the plant genome are still not completely understood. A large number of integration events have been analyzed in different species, shedding light on the molecular mechanisms involved, and on the frequent transfer of vector sequences outside the T-DNA borders, the so-called vector backbone (VB) sequences. In this work, we characterized 46 transgenic alfalfa (Medicago sativa L.) plants (events), generated in previous works, for the presence of VB tracts, and sequenced several T-DNA/genomic DNA (gDNA) junctions. We observed that about 29% of the transgenic events contained VB sequences, within the range reported in other species. Sequence analysis of the T-DNA/gDNA junctions evidenced larger deletions at LBs compared to RBs and insertions probably originated by different integration mechanisms. Overall, our findings in alfalfa are consistent with those in other plant species. This work extends the knowledge on the molecular events of T-DNA integration and can help to design better transformation protocols for alfalfa. PMID:28895894

  12. Regulation of Oncogene Expression in T-DNA-Transformed Host Plant Cells

    Science.gov (United States)

    Zhang, Yi; Lee, Chil-Woo; Wehner, Nora; Imdahl, Fabian; Svetlana, Veselova; Weiste, Christoph; Dröge-Laser, Wolfgang; Deeken, Rosalia

    2015-01-01

    Virulent Agrobacterium tumefaciens strains integrate their T-DNA into the plant genome where the encoded agrobacterial oncogenes are expressed and cause crown gall disease. Essential for crown gall development are IaaH (indole-3-acetamide hydrolase), IaaM (tryptophan monooxygenase) and Ipt (isopentenyl transferase), which encode enzymes for the biosynthesis of auxin (IaaH, IaaM) and cytokinin (Ipt). Although these oncogenes are well studied as the tumor-inducing principle, nothing is known about the regulation of oncogene expression in plant cells. Our studies show that the intergenic regions (IGRs) between the coding sequences (CDS) of the three oncogenes function as promoters in plant cells. These promoters possess a eukaryotic sequence organization and cis-regulatory elements for the binding of plant transcription factors. WRKY18, WRKY40, WRKY60 and ARF5 were identified as activators of the Ipt promoter whereas IaaH and IaaM is constitutively expressed and no transcription factor further activates their promoters. Consistent with these results, the wrky triple mutant plants in particular, develops smaller crown galls than wild-type and exhibits a reduced Ipt transcription, despite the presence of an intact ARF5 gene. WRKY40 and WRKY60 gene expression is induced by A. tumefaciens within a few hours whereas the ARF5 gene is transcribed later during crown gall development. The WRKY proteins interact with ARF5 in the plant nucleus, but only WRKY40 together with ARF5 synergistically boosts the activation of the Ipt promoter in an auxin-dependent manner. From our data, we propose that A. tumefaciens initially induces WRKY40 gene expression as a pathogen defense response of the host cell. The WRKY protein is recruited to induce Ipt expression, which initiates cytokinin-dependent host cell division. With increasing auxin levels triggered by ubiquitous expression of IaaH and IaaM, ARF5 is activated and interacts with WRKY40 to potentiate Ipt expression and balance

  13. Regulation of oncogene expression in T-DNA-transformed host plant cells.

    Science.gov (United States)

    Zhang, Yi; Lee, Chil-Woo; Wehner, Nora; Imdahl, Fabian; Svetlana, Veselova; Weiste, Christoph; Dröge-Laser, Wolfgang; Deeken, Rosalia

    2015-01-01

    Virulent Agrobacterium tumefaciens strains integrate their T-DNA into the plant genome where the encoded agrobacterial oncogenes are expressed and cause crown gall disease. Essential for crown gall development are IaaH (indole-3-acetamide hydrolase), IaaM (tryptophan monooxygenase) and Ipt (isopentenyl transferase), which encode enzymes for the biosynthesis of auxin (IaaH, IaaM) and cytokinin (Ipt). Although these oncogenes are well studied as the tumor-inducing principle, nothing is known about the regulation of oncogene expression in plant cells. Our studies show that the intergenic regions (IGRs) between the coding sequences (CDS) of the three oncogenes function as promoters in plant cells. These promoters possess a eukaryotic sequence organization and cis-regulatory elements for the binding of plant transcription factors. WRKY18, WRKY40, WRKY60 and ARF5 were identified as activators of the Ipt promoter whereas IaaH and IaaM is constitutively expressed and no transcription factor further activates their promoters. Consistent with these results, the wrky triple mutant plants in particular, develops smaller crown galls than wild-type and exhibits a reduced Ipt transcription, despite the presence of an intact ARF5 gene. WRKY40 and WRKY60 gene expression is induced by A. tumefaciens within a few hours whereas the ARF5 gene is transcribed later during crown gall development. The WRKY proteins interact with ARF5 in the plant nucleus, but only WRKY40 together with ARF5 synergistically boosts the activation of the Ipt promoter in an auxin-dependent manner. From our data, we propose that A. tumefaciens initially induces WRKY40 gene expression as a pathogen defense response of the host cell. The WRKY protein is recruited to induce Ipt expression, which initiates cytokinin-dependent host cell division. With increasing auxin levels triggered by ubiquitous expression of IaaH and IaaM, ARF5 is activated and interacts with WRKY40 to potentiate Ipt expression and balance

  14. Regulation of oncogene expression in T-DNA-transformed host plant cells.

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2015-01-01

    Full Text Available Virulent Agrobacterium tumefaciens strains integrate their T-DNA into the plant genome where the encoded agrobacterial oncogenes are expressed and cause crown gall disease. Essential for crown gall development are IaaH (indole-3-acetamide hydrolase, IaaM (tryptophan monooxygenase and Ipt (isopentenyl transferase, which encode enzymes for the biosynthesis of auxin (IaaH, IaaM and cytokinin (Ipt. Although these oncogenes are well studied as the tumor-inducing principle, nothing is known about the regulation of oncogene expression in plant cells. Our studies show that the intergenic regions (IGRs between the coding sequences (CDS of the three oncogenes function as promoters in plant cells. These promoters possess a eukaryotic sequence organization and cis-regulatory elements for the binding of plant transcription factors. WRKY18, WRKY40, WRKY60 and ARF5 were identified as activators of the Ipt promoter whereas IaaH and IaaM is constitutively expressed and no transcription factor further activates their promoters. Consistent with these results, the wrky triple mutant plants in particular, develops smaller crown galls than wild-type and exhibits a reduced Ipt transcription, despite the presence of an intact ARF5 gene. WRKY40 and WRKY60 gene expression is induced by A. tumefaciens within a few hours whereas the ARF5 gene is transcribed later during crown gall development. The WRKY proteins interact with ARF5 in the plant nucleus, but only WRKY40 together with ARF5 synergistically boosts the activation of the Ipt promoter in an auxin-dependent manner. From our data, we propose that A. tumefaciens initially induces WRKY40 gene expression as a pathogen defense response of the host cell. The WRKY protein is recruited to induce Ipt expression, which initiates cytokinin-dependent host cell division. With increasing auxin levels triggered by ubiquitous expression of IaaH and IaaM, ARF5 is activated and interacts with WRKY40 to potentiate Ipt expression and

  15. Agrobacterium tumefaciens VirC2 enhances T-DNA transfer and virulence through its C-terminal ribbon-helix-helix DNA-binding fold.

    Science.gov (United States)

    Lu, Jun; den Dulk-Ras, Amke; Hooykaas, Paul J J; Glover, J N Mark

    2009-06-16

    Agrobacterium tumefaciens VirC2 stimulates processing of single-stranded T-DNA that is translocated into plants to induce tumor formation, but how VirC2 functions is unclear. Here, we report the 1.7-A X-ray crystal structure of its trypsin-resistant C-terminal domain, VirC2(82-202), which reveals a form of the ribbon-helix-helix (RHH) DNA-binding fold contained within a single polypeptide chain. DNA-binding assays and mutagenesis indicate that VirC2 uses this RHH fold to bind double-stranded DNA but not single-stranded DNA. Mutations that severely affect VirC2 DNA binding are highly deleterious for both T-DNA transfer into yeast and the virulence of A. tumefaciens in different plants including Nicotiana glauca and Kalanchoe daigremontiana. These data suggest that VirC2 enhances T-DNA transfer and virulence through DNA binding with its RHH fold. The RHH fold of VirC2 is the first crystal structure representing a group of predicted RHH proteins that facilitate endonucleolytic processing of DNA for horizontal gene transfer.

  16. Agrobacterium tumefaciens VirC2 enhances T-DNA transfer and virulence through its C-terminal ribbon–helix–helix DNA-binding fold

    Science.gov (United States)

    Lu, Jun; den Dulk-Ras, Amke; Hooykaas, Paul J. J.; Glover, J. N. Mark

    2009-01-01

    Agrobacterium tumefaciens VirC2 stimulates processing of single-stranded T-DNA that is translocated into plants to induce tumor formation, but how VirC2 functions is unclear. Here, we report the 1.7-Å X-ray crystal structure of its trypsin-resistant C-terminal domain, VirC282–202, which reveals a form of the ribbon-helix-helix (RHH) DNA-binding fold contained within a single polypeptide chain. DNA-binding assays and mutagenesis indicate that VirC2 uses this RHH fold to bind double-stranded DNA but not single-stranded DNA. Mutations that severely affect VirC2 DNA binding are highly deleterious for both T-DNA transfer into yeast and the virulence of A. tumefaciens in different plants including Nicotiana glauca and Kalanchoe daigremontiana. These data suggest that VirC2 enhances T-DNA transfer and virulence through DNA binding with its RHH fold. The RHH fold of VirC2 is the first crystal structure representing a group of predicted RHH proteins that facilitate endonucleolytic processing of DNA for horizontal gene transfer. PMID:19482939

  17. Optimized integration of T-DNA in the taxol-producing fungus ...

    African Journals Online (AJOL)

    We previously reported a taxol-producing fungus Pestalotiopsis malicola. There, we described the transformation of the fungus mediated by Agrobacterium tumefaciens. T-DNA carrying the selection marker was transferred into the fungus and randomly integrated into the genome as shown by Southern blotting.

  18. Genetic transformation in two potato cultivars with T-DNA from disarmed Agrobacterium

    NARCIS (Netherlands)

    Ooms, G.; Burrell, M.M.; Karp, A.; Bevan, M.; Hille, J.

    1987-01-01

    Derivatives of potato (Solanum tuberosum cv.'s 'Maris Bard' and 'Desiree') transformed with disarmed T-DNA from genetically engineered Agrobacterium tumefaciens strains were isolated. The transformed plants were recovered from shoot-forming tumours induced by infection of wounds with mixed-cultures

  19. T-DNA integration patterns in transgenic maize lines mediated by ...

    African Journals Online (AJOL)

    Jane

    2011-10-03

    Oct 3, 2011 ... T-DNA can induce chromosomal rearrange-ment including translocation, inversion, deletion and insertion. (Zeng et al., 2010; Zhu et al., 2010). Furthermore, various lengths of the bacterial plasmid backbone DNA sequence were found contained in the host genome of. Agrobacterium-mediated transformats ...

  20. Transformation of the cultivated mushroom Agaricus bisporus (Lange) using T-DNA from Agrobacterium tumefaciens.

    NARCIS (Netherlands)

    Mikosch, T.S.P.; Lavrijssen, B.; Griensven, van L.J.L.D.

    2001-01-01

    Agrobacterium tumefaciens is known to transfer parts of its tumour-inducing plasmid, the T-DNA, to plants, yeasts and filamentous fungi. We have used this system to transform germinating basidiospores and vegetative mycelium of a commercial strain of the cultivated basidiomycete Agaricus bisporus.

  1. The Arabidopsis SKU5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth

    Science.gov (United States)

    Sedbrook, John C.; Carroll, Kathleen L.; Hung, Kai F.; Masson, Patrick H.; Somerville, Chris R.

    2002-01-01

    To investigate how roots respond to directional cues, we characterized a T-DNA-tagged Arabidopsis mutant named sku5 in which the roots skewed and looped away from the normal downward direction of growth on inclined agar surfaces. sku5 roots and etiolated hypocotyls were slightly shorter than normal and exhibited a counterclockwise (left-handed) axial rotation bias. The surface-dependent skewing phenotype disappeared when the roots penetrated the agar surface, but the axial rotation defect persisted, revealing that these two directional growth processes are separable. The SKU5 gene belongs to a 19-member gene family designated SKS (SKU5 Similar) that is related structurally to the multiple-copper oxidases ascorbate oxidase and laccase. However, the SKS proteins lack several of the conserved copper binding motifs characteristic of copper oxidases, and no enzymatic function could be assigned to the SKU5 protein. Analysis of plants expressing SKU5 reporter constructs and protein gel blot analysis showed that SKU5 was expressed most strongly in expanding tissues. SKU5 was glycosylated and modified by glycosyl phosphatidylinositol and localized to both the plasma membrane and the cell wall. Our observations suggest that SKU5 affects two directional growth processes, possibly by participating in cell wall expansion.

  2. Twisting Right to Left: A…A Mismatch in a CAG Trinucleotide Repeat Overexpansion Provokes Left-Handed Z-DNA Conformation

    Science.gov (United States)

    2015-01-01

    Conformational polymorphism of DNA is a major causative factor behind several incurable trinucleotide repeat expansion disorders that arise from overexpansion of trinucleotide repeats located in coding/non-coding regions of specific genes. Hairpin DNA structures that are formed due to overexpansion of CAG repeat lead to Huntington’s disorder and spinocerebellar ataxias. Nonetheless, DNA hairpin stem structure that generally embraces B-form with canonical base pairs is poorly understood in the context of periodic noncanonical A…A mismatch as found in CAG repeat overexpansion. Molecular dynamics simulations on DNA hairpin stems containing A…A mismatches in a CAG repeat overexpansion show that A…A dictates local Z-form irrespective of starting glycosyl conformation, in sharp contrast to canonical DNA duplex. Transition from B-to-Z is due to the mechanistic effect that originates from its pronounced nonisostericity with flanking canonical base pairs facilitated by base extrusion, backbone and/or base flipping. Based on these structural insights we envisage that such an unusual DNA structure of the CAG hairpin stem may have a role in disease pathogenesis. As this is the first study that delineates the influence of a single A…A mismatch in reversing DNA helicity, it would further have an impact on understanding DNA mismatch repair. PMID:25876062

  3. Twisting right to left: A…A mismatch in a CAG trinucleotide repeat overexpansion provokes left-handed Z-DNA conformation.

    Directory of Open Access Journals (Sweden)

    Noorain Khan

    2015-04-01

    Full Text Available Conformational polymorphism of DNA is a major causative factor behind several incurable trinucleotide repeat expansion disorders that arise from overexpansion of trinucleotide repeats located in coding/non-coding regions of specific genes. Hairpin DNA structures that are formed due to overexpansion of CAG repeat lead to Huntington's disorder and spinocerebellar ataxias. Nonetheless, DNA hairpin stem structure that generally embraces B-form with canonical base pairs is poorly understood in the context of periodic noncanonical A…A mismatch as found in CAG repeat overexpansion. Molecular dynamics simulations on DNA hairpin stems containing A…A mismatches in a CAG repeat overexpansion show that A…A dictates local Z-form irrespective of starting glycosyl conformation, in sharp contrast to canonical DNA duplex. Transition from B-to-Z is due to the mechanistic effect that originates from its pronounced nonisostericity with flanking canonical base pairs facilitated by base extrusion, backbone and/or base flipping. Based on these structural insights we envisage that such an unusual DNA structure of the CAG hairpin stem may have a role in disease pathogenesis. As this is the first study that delineates the influence of a single A…A mismatch in reversing DNA helicity, it would further have an impact on understanding DNA mismatch repair.

  4. Long SAGE analysis of genes differentially expressed in the midgut ...

    African Journals Online (AJOL)

    USER

    purified using an Oligotex® Messenger ribonucleic acid (mRNA) Midi kit (Qiagen .... to the GO terms. The number of genes is the number of times the GO term is used to annotate genes in the cluster. The left-hand shows its proportion in total genes with GO terms ...... Eukaryotic translation initiation factor 5A. LOC693075.

  5. Molecular analysis of Agrobacterium T-DNA integration in tomato reveals a role for left border sequence homology in most integration events.

    Science.gov (United States)

    Thomas, Colwyn M; Jones, Jonathan D G

    2007-10-01

    Studies in several plants have shown that Agrobacterium tumefaciens T-DNA can integrate into plant chromosomal DNA by different mechanisms involving single-stranded (ss) or double-stranded (ds) forms. One mechanism requires sequence homology between plant target and ssT-DNA border sequences and another double-strand-break repair in which preexisting chromosomal DSBs "capture" dsT-DNAs. To learn more about T-DNA integration in Solanum lycopersicum we characterised 98 T-DNA/plant DNA junction sequences and show that T-DNA left border (LB) and right border transfer is much more variable than previously reported in Arabidopsis thaliana and Populus tremula. The analysis of seven plant target sequences showed that regions of homology between the T-DNA LB and plant chromosomal DNA plays an important role in T-DNA integration. One T-DNA insertion generated a target sequence duplication that resulted from nucleolytic processing of a LB/plant DNA heteroduplex that generated a DSB in plant chromosomal DNA. One broken end contained a captured T-DNA that served as a template for DNA repair synthesis. We propose that most T-DNA integrations in tomato require sequence homology between the ssT-DNA LB and plant target DNA which results in the generation of DSBs in plant chromosomal DNA.

  6. Left Handed Materials in Magnetic Nanocomposites

    Science.gov (United States)

    2003-07-01

    2003 University of Delaware All rights reservedXiao ONR Review - 6 Negative Index of Refraction Air(n0=1) RHM with n>0 ?i ?r Air(n0=1) LHM with nɘ...i ?r ɘ According to Snell’s Law: n n i r θ θ sin sin 0= Reversed refrection can be observed at interface between RHM and LHM. 1 July 2003© 2003...reservedXiao ONR Review - 18 Direct Prove of Negative Refraction Index in Open Space Negative refraction index can be proved by the fact the

  7. Synthesis of C-linked carbo-β2-amino acids and β2-peptides: design of new motifs for left-handed 12/10- and 10/12-mixed helices.

    Science.gov (United States)

    Sharma, Gangavaram V M; Reddy, Nelli Yella; Ravi, Rapolu; Sreenivas, Bommagani; Sridhar, Gattu; Chatterjee, Deepak; Kunwar, Ajit C; Hofmann, Hans-Jörg

    2012-12-14

    C-linked carbo-β(2)-amino acids (β(2)-Caa), a new class of β-amino acid with a carbohydrate side chain having d-xylo configuration, were prepared from d-glucose. The main idea behind the design of the new β-amino acids was to move the steric strain of the bulky carbohydrate side chain from the Cβ- to the Cα-carbon atom and to explore its influence on the folding propensities in peptides with alternating (R)- and (S)-β(2)-Caas. The tetra- and hexapeptides derived were studied employing NMR (in CDCl(3)), CD, and molecular dynamics simulations. The β(2)-peptides of the present study form left-handed 12/10- and 10/12-mixed helices independent of the order of the alternating chiral amino acids in the sequence and result in a new motif. These results differ from earlier findings on β(3)-peptides of the same design, containing a carbohydrate side chain with d-xylo configuration, which form exclusively right-handed 12/10-mixed helices. Quantum chemical calculations employing ab initio MO theory suggest the side chain chirality as an important factor for the observed definite left- or right-handedness of the helices in the β(2)- and β(3)-peptides.

  8. Analysis of T-DNA/Host-Plant DNA Junction Sequences in Single-Copy Transgenic Barley Lines

    Directory of Open Access Journals (Sweden)

    Joanne G. Bartlett

    2014-01-01

    Full Text Available Sequencing across the junction between an integrated transfer DNA (T-DNA and a host plant genome provides two important pieces of information. The junctions themselves provide information regarding the proportion of T-DNA which has integrated into the host plant genome, whilst the transgene flanking sequences can be used to study the local genetic environment of the integrated transgene. In addition, this information is important in the safety assessment of GM crops and essential for GM traceability. In this study, a detailed analysis was carried out on the right-border T-DNA junction sequences of single-copy independent transgenic barley lines. T-DNA truncations at the right-border were found to be relatively common and affected 33.3% of the lines. In addition, 14.3% of lines had rearranged construct sequence after the right border break-point. An in depth analysis of the host-plant flanking sequences revealed that a significant proportion of the T-DNAs integrated into or close to known repetitive elements. However, this integration into repetitive DNA did not have a negative effect on transgene expression.

  9. Non-oncogenic T-region mutants of Agrobacterium tumefaciens do transfer T-DNA into plant cells

    NARCIS (Netherlands)

    Hille, Jacques; Wullems, George; Schilperoort, Rob

    1983-01-01

    A new procedure for site-directed mutagenesis has been applied to the shooting and rooting loci of T-DNA of an octopine Ti-plasmid of Agrobacterium tumefaciens. Mutants have been obtained which induced tumours that either developed shoots or produced more roots than normally observed. Double

  10. Agrobacterium May Delay Plant Nonhomologous End-Joining DNA Repair via XRCC4 to Favor T-DNA Integration[W

    Science.gov (United States)

    Vaghchhipawala, Zarir E.; Vasudevan, Balaji; Lee, Seonghee; Morsy, Mustafa R.; Mysore, Kirankumar S.

    2012-01-01

    Agrobacterium tumefaciens is a soilborne pathogen that causes crown gall disease in many dicotyledonous plants by transfer of a portion of its tumor-inducing plasmid (T-DNA) into the plant genome. Several plant factors that play a role in Agrobacterium attachment to plant cells and transport of T-DNA to the nucleus have been identified, but the T-DNA integration step during transformation is poorly understood and has been proposed to occur via nonhomologous end-joining (NHEJ)–mediated double-strand DNA break (DSB) repair. Here, we report a negative role of X-RAY CROSS COMPLEMENTATION GROUP4 (XRCC4), one of the key proteins required for NHEJ, in Agrobacterium T-DNA integration. Downregulation of XRCC4 in Arabidopsis and Nicotiana benthamiana increased stable transformation due to increased T-DNA integration. Overexpression of XRCC4 in Arabidopsis decreased stable transformation due to decreased T-DNA integration. Interestingly, XRCC4 directly interacted with Agrobacterium protein VirE2 in a yeast two-hybrid system and in planta. VirE2-expressing Arabidopsis plants were more susceptible to the DNA damaging chemical bleomycin and showed increased stable transformation. We hypothesize that VirE2 titrates or excludes active XRCC4 protein available for DSB repair, thus delaying the closure of DSBs in the chromosome, providing greater opportunity for T-DNA to integrate. PMID:23064322

  11. Structured lifestyle intervention based on a trans-cultural diabetes-specific nutrition algorithm (tDNA) in individuals with type 2 diabetes: a randomized controlled trial

    Science.gov (United States)

    Chee, Winnie S S; Gilcharan Singh, Harvinder Kaur; Hamdy, Osama; Mechanick, Jeffrey I; Lee, Verna K M; Barua, Ankur; Mohd Ali, Siti Zubaidah; Hussein, Zanariah

    2017-01-01

    Objective Trans-cultural diabetes nutrition algorithm (tDNA) was created by international task force and culturally customized for Malaysian population. This study was designed to evaluate its effectiveness versus usual diabetes care in primary care settings. Research design and methods We randomized 230 patients with overweight/obesity, type 2 diabetes, and glycated hemoglobin (A1c) 7%–11% to receive usual care (UC) or UC with tDNA for 6 months. The tDNA intervention consisted of structured low-calorie meal plan, diabetes-specific meal replacements, and increased physical activity. Participants were counseled either through motivational interviewing (tDNA-MI) or conventional counseling (tDNA-CC). The UC group received standard dietary and exercise advice through conventional counseling. All patients were followed for another 6 months after intervention. Results At 6 months, A1c decreased significantly in tDNA-MI (−1.1±0.1%, pdiabetes control and body weight in primary care setting. PMID:29435347

  12. Hypervirulence of Agrobacterium tumefaciens A281 is encoded in a region of pTiBo542 outside of T-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Hood, E.E.; Helmer, G.L.; Fraley, R.T.; Chilton, M.D.

    1986-12-01

    A binary-vectory strategy was used to study the hypervirulence of Agrobacterium tumefaciens A281, an L,L-succinamopine strain. Strain A281 is hypervirulent on several solanaceous plants. Plasmids were constructed (pCS65 and pCS277) carrying either the transferred DNA (T-DNA) or the remainder of the tumor-inducing (Ti) plasmid (pEHA101) from this strain and tested each of these constructs were tested in trans with complementary each of regions from heterologous Ti plasmids. Hypervirulence on tobacco could be reconstructed in a bipartite strain with the L,L-succinamopine T-DNA and the vir region on separate plasmids. pEHA101 was able to complement octopine T-DNA to hypervirulence on tobacco and tomato plants. Nopaline T-DNA was complemented better on tomato plants by pEHA101 than it was by its own nopaline vir region, but not to hypervirulence. L,L-Succinamopine T-DNA could not be complemented to hypervirulence on tobacco and tomato plants with either heterologous vir region. From these results the authors suggest that the hypervirulence of strain A281 is due to non-T-DNA sequences on the Ti plasmid.

  13. Genetic transformation and gene silencing mediated by multiple copies of a transgene in eastern white pine.

    Science.gov (United States)

    Tang, Wei; Newton, Ronald J; Weidner, Douglas A

    2007-01-01

    An efficient transgenic eastern white pine (Pinus strobus L.) plant regeneration system has been established using Agrobacterium tumefaciens strain GV3850-mediated transformation and the green fluorescent protein (gfp) gene as a reporter in this investigation. Stable integration of transgenes in the plant genome of pine was confirmed by polymerase chain reaction (PCR), Southern blot, and northern blot analyses. Transgene expression was analysed in pine T-DNA transformants carrying different numbers of copies of T-DNA insertions. Post-transcriptional gene silencing (PTGS) was mostly obtained in transgenic lines with more than three copies of T-DNA, but not in transgenic lines with one copy of T-DNA. In situ hybridization chromosome analysis of transgenic lines demonstrated that silenced transgenic lines had two or more T-DNA insertions in the same chromosome. These results suggest that two or more T-DNA insertions in the same chromosome facilitate efficient gene silencing in transgenic pine cells expressing green fluorescent protein. There were no differences in shoot differentiation and development between transgenic lines with multiple T-DNA copies and transgenic lines with one or two T-DNA copies.

  14. [Construction of T-DNA insertion mutants of Botrytis cinerea via Agrobacterium tumefaciens mediated transformation and sequence analysis of insertion site].

    Science.gov (United States)

    Feng, Juan; Zhu, Tingheng; Cui, Zhifeng; Wang, Kun

    2010-02-01

    Construction of Botrytis cinerea T-DNA insertion mutant library through Agrobacterium-mediated transformation and for further understanding of the molecular mechanisms underlying the pathogenicity of Botrytis cinerea. Agrobacterium containing the binary vector pCMBIA1390 was used for transformation of Botrytis cinerea. Hygromycin resistant transformants were screened out and subjected to biological and morphological observation, Detached tomato leaves were used for pathogenicity assay. The flanking sequence of T-DNA inserted in mutant genome was cloned and analyzed by using TAIL-PCR. A variety of mutants were obtained and important phenotypes including reduction in growth rate, loss or reduction in conidiation and loss of pathogenicity were screened out. The T-DNA flanking sequence of one of the mutants was successfully amplified with TAIL-PCR. Agrobacterium-mediated transformation system of Botrytis cinerea was established and a T-DNA insertion mutants library was constructed. TAIL-PCR was an effective method for isolating the flanking sequence of T-DNA inserted in genome.

  15. Recovery of Moraxella ovis from the bovine respiratory tract and differentiation of Moraxella species by tDNA-intergenic spacer PCR.

    Science.gov (United States)

    Catry, Boudewijn; Boyen, Filip; Baele, Margo; Dewulf, Jeroen; de Kruif, Aart; Vaneechoutte, Mario; Haesebrouck, Freddy; Decostere, Annemie

    2007-03-10

    The purpose of the present study was to identify Moraxella (M.)--like organisms recovered from calves suffering from respiratory disease down to species level by means of tDNA-intergenic spacer length polymorphism analysis (tDNA-PCR), and to perform antimicrobial susceptibility testing of these isolates using an agar dilution technique. A total of 16 isolates originating from 12 unrelated occasions were identified as Moraxella ovis, and tDNA fingerprinting showed clear delineation from other Moraxella species. The minimal inhibitory concentrations (in microg/mL) for 90% of the investigated isolates were combination trimethoprim-sulfonamides; 4 for erythromycin; 8 for tilmicosin; 1 for florfenicol and 0.125 for enrofloxacin.

  16. Leptogenesis from Left-Handed Neutrino Production during Axion Inflation.

    Science.gov (United States)

    Adshead, Peter; Sfakianakis, Evangelos I

    2016-03-04

    We propose that the observed matter-antimatter asymmetry can be naturally produced as a by-product of axion-driven slow-roll inflation by coupling the axion to standard model neutrinos. We assume that grand unified theory scale right-handed neutrinos are responsible for the masses of the standard model neutrinos and that the Higgs field is light during inflation and develops a Hubble-scale root-mean-square value. In this setup, the rolling axion generates a helicity asymmetry in standard model neutrinos. Following inflation, this helicity asymmetry becomes equal to a net lepton number as the Higgs condensate decays and is partially reprocessed by the SU(2)_{L} sphaleron into a net baryon number.

  17. Learning Conflict Among Mixed-Dominance Left-Handed Individuals.

    Science.gov (United States)

    Blai, Boris, Jr.

    This study investigates the hypothesis that it is mixed-dominance among left handers (i.e. left handedness and right eye and/or foot dominance), that is related to academic learning difficulties among such individuals, rather than the generally held notion that their difficulties stem from the fact that they are left handers in a "right handed…

  18. Left handed composite materials in the optical range

    NARCIS (Netherlands)

    Voskoboynikova, O.; Dyankov, G.; Wijers, Christianus M.J.

    2005-01-01

    The purpose of this paper is to show that semiconductor nano-structures built from non-magnetic InAs/GaAs nano-rings can exhibit simultaneously negative effective permittivity and permeability over a certain optical frequency range. The structures are resonant and have this property near the edge of

  19. Left-handed Z-DNA: structure and function

    Science.gov (United States)

    Herbert, A.; Rich, A.

    1999-01-01

    Z-DNA is a high energy conformer of B-DNA that forms in vivo during transcription as a result of torsional strain generated by a moving polymerase. An understanding of the biological role of Z-DNA has advanced with the discovery that the RNA editing enzyme double-stranded RNA adenosine deaminase type I (ADAR1) has motifs specific for the Z-DNA conformation. Editing by ADAR1 requires a double-stranded RNA substrate. In the cases known, the substrate is formed by folding an intron back onto the exon that is targeted for modification. The use of introns to direct processing of exons requires that editing occurs before splicing. Recognition of Z-DNA by ADAR1 may allow editing of nascent transcripts to be initiated immediately after transcription, ensuring that editing and splicing are performed in the correct sequence. Structural characterization of the Z-DNA binding domain indicates that it belongs to the winged helix-turn-helix class of proteins and is similar to the globular domain of histone-H5.

  20. Commentary: Left Hand, Right Hand and on the Other Hand

    Science.gov (United States)

    Parslow, Graham R.

    2011-01-01

    It was deeply ingrained in the author from his undergraduate studies of psychology and courses in learning theory that people have a rational left brain and a creative right brain. Learning theory suggested that activities needed to be tailored to develop both hemispheres. Handedness in relation to abilities has been commented on from the 1800s by…

  1. challenges left-handed students face in kenyan girls' secondary

    African Journals Online (AJOL)

    IICBA01

    positions in uncomfortable desks, handling and manipulating of some apparatus during practical work among others. These challenges posed many disadvantages to the students as they reported inability to finish timed tasks. Majority of the teachers were aware of the students challenges but gave insufficient help.

  2. Transformation of apple (Malus × domestica) using mutants of apple acetolactate synthase as a selectable marker and analysis of the T-DNA integration sites.

    Science.gov (United States)

    Yao, Jia-Long; Tomes, Sumathi; Gleave, Andrew P

    2013-05-01

    Apple acetolactate synthase mutants were generated by site-specific mutagenesis and successfully used as selection marker in tobacco and apple transformation. T-DNA/Apple genome junctions were analysed using genome-walking PCR and sequencing. An Agrobacterium-mediated genetic transformation system was developed for apple (Malus × domestica), using mutants of apple acetolactate synthase (ALS) as a selectable marker. Four apple ALS mutants were generated by site-specific mutagenesis and subsequently cloned under the transcriptional control of the CaMV 35S promoter and ocs 3' terminator, in a pART27-derived plant transformation vector. Three of the four mutations were found to confer resistance to the herbicide Glean(®), containing the active agent chlorsulfuron, in tobacco (Nicotiana tabacum) transformation. In apple transformation, leaf explants infected with Agrobacterium tumefaciens EHA105 containing one of the three ALS mutants resulted in the production of shoots on medium containing 2-8 μg L(-1) Glean(®), whilst uninfected wild-type explants failed to regenerate shoots or survive on medium containing 1 and 3 μg L(-1) Glean(®), respectively. Glean(®)-resistant, regenerated shoots were further multiplied and rooted on medium containing 10 μg L(-1) Glean(®). The T-DNA and apple genome-DNA junctions from eight rooted transgenic apple plants were analysed using genome-walking PCR amplification and sequencing. This analysis confirmed T-DNA integration into the apple genome, identified the genome integration sites and revealed the extent of any vector backbone integration, T-DNA rearrangements and deletions of apple genome DNA at the sites of integration.

  3. Natural genetic transformation by agrobacterium rhizogenes . Annual flowering in two biennials, belgian endive and carrot

    Science.gov (United States)

    Limami; Sun; Douat; Helgeson; Tepfer

    1998-10-01

    Genetic transformation of Belgian endive (Cichorium intybus) and carrot (Daucus carota) by Agrobacterium rhizogenes resulted in a transformed phenotype, including annual flowering. Back-crossing of transformed (R1) endive plants produced a line that retained annual flowering in the absence of the other traits associated with A. rhizogenes transformation. Annualism was correlated with the segregation of a truncated transferred DNA (T-DNA) insertion. During vegetative growth, carbohydrate reserves accumulated normally in these annuals, and they were properly mobilized prior to anthesis. The effects of individual root-inducing left-hand T-DNA genes on flowering were tested in carrot, in which rolC (root locus) was the primary promoter of annualism and rolD caused extreme dwarfism. We discuss the possible adaptive significance of this attenuation of the phenotypic effects of root-inducing left-hand T-DNA.

  4. Isolation and charactarization of T-DNA-insertion Mutants of Arabidopsis thaliana that are Tolerant to Salt

    International Nuclear Information System (INIS)

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

    2006-01-01

    In order to provide an insight into physiological mechanisms underlying salt tolerance in plants,T-DNA insertionally mutagenized seeds of Arabidopsis thaliana were screened on media containing 150-175 millimolar sodium chloride (mM Nacl) for an ability to germinate with formation of two green expanded cotyledons.Under these saline conditions the wild-type (WT) seeds of A.thaliana do not germinate. Two different mutants,NN3 and NN143 were isolated. Genetic analysis of the F1 and F2 generations indicates that the salt tolerance trait in mutant NN3 is recessive and dominant in mutant NN143. Allelism test indicates that mutants NN3 and NN143 are not allelic to each other, but they are alleic to aba and abi mutants respectively. When subjected to water stress imposed by 175mM Nacl for two weeks,kanamycin homozygous seeds of mutants NN3 and NN143 attained germination levels of 97% and 65% respectively. At this concentration of salt, the wild-type seeds are incapable of germination. On 300mM mannitol, a non-ionic osmoticum, mutants NN143 and NN3 and wild type attained a germination levels of 77%, 95% and 2% respectively. The biomass of mutant NN3 seedlings grown on a medium containing 150 mM NaCl was significanlly greater than that of mutant NN143.Between 104 and 145 hours after germination on media containing 175 mM NaCl and 300mM mannitol,germination levels of mutant NN3 were significantly higher than those of mutant NN143.However, both attain the same level of germination after 200 hours. Mutant NN43 is capable of germination on a medium containing 2-6 μM (micromolar) abscisic acid (ABA) with germination ranging from 11to100%. After two weeks on 2 μ ABA, it attained 100% germination and the wild type and mutant NN3 did not germinate. The biomass of NN143 seedlings grown on ABA-free medium and those grown on 2 μM ABA were not significantly different. In presence of both 1μABA and 250mM mannitol, mutant NN143 seedlings achieved 60% germination compared to 93

  5. Expression of VP60 gene from rabbit haemorrhagic disease virus ...

    African Journals Online (AJOL)

    The VP60 gene from rabbit haemorrhagic disease virus (RHDV) YL strain in Northeast of China, under control of the ats1A promoter from Rubisco small subunit genes of Arabidopsis thaliana, was introduced into the transfer deoxyribonucleic acid (T-DNA) region of plant transfer vector pCAMBIA1300 and transferred to ...

  6. Selection of Arabidopsis mutants overexpressing genes driven by the promoter of an auxin-inducible glutathione S-transferase gene

    NARCIS (Netherlands)

    Kop, D.A.M. van der; Schuyer, M.; Pinas, J.E.; Zaal, B.J. van der; Hooykaas, P.J.J.

    1999-01-01

    Transgenic arabidopsis plants were isolated that contained a T-DNA construct in which the promoter of an auxin-inducible glutathione S-transferase (GST) gene from tobacco was fused to the kanamycin resistance (nptII) as well as to the β-glucuronidase (gusA) reporter gene. Subsequently, seeds were

  7. The genome of cultivated sweet potato contains Agrobacterium T-DNAs with expressed genes: An example of a naturally transgenic food crop

    Science.gov (United States)

    Kyndt, Tina; Quispe, Dora; Zhai, Hong; Jarret, Robert; Ghislain, Marc; Liu, Qingchang; Gheysen, Godelieve

    2015-01-01

    Agrobacterium rhizogenes and Agrobacterium tumefaciens are plant pathogenic bacteria capable of transferring DNA fragments [transfer DNA (T-DNA)] bearing functional genes into the host plant genome. This naturally occurring mechanism has been adapted by plant biotechnologists to develop genetically modified crops that today are grown on more than 10% of the world’s arable land, although their use can result in considerable controversy. While assembling small interfering RNAs, or siRNAs, of sweet potato plants for metagenomic analysis, sequences homologous to T-DNA sequences from Agrobacterium spp. were discovered. Simple and quantitative PCR, Southern blotting, genome walking, and bacterial artificial chromosome library screening and sequencing unambiguously demonstrated that two different T-DNA regions (IbT-DNA1 and IbT-DNA2) are present in the cultivated sweet potato (Ipomoea batatas [L.] Lam.) genome and that these foreign genes are expressed at detectable levels in different tissues of the sweet potato plant. IbT-DNA1 was found to contain four open reading frames (ORFs) homologous to the tryptophan-2-monooxygenase (iaaM), indole-3-acetamide hydrolase (iaaH), C-protein (C-prot), and agrocinopine synthase (Acs) genes of Agrobacterium spp. IbT-DNA1 was detected in all 291 cultigens examined, but not in close wild relatives. IbT-DNA2 contained at least five ORFs with significant homology to the ORF14, ORF17n, rooting locus (Rol)B/RolC, ORF13, and ORF18/ORF17n genes of A. rhizogenes. IbT-DNA2 was detected in 45 of 217 genotypes that included both cultivated and wild species. Our finding, that sweet potato is naturally transgenic while being a widely and traditionally consumed food crop, could affect the current consumer distrust of the safety of transgenic food crops. PMID:25902487

  8. The genome of cultivated sweet potato contains Agrobacterium T-DNAs with expressed genes: An example of a naturally transgenic food crop.

    Science.gov (United States)

    Kyndt, Tina; Quispe, Dora; Zhai, Hong; Jarret, Robert; Ghislain, Marc; Liu, Qingchang; Gheysen, Godelieve; Kreuze, Jan F

    2015-05-05

    Agrobacterium rhizogenes and Agrobacterium tumefaciens are plant pathogenic bacteria capable of transferring DNA fragments [transfer DNA (T-DNA)] bearing functional genes into the host plant genome. This naturally occurring mechanism has been adapted by plant biotechnologists to develop genetically modified crops that today are grown on more than 10% of the world's arable land, although their use can result in considerable controversy. While assembling small interfering RNAs, or siRNAs, of sweet potato plants for metagenomic analysis, sequences homologous to T-DNA sequences from Agrobacterium spp. were discovered. Simple and quantitative PCR, Southern blotting, genome walking, and bacterial artificial chromosome library screening and sequencing unambiguously demonstrated that two different T-DNA regions (IbT-DNA1 and IbT-DNA2) are present in the cultivated sweet potato (Ipomoea batatas [L.] Lam.) genome and that these foreign genes are expressed at detectable levels in different tissues of the sweet potato plant. IbT-DNA1 was found to contain four open reading frames (ORFs) homologous to the tryptophan-2-monooxygenase (iaaM), indole-3-acetamide hydrolase (iaaH), C-protein (C-prot), and agrocinopine synthase (Acs) genes of Agrobacterium spp. IbT-DNA1 was detected in all 291 cultigens examined, but not in close wild relatives. IbT-DNA2 contained at least five ORFs with significant homology to the ORF14, ORF17n, rooting locus (Rol)B/RolC, ORF13, and ORF18/ORF17n genes of A. rhizogenes. IbT-DNA2 was detected in 45 of 217 genotypes that included both cultivated and wild species. Our finding, that sweet potato is naturally transgenic while being a widely and traditionally consumed food crop, could affect the current consumer distrust of the safety of transgenic food crops.

  9. The potential of virus-induced gene silencing for speeding up functional characterization of plant genes

    NARCIS (Netherlands)

    Benedito, V.A.; Visser, P.B.; Angenent, G.C.; Krens, F.A.

    2004-01-01

    Virus-induced gene silencing (VIGS) has been shown to be of great potential in plant reverse genetics. Advantages of VIGS over other approaches, such as T-DNA or transposon tagging, include the circumvention of plant transformation, methodological simplicity and robustness, and speedy results. These

  10. T-DNA transfer from Agrobacterium tumefaciens to the ectomycorrhizal fungus Pisolithus microcarpus Transferencia de T-DNA de Agrobacterium tumefaciens al hongo ectomicorrícico Pisolithus microcarpus

    Directory of Open Access Journals (Sweden)

    A.G. Pardo

    2005-06-01

    Full Text Available The model ectomycorrhizal fungus Pisolithus microcarpus isolate 441 was transformed by using Agrobacterium tumefaciens LBA1100 and AGL-1. The selection marker was the Shble gene of Streptoallotecius hidustanus, conferring resistance to phleomycin, under the control of the gpd gene promoter and terminator of Schizophyllum commune. Transformation resulted in phleomycin resistant clones which were confirmed by PCR to contain the resistance cassette. A. tumefaciens-mediated gene transfer would allow the development of RNA interference technology in P. microcarpus.El hongo ectomicorrícico modelo Pisolithus microcarpus aislamiento 441 fue transformado utilizando Agrobacterium tumefaciens LBA 1100 y AGL-1. El marcador de selección fue el gen Shble de Streptoallotecius hidustanus, el cual confiere resistencia a fleomicina, bajo el control del promotor y terminador del gen gpd de Schizophyllum commune. La transformación resultó en clones resistentes a fleomicina comprobándose por PCR la presencia del transgen. La transferencia génica mediada por Agrobacterium podría permitir el desarrollo de la tecnología de interferencia por ARN en P. microcarpus.

  11. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  12. THE ARABIDOPSIS ATLIG4 GENE IS REQUIRED FOR THE REPAIR OF DNA DAMAGE, BUT NOT FOR THE INTEGRATION OF AGROBACTERIUM T-DNA. (R829479C001)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Gene Discovery and Functional Analyses in the Model Plant Arabidopsis

    DEFF Research Database (Denmark)

    Feng, Cai-ping; Mundy, J.

    2006-01-01

    The present mini-review describes newer methods and strategies, including transposon and T-DNA insertions, TILLING, Deleteagene, and RNA interference, to functionally analyze genes of interest in the model plant Arabidopsis. The relative advantages and disadvantages of the systems are also...

  14. Nucleotide sequence of the Agrobacterium tumefaciens octopine Ti plasmid-encoded tmr gene

    NARCIS (Netherlands)

    Heidekamp, F.; Dirkse, W.G.; Hille, J.; Ormondt, H. van

    1983-01-01

    The nucleotide sequence of the tmr gene, encoded by the octopine Ti plasmid from Agrobacterium tumefaciens (pTiAch5), was determined. The T-DNA, which encompasses this gene, is involved in tumor formation and maintenance, and probably mediates the cytokinin-independent growth of transformed plant

  15. An efficient marker-free vector for clean gene transfer into plants ...

    African Journals Online (AJOL)

    A marker-free vector, pBINMF, for clean gene transfer was constructed based on the binary vector pBINPLUS. Vector pBINMF, carrying only a multiple cloning site (MCS) between the left and the right T-DNA border, was suitable to directly generate marker-free transgenic plants (MFTPs) without any vector sequences ...

  16. Identification of novel genes in the carotenogenic and oleaginous yeast Rhodotorula toruloides through genome-wide insertional mutagenesis.

    Science.gov (United States)

    Liu, Yanbin; Koh, Chong Mei John; Yap, Sihui Amy; Du, Minge; Hlaing, Mya Myintzu; Ji, Lianghui

    2018-02-21

    Rhodotorula toruloides is an outstanding producer of lipids and carotenoids. Currently, information on the key metabolic pathways and their molecular basis of regulation remains scarce, severely limiting efforts to engineer it as an industrial host. We have adapted Agrobacterium tumefaciens-mediated transformation (ATMT) as a gene-tagging tool for the identification of novel genes in R. toruloides. Multiple factors affecting transformation efficiency in several species in the Pucciniomycotina subphylum were optimized. The Agrobacterium transfer DNA (T-DNA) showed predominantly single-copy chromosomal integrations in R. toruloides, which were trackable by high efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR). To demonstrate the application of random T-DNA insertions for strain improvement and gene hunting, 3 T-DNA insertional libraries were screened against cerulenin, nile red and tetrazolium violet respectively, resulting in the identification of 22 mutants with obvious phenotypes in fatty acid or lipid metabolism. Similarly, 5 carotenoid biosynthetic mutants were obtained through visual screening of the transformants. To further validate the gene tagging strategy, one of the carotenoid production mutants, RAM5, was analyzed in detail. The mutant had a T-DNA inserted at the putative phytoene desaturase gene CAR1. Deletion of CAR1 by homologous recombination led to a phenotype similar to RAM5 and it could be genetically complemented by re-introduction of the wild-type CAR1 genome sequence. T-DNA insertional mutagenesis is an efficient forward genetic tool for gene discovery in R. toruloides and related oleaginous yeast species. It is also valuable for metabolic engineering in these hosts. Further analysis of the 27 mutants identified in this study should augment our knowledge of the lipid and carotenoid biosynthesis, which may be exploited for oil and isoprenoid metabolic engineering.

  17. T-DNA Tagging-Based Gain-of-Function of OsHKT1;4 Reinforces Na Exclusion from Leaves and Stems but Triggers Na Toxicity in Roots of Rice Under Salt Stress

    Directory of Open Access Journals (Sweden)

    Yuuka Oda

    2018-01-01

    Full Text Available The high affinity K+ transporter 1;4 (HKT1;4 in rice (Oryza sativa, which shows Na+ selective transport with little K+ transport activity, has been suggested to be involved in reducing Na in leaves and stems under salt stress. However, detailed physiological roles of OsHKT1;4 remain unknown. Here, we have characterized a transfer DNA (T-DNA insertion mutant line of rice, which overexpresses OsHKT1;4, owing to enhancer elements in the T-DNA, to gain an insight into the impact of OsHKT1;4 on salt tolerance of rice. The homozygous mutant (the O/E line accumulated significantly lower concentrations of Na in young leaves, stems, and seeds than the sibling WT line under salt stress. Interestingly, however, the mutation rendered the O/E plants more salt sensitive than WT plants. Together with the evaluation of biomass of rice lines, rhizosphere acidification assays using a pH indicator bromocresol purple and 22NaCl tracer experiments have led to an assumption that roots of O/E plants suffered heavier damages from Na which excessively accumulated in the root due to increased activity of Na+ uptake and Na+ exclusion in the vasculature. Implications toward the application of the HKT1-mediated Na+ exclusion system to the breeding of salt tolerant crop cultivars will be discussed.

  18. Molecular characterization of transgenic shallots (Allium cepa L.) by adaptor ligation PCR (AL-PCR) and sequencing of genomic DNA flanking T-DNA borders

    NARCIS (Netherlands)

    Zheng, S.J.; Henken, G.; Sofiari, E.; Jacobsen, E.; Krens, F.A.

    2001-01-01

    Genomic DNA blot hybridization is traditionally used to demonstrate that, via genetic transformation, foreign genes are integrated into host genomes. However, in large genome species, such as Allium cepa L., the use of genomic DNA blot hybridization is pushed towards its limits, because a

  19. Binary transformation systems based on 'shooter' mutants of Agrobacterium tumefaciens: a simple, efficient and universal gene transfer technology that permits marker gene elimination.

    Science.gov (United States)

    Mihálka, V; Balázs, E; Nagy, I

    2003-04-01

    A simple transformation procedure with a positive selection scheme using the expression of the isopentenyl transferase ( ipt) gene of transfer DNA (T-DNA) 'shooter' mutants of Agrobacterium tumefaciens was elaborated. After comparing several 'shooter' mutants we found that particular strains frequently produced phenotypically normal shoots after co-culturing with tobacco leaf explants. Shoots selected for normal phenotype showed apical dominance and could be rooted with the same efficiency as non-transformed shoots. When binary vectors were introduced into these strains, stably integrated binary vector T-DNA sequences were found in some regenerants, which were produced under non-selective conditions on growth-regulator-free medium. Such phenotypically normal transformants typically lacked a stably integrated ipt gene. Normal looking shoots could also be produced in tomato, muskmelon and sweet pepper.

  20. Pressler's Quantumization of the Atom and The Left-handed Electron's Internal Structure

    Science.gov (United States)

    Pressler, David E.

    2000-03-01

    A new theory of superconductivity will be presented. In addition, I will reveal the answer to one of the most intriguing questions in science since the elusive electron particle was discovered by J. J. Thomson: Exactly what is the electron particle and why does it exhibit both particle and wave characteristics. Specifically, how does the electron exhibit an intrinsic magnetic field and, inside the atom, how does it exhibit angular momentum. I will describe, in detail, particle pair production. The fundamental physical theoretical parameters, the physical mass and charge, of all elementary particles is introduced. The fundamental neutron particle’s internal structure is also illustrated. The electron radius is estimated to eight significant figures. I will present a novel theory concerning atomic structure, the position and nature of the electron inside the atom, and the nature of bonding, i.e., the covalent bond is described in terms of the interactions of atomic magnetic fields. Precise bond angles and distances of the molecule are considered. This new concept is consistent with experimental evidence and adheres strictly to the valence-shell electron-pair repulsion (VSEPR) model presently used in chemistry. I will explain the atomic model concept as being a true harmonic oscillator; periodic motion of the electron at resonant frequency produces radiation at discrete frequencies or line spectra because the electron is under the action of two restoring forces.

  1. Comparison of scholastic performances of left handed and right handed students.

    Science.gov (United States)

    Sharma, R B; Goyal, M; Singh, J

    1993-10-01

    An attempt was made to compare the scholastic performance among left and right handed students. Both academic and extra curricular areas were studied among 3608 students from 6th to 12th class, from 10 schools in a rural subdivision of north east Rajasthan. General incidence of left handedness was 8.6% among students, higher in females (12.4%) as compared to males (8.1%). Right handed students performed better in aggregate as well as in individual academic areas (p performers as far as sports and games area was concerned, while right handed students tended to be average performers. Overall handedness affected both the academic and extra-curricular activities except behavior and discipline area (p > 0.05).

  2. The Economic Consequences of Being Left-Handed: Some Sinister Results

    Science.gov (United States)

    Denny, Kevin; O' Sullivan, Vincent

    2007-01-01

    This paper estimates the effects of handedness on earnings. Augmenting a conventional earnings equation with an indicator of left-handedness shows there is a positive effect on male earnings with manual workers enjoying a slightly larger premium. These results are inconsistent with the view that left-handers in general are handicapped either…

  3. Implications of Being Left-Handed as Related To Being Right-Handed.

    Science.gov (United States)

    Thomas, Jana H.

    Research indicates that there are physical and social, and possibly cognitive, differences between left-handers and right-handers. The three substantive sections of this colloquium paper cover brain functions, theories pertaining to the genesis of handedness, and cognitive development as related to handedness. Section 1 provides a brief…

  4. Scattering properties of a cylinder fabricated from a left-handed material

    Czech Academy of Sciences Publication Activity Database

    Kuzmiak, Vladimír; Maradudin, A. A.

    2002-01-01

    Roč. 66, č. 4 (2002), s. 045116/1-045116/7 ISSN 0163-1829 R&D Projects: GA MŠk ME 141 Grant - others:NSF(US) INT-932651 Institutional research plan: CEZ:AV0Z2067918 Keywords : photonic band gap * electromagnetic wave propagation * nonlinear media Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.327, year: 2002

  5. The Left-Handed Child in a Right-Handed World.

    Science.gov (United States)

    Hackney, Clinton S.

    This concise pamphlet describes methods of determining hand dominance in children. The pamphlet states that the child should be observed in certain procedures without being told that he or she is being tested. Among the test procedures suggested are activities with a hand puppet, hammering nails, and throwing a ball. The pamphlet offers directions…

  6. The Performance of Left-Handed Participants on a Preferential Reaching Test

    Science.gov (United States)

    Mamolo, Carla M.; Roy, Eric A.; Bryden, Pamela J.; Rohr, Linda E.

    2005-01-01

    Previous research in our laboratory has examined the distribution of preferred hand (PH) reaches in working space with right-handed participants. In one study, we examined the effects of tool position and task demands on the frequency of PH reaches with right-handers (Mamolo, Roy, Bryden, & Rohr, 2004). We found that PH reaches were at a maximum…

  7. Left hand finger force in violin playing: tempo, loudness, and finger differences.

    Science.gov (United States)

    Kinoshita, Hiroshi; Obata, Satoshi

    2009-07-01

    A three-dimensional force transducer was installed in the neck of a violin under the A string at the D5 position in order to study the force with which the violinist clamps the string against the fingerboard under normal playing conditions. Violinists performed repetitive sequences of open A- and fingered D-tones using the ring finger at tempi of 1, 2, 4, 8, and 16 notes/s at mezzo-forte. At selected tempi, the effects of dynamic level and the use of different fingers were investigated as well. The force profiles were clearly dependent on tempo and dynamic level. At slow tempi, the force profiles were characterized by an initial pulse followed by a level force to the end of the finger contact period. At tempi higher than 2 Hz, only pulsed profiles were observed. The peak force exceeded 4.5 N at 1 and 2 Hz and decreased to 1.7 N at 16 Hz. All force and impulse values were lower at softer dynamic levels, and when using the ring or little finger compared to the index finger.

  8. CGG repeats associated with fragile X chromosome form left-handed Z-DNA structure

    Czech Academy of Sciences Publication Activity Database

    Renčiuk, Daniel; Kypr, Jaroslav; Vorlíčková, Michaela

    2011-01-01

    Roč. 95, č. 3 (2011), s. 174-181 ISSN 0006-3525 R&D Projects: GA ČR(CZ) GA202/07/0094; GA AV ČR(CZ) IAA100040701 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : fragile X chromosome syndrome * Z-DNA * trinucleotide repeats Subject RIV: BO - Biophysics Impact factor: 2.870, year: 2011

  9. Scattering of electromagnetic waves by a graphene-coated thin cylinder of left-handed metamaterial

    Science.gov (United States)

    Pashaeiadl, Hamid; Naserpour, Mahin; Zapata-Rodríguez, Carlos J.

    2018-04-01

    In this paper we explored the scattering behavior of thin cylinders made of LHM and coated by a monoatomic graphene layer. A spectral tunability of the resonance peaks is evidenced by altering the chemical potential of the graphene coating, a fact that occurs at any state of polarization of the incident plane wave in opposition to the case of scatterers of dielectric core. On the contrary, no invisibility condition can be satisfied for dielectric environments. A singular performance is also found for cylinders with permittivity and permeability near zero. Practical implementations of our results can be carried out in sensing and wave manipulation driven by metamaterials.

  10. Spectroscopic and immunochemical characterization of left-handed Z RNA under physiological conditions

    International Nuclear Information System (INIS)

    Hardin, C.C.; Zarling, D.A.; Tinoco, I. Jr.

    1986-01-01

    Limited chemical brominination of poly[r(C-G)] results in partial modification of guanine C8 and cytosine C5 producing a mixture of A and Z RNA forms in 110 mM NaCl buffer at 37 0 C. 1 H NMR of Br-poly[r(C-G)] shows a 1:1 mixture of A and Z RNAs. Nuclear Overhauser effect (NOE) experiments permit complete assignments of GH8, CH6, CH5, GH1' and CH1 resonances in both the A and Z forms. Distance estimates obtained from GH8 to GH1' NOEs demonstrate that even unbrominated guanine residues in these polynucleotides undergo a transition to the syn conformation (Z form). The Z form of Br-poly[r(C-G)] in 110 mM NaCl has a guanine Raman scattering band at 643 cm -1 in agreement with the band in the Z form of poly[r(C-G)] stabilized by 6 M NaClO 4 . In A RNA the band is at 671 cm -1 . The corresponding shift in DNA is from 682 cm -1 (B DNA) to 625 cm -1 (Z DNA). This suggests different glycosidic torsion angles in Z RNA and Z DNA. Inoculating rabbits with Br-poly[r(C-G)] produces polyclonal antibodies specific for the Z forms of RNA and DNA (i.e., poly[d(br 5 C-G)] or poly[d(io 5 C-G)] as judged by radioimmunoassay in 100 mM NaCl buffers. Phosphate buffer or certain high ionic strength conditions affect the recognition of Z RNA and Z DNA by anti-Z RNA or anti-Z DNA IgGs suggesting that one determinant recognized by these antibodies is the zig-zag phosphodiester backbone

  11. Isolated and painless (? atrophy of the infraspinatus muscle: left handed versus right handed volleyball players

    Directory of Open Access Journals (Sweden)

    Thiago D. Gonçalves Côelho

    1994-12-01

    Full Text Available The suprascapular nerve originates from the upper trunk of the brachial plexus or less frequently from the root of C5. It runs a short way and crosses the suprascapular notch. It innervates the supraspinatus muscle and the acromioclavicular and glenohumeral joints. Then, it crosses the lateral edge of the spine of the scapula passing through the spinoglenoid notch, and innervates the infraspinatus muscle. These are potential sites of injury to the suprascapular nerve. Three cases of suprascapular nerve entrapment causing an isolated infraspinatus muscle atrophy in volleyball players were studied. It is suggested the hypothesis that the nature of the smash, in which the athlete uses the arm violently, more than does in volleyball service or in the art of reception, is the key to the pathogenesis of the lesion in volleyball players.

  12. Learned movements in a left-handed pianist: an f-MRI evaluation.

    Science.gov (United States)

    Moretti, R; Torre, P; Antonello, R M; Ukmar, M; Longo, R; Bava, A

    2002-11-01

    The spatial arrangement of neuronal sources for digit movement is non somatotopic, and is structured as extensively arranged through different regional cortex. We have functionally examined the cerebro-cortical activation during simple and complex motor sequences, before and after learning sessions, in healthy volunteers, both considering left- and right-dominant hand use, and left non dominant hand use, skillfulness and educational level. We discuss the results with a review on the topic. Copyright 2002 Elsevier Science Ltd.

  13. Increased 1-aminocyclopropane-1-carboxylate deaminase activity enhances Agrobacterium tumefaciens-mediated gene delivery into plant cells.

    Science.gov (United States)

    Someya, Tatsuhiko; Nonaka, Satoko; Nakamura, Kouji; Ezura, Hiroshi

    2013-10-01

    Agrobacterium-mediated transformation is a useful tool for the genetic modification in plants, although its efficiency is low for several plant species. Agrobacterium-mediated transformation has three major steps in laboratory-controlled experiments: the delivery of T-DNA into plant cells, the selection of transformed plant cells, and the regeneration of whole plants from the selected cells. Each of these steps must be optimized to improve the efficiency of Agrobacterium-mediated plant transformation. It has been reported that increasing the number of cells transformed by T-DNA delivery can improve the frequency of stable transformation. Previously, we demonstrated that a reduction in ethylene production by plant cells during cocultivation with A. tumefaciens-expressing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase resulted in increased T-DNA delivery into the plant cells. In this study, to further improve T-DNA delivery by A. tumefaciens, we modified the expression cassette of the ACC deaminase gene using vir gene promoter sequences. The ACC deaminase gene driven by the virD1 promoter was expressed at a higher level, resulting in a higher ACC deaminase activity in this A. tumefaciens strain than in the strain with the lac promoter used in a previous study. The newly developed A. tumefaciens strain improves the delivery of T-DNA into Solanum lycopersicum (tomato) and Erianthus ravennae plants and thus may be a powerful tool for the Agrobacterium-mediated genetic engineering of plants. © 2013 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  14. Prospective blinded study of somatic mutation detection in cell-free DNA utilizing a targeted 54-gene next generation sequencing panel in metastatic solid tumor patients.

    Science.gov (United States)

    Kim, Seung Tae; Lee, Won-Suk; Lanman, Richard B; Mortimer, Stefanie; Zill, Oliver A; Kim, Kyoung-Mee; Jang, Kee Taek; Kim, Seok-Hyung; Park, Se Hoon; Park, Joon Oh; Park, Young Suk; Lim, Ho Yeong; Eltoukhy, Helmy; Kang, Won Ki; Lee, Woo Yong; Kim, Hee-Cheol; Park, Keunchil; Lee, Jeeyun; Talasaz, AmirAli

    2015-11-24

    Sequencing of the mutant allele fraction of circulating cell-free DNA (cfDNA) derived from tumors is increasingly utilized to detect actionable genomic alterations in cancer. We conducted a prospective blinded study of a comprehensive cfDNA sequencing panel with 54 cancer genes. To evaluate the concordance between cfDNA and tumor DNA (tDNA), sequencing results were compared between cfDNA from plasma and genomic tumor DNA (tDNA). Utilizing next generation digital sequencing technology (DST), we profiled approximately 78,000 bases encoding 512 complete exons in the targeted genes in cfDNA from plasma. Seventy-five patients were prospectively enrolled between February 2013 and March 2014, including 61 metastatic cancer patients and 14 clinical stage II CRC patients with matched plasma and tissue samples. Using the 54-gene panel, we detected at least one somatic mutation in 44 of 61 tDNA (72.1%) and 29 of 44 (65.9%) cfDNA. The overall concordance rate of cfDNA to tDNA was 85.9%, when all detected mutations were considered. We collected serial cfDNAs during cetuximab-based treatment in 2 metastatic KRAS wild-type CRC patients, one with acquired resistance and one with primary resistance. We demonstrate newly emerged KRAS mutation in cfDNA 1.5 months before radiologic progression. Another patient had a newly emerged PIK3CA H1047R mutation on cfDNA analysis at progression during cetuximab/irinotecan chemotherapy with gradual increase in allele frequency from 0.8 to 2.1%. This blinded, prospective study of a cfDNA sequencing showed high concordance to tDNA suggesting that the DST approach may be used as a non-invasive biopsy-free alternative to conventional sequencing using tumor biopsy.

  15. Genes and Gene Therapy

    Science.gov (United States)

    ... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  16. Identifying pathogenicity genes in the rubber tree anthracnose fungus Colletotrichum gloeosporioides through random insertional mutagenesis.

    Science.gov (United States)

    Cai, Zhiying; Li, Guohua; Lin, Chunhua; Shi, Tao; Zhai, Ligang; Chen, Yipeng; Huang, Guixiu

    2013-07-19

    To gain more insight into the molecular mechanisms of Colletotrichum gloeosporioides pathogenesis, Agrobacterium tumefaciens-mediated transformation (ATMT) was used to identify mutants of C. gloeosporioides impaired in pathogenicity. An ATMT library of 4128 C. gloeosporioides transformants was generated. Transformants were screened for defects in pathogenicity with a detached copper brown leaf assay. 32 mutants showing reproducible pathogenicity defects were obtained. Southern blot analysis showed 60.4% of the transformants had single-site T-DNA integrations. 16 Genomic sequences flanking T-DNA were recovered from mutants by thermal asymmetric interlaced PCR, and were used to isolate the tagged genes from the genome sequence of wild-type C. gloeosporioides by Basic Local Alignment Search Tool searches against the local genome database of the wild-type C. gloeosporioides. One potential pathogenicity genes encoded calcium-translocating P-type ATPase. Six potential pathogenicity genes had no known homologs in filamentous fungi and were likely to be novel fungal virulence factors. Two putative genes encoded Glycosyltransferase family 28 domain-containing protein and Mov34/MPN/PAD-1 family protein, respectively. Five potential pathogenicity genes had putative function matched with putative protein of other Colletotrichum species. Two known C. gloeosporioides pathogenicity genes were also identified, the encoding Glomerella cingulata hard-surface induced protein and C. gloeosporioides regulatory subunit of protein kinase A gene involved in cAMP-dependent PKA signal transduction pathway. Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. The nature of the transition mismatches with Watson-Crick architecture: the G*·T or G·T* DNA base mispair or both? A QM/QTAIM perspective for the biological problem.

    Science.gov (United States)

    Brovarets', Ol'ha O; Hovorun, Dmytro M

    2015-01-01

    This study provides the first accurate investigation of the tautomerization of the biologically important guanine*·thymine (G*·T) DNA base mispair with Watson-Crick geometry, involving the enol mutagenic tautomer of the G and the keto tautomer of the T, into the G·T* mispair (∆G = .99 kcal mol(-1), population = 15.8% obtained at the MP2 level of quantum-mechanical theory in the continuum with ε = 4), formed by the keto tautomer of the G and the enol mutagenic tautomer of the T base, using DFT and MP2 methods in vacuum and in the weakly polar medium (ε = 4), characteristic for the hydrophobic interfaces of specific protein-nucleic acid interactions. We were first able to show that the G*·T↔G·T* tautomerization occurs through the asynchronous concerted double proton transfer along two antiparallel O6H···O4 and N1···HN3 H-bonds and is assisted by the third N2H···O2 H-bond, that exists along the entire reaction pathway. The obtained results indicate that the G·T* base mispair is stable from the thermodynamic point of view complex, while it is dynamically unstable structure in vacuum and dynamically stable structure in the continuum with ε = 4 with lifetime of 6.4·10(-12) s, that, on the one side, makes it possible to develop all six low-frequency intermolecular vibrations, but, on the other side, it is by three orders less than the time (several ns) required for the replication machinery to forcibly dissociate a base pair into the monomers during DNA replication. One of the more significant findings to emerge from this study is that the short-lived G·T* base mispair, which electronic interaction energy between the bases (-23.76 kcal mol(-1)) exceeds the analogical value for the G·C Watson-Crick nucleobase pair (-20.38 kcal mol(-1)), "escapes from the hands" of the DNA replication machinery by fast transforming into the G*·T mismatch playing an indirect role of its supplier during the DNA replication. So

  18. Selectable antibiotic resistance marker gene-free transgenic rice harbouring the garlic leaf lectin gene exhibits resistance to sap-sucking planthoppers.

    Science.gov (United States)

    Sengupta, Subhadipa; Chakraborti, Dipankar; Mondal, Hossain A; Das, Sampa

    2010-03-01

    Rice, the major food crop of world is severely affected by homopteran sucking pests. We introduced coding sequence of Allium sativum leaf agglutinin, ASAL, in rice cultivar IR64 to develop sustainable resistance against sap-sucking planthoppers as well as eliminated the selectable antibiotic-resistant marker gene hygromycin phosphotransferase (hpt) exploiting cre/lox site-specific recombination system. An expression vector was constructed containing the coding sequence of ASAL, a potent controlling agent against green leafhoppers (GLH, Nephotettix virescens) and brown planthopper (BPH, Nilaparvata lugens). The selectable marker (hpt) gene cassette was cloned within two lox sites of the same vector. Alongside, another vector was developed with chimeric cre recombinase gene cassette. Reciprocal crosses were performed between three single-copy T(0) plants with ASAL- lox-hpt-lox T-DNA and three single-copy T(0) plants with cre-bar T-DNA. Marker gene excisions were detected in T(1) hybrids through hygromycin sensitivity assay. Molecular analysis of T(1) plants exhibited 27.4% recombination efficiency. T(2) progenies of L03C04(1) hybrid parent showed 25% cre negative ASAL-expressing plants. Northern blot, western blot and ELISA showed significant level of ASAL expression in five marker-free T(2) progeny plants. In planta bioassay of GLH and BPH performed on these T(2) progenies exhibited radical reduction in survivability and fecundity compared with the untransformed control plants.

  19. Identification of a splicing coactivator gene that affects the production of ochratoxin a in Aspergillus carbonarius

    Directory of Open Access Journals (Sweden)

    Lígia Uno Lunardi

    2009-11-01

    Full Text Available Ochratoxin A is a mycotoxin produced by some fungi species. Among them, Aspergillus carbonarius is considered a powerful producer. Genes involved in the ochratoxin A biosynthesis pathway have been identified in some producer species. However, there are few studies that purpose to identify these genes in A. carbonarius. The use of insertion mutants to identify genes associated with certain properties has been increased in the literature. In this work, the region of T-DNA integration was investigated in one A. carbonarius ochratoxin-defective mutant previously obtained by Agrobacterium tumefaciens-mediated transformation, in order to find an association between interrupted gene and the biosynthesis of ochratoxin A. The integration occurred in a gene that possibly encodes a splicing coactivator protein. The analysis of the relative expression of the splicing coativator gene from A. carbonarius wild type strain in four different media showed high correlation between the transcript levels and the ochratoxin A production.A ocratoxina A é uma micotoxina frequentemente encontrada em uma grande variedade de produtos alimentares e apresenta efeitos nefrotóxicos e potencial carcinogênico para animais e humanos. É naturalmente produzida por algumas espécies fúngicas, como Aspergillus carbonarius, que é considerado um potente produtor. Apesar disso, o número de estudos que visam identificar genes que são essenciais para a biossíntese de ocratoxina em A. carbonarius é ainda reduzido. Um mutante de A. carbonarius com baixa produção de ocratoxina A previamente obtido por transformação mediada por Agrobacterium tumefaciens foi investigado com o objetivo de encontrar uma associação entre o gene interrompido e a biossíntese desta micotoxina. Os resultados mostraram a ocorrência de uma junção não exata entre o T-DNA e o DNA genômico do fungo durante o evento de integração. A integração do T-DNA no genoma do mutante T188 provocou dele

  20. Gene Function Analysis in the Ubiquitous Human Commensal and Pathogen Malassezia Genus

    Directory of Open Access Journals (Sweden)

    Giuseppe Ianiri

    2016-11-01

    Full Text Available The genus Malassezia includes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation of Malassezia furfur and Malassezia sympodialis using Agrobacterium tumefaciens delivery of transfer DNA (T-DNA molecules. These T-DNAs can insert randomly into the genome. In the case of M. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of the ADE2 gene for purine biosynthesis and of the LAC2 gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible in Malassezia species.

  1. Suppression of different classes of somatic mutations in Arabidopsis by vir gene-expressing Agrobacterium strains.

    Science.gov (United States)

    Shah, Jasmine M; Ramakrishnan, Anantha Maharasi; Singh, Amit Kumar; Ramachandran, Subalakshmi; Unniyampurath, Unnikrishnan; Jayshankar, Ajitha; Balasundaram, Nithya; Dhanapal, Shanmuhapreya; Hyde, Geoff; Baskar, Ramamurthy

    2015-08-26

    Agrobacterium infection, which is widely used to generate transgenic plants, is often accompanied by T-DNA-linked mutations and transpositions in flowering plants. It is not known if Agrobacterium infection also affects the rates of point mutations, somatic homologous recombinations (SHR) and frame-shift mutations (FSM). We examined the effects of Agrobacterium infection on five types of somatic mutations using a set of mutation detector lines of Arabidopsis thaliana. To verify the effect of secreted factors, we exposed the plants to different Agrobacterium strains, including wild type (Ach5), its derivatives lacking vir genes, oncogenes or T-DNA, and the heat-killed form for 48 h post-infection; also, for a smaller set of strains, we examined the rates of three types of mutations at multiple time-points. The mutation detector lines carried a non-functional β-glucuronidase gene (GUS) and a reversion of mutated GUS to its functional form resulted in blue spots. Based on the number of blue spots visible in plants grown for a further two weeks, we estimated the mutation frequencies. For plants co-cultivated for 48 h with Agrobacterium, if the strain contained vir genes, then the rates of transversions, SHRs and FSMs (measured 2 weeks later) were lower than those of uninfected controls. In contrast, co-cultivation for 48 h with any of the Agrobacterium strains raised the transposition rates above control levels. The multiple time-point study showed that in seedlings co-cultivated with wild type Ach5, the reduced rates of transversions and SHRs after 48 h co-cultivation represent an apparent suppression of an earlier short-lived increase in mutation rates (peaking for plants co-cultivated for 3 h). An increase after 3 h co-cultivation was also seen for rates of transversions (but not SHR) in seedlings exposed to the strain lacking vir genes, oncogenes and T-DNA. However, the mutation rates in plants co-cultivated for longer times with this strain subsequently

  2. Horizontal Gene Transfer Contributes to Plant Evolution: The Case of Agrobacterium T-DNAs

    Science.gov (United States)

    Quispe-Huamanquispe, Dora G.; Gheysen, Godelieve; Kreuze, Jan F.

    2017-01-01

    Horizontal gene transfer (HGT) can be defined as the acquisition of genetic material from another organism without being its offspring. HGT is common in the microbial world including archaea and bacteria, where HGT mechanisms are widely understood and recognized as an important force in evolution. In eukaryotes, HGT now appears to occur more frequently than originally thought. Many studies are currently detecting novel HGT events among distinct lineages using next-generation sequencing. Most examples to date include gene transfers from bacterial donors to recipient organisms including fungi, plants, and animals. In plants, one well-studied example of HGT is the transfer of the tumor-inducing genes (T-DNAs) from some Agrobacterium species into their host plant genomes. Evidence of T-DNAs from Agrobacterium spp. into plant genomes, and their subsequent maintenance in the germline, has been reported in Nicotiana, Linaria and, more recently, in Ipomoea species. The transferred genes do not produce the usual disease phenotype, and appear to have a role in evolution of these plants. In this paper, we review previous reported cases of HGT from Agrobacterium, including the transfer of T-DNA regions from Agrobacterium spp. to the sweetpotato [Ipomoea batatas (L.) Lam.] genome which is, to date, the sole documented example of a naturally-occurring incidence of HGT from Agrobacterium to a domesticated crop plant. We also discuss the possible evolutionary impact of T-DNA acquisition on plants. PMID:29225610

  3. 77 FR 24264 - Notice of Receipt of Petition for Decision That Nonconforming Left-Hand Drive 2006 Land Rover...

    Science.gov (United States)

    2012-04-23

    ... Windshield Defrosting and Defogging Systems, 104 Windshield Wiping and Washing Systems, 106 Brake Hoses, 113..., and Roof Panel Systems, 119 New Pneumatic Tires for Vehicles other than passenger Cars, 124... Passenger Cars: installation of a tire and rim information placard. Standard No. 301 Fuel System Integrity...

  4. (CGA)4: parallel, anti-parallel, right-handed and left-handed homoduplexes of a trinucleotide repeat DNA

    Czech Academy of Sciences Publication Activity Database

    Kejnovská, Iva; Tůmová, Marcela; Vorlíčková, Michaela

    2001-01-01

    Roč. 1527, 1-2 (2001), s. 73-80 ISSN 0304-4165 R&D Projects: GA ČR GA204/98/1027; GA ČR GA204/01/0561 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA conformational polymorphism * circular dichroism * Z-DNA Subject RIV: BO - Biophysics Impact factor: 1.849, year: 2000

  5. Relative Age Effects Are a Developmental Problem in Tennis: But Not Necessarily when You're Left-Handed!

    Science.gov (United States)

    Loffing, Florian; Schorer, Jorg; Cobley, Steve P.

    2010-01-01

    Relative Age Effects (RAEs), describing attainment inequalities as a result of interactions between biological age and age-grouping procedures, have been demonstrated across many sports contexts. This study examined whether an additional individual characteristic (i.e., handedness) mediated RAEs in tennis. Relative age and handedness distributions…

  6. Left-handed properties of manganite-perovskites La1-xSrxMnO3 at various dopant concentrations

    Directory of Open Access Journals (Sweden)

    D. P. Belozorov

    2014-03-01

    Full Text Available The experimental study of Double Negative (DNG state of electromagnetic wave propagating in lanthanum manganite-perovskites doped with strontium La1-xSrxMnO3 is provided firstly below individual Curie temperatures (in ferromagnetic metal state (FM for La1-xSrxMnO3. Various dopant concentrations are considered for ceramic specimens: x = 0.15;  0.225;  0.3;  0.45;  0.6. It is shown that dependence of the DNG-peak intensity on dopant concentration is sharply non-monotone with maximum at the dopant concentrations x = 0.225 – 0.3. This behaviour follows the change of Curie temperature with increase of dopant concentration in such substances. The obtained dependence of DNG peak intensity supports the opinion concerning the role of disorder in highly doped manganite-perovskite magnetic ceramics under study.

  7. Reflex sympathetic dystrophy of the left hand and motor impairments of the unaffected right hand : impaired central motor processing?

    NARCIS (Netherlands)

    Ribbers, Gerard M.; Mulder, Theo; Geurts, Alexander C.; Den Otter, R.A.

    Objective: To test whether central motor processing can be impaired in chronic reflex sympathetic dystrophy (RSD). Design: Experimental 2-group analysis. Setting: Tertiary care center in the Netherlands. Participants: Five patients with stage 3 RSD of the left forearm, free of symptoms and

  8. Different distal-proximal movement balances in right- and left-hand writing may hint at differential premotor cortex involvement

    NARCIS (Netherlands)

    Potgieser, A. R. E.; de Jong, B. M.

    2011-01-01

    Right-handed people generally write with their right hand. Language expressed in script is thus performed with the hand also preferred for skilled motor tasks. This may suggest an efficient functional interaction between the language area of Broca and the adjacent ventral premotor cortex (PMv) in

  9. Exploring Left-Hand-Side substitutions in the benzoxazinone series of 4-amino-piperidine bacterial type IIa topoisomerase inhibitors.

    Science.gov (United States)

    Geng, Bolin; Comita-Prevoir, Janelle; Eyermann, Charles J; Reck, Folkert; Fisher, Stewart

    2011-09-15

    An SAR survey at the C-6 benzoxazinone position of a novel scaffold which inhibits bacterial type IIa topoisomerase demonstrates that a range of small electron donating groups (EDG) and electron withdrawing groups (EWG) are tolerated for antibacterial activity. Cyano was identified as a preferred substituent that affords good antibacterial potency while minimizing hERG cardiac channel activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Studying Genes

    Science.gov (United States)

    ... NIGMS NIGMS Home > Science Education > Studying Genes Studying Genes Tagline (Optional) Middle/Main Content Area PDF Version (382 KB) Other Fact Sheets What are genes? Genes are segments of DNA that contain instructions ...

  11. Gene Therapy

    Science.gov (United States)

    Gene therapy Overview Gene therapy involves altering the genes inside your body's cells in an effort to treat or stop disease. Genes contain your ... that don't work properly can cause disease. Gene therapy replaces a faulty gene or adds a new ...

  12. [Opine biosynthesis and catabolism genes of Agrobacterium tumefaciens and Agrobacterium rhizogenes].

    Science.gov (United States)

    Vladimirov, I A; Matveeva, T V; Lutova, L A

    2015-02-01

    Agrobacterium is a genus of soil bacteria with the ability to transform plant cells by a T-DNA-sequence located on the pTi/pRi- plasmid containing a set of genes expressed in plant cells. Expression of these genes leads to a proliferation of transformed cells, with the subsequent formation of tumors or growths of roots and the synthesis of opines--products of the condensation of amino acids with ketoacids or sugars used by Agrobacteria as a source of carbon and nitrogen. In this review, we systematized the information about most common opines in plant--Agrobacterium systems and their biosynthesis and catabolism genes, as well as the role of opines in the interaction of pathogenic Agrobacterium with plants and with other Agrobacterium strains, including the genetic consequences of such interactions.

  13. Dipeptidyl peptidase IV is involved in the cellulose-responsive induction of cellulose biomass-degrading enzyme genes in Aspergillus aculeatus.

    Science.gov (United States)

    Tani, Shuji; Yuki, Shota; Kunitake, Emi; Sumitani, Jun-Ichi; Kawaguchi, Takashi

    2017-06-01

    We screened for factors involved in the cellulose-responsive induction of cellulose biomass-degrading enzyme genes from approximately 12,000 Aspergillus aculeatus T-DNA insertion mutants harboring a transcriptional fusion between the FIII-avicelase gene (cbhI) promoter and the orotidine 5'-monophosphate decarboxylase gene. Analysis of 5-fluoroorodic acid (5-FOA) sensitivity, cellulose utilization, and cbhI expression of the mutants revealed that a mutant harboring T-DNA at the dipeptidyl peptidase IV (dppIV) locus had acquired 5-FOA resistance and was deficient in cellulose utilization and cbhI expression. The deletion of dppIV resulted in a significant reduction in the cellulose-responsive expression of both cbhI as well as genes controlled by XlnR-independent and XlnR-dependent signaling pathways at an early phase in A. aculeatus. In contrast, the dppIV deletion did not affect the xylose-responsive expression of genes under the control of XlnR. These results demonstrate that DppIV participates in cellulose-responsive induction in A. aculeatus.

  14. The Arabidopsis thaliana rlp mutations revert the ectopic leaf blade formation conferred by activation tagging of the LEP gene

    DEFF Research Database (Denmark)

    van der Graaff, Eric; Nussbaumer, C; Keller, Bente

    2003-01-01

    Activation tagging of the gene LEAFY PETIOLE (LEP) with a T-DNA construct induces ectopic leaf blade formation in Arabidopsis, which results in a leafy petiole phenotype. In addition, the number of rosette leaves produced prior to the onset of bolting is reduced, and the rate of leaf initiation...... is retarded by the activation tagged LEP gene. The ectopic leaf blade results from an invasion of the petiole region by the wild-type leaf blade. In order to isolate mutants that are specifically disturbed in the outgrowth of the leaf blade, second site mutagenesis was performed using ethane methanesulphonate...... (EMS) on a transgenic line that harbours the activation-tagged LEP gene and exhibits the leafy petiole phenotype. A collection of revertant for leafy petiole (rlp lines was isolated that form petiolated rosette leaves in the presence of the activated LEP gene, and could be classified into three groups...

  15. gene structure, gene expression

    Indian Academy of Sciences (India)

    and seedling leaves were sampled at 6 h after the treatment. For cold stress, the seedlings were transferred to 4◦C growth chamber for 30 min. Control seedlings were exposed to none of these treatments. To examine the expression patterns of these predicted genes in Poplar and to further confirm their stress responsive-.

  16. DNA methylation mediated control of gene expression is critical for development of crown gall tumors.

    Directory of Open Access Journals (Sweden)

    Jochen Gohlke

    Full Text Available Crown gall tumors develop after integration of the T-DNA of virulent Agrobacterium tumefaciens strains into the plant genome. Expression of the T-DNA-encoded oncogenes triggers proliferation and differentiation of transformed plant cells. Crown gall development is known to be accompanied by global changes in transcription, metabolite levels, and physiological processes. High levels of abscisic acid (ABA in crown galls regulate expression of drought stress responsive genes and mediate drought stress acclimation, which is essential for wild-type-like tumor growth. An impact of epigenetic processes such as DNA methylation on crown gall development has been suggested; however, it has not yet been investigated comprehensively. In this study, the methylation pattern of Arabidopsis thaliana crown galls was analyzed on a genome-wide scale as well as at the single gene level. Bisulfite sequencing analysis revealed that the oncogenes Ipt, IaaH, and IaaM were unmethylated in crown galls. Nevertheless, the oncogenes were susceptible to siRNA-mediated methylation, which inhibited their expression and subsequently crown gall growth. Genome arrays, hybridized with methylated DNA obtained by immunoprecipitation, revealed a globally hypermethylated crown gall genome, while promoters were rather hypomethylated. Mutants with reduced non-CG methylation developed larger tumors than the wild-type controls, indicating that hypermethylation inhibits plant tumor growth. The differential methylation pattern of crown galls and the stem tissue from which they originate correlated with transcriptional changes. Genes known to be transcriptionally inhibited by ABA and methylated in crown galls became promoter methylated upon treatment of A. thaliana with ABA. This suggests that the high ABA levels in crown galls may mediate DNA methylation and regulate expression of genes involved in drought stress protection. In summary, our studies provide evidence that epigenetic processes

  17. Identification of genes associated with asexual reproduction in Phyllosticta citricarpa mutants obtained through Agrobacterium tumefaciens transformation.

    Science.gov (United States)

    Goulin, Eduardo Henrique; Savi, Daiani Cristina; Petters, Desirrê Alexia Lourenço; Kava, Vanessa; Galli-Terasawa, Lygia; Silva, Geraldo José; Glienke, Chirlei

    2016-11-01

    Phyllosticta citricarpa is the epidemiological agent of Citrus Black Spot (CBS) disease, which is responsible for large economic losses worldwide. CBS is characterized by the presence of spores (pycnidiospores) in dark lesions of fruit, which are also responsible for short distance dispersal of the disease. The identification of genes involved in asexual reproduction of P. citricarpa can be an alternative for directional disease control. We analyzed a library of mutants obtained through Agrobacterium tumefaciens transformation system, looking for alterations in growth and reproductive structure formation. Two mutant strains were found to have lost the ability to form pycnidia. The flanking T-DNA insertion regions were identified on P. citricarpa genome by using blast analysis and further gene prediction. The predicted genes containing the T-DNA insertions were identified as Spindle Poison Sensitivity Scp3, Ion Transport protein, and Cullin Binding proteins. The Ion Transport and Cullin Binding proteins are known to be correlated with sexual and asexual reproduction in fungi; however, the exact mechanism by which these proteins act on spore formation in P. citricarpa needs to be better characterized. The Scp3 proteins are suggested here for the first time as being associated with asexual reproduction in fungus. This protein is associated with microtubule formation, and as microtubules play an essential role as spindle machinery for chromosome segregation and cytokinesis, insertions in this gene can lead to abnormal formations, such as that observed here in P. citricarpa. We suggest these genes as new targets for fungicide development and CBS disease control, by iRNA. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Lox-dependent gene expression in transgenic plants obtained via Agrobacterium-mediated transformation.

    Science.gov (United States)

    Shcherbak, N; Kishchenko, O; Sakhno, L; Komarnytsky, I; Kuchuk, M

    2013-01-01

    Lox sites of the Cre/lox recombination system from bacteriophage P1 were analyzed for their ability to affect on transgene expression when inserted upstream from a gene coding sequence adjacent to the right border (RB) of T-DNA. Wild and mutated types of lox sites were tested for their effect upon bar gene expression in plants obtained via Agrobacterium-mediated and biolistic transformation methods. Lox-mediated expression of bar gene, recognized by resistance of transgenic plants to PPT, occurred only in plants obtained via Agrobacterium-mediated transformation. RT-PCR analysis confirms that PPT-resistant phenotype of transgenic plants obtained via Agrobacterium-mediated transformation was caused by activation of bar gene. The plasmid with promoterless gus gene together with the lox site adjacent to the RB was constructed and transferred to Nicotiana tabacum as well. Transgenic plants exhibited GUS activity and expression of gus gene was detected in plant leaves. Expression of bar gene from the vectors containing lox site near RB allowed recovery of numerous PPT-resistant transformants of such important crops as Beta vulgaris, Brassica napus, Lactuca sativa and Solanum tuberosum. Our results demonstrate that the lox site sequence adjacent to the RB can be used to control bar gene expression in transgenic plants.

  19. Transcriptomic variation among six Arabidopsis thaliana accessions identified several novel genes controlling aluminium tolerance.

    Science.gov (United States)

    Kusunoki, Kazutaka; Nakano, Yuki; Tanaka, Keisuke; Sakata, Yoichi; Koyama, Hiroyuki; Kobayashi, Yuriko

    2017-02-01

    Differences in the expression levels of aluminium (Al) tolerance genes are a known determinant of Al tolerance among plant varieties. We combined transcriptomic analysis of six Arabidopsis thaliana accessions with contrasting Al tolerance and a reverse genetic approach to identify Al-tolerance genes responsible for differences in Al tolerance between accession groups. Gene expression variation increased in the signal transduction process under Al stress and in growth-related processes in the absence of stress. Co-expression analysis and promoter single nucleotide polymorphism searching suggested that both trans-acting polymorphisms of Al signal transduction pathway and cis-acting polymorphisms in the promoter sequences caused the variations in gene expression associated with Al tolerance. Compared with the wild type, Al sensitivity increased in T-DNA knockout (KO) lines for five genes, including TARGET OF AVRB OPERATION1 (TAO1) and an unannotated gene (At5g22530). These were identified from 53 Al-inducible genes showing significantly higher expression in tolerant accessions than in sensitive accessions. These results indicate that the difference in transcriptional signalling is partly associated with the natural variation in Al tolerance in Arabidopsis. Our study also demonstrates the feasibility of comparative transcriptome analysis by using natural genetic variation for the identification of genes responsible for Al stress tolerance. © 2016 John Wiley & Sons Ltd.

  20. A combination of gene expression ranking and co-expression network analysis increases discovery rate in large-scale mutant screens for novel Arabidopsis thaliana abiotic stress genes.

    Science.gov (United States)

    Ransbotyn, Vanessa; Yeger-Lotem, Esti; Basha, Omer; Acuna, Tania; Verduyn, Christoph; Gordon, Michal; Chalifa-Caspi, Vered; Hannah, Matthew A; Barak, Simon

    2015-05-01

    As challenges to food security increase, the demand for lead genes for improving crop production is growing. However, genetic screens of plant mutants typically yield very low frequencies of desired phenotypes. Here, we present a powerful computational approach for selecting candidate genes for screening insertion mutants. We combined ranking of Arabidopsis thaliana regulatory genes according to their expression in response to multiple abiotic stresses (Multiple Stress [MST] score), with stress-responsive RNA co-expression network analysis to select candidate multiple stress regulatory (MSTR) genes. Screening of 62 T-DNA insertion mutants defective in candidate MSTR genes, for abiotic stress germination phenotypes yielded a remarkable hit rate of up to 62%; this gene discovery rate is 48-fold greater than that of other large-scale insertional mutant screens. Moreover, the MST score of these genes could be used to prioritize them for screening. To evaluate the contribution of the co-expression analysis, we screened 64 additional mutant lines of MST-scored genes that did not appear in the RNA co-expression network. The screening of these MST-scored genes yielded a gene discovery rate of 36%, which is much higher than that of classic mutant screens but not as high as when picking candidate genes from the co-expression network. The MSTR co-expression network that we created, AraSTressRegNet is publicly available at http://netbio.bgu.ac.il/arnet. This systems biology-based screening approach combining gene ranking and network analysis could be generally applicable to enhancing identification of genes regulating additional processes in plants and other organisms provided that suitable transcriptome data are available. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Splicing factor SR34b mutation reduces cadmium tolerance in Arabidopsis by regulating iron-regulated transporter 1 gene

    International Nuclear Information System (INIS)

    Zhang, Wentao; Du, Bojing; Liu, Di; Qi, Xiaoting

    2014-01-01

    Highlights: • Arabidopsis splicing factor SR34b gene is cadmium-inducible. • SR34b T-DNA insertion mutant is sensitive to cadmium due to high cadmium uptake. • SR34b is a regulator of cadmium transporter IRT1 at the posttranscription level. • These results highlight the roles of splicing factors in cadmium tolerance of plant. - Abstract: Serine/arginine-rich (SR) proteins are important splicing factors. However, the biological functions of plant SR proteins remain unclear especially in abiotic stresses. Cadmium (Cd) is a non-essential element that negatively affects plant growth and development. In this study, we provided clear evidence for SR gene involved in Cd tolerance in planta. Systemic expression analysis of 17 Arabidopsis SR genes revealed that SR34b is the only SR gene upregulated by Cd, suggesting its potential roles in Arabidopsis Cd tolerance. Consistent with this, a SR34b T-DNA insertion mutant (sr34b) was moderately sensitive to Cd, which had higher Cd 2+ uptake rate and accumulated Cd in greater amounts than wild-type. This was due to the altered expression of iron-regulated transporter 1 (IRT1) gene in sr34b mutant. Under normal growth conditions, IRT1 mRNAs highly accumulated in sr34b mutant, which was a result of increased stability of IRT1 mRNA. Under Cd stress, however, sr34b mutant plants had a splicing defect in IRT1 gene, thus reducing the IRT1 mRNA accumulation. Despite of this, sr34b mutant plants still constitutively expressed IRT1 proteins under Cd stress, thereby resulting in Cd stress-sensitive phenotype. We therefore propose the essential roles of SR34b in posttranscriptional regulation of IRT1 expression and identify it as a regulator of Arabidopsis Cd tolerance

  2. Splicing factor SR34b mutation reduces cadmium tolerance in Arabidopsis by regulating iron-regulated transporter 1 gene

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wentao; Du, Bojing; Liu, Di; Qi, Xiaoting, E-mail: qixiaoting@cnu.edu.cn

    2014-12-12

    Highlights: • Arabidopsis splicing factor SR34b gene is cadmium-inducible. • SR34b T-DNA insertion mutant is sensitive to cadmium due to high cadmium uptake. • SR34b is a regulator of cadmium transporter IRT1 at the posttranscription level. • These results highlight the roles of splicing factors in cadmium tolerance of plant. - Abstract: Serine/arginine-rich (SR) proteins are important splicing factors. However, the biological functions of plant SR proteins remain unclear especially in abiotic stresses. Cadmium (Cd) is a non-essential element that negatively affects plant growth and development. In this study, we provided clear evidence for SR gene involved in Cd tolerance in planta. Systemic expression analysis of 17 Arabidopsis SR genes revealed that SR34b is the only SR gene upregulated by Cd, suggesting its potential roles in Arabidopsis Cd tolerance. Consistent with this, a SR34b T-DNA insertion mutant (sr34b) was moderately sensitive to Cd, which had higher Cd{sup 2+} uptake rate and accumulated Cd in greater amounts than wild-type. This was due to the altered expression of iron-regulated transporter 1 (IRT1) gene in sr34b mutant. Under normal growth conditions, IRT1 mRNAs highly accumulated in sr34b mutant, which was a result of increased stability of IRT1 mRNA. Under Cd stress, however, sr34b mutant plants had a splicing defect in IRT1 gene, thus reducing the IRT1 mRNA accumulation. Despite of this, sr34b mutant plants still constitutively expressed IRT1 proteins under Cd stress, thereby resulting in Cd stress-sensitive phenotype. We therefore propose the essential roles of SR34b in posttranscriptional regulation of IRT1 expression and identify it as a regulator of Arabidopsis Cd tolerance.

  3. Production of dammarane-type sapogenins in rice by expressing the dammarenediol-II synthase gene from Panax ginseng C.A. Mey.

    Science.gov (United States)

    Huang, Zhiwei; Lin, Juncheng; Cheng, Zuxin; Xu, Ming; Huang, Xinying; Yang, Zhijian; Zheng, Jingui

    2015-10-01

    Ginsenosides are the main active ingredients in Chinese medicinal ginseng; 2,3-oxidosqualene is a precursor metabolite to ginsenosides that is present in rice. Because rice lacks a key rate-limiting enzyme (dammarenediol-II synthase, DS), rice cannot synthesize dammarane-type ginsenosides. In this study, the ginseng (Panax ginseng CA Mey.) DS gene (GenBank: AB265170.1) was transformed into rice using agrobacterium, and 64 rice transgenic plants were produced. The Transfer-DNA (T-DNA) insertion sites in homozygous lines of the T2 generation were determined by using high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR) and differed in all tested lines. One to two copies of the T-DNA were present in each transformant, and real-time PCR and Western blotting showed that the transformed DS gene could be transcribed and highly expressed. High performance liquid chromatography (HPLC) analysis showed that the dammarane-type sapogenin 20(S)-protopanaxadiol (PPD) content was 0.35-0.59 mg/g dw and the dammarane-type sapogenin 20(S)-protopanaxatriol (PPT) content was 0.23-0.43 mg/g dw in the transgenic rice. LC/MS analysis confirmed production of PPD and PPT. These results indicate that a new "ginseng rice" germplasm containing dammarane-type sapogenins has been successfully developed by transforming the ginseng DS gene into rice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. How the Sequence of a Gene Specifies Structural Symmetry in Proteins.

    Directory of Open Access Journals (Sweden)

    Xiaojuan Shen

    Full Text Available Internal symmetry is commonly observed in the majority of fundamental protein folds. Meanwhile, sufficient evidence suggests that nascent polypeptide chains of proteins have the potential to start the co-translational folding process and this process allows mRNA to contain additional information on protein structure. In this paper, we study the relationship between gene sequences and protein structures from the viewpoint of symmetry to explore how gene sequences code for structural symmetry in proteins. We found that, for a set of two-fold symmetric proteins from left-handed beta-helix fold, intragenic symmetry always exists in their corresponding gene sequences. Meanwhile, codon usage bias and local mRNA structure might be involved in modulating translation speed for the formation of structural symmetry: a major decrease of local codon usage bias in the middle of the codon sequence can be identified as a common feature; and major or consecutive decreases in local mRNA folding energy near the boundaries of the symmetric substructures can also be observed. The results suggest that gene duplication and fusion may be an evolutionarily conserved process for this protein fold. In addition, the usage of rare codons and the formation of higher order of secondary structure near the boundaries of symmetric substructures might have coevolved as conserved mechanisms to slow down translation elongation and to facilitate effective folding of symmetric substructures. These findings provide valuable insights into our understanding of the mechanisms of translation and its evolution, as well as the design of proteins via symmetric modules.

  5. Non-canonical structure, function and phylogeny of the Bsister MADS-box gene OsMADS30 of rice (Oryza sativa).

    Science.gov (United States)

    Schilling, Susanne; Gramzow, Lydia; Lobbes, Dajana; Kirbis, Alexander; Weilandt, Lisa; Hoffmeier, Andrea; Junker, Astrid; Weigelt-Fischer, Kathleen; Klukas, Christian; Wu, Feng; Meng, Zheng; Altmann, Thomas; Theißen, Günter

    2015-12-01

    Bsister MADS-box genes play key roles in female reproductive organ and seed development throughout seed plants. This view is supported by their high conservation in terms of sequence, expression and function. In grasses, there are three subclades of Bsister genes: the OsMADS29-, the OsMADS30- and the OsMADS31-like genes. Here, we report on the evolution of the OsMADS30-like genes. Our analyses indicate that these genes evolved under relaxed purifying selection and are rather weakly expressed. OsMADS30, the representative of the OsMADS30-like genes from rice (Oryza sativa), shows strong sequence deviations in its 3' region when compared to orthologues from other grass species. We show that this is due to a 2.4-kbp insertion, possibly of a hitherto unknown helitron, which confers a heterologous C-terminal domain to OsMADS30. This putative helitron is not present in the OsMADS30 orthologues from closely related wild rice species, pointing to a relatively recent insertion event. Unlike other Bsister mutants O. sativa plants carrying a T-DNA insertion in the OsMADS30 gene do not show aberrant seed phenotypes, indicating that OsMADS30 likely does not have a canonical 'Bsister function'. However, imaging-based phenotyping of the T-DNA carrying plants revealed alterations in shoot size and architecture. We hypothesize that sequence deviations that accumulated during a period of relaxed selection in the gene lineage that led to OsMADS30 and the alteration of the C-terminal domain might have been a precondition for a potential neo-functionalization of OsMADS30 in O. sativa. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  6. Gene expression

    International Nuclear Information System (INIS)

    Hildebrand, C.E.; Crawford, B.D.; Walters, R.A.; Enger, M.D.

    1983-01-01

    We prepared probes for isolating functional pieces of the metallothionein locus. The probes enabled a variety of experiments, eventually revealing two mechanisms for metallothionein gene expression, the order of the DNA coding units at the locus, and the location of the gene site in its chromosome. Once the switch regulating metallothionein synthesis was located, it could be joined by recombinant DNA methods to other, unrelated genes, then reintroduced into cells by gene-transfer techniques. The expression of these recombinant genes could then be induced by exposing the cells to Zn 2+ or Cd 2+ . We would thus take advantage of the clearly defined switching properties of the metallothionein gene to manipulate the expression of other, perhaps normally constitutive, genes. Already, despite an incomplete understanding of how the regulatory switch of the metallothionein locus operates, such experiments have been performed successfully

  7. The ROOT HAIRLESS 1 gene encodes a nuclear protein required for root hair initiation in Arabidopsis.

    Science.gov (United States)

    Schneider, K; Mathur, J; Boudonck, K; Wells, B; Dolan, L; Roberts, K

    1998-07-01

    The epidermis of Arabidopsis wild-type primary roots, in which some cells grow hairs and others remain hairless in a position-dependent manner, has become an established model system to study cell differentiation. Here we present a molecular analysis of the RHL1 (ROOT HAIRLESS 1) gene that, if mutated, prevents the formation of hairs on primary roots and causes a seedling lethal phenotype. We have cloned the RHL1 gene by use of a T-DNA-tagged mutant and found that it encodes a protein that appears to be plant specific. The predicted RHL1 gene product is a small hydrophilic protein (38.9 kD) containing putative nuclear localization signals and shows no significant homology to any known amino acid sequence. We demonstrate that a 78-amino-acid sequence at its amino terminus is capable of directing an RHL1-GFP fusion protein to the nucleus. The RHL1 transcript is present throughout the wild-type plant and in suspension culture cells, but in very low amounts, suggesting a regulatory function for the RHL1 protein. Structural evidence suggests a role for the RHL1 gene product in the nucleolus. We have examined the genetic relationship between RHL1 and GL2, an inhibitor of root hair initiation in non-hair cells. Our molecular and genetic data with double mutants, together with the expression analysis of a GL2 promoter-GUS reporter gene construct, indicate that the RHL1 gene acts independently of GL2.

  8. Efficient transformation and expression of gfp gene in Valsa mali var. mali.

    Science.gov (United States)

    Chen, Liang; Sun, Gengwu; Wu, Shujing; Liu, Huixiang; Wang, Hongkai

    2015-01-01

    Valsa mali var. mali, the causal agent of valsa canker of apple, causes great loss of apple production in apple producing regions. The pathogenic mechanism of the pathogen has not been studied extensively, thus a suitable gene marker for pathogenic invasion analysis and a random insertion of T-DNA for mutants are desirable. In this paper, we reported the construction of a binary vector pKO1-HPH containing a positive selective gene hygromycin phosphotransferase (hph), a reporter gene gfp conferring green fluorescent protein, and an efficient protocol for V. mali var. mali transformation mediated by Agrobacterium tumefaciens. A transformation efficiency up to about 75 transformants per 10(5) conidia was achieved when co-cultivation of V. mali var. mali and A. tumefaciens for 48 h in A. tumefaciens inductive medium agar plates. The insertions of hph gene and gfp gene into V. mali var. mali genome verified by polymerase chain reaction and southern blot analysis showed that 10 randomly-selected transformants exhibited a single, unique hybridization pattern. This is the first report of A. tumefaciens-mediated transformation of V. mali var mali carrying a 'reporter' gfp gene that stably and efficiently expressed in the transformed V. mali var. mali species.

  9. Physiological Consequences of Genetic Transformation: Result of Target Gene Expression or Stress Reaction?

    Directory of Open Access Journals (Sweden)

    A.G. Enikeev

    2015-06-01

    Full Text Available The transgenic and non-transgenic tobacco cell cultures were analyzed for resistance to abiotic and biotic stress. The different physiological reaction of cell culture depending on T-DNA structure (or transgen structure was observed. The cell culture transformed by disarmed Agrobacterium tumefaciense A699 with pCNL 65 nptII demonstrated the same stress-resistance as non-transgenic control cell culture. The cell culture transformed by Agrobacterium tumefaciense LBA 4400 pBiCaMV nptII + hsp101 showed a raised stress-resistance to high temperature, high KF concentration, and to the action of Clavibacter michiganensis ssp sepidonicus. Obviously, the expression of transferred arabodopsis gene hsp101 provides protection properties of transgenic cell culture under the influence of various stress factors. Moreover, that agrobacterial transformation as previous stress-factor is supposed to make a contribution to formation of transgenic cell culture cross-resistance.

  10. Efficient gene targeting in Penicillium chrysogenum using novel Agrobacterium-mediated transformation approaches.

    Science.gov (United States)

    de Boer, Paulo; Bronkhof, Jurian; Dukiќ, Karolina; Kerkman, Richard; Touw, Hesselien; van den Berg, Marco; Offringa, Remko

    2013-12-01

    The industrial production of β-lactam antibiotics by Penicillium chrysogenum has increased tremendously over the last decades, however, further optimization via classical strain and process improvement has reached its limits. The availability of the genome sequence provides new opportunities for directed strain improvement, but this requires the establishment of an efficient gene targeting (GT) system. Recently, mutations affecting the non-homologous end joining (NHEJ) pathway were shown to increase GT efficiencies following PEG-mediated DNA transfer in P. chrysogenum from 1% to 50%. Apart from direct DNA transfer many fungi can efficiently be transformed using the T-DNA transfer system of the soil bacterium Agrobacterium tumefaciens, however, for P. chrysogenum no robust system for Agrobacterium-mediated transformation was available. We obtained efficient AMT of P. chrysogenum spores with the nourseothricin acetyltransferase gene as selection marker, and using this system we investigated if AMT in a NHEJ mutant background could further enhance GT efficiencies. In general, AMT resulted in higher GT efficiencies than direct DNA transfer, although the final frequencies depended on the Agrobacterium strain and plasmid backbone used. Providing overlapping and complementing fragments on two different plasmid backbones via the same Agrobacterium host was shown to be most effective. This so-called split-marker or bi-partite method resulted in highly efficient GT (>97%) almost exclusively without additional ectopic T-DNA insertions. As this method provides for an efficient GT method independent of protoplasts, it can be applied to other fungi for which no protoplasts can be generated or for which protoplast transformation leads to varying results. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Trichoderma genes

    Science.gov (United States)

    Foreman, Pamela [Los Altos, CA; Goedegebuur, Frits [Vlaardingen, NL; Van Solingen, Pieter [Naaldwijk, NL; Ward, Michael [San Francisco, CA

    2012-06-19

    Described herein are novel gene sequences isolated from Trichoderma reesei. Two genes encoding proteins comprising a cellulose binding domain, one encoding an arabionfuranosidase and one encoding an acetylxylanesterase are described. The sequences, CIP1 and CIP2, contain a cellulose binding domain. These proteins are especially useful in the textile and detergent industry and in pulp and paper industry.

  12. The Tzs protein and exogenous cytokinin affect virulence gene expression and bacterial growth of Agrobacterium tumefaciens.

    Science.gov (United States)

    Hwang, Hau-Hsuan; Yang, Fong-Jhih; Cheng, Tun-Fang; Chen, Yi-Chun; Lee, Ying-Ling; Tsai, Yun-Long; Lai, Erh-Min

    2013-09-01

    The soil phytopathogen Agrobacterium tumefaciens causes crown gall disease in a wide range of plant species. The neoplastic growth at the infection sites is caused by transferring, integrating, and expressing transfer DNA (T-DNA) from A. tumefaciens into plant cells. A trans-zeatin synthesizing (tzs) gene is located in the nopaline-type tumor-inducing plasmid and causes trans-zeatin production in A. tumefaciens. Similar to known virulence (Vir) proteins that are induced by the vir gene inducer acetosyringone (AS) at acidic pH 5.5, Tzs protein is highly induced by AS under this growth condition but also constitutively expressed and moderately upregulated by AS at neutral pH 7.0. We found that the promoter activities and protein levels of several AS-induced vir genes increased in the tzs deletion mutant, a mutant with decreased tumorigenesis and transient transformation efficiencies, in Arabidopsis roots. During AS induction and infection of Arabidopsis roots, the tzs deletion mutant conferred impaired growth, which could be rescued by genetic complementation and supplementing exogenous cytokinin. Exogenous cytokinin also repressed vir promoter activities and Vir protein accumulation in both the wild-type and tzs mutant bacteria with AS induction. Thus, the tzs gene or its product, cytokinin, may be involved in regulating AS-induced vir gene expression and, therefore, affect bacterial growth and virulence during A. tumefaciens infection.

  13. Suppression of PCD-related genes affects salt tolerance in Arabidopsis.

    Science.gov (United States)

    Bahieldin, Ahmed; Alqarni, Dhafer A M; Atef, Ahmed; Gadalla, Nour O; Al-matary, Mohammed; Edris, Sherif; Al-Kordy, Magdy A; Makki, Rania M; Al-Doss, Abdullah A; Sabir, Jamal S M; Mutwakil, Mohammed H Z; El-Domyati, Fotouh M

    2016-01-01

    This work aims at examining a natural exciting phenomenon suggesting that suppression of genes inducing programmed cell death (PCD) might confer tolerance against abiotic stresses in plants. PCD-related genes were induced in tobacco under oxalic acid (OA) treatment (20 mM), and plant cells were characterized to confirm the incidence of PCD. The results indicated that PCD was triggered 24 h after the exposure to OA. Then, RNAs were extracted from tobacco cells 0, 2, 6, 12 and 24 h after treatment for deep sequencing. RNA-Seq analyses were done with a special emphasis to clusters whose PCD-related genes were upregulated after 2 h of OA exposure. Accordingly, 23 tobacco PCD-related genes were knocked down via virus-induced gene silencing (VIGS), whereas our results indicated the influence of five of them on inducing or suppressing PCD. Knockout T-DNA insertion mutants of these five genes in Arabidopsis were tested under salt stress (0, 100, 150, and 200 mM NaCl), and the results indicated that a mutant of an antiapoptotic gene, namely Bax Inhibitor-1 (BI-1), whose VIGS induced PCD in tobacco, was salt sensitive, while a mutant of an apoptotic gene, namely mildew resistance locus O (Mlo), whose VIGS suppressed PCD, was salt tolerant as compared to the WT (Col) control. These data support our hypothesis that retarding PCD-inducing genes can result in higher levels of salt tolerance, while retarding PCD-suppressing genes can result in lower levels of salt tolerance in plants. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  14. Immunoglobulin genes

    National Research Council Canada - National Science Library

    Honjo, T; Alt, F. W; Rabbitts, T. H

    1989-01-01

    ... Cataloguing in Publication Data Immunoglobulin genes 1. Vertebrates. Immunoglobulins 1. Honjo, T. II. Alt, F.W. III. Rabbitts, T.H. 612'. 118223 ISBN 0-12-354865-9 This book is printed on acid-free paper ( T...

  15. Ageing genes

    DEFF Research Database (Denmark)

    Rattan, Suresh

    2018-01-01

    The idea of gerontogenes is in line with the evolutionary explanation of ageing as being an emergent phenomenon as a result of the imperfect maintenance and repair systems. Although evolutionary processes did not select for any specific ageing genes that restrict and determine the lifespan...... of an individual, the term ‘gerontogenes’ primarily refers to any genes that may seem to influence ageing and longevity, without being specifically selected for that role. Such genes can also be called ‘virtual gerontogenes’ by virtue of their indirect influence on the rate and process of ageing. More than 1000...... virtual gerontogenes have been associated with ageing and longevity in model organisms and humans. The ‘real’ genes, which do influence the essential lifespan of a species, and have been selected for in accordance with the evolutionary life history of the species, are known as the longevity assurance...

  16. Revisiting the Balazs thought experiment in the case of a left-handed material: electromagnetic-pulse-induced displacement of a dispersive, dissipative negative-index slab.

    Science.gov (United States)

    Chau, Kenneth J; Lezec, Henri J

    2012-04-23

    We propose a set of postulates to describe the mechanical interaction between a plane-wave electromagnetic pulse and a dispersive, dissipative slab having a refractive index of arbitrary sign. The postulates include the Abraham electromagnetic momentum density, a generalized Lorentz force law, and a model for absorption-driven mass transfer from the pulse to the medium. These opto-mechanical mechanisms are incorporated into a one-dimensional finite-difference time-domain algorithm that solves Maxwell's equations and calculates the instantaneous force densities exerted by the pulse onto the slab, the momentum-per-unit-area of the pulse and slab, and the trajectories of the slab and system center-of-mass. We show that the postulates are consistent with conservation of global energy, momentum, and center-of-mass velocity at all times, even for cases in which the refractive index of the slab is negative or zero. Consistency between the set of postulates and well-established conservation laws reinforces the Abraham momentum density as the one true electromagnetic momentum density and enables, for the first time, identification of the correct form of the electromagnetic mass density distribution and development of an explicit model for mass transfer due to absorption, for the most general case of a ponderable medium that is both dispersive and dissipative. © 2012 Optical Society of America

  17. Enantioselective allylations of selected alpha, beta, gamma, delta-unsaturated aldehydes by axially chiral N,N'-dioxides. Synthesis of the left-hand part of papulacandin D

    Czech Academy of Sciences Publication Activity Database

    Vlašaná, K.; Betík, R.; Valterová, Irena; Nečas, D.; Kotora, M.

    2016-01-01

    Roč. 3, č. 3 (2016), s. 301-305 ISSN 2213-3372 Institutional support: RVO:61388963 Keywords : allylation * aldehyde * Lewis base * asymmetric synthesis * organocatalysis * homoallylic alcohol s Subject RIV: CC - Organic Chemistry

  18. A model balancing cooperation and competition can explain our right-handed world and the dominance of left-handed athletes

    Science.gov (United States)

    Abrams, Daniel M.; Panaggio, Mark J.

    2012-01-01

    An overwhelming majority of humans are right-handed. Numerous explanations for individual handedness have been proposed, but this population-level handedness remains puzzling. Here, we present a novel mathematical model and use it to test the idea that population-level hand preference represents a balance between selective costs and benefits arising from cooperation and competition in human evolutionary history. We use the selection of elite athletes as a test-bed for our evolutionary model and find evidence for the validity of this idea. Our model gives the first quantitative explanation for the distribution of handedness both across and within many professional sports. It also predicts strong lateralization of hand use in social species with limited combative interaction, and elucidates the absence of consistent population-level ‘pawedness’ in some animal species. PMID:22535700

  19. Relationship between the Short-Term Visual Memory and IQ in the Right-and Left-Handed Subjects Trained in Different Educational Programs: I-General Assessment

    Science.gov (United States)

    Yilmaz, Yavuz; Yetkin, Yalçin

    2014-01-01

    The relationship between mean intelligence quotient (IQ), hand preferences and visual memory (VM) were investigated on (N = 612) males and females students trained in different educational programs in viewpoint of laterality. IQ was assessed by cattle's culture Fair intelligence test-A (CCFIT-A). The laterality of the one side of the body was…

  20. Agrobacterium Mediated Transformation of Fld and GUS Genes into Canola for Salinity Stress

    Directory of Open Access Journals (Sweden)

    Niapour, Nazila

    2013-04-01

    Full Text Available Salinity is one of the major abiotic stress which limits wide spread canola cultivation. One way to overcome this problem could be transfection, to produce tolerable species. Cotyledonary and hypocotyls explants obtained from 4 and 7 days old seedling of Elite and RJS003 varieties were utilized in this study. Genetic transformation was implemented through Agrobacterium tumefaciens LBA4404 containing PBI121 plasmid and Agrobacterium tumefaciens C58, LBA4404, AGL0 and EHA 101 strains which contain P6u- ubi- fvt1 construct. The T-DNA region of P6u- Ubi- Fvt1 plasmid included HPT (Hygromycin phosphotransferase plant selectable marker and Fld (flavodoxin gene. PBI121 plasmid had NptII (Neomycin phosphotransferase plant Selectable marker and β-glucuronidase (GUS reporter genes. Transfected explants were analyzed by PCR and histochemical assay for Fld and Gus genes, respectively. Our data indicated that the cotyledonary explants of both cultivars were incompetent to be infected with Fld gens. However, the transformation in Elite hypocotyls explants with Agrobacterium tumefaciens C58 and LBA 4404 strains were confirmed through PCR product and histochemical evaluation for Fld and GUS genes, respectively. Therefore, the result of this manuscript may to certain degree fulfill the endeavor appointed to this oilseed.

  1. Gene Locater

    DEFF Research Database (Denmark)

    Anwar, Muhammad Zohaib; Sehar, Anoosha; Rehman, Inayat-Ur

    2012-01-01

    software's for calculating recombination frequency is mostly limited to the range and flexibility of this type of analysis. GENE LOCATER is a fully customizable program for calculating recombination frequency, written in JAVA. Through an easy-to-use interface, GENE LOCATOR allows users a high degree...... of flexibility in calculating genetic linkage and displaying linkage group. Among other features, this software enables user to identify linkage groups with output visualized graphically. The program calculates interference and coefficient of coincidence with elevated accuracy in sample datasets. AVAILABILITY......: The database is available for free at http://www.moperandib.com....

  2. Gene Function Analysis in the Ubiquitous Human Commensal and Pathogen Malassezia Genus.

    Science.gov (United States)

    Ianiri, Giuseppe; Averette, Anna F; Kingsbury, Joanne M; Heitman, Joseph; Idnurm, Alexander

    2016-11-29

    The genus Malassezia includes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation of Malassezia furfur and Malassezia sympodialis using Agrobacterium tumefaciens delivery of transfer DNA (T-DNA) molecules. These T-DNAs can insert randomly into the genome. In the case of M. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of the ADE2 gene for purine biosynthesis and of the LAC2 gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible in Malassezia species. Species in the genus Malassezia are a defining component of the microbiome of the surface of mammals. They are also associated with a wide range of skin disease symptoms. Many species are difficult to culture in vitro, and although genome sequences are available for the species in this genus, it has not been possible to assess gene function to date. In this study, we pursued a series of possible transformation methods and identified one that allows the introduction of DNA into two species of Malassezia, including the ability to make targeted integrations into the genome such that genes can be deleted. This research opens a new direction in terms of now being able to analyze gene functions in this little understood genus. These tools will contribute to define the mechanisms that lead to the commensalism and pathogenicity in this group of obligate fungi that are predominant on the skin of mammals. Copyright © 2016 Ianiri et al.

  3. Biological activity of the tzs gene of nopaline Agrobacterium tumefaciens GV3101 in plant regeneration and genetic transformation.

    Science.gov (United States)

    Han, Zhao-Fen; Hunter, David M; Sibbald, Susan; Zhang, Ji-Shu; Tian, Lining

    2013-11-01

    Agrobacterium tumefaciens has been widely used in plant genetic transformation. Hormone-encoding genes residing in the T-DNA region have been removed, resulting in disarmed Agrobacterium strains that are used in various transformation experiments. Nopaline Agrobacterium strains, however, carry another hormone gene, trans-zeatin synthesizing (tzs), that codes for trans-zeatin in the virulence region of the tumor-inducing plasmids. We investigated the activity and function of the tzs gene of a nopaline Agrobacterium sp. strain GV3101 in plant in vitro regeneration. Leaf explants of tobacco and Nicotiana benthamiana co-cultured with strain GV3101 exhibited active shoot regeneration in media without added plant growth regulators. On medium without plant growth regulators, transgenic shoots were also induced from explants co-cultured with GV3101 containing a binary vector. Enzyme-linked immunosorbent assay showed that cell-free extracts of Agrobacterium sp. strain GV3101 culture contained the trans-zeatin at 860 ng/liter. Polymerase chain reaction using tzs-specific primers showed that the tzs gene was present in strain GV3101 but not in other Agrobacterium strains. The study showed that the tzs gene in GV3101 was actively expressed, and that trans-zeatin produced in the Agrobacterium strain can promote plant shoot regeneration.

  4. Genetic engineering of cotton with a novel cry2AX1 gene to impart insect resistance against Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Karunamurthy Dhivya

    2016-09-01

    Full Text Available Embryogenic calli of cotton (Coker310 were cocultivated with the Agrobacterium tumefaciens strain LBA4404 harbouring the codon-optimised, chimeric cry2AX1 gene consisting of sequences from cry2Aa and cry2Ac genes isolated from Indian strains of Bacillus thuringiensis. Forty-eight putative transgenic plants were regenerated, and PCR analysis of these plants revealed the presence of the cry2AX1 gene in 40 plants. Southern blot hybridisation analysis of selected transgenic plants confirmed stable T-DNA integration in the genome of transformed plants. The level of Cry2AX1 protein expression in PCR positive plants ranged from 4.9 to 187.5 ng g-1 of fresh tissue. A transgenic cotton event, TP31, expressing the cry2AX1 gene showed insecticidal activity of 56.66 per cent mortality against Helicoverpa armigera in detached leaf disc bioassay. These results indicate that the chimeric cry2AX1 gene expressed in transgenic cotton has insecticidal activity against H. armigera.

  5. Identification and analysis of novel genes involved in gravitropism of Arabidopsis thaliana.

    Science.gov (United States)

    Morita, Miyo T.; Tasaka, Masao; Masatoshi Taniguchi, .

    2012-07-01

    Gravitropism is a continuous control with regard to the orientation and juxtaposition of the various parts of the plant body in response to gravity. In higher plants, the relative directional change of gravity is mainly suscepted in specialized cells called statocytes, followed by signal conversion from physical information into physiological information within the statocytes. We have studied the early process of shoot gravitropism, gravity sensing and signaling process, mainly by molecular genetic approach. In Arabidopsis shoot, statocytes are the endodermal cells. sgr1/scarcrow (scr) and sgr7/short-root (shr) mutants fail to form the endodermis and to respond to gravity in their inflorescence stems. Since both SGR1/SCR and SGR7/SHR are transcriptional factors, at least a subset of their downstream genes can be expected to be involved in gravitropism. In addition, eal1 (endodermal-amyloplast less 1), which exhibits no gravitropism in inflorescence stem but retains ability to form endodermis, is a hypomorphic allele of sgr7/shr. Take advantage of these mutants, we performed DNA microarray analysis and compared gene expression profiles between wild type and the mutants. We found that approx. 40 genes were commonly down-regulated in these mutants and termed them DGE (DOWN-REGULATED GENE IN EAL1) genes. DGE1 has sequence similarity to Oryza sativa LAZY1 that is involved in shoot gravitropism of rice. DGE2 has a short region homologous to DGE1. DTL (DGE TWO-LIKE}) that has 54% identity to DGE2 is found in Arabidopsis genome. All three genes are conserved in angiosperm but have no known functional domains or motifs. We analyzed T-DNA insertion for these genes in single or multiple combinations. In dge1 dge2 dtl triple mutant, gravitropic response of shoot, hypocotyl and root dramatically reduced. Now we are carrying out further physiological and molecular genetic analysis of the triple mutant.

  6. Dissecting a hidden gene duplication: the Arabidopsis thaliana SEC10 locus.

    Directory of Open Access Journals (Sweden)

    Nemanja Vukašinović

    Full Text Available Repetitive sequences present a challenge for genome sequence assembly, and highly similar segmental duplications may disappear from assembled genome sequences. Having found a surprising lack of observable phenotypic deviations and non-Mendelian segregation in Arabidopsis thaliana mutants in SEC10, a gene encoding a core subunit of the exocyst tethering complex, we examined whether this could be explained by a hidden gene duplication. Re-sequencing and manual assembly of the Arabidopsis thaliana SEC10 (At5g12370 locus revealed that this locus, comprising a single gene in the reference genome assembly, indeed contains two paralogous genes in tandem, SEC10a and SEC10b, and that a sequence segment of 7 kb in length is missing from the reference genome sequence. Differences between the two paralogs are concentrated in non-coding regions, while the predicted protein sequences exhibit 99% identity, differing only by substitution of five amino acid residues and an indel of four residues. Both SEC10 genes are expressed, although varying transcript levels suggest differential regulation. Homozygous T-DNA insertion mutants in either paralog exhibit a wild-type phenotype, consistent with proposed extensive functional redundancy of the two genes. By these observations we demonstrate that recently duplicated genes may remain hidden even in well-characterized genomes, such as that of A. thaliana. Moreover, we show that the use of the existing A. thaliana reference genome sequence as a guide for sequence assembly of new Arabidopsis accessions or related species has at least in some cases led to error propagation.

  7. Functional analysis of agrobacterium virulence genes

    NARCIS (Netherlands)

    Niu, Xiaolei

    2013-01-01

    Agrobacterium tumefaciens is a gram-negative soil bacterium that induces plant tumors by transferring a segment of DNA, called T-DNA, into plant cells. Under laboratory conditions, Agrobacterium can also transform many different non-plant organisms such as the yeast Saccharomyces cerevisiae. During

  8. Complementation analysis of Agrobacterium tumefaciens Ti plasmid virB genes by use of a vir promoter expression vector: virB9, virB10, and virB11 are essential virulence genes.

    Science.gov (United States)

    Ward, J E; Dale, E M; Christie, P J; Nester, E W; Binns, A N

    1990-01-01

    The virB gene products of the Agrobacterium tumefaciens tumor-inducing (Ti) plasmid have been proposed to mediate T-DNA transport through the bacterial cell wall into plant cells. Previous genetic analysis of the approximately 9.5-kilobase-pair virB operon has been limited to transposon insertion mutagenesis. Due to the polarity of the transposon insertions, only the last gene in the operon, virB11, is known to provide an essential virulence function. We have now begun to assess the contribution of the other virB genes to virulence. First, several previously isolated Tn3-HoHo1 insertions in the 3' end of the virB operon were precisely mapped by nucleotide sequence analysis. Protein extracts from A. tumefaciens strains harboring these insertions on the Ti plasmid were subjected to immunostaining analysis with VirB4-, VirB10-, and VirB11-specific antisera to determine the effect of the insertion on virB gene expression. In this manner, avirulent mutants containing polar insertions in the virB9 and virB10 genes were identified. To carry out a complementation analysis with these virB mutants, expression vectors were constructed that allow cloned genes to be expressed from the virB promoter in A. tumefaciens. These plasmids were used to express combinations of the virB9, virB10, and virB11 genes in trans in the virB insertion mutants, thereby creating strains lacking only one of these three virB gene products. Virulence assays on Kalanchoe daigremontiana demonstrated that in addition to virB11, the virB9 and virB10 genes are required for tumorigenicity. Images PMID:2203743

  9. A gene co-expression network predicts functional genes controlling the re-establishment of desiccation tolerance in germinated Arabidopsis thaliana seeds.

    Science.gov (United States)

    Costa, Maria Cecília D; Righetti, Karima; Nijveen, Harm; Yazdanpanah, Farzaneh; Ligterink, Wilco; Buitink, Julia; Hilhorst, Henk W M

    2015-08-01

    During re-establishment of desiccation tolerance (DT), early events promote initial protection and growth arrest, while late events promote stress adaptation and contribute to survival in the dry state. Mature seeds of Arabidopsis thaliana are desiccation tolerant, but they lose desiccation tolerance (DT) while progressing to germination. Yet, there is a small developmental window during which DT can be rescued by treatment with abscisic acid (ABA). To gain temporal resolution and identify relevant genes in this process, data from a time series of microarrays were used to build a gene co-expression network. The network has two regions, namely early response (ER) and late response (LR). Genes in the ER region are related to biological processes, such as dormancy, acquisition of DT and drought, amplification of signals, growth arrest and induction of protection mechanisms (such as LEA proteins). Genes in the LR region lead to inhibition of photosynthesis and primary metabolism, promote adaptation to stress conditions and contribute to seed longevity. Phenotyping of 12 hubs in relation to re-establishment of DT with T-DNA insertion lines indicated a significant increase in the ability to re-establish DT compared with the wild-type in the lines cbsx4, at3g53040 and at4g25580, suggesting the operation of redundant and compensatory mechanisms. Moreover, we show that re-establishment of DT by polyethylene glycol and ABA occurs through partially overlapping mechanisms. Our data confirm that co-expression network analysis is a valid approach to examine data from time series of transcriptome analysis, as it provides promising insights into biologically relevant relations that help to generate new information about the roles of certain genes for DT.

  10. pSiM24 is a novel versatile gene expression vector for transient assays as well as stable expression of foreign genes in plants.

    Directory of Open Access Journals (Sweden)

    Dipak Kumar Sahoo

    Full Text Available We have constructed a small and highly efficient binary Ti vector pSiM24 for plant transformation with maximum efficacy. In the pSiM24 vector, the size of the backbone of the early binary vector pKYLXM24 (GenBank Accession No. HM036220; a derivative of pKYLX71 was reduced from 12.8 kb to 7.1 kb. The binary vector pSiM24 is composed of the following genetic elements: left and right T-DNA borders, a modified full-length transcript promoter (M24 of Mirabilis mosaic virus with duplicated enhancer domains, three multiple cloning sites, a 3'rbcsE9 terminator, replication functions for Escherichia coli (ColE1 and Agrobacterium tumefaciens (pRK2-OriV and the replicase trfA gene, selectable marker genes for kanamycin resistance (nptII and ampicillin resistance (bla. The pSiM24 plasmid offers a wide selection of cloning sites, high copy numbers in E. coli and a high cloning capacity for easily manipulating different genetic elements. It has been fully tested in transferring transgenes such as green fluorescent protein (GFP and β-glucuronidase (GUS both transiently (agro-infiltration, protoplast electroporation and biolistic and stably in plant systems (Arabidopsis and tobacco using both agrobacterium-mediated transformation and biolistic procedures. Not only reporter genes, several other introduced genes were also effectively expressed using pSiM24 expression vector. Hence, the pSiM24 vector would be useful for various plant biotechnological applications. In addition, the pSiM24 plasmid can act as a platform for other applications, such as gene expression studies and different promoter expressional analyses.

  11. Genes and Hearing Loss

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Genes and Hearing Loss Genes and Hearing Loss Patient ... mutation may only have dystopia canthorum. How Do Genes Work? Genes are a road map for the ...

  12. Identification of Arabidopsis candidate genes in response to biotic and abiotic stresses using comparative microarrays.

    Directory of Open Access Journals (Sweden)

    Arjun Sham

    Full Text Available Plants have evolved with intricate mechanisms to cope with multiple environmental stresses. To adapt with biotic and abiotic stresses, plant responses involve changes at the cellular and molecular levels. The current study was designed to investigate the effects of combinations of different environmental stresses on the transcriptome level of Arabidopsis genome using public microarray databases. We investigated the role of cyclopentenones in mediating plant responses to environmental stress through TGA (TGACG motif-binding factor transcription factor, independently from jasmonic acid. Candidate genes were identified by comparing plants inoculated with Botrytis cinerea or treated with heat, salt or osmotic stress with non-inoculated or non-treated tissues. About 2.5% heat-, 19% salinity- and 41% osmotic stress-induced genes were commonly upregulated by B. cinerea-treatment; and 7.6%, 19% and 48% of genes were commonly downregulated by B. cinerea-treatment, respectively. Our results indicate that plant responses to biotic and abiotic stresses are mediated by several common regulatory genes. Comparisons between transcriptome data from Arabidopsis stressed-plants support our hypothesis that some molecular and biological processes involved in biotic and abiotic stress response are conserved. Thirteen of the common regulated genes to abiotic and biotic stresses were studied in detail to determine their role in plant resistance to B. cinerea. Moreover, a T-DNA insertion mutant of the Responsive to Dehydration gene (rd20, encoding for a member of the caleosin (lipid surface protein family, showed an enhanced sensitivity to B. cinerea infection and drought. Overall, the overlapping of plant responses to abiotic and biotic stresses, coupled with the sensitivity of the rd20 mutant, may provide new interesting programs for increased plant resistance to multiple environmental stresses, and ultimately increases its chances to survive. Future research

  13. An Arabidopsis NPR1-like gene, NPR4, is required for disease resistance.

    Science.gov (United States)

    Liu, Guosheng; Holub, Eric B; Alonso, Jose M; Ecker, Joseph R; Fobert, Pierre R

    2005-01-01

    The Arabidopsis genome contains six NPR1-related genes. Given the pivotal role played by NPR1 in controlling salicylic acid (SA)-mediated gene expression and disease resistance, functional characterization of other family members appears to be justified. Reverse genetics was used to analyze the role of one NPR1-like gene, which we called NPR4. The NPR4 protein shares 36% identity with NPR1 and interacts with the same spectrum of TGA transcription factors in yeast two-hybrid assays. Plants with T-DNA insertions in NPR4 are more susceptible to the virulent bacterial pathogen Pseudomonas syringe pv. tomato DC3000. This phenotype is complemented by expression of the wild type NPR4 coding region. As determined by the parasite reproduction, the npr4-1 mutant is more susceptible to the fungal pathogen Erysiphe cichoracearum, but does not differ markedly from wild type in its interaction with virulent and avirulent strains of the oomycete Peronospora parasitica. In leaves of wild-type plants, NPR4 mRNA levels increase following pathogen challenge or SA treatment, and decrease rapidly following methyl jasmonic acid (MeJA) treatment. Transcripts of the pathogenesis-related (PR) genes PR-1, PR-2, and PR-5 are only marginally reduced in the npr4-1 mutant following pathogen challenge or SA treatment. This reduction of PR gene expression is more pronounced when leaves are challenged with the bacterial pathogen following SA treatment. Expression of the jasmonic acid-dependent pathway marker gene PDF1.2 is compromised in npr4-1 leaves following application of MeJA or a combination of SA and MeJA. These results indicate that NPR4 is required for basal defense against pathogens, and that it may be implicated in the cross-talk between the SA- and JA-dependent signaling pathways.

  14. Identification of Arabidopsis candidate genes in response to biotic and abiotic stresses using comparative microarrays.

    Science.gov (United States)

    Sham, Arjun; Moustafa, Khaled; Al-Ameri, Salma; Al-Azzawi, Ahmed; Iratni, Rabah; AbuQamar, Synan

    2015-01-01

    Plants have evolved with intricate mechanisms to cope with multiple environmental stresses. To adapt with biotic and abiotic stresses, plant responses involve changes at the cellular and molecular levels. The current study was designed to investigate the effects of combinations of different environmental stresses on the transcriptome level of Arabidopsis genome using public microarray databases. We investigated the role of cyclopentenones in mediating plant responses to environmental stress through TGA (TGACG motif-binding factor) transcription factor, independently from jasmonic acid. Candidate genes were identified by comparing plants inoculated with Botrytis cinerea or treated with heat, salt or osmotic stress with non-inoculated or non-treated tissues. About 2.5% heat-, 19% salinity- and 41% osmotic stress-induced genes were commonly upregulated by B. cinerea-treatment; and 7.6%, 19% and 48% of genes were commonly downregulated by B. cinerea-treatment, respectively. Our results indicate that plant responses to biotic and abiotic stresses are mediated by several common regulatory genes. Comparisons between transcriptome data from Arabidopsis stressed-plants support our hypothesis that some molecular and biological processes involved in biotic and abiotic stress response are conserved. Thirteen of the common regulated genes to abiotic and biotic stresses were studied in detail to determine their role in plant resistance to B. cinerea. Moreover, a T-DNA insertion mutant of the Responsive to Dehydration gene (rd20), encoding for a member of the caleosin (lipid surface protein) family, showed an enhanced sensitivity to B. cinerea infection and drought. Overall, the overlapping of plant responses to abiotic and biotic stresses, coupled with the sensitivity of the rd20 mutant, may provide new interesting programs for increased plant resistance to multiple environmental stresses, and ultimately increases its chances to survive. Future research directions towards a

  15. CRISPR/Cas9-induced Targeted Mutagenesis and Gene Replacement to Generate Long-shelf Life Tomato Lines.

    Science.gov (United States)

    Yu, Qing-Hui; Wang, Baike; Li, Ning; Tang, Yaping; Yang, Shengbao; Yang, Tao; Xu, Juan; Guo, Chunmiao; Yan, Peng; Wang, Qiang; Asmutola, Patiguli

    2017-09-19

    Quickly and precisely gain genetically enhanced breeding elites with value-adding performance traits is desired by the crop breeders all the time. The present of gene editing technologies, especially the CRISPR/Cas9 system with the capacities of efficiency, versatility and multiplexing provides a reasonable expectation towards breeding goals. For exploiting possible application to accelerate the speed of process at breeding by CRISPR/Cas9 technology, in this study, the Agrobacterium tumefaciens-mediated CRISPR/Cas9 system transformation method was used for obtaining tomato ALC gene mutagenesis and replacement, in absence and presence of the homologous repair template. The average mutation frequency (72.73%) and low replacement efficiency (7.69%) were achieved in T 0 transgenic plants respectively. None of homozygous mutation was detected in T 0 transgenic plants, but one plant carry the heterozygous genes (Cas9/*-ALC/alc) was stably transmitted to T 1 generations for segregation and genotyping. Finally, the desired alc homozygous mutants without T-DNA insertion (*/*-alc/alc) in T 1 generations were acquired and further confirmed by genotype and phenotype characterization, with highlight of excellent storage performance, thus the recessive homozygous breeding elites with the character of long-shelf life were generated. Our results support that CRISPR/Cas9-induced gene replacement via HDR provides a valuable method for breeding elite innovation in tomato.

  16. Loss-of-function mutations in chitin responsive genes show increased susceptibility to the powdery mildew pathogen Erysiphe cichoracearum.

    Science.gov (United States)

    Ramonell, Katrina; Berrocal-Lobo, Marta; Koh, Serry; Wan, Jinrong; Edwards, Herb; Stacey, Gary; Somerville, Shauna

    2005-06-01

    Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. The expression patterns elicited by the chito-octamer and hydrolyzed chitin were similar. Microarray expression profiles for several genes were verified via northern analysis or quantitative reverse transcription-PCR. We characterized T-DNA insertion mutants for nine chito-oligomer responsive genes. Three of the mutants were more susceptible to the fungal pathogen, powdery mildew, than wild type as measured by conidiophore production. These three mutants included mutants of genes for two disease resistance-like proteins and a putative E3 ligase. The isolation of loss-of-function mutants with enhanced disease susceptibility provides direct evidence that the chito-octamer is an important oligosaccharide elicitor of plant defenses. Also, this study demonstrates the value of microarray data for identifying new components of uncharacterized signaling pathways.

  17. Gene expression and gene therapy imaging

    International Nuclear Information System (INIS)

    Rome, Claire; Couillaud, Franck; Moonen, Chrit T.W.

    2007-01-01

    The fast growing field of molecular imaging has achieved major advances in imaging gene expression, an important element of gene therapy. Gene expression imaging is based on specific probes or contrast agents that allow either direct or indirect spatio-temporal evaluation of gene expression. Direct evaluation is possible with, for example, contrast agents that bind directly to a specific target (e.g., receptor). Indirect evaluation may be achieved by using specific substrate probes for a target enzyme. The use of marker genes, also called reporter genes, is an essential element of MI approaches for gene expression in gene therapy. The marker gene may not have a therapeutic role itself, but by coupling the marker gene to a therapeutic gene, expression of the marker gene reports on the expression of the therapeutic gene. Nuclear medicine and optical approaches are highly sensitive (detection of probes in the picomolar range), whereas MRI and ultrasound imaging are less sensitive and require amplification techniques and/or accumulation of contrast agents in enlarged contrast particles. Recently developed MI techniques are particularly relevant for gene therapy. Amongst these are the possibility to track gene therapy vectors such as stem cells, and the techniques that allow spatiotemporal control of gene expression by non-invasive heating (with MRI guided focused ultrasound) and the use of temperature sensitive promoters. (orig.)

  18. Imaging reporter gene for monitoring gene therapy

    International Nuclear Information System (INIS)

    Beco, V. de; Baillet, G.; Tamgac, F.; Tofighi, M.; Weinmann, P.; Vergote, J.; Moretti, J.L.; Tamgac, G.

    2002-01-01

    Scintigraphic images can be obtained to document gene function at cellular level. This approach is presented here and the use of a reporter gene to monitor gene therapy is described. Two main ways are presented: either the use of a reporter gene coding for an enzyme the action of which will be monitored by radiolabeled pro-drug, or a cellular receptor gene, the action of which is documented by a radio labeled cognate receptor ligand. (author)

  19. Whole-genome resequencing and transcriptomic analysis to identify genes involved in leaf-color diversity in ornamental rice plants.

    Directory of Open Access Journals (Sweden)

    Chang-Kug Kim

    Full Text Available Rice field art is a large-scale art form in which people design rice fields using various kinds of ornamental rice plants with different leaf colors. Leaf color-related genes play an important role in the study of chlorophyll biosynthesis, chloroplast structure and function, and anthocyanin biosynthesis. Despite the role of different metabolites in the traditional relationship between leaf and color, comprehensive color-specific metabolite studies of ornamental rice have been limited. We performed whole-genome resequencing and transcriptomic analysis of regulatory patterns and genetic diversity among different rice cultivars to discover new genetic mechanisms that promote enhanced levels of various leaf colors. We resequenced the genomes of 10 rice leaf-color accessions to an average of 40× reads depth and >95% coverage and performed 30 RNA-seq experiments using the 10 rice accessions sampled at three developmental stages. The sequencing results yielded a total of 1,814 × 106 reads and identified an average of 713,114 SNPs per rice accession. Based on our analysis of the DNA variation and gene expression, we selected 47 candidate genes. We used an integrated analysis of the whole-genome resequencing data and the RNA-seq data to divide the candidate genes into two groups: genes related to macronutrient (i.e., magnesium and sulfur transport and genes related to flavonoid pathways, including anthocyanidin biosynthesis. We verified the candidate genes with quantitative real-time PCR using transgenic T-DNA insertion mutants. Our study demonstrates the potential of integrated screening methods combined with genetic-variation and transcriptomic data to isolate genes involved in complex biosynthetic networks and pathways.

  20. Discrete redox signaling pathways regulate photosynthetic light-harvesting and chloroplast gene transcription.

    Directory of Open Access Journals (Sweden)

    John F Allen

    Full Text Available In photosynthesis in chloroplasts, two related regulatory processes balance the actions of photosystems I and II. These processes are short-term, post-translational redistribution of light-harvesting capacity, and long-term adjustment of photosystem stoichiometry initiated by control of chloroplast DNA transcription. Both responses are initiated by changes in the redox state of the electron carrier, plastoquinone, which connects the two photosystems. Chloroplast Sensor Kinase (CSK is a regulator of transcription of chloroplast genes for reaction centres of the two photosystems, and a sensor of plastoquinone redox state. We asked whether CSK is also involved in regulation of absorbed light energy distribution by phosphorylation of light-harvesting complex II (LHC II. Chloroplast thylakoid membranes isolated from a CSK T-DNA insertion mutant and from wild-type Arabidopsis thaliana exhibit similar light- and redox-induced (32P-labelling of LHC II and changes in 77 K chlorophyll fluorescence emission spectra, while room-temperature chlorophyll fluorescence emission transients from Arabidopsis leaves are perturbed by inactivation of CSK. The results indicate indirect, pleiotropic effects of reaction centre gene transcription on regulation of photosynthetic light-harvesting in vivo. A single, direct redox signal is transmitted separately to discrete transcriptional and post-translational branches of an integrated cytoplasmic regulatory system.

  1. One-step Agrobacterium mediated transformation of eight genes essential for rhizobium symbiotic signaling using the novel binary vector system pHUGE.

    Directory of Open Access Journals (Sweden)

    Andreas Untergasser

    Full Text Available Advancement in plant research is becoming impaired by the fact that the transfer of multiple genes is difficult to achieve. Here we present a new binary vector for Agrobacterium tumefaciens mediated transformation, pHUGE-Red, in concert with a cloning strategy suited for the transfer of up to nine genes at once. This vector enables modular cloning of large DNA fragments by employing Gateway technology and contains DsRED1 as visual selection marker. Furthermore, an R/Rs inducible recombination system was included allowing subsequent removal of the selection markers in the newly generated transgenic plants. We show the successful use of pHUGE-Red by transferring eight genes essential for Medicago truncatula to establish a symbiosis with rhizobia bacteria as one 74 kb T-DNA into four non-leguminous species; strawberry, poplar, tomato and tobacco. We provide evidence that all transgenes are expressed in the root tissue of the non-legumes. Visual control during the transformation process and subsequent marker gene removal makes the pHUGE-Red vector an excellent tool for the efficient transfer of multiple genes.

  2. How Genes Evolve

    Indian Academy of Sciences (India)

    which they are found e.g. the evolution of the gene coding for the protein cytochrome-C which is part ofthe respiratory apparatus. On the contrary, paralogous genes are descendants of a duplicated gene. Paralogous genes therefore evolve within the same species as well as in different species e.g. genes coding for alpha ...

  3. Overexpressing the Multiple-Stress Responsive Gene At1g74450 Reduces Plant Height and Male Fertility in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Anne M Visscher

    Full Text Available A subset of genes in Arabidopsis thaliana is known to be up-regulated in response to a wide range of different environmental stress factors. However, not all of these genes are characterized as yet with respect to their functions. In this study, we used transgenic knockout, overexpression and reporter gene approaches to try to elucidate the biological roles of five unknown multiple-stress responsive genes in Arabidopsis. The selected genes have the following locus identifiers: At1g18740, At1g74450, At4g27652, At4g29780 and At5g12010. Firstly, T-DNA insertion knockout lines were identified for each locus and screened for altered phenotypes. None of the lines were found to be visually different from wildtype Col-0. Secondly, 35S-driven overexpression lines were generated for each open reading frame. Analysis of these transgenic lines showed altered phenotypes for lines overexpressing the At1g74450 ORF. Plants overexpressing the multiple-stress responsive gene At1g74450 are stunted in height and have reduced male fertility. Alexander staining of anthers from flowers at developmental stage 12-13 showed either an absence or a reduction in viable pollen compared to wildtype Col-0 and At1g74450 knockout lines. Interestingly, the effects of stress on crop productivity are most severe at developmental stages such as male gametophyte development. However, the molecular factors and regulatory networks underlying environmental stress-induced male gametophytic alterations are still largely unknown. Our results indicate that the At1g74450 gene provides a potential link between multiple environmental stresses, plant height and pollen development. In addition, ruthenium red staining analysis showed that At1g74450 may affect the composition of the inner seed coat mucilage layer. Finally, C-terminal GFP fusion proteins for At1g74450 were shown to localise to the cytosol.

  4. Identification and characterization of ANAC042, a transcription factor family gene involved in the regulation of camalexin biosynthesis in Arabidopsis.

    Science.gov (United States)

    Saga, Hirohisa; Ogawa, Takumi; Kai, Kosuke; Suzuki, Hideyuki; Ogata, Yoshiyuki; Sakurai, Nozomu; Shibata, Daisuke; Ohta, Daisaku

    2012-05-01

    Camalexin is the major phytoalexin in Arabidopsis. An almost complete set of camalexin biosynthetic enzymes have been elucidated but only limited information is available regarding molecular mechanisms regulating camalexin biosynthesis. Here, we demonstrate that ANAC042, a member of the NAM, ATAF1/2, and CUC2 (NAC) transcription factor family genes, is involved in camalexin biosynthesis induction. T-DNA insertion mutants of ANAC042 failed to accumulate camalexin at the levels achieved in the wild type, and were highly susceptible to Alternaria brassicicola infection. The camalexin biosynthetic genes CYP71A12, CYP71A13, and CYP71B15/PAD3 were not fully induced in the mutants, indicating that the camalexin defects were at least partly a result of reduced expression levels of these P450 genes. β-Glucuronidase (GUS)-reporter assays demonstrated tissue-specific induction of ANAC042 in response to differential pathogen infections. Bacterial flagellin (Flg22) induced ANAC042 expression in the root-elongation zone, the camalexin biosynthetic site, and the induction was abolished in the presence of either a general kinase inhibitor (K252a), a Ca(2+)-chelator (BAPTA), or methyl jasmonate. The GUS-reporter assay revealed repression of the Flg22-dependent ANAC042 expression in the ethylene-insensitive ein2-1 background but not in sid2-2 plants defective for salicylic acid biosynthesis. We discuss ANAC042 as a key transcription factor involved in previously unknown regulatory mechanisms to induce phytoalexin biosynthesis in Arabidopsis.

  5. AtCSLD3, a cellulose synthase-like gene important for root hair growth in arabidopsis.

    Science.gov (United States)

    Wang, X; Cnops, G; Vanderhaeghen, R; De Block, S; Van Montagu, M; Van Lijsebettens, M

    2001-06-01

    A member of the cellulose synthase-like (subfamily D) gene family of Arabidopsis, AtCSLD3, has been identified by T-DNA tagging. The analysis of the corresponding mutant, csld3-1, showed that the AtCSLD3 gene plays a role in root hair growth in plants. Root hairs grow in phases: First a bulge is formed and then the root hair elongates by polarized growth, the so-called "tip growth." In the mutant, root hairs were initiated at the correct position and grew into a bulge, but their elongation was severely reduced. The tips of the csld3-1 root hairs easily leaked cytoplasm, indicating that the tensile strength of the cell wall had changed at the site of the tip. Based on the mutant phenotype and the functional conservation between CSLD3 and the genuine cellulose synthase proteins, we hypothesized that the CSLD3 protein is essential for the synthesis of polymers for the fast-growing primary cell wall at the root hair tip. The distinct mutant phenotype and the ubiquitous expression pattern indicate that the CSLD3 gene product is only limiting at the zone of the root hair tip, suggesting particular physical properties of the cell wall at this specific site of the root hair cell.

  6. Identificación y caracterización molecular de secuencias homólogas al T-DNA del plásmido Ti de Agrobacterium spp. insertados en el genoma de Ipomoea batatas (L.) Lam “camote” y especies silvestres relacionadas

    OpenAIRE

    Quispe Huamanquispe, Dora Graciela

    2012-01-01

    La transferencia horizontal de genes (HGT) ha sido uno de los temas más debatidos en biología evolutiva durante las últimas dos décadas debido a que esto ha desafiado considerablemente nuestra visión acerca de la historia evolutiva de los genomas. Este tipo de eventos no solo se restringe a bacterias, sino también parece tener un gran impacto en todos los grupos de organismos, incluyendo plantas y animales superiores, al menos en las primeras etapas de su evolución. Considerando la importanci...

  7. Imaging gene expression in gene therapy

    International Nuclear Information System (INIS)

    Wiebe, Leonard I.

    1997-01-01

    Full text. Gene therapy can be used to introduce new genes, or to supplement the function of indigenous genes. At the present time, however, there is non-invasive test to demonstrate efficacy of the gene transfer and expression processes. It has been postulated that scintigraphic imaging can offer unique information on both the site at which the transferred gene is expressed, and the degree of expression, both of which are critical issue for safety and clinical efficacy. Many current studies are based on 'suicide gene therapy' of cancer. Cells modified to express these genes commit metabolic suicide in the presence of an enzyme encoded by the transferred gene and a specifically-convertible pro drug. Pro drug metabolism can lead to selective metabolic trapping, required for scintigraphy. Herpes simplex virus type-1 thymidine kinase (H S V-1 t k + ) has been use for 'suicide' in vivo tumor gene therapy. It has been proposed that radiolabelled nucleosides can be used as radiopharmaceuticals to detect H S V-1 t k + gene expression where the H S V-1 t k + gene serves a reporter or therapeutic function. Animal gene therapy models have been studied using purine-([ 18 F]F H P G; [ 18 F]-A C V), and pyrimidine- ([ 123 / 131 I]I V R F U; [ 124 / 131I ]) antiviral nucleosides. Principles of gene therapy and gene therapy imaging will be reviewed and experimental data for [ 123 / 131I ]I V R F U imaging with the H S V-1 t k + reporter gene will be presented

  8. High-efficiency gene targeting in hexaploid wheat using DNA replicons and CRISPR/Cas9.

    Science.gov (United States)

    Gil-Humanes, Javier; Wang, Yanpeng; Liang, Zhen; Shan, Qiwei; Ozuna, Carmen V; Sánchez-León, Susana; Baltes, Nicholas J; Starker, Colby; Barro, Francisco; Gao, Caixia; Voytas, Daniel F

    2017-03-01

    The ability to edit plant genomes through gene targeting (GT) requires efficient methods to deliver both sequence-specific nucleases (SSNs) and repair templates to plant cells. This is typically achieved using Agrobacterium T-DNA, biolistics or by stably integrating nuclease-encoding cassettes and repair templates into the plant genome. In dicotyledonous plants, such as Nicotinana tabacum (tobacco) and Solanum lycopersicum (tomato), greater than 10-fold enhancements in GT frequencies have been achieved using DNA virus-based replicons. These replicons transiently amplify to high copy numbers in plant cells to deliver abundant SSNs and repair templates to achieve targeted gene modification. In the present work, we developed a replicon-based system for genome engineering of cereal crops using a deconstructed version of the wheat dwarf virus (WDV). In wheat cells, the replicons achieve a 110-fold increase in expression of a reporter gene relative to non-replicating controls. Furthermore, replicons carrying CRISPR/Cas9 nucleases and repair templates achieved GT at an endogenous ubiquitin locus at frequencies 12-fold greater than non-viral delivery methods. The use of a strong promoter to express Cas9 was critical to attain these high GT frequencies. We also demonstrate gene-targeted integration by homologous recombination (HR) in all three of the homoeoalleles (A, B and D) of the hexaploid wheat genome, and we show that with the WDV replicons, multiplexed GT within the same wheat cell can be achieved at frequencies of ~1%. In conclusion, high frequencies of GT using WDV-based DNA replicons will make it possible to edit complex cereal genomes without the need to integrate GT reagents into the genome. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  9. Root-specific expression of opine genes and opine accumulation in some cultivars of the naturally occurring genetically modified organism Nicotiana tabacum.

    Science.gov (United States)

    Chen, Ke; de Borne, François Dorlhac; Julio, Emilie; Obszynski, Julie; Pale, Patrick; Otten, Léon

    2016-08-01

    Previous studies have shown that Nicotiana tabacum contains three Agrobacterium-derived T-DNA sequences inherited from its paternal ancestor Nicotiana tomentosiformis. Among these, the TB locus carries an intact mannopine synthase 2' gene (TB-mas2'). This gene is similar to the Agrobacterium rhizogenes A4-mas2' gene that encodes the synthesis of the Amadori compound deoxyfructosyl-glutamine (DFG or santhopine). In this study we show that TB-mas2' is expressed at very low levels in N. tomentosiformis and in most N. tabacum cultivars; however, some cultivars show high TB-mas2' expression levels. The TB-mas2' promoter sequences of low- and high-expressing cultivars are identical. The low/high level of expression segregates as a single Mendelian factor in a cross between a low- and a high-expression cultivar. pTB-mas2'-GUS and pA4-mas2'-GUS reporter genes were stably introduced in N. benthamiana. Both were mainly expressed in the root expansion zone and leaf vasculature. Roots of tobacco cultivars with high TB-mas2' expression contain detectable levels of DFG. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  10. Loss-of-Function Mutations in Chitin Responsive Genes Show Increased Susceptibility to the Powdery Mildew Pathogen Erysiphe cichoracearum1[w

    Science.gov (United States)

    Ramonell, Katrina; Berrocal-Lobo, Marta; Koh, Serry; Wan, Jinrong; Edwards, Herb; Stacey, Gary; Somerville, Shauna

    2005-01-01

    Chitin is a major component of fungal walls and insect exoskeletons. Plants produce chitinases upon pathogen attack and chito-oligomers induce defense responses in plants, though the exact mechanism behind this response is unknown. Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis (Arabidopsis thaliana) seedlings to chito-octamers and hydrolyzed chitin after 30 min of treatment. The expression patterns elicited by the chito-octamer and hydrolyzed chitin were similar. Microarray expression profiles for several genes were verified via northern analysis or quantitative reverse transcription-PCR. We characterized T-DNA insertion mutants for nine chito-oligomer responsive genes. Three of the mutants were more susceptible to the fungal pathogen, powdery mildew, than wild type as measured by conidiophore production. These three mutants included mutants of genes for two disease resistance-like proteins and a putative E3 ligase. The isolation of loss-of-function mutants with enhanced disease susceptibility provides direct evidence that the chito-octamer is an important oligosaccharide elicitor of plant defenses. Also, this study demonstrates the value of microarray data for identifying new components of uncharacterized signaling pathways. PMID:15923325

  11. A Genetic Screen for Pathogenicity Genes in the Hemibiotrophic Fungus Colletotrichum higginsianum Identifies the Plasma Membrane Proton Pump Pma2 Required for Host Penetration.

    Directory of Open Access Journals (Sweden)

    Martin Korn

    Full Text Available We used insertional mutagenesis by Agrobacterium tumefaciens mediated transformation (ATMT to isolate pathogenicity mutants of Colletotrichum higginsianum. From a collection of 7200 insertion mutants we isolated 75 mutants with reduced symptoms. 19 of these were affected in host penetration, while 17 were affected in later stages of infection, like switching to necrotrophic growth. For 16 mutants the location of T-DNA insertions could be identified by PCR. A potential plasma membrane H(+-ATPase Pma2 was targeted in five independent insertion mutants. We genetically inactivated the Ku80 component of the non-homologous end-joining pathway in C. higginsianum to establish an efficient gene knockout protocol. Chpma2 deletion mutants generated by homologous recombination in the ΔChku80 background form fully melanized appressoria but entirely fail to penetrate the host tissue and are non-pathogenic. The ChPMA2 gene is induced upon appressoria formation and infection of A. thaliana. Pma2 activity is not important for vegetative growth of saprophytically growing mycelium, since the mutant shows no growth penalty under these conditions. Colletotrichum higginsianum codes for a closely related gene (ChPMA1, which is highly expressed under most growth conditions. ChPMA1 is more similar to the homologous yeast genes for plasma membrane pumps. We propose that expression of a specific proton pump early during infection may be common to many appressoria forming fungal pathogens as we found ChPMA2 orthologs in several plant pathogenic fungi.

  12. Gene cluster statistics with gene families.

    Science.gov (United States)

    Raghupathy, Narayanan; Durand, Dannie

    2009-05-01

    Identifying genomic regions that descended from a common ancestor is important for understanding the function and evolution of genomes. In distantly related genomes, clusters of homologous gene pairs are evidence of candidate homologous regions. Demonstrating the statistical significance of such "gene clusters" is an essential component of comparative genomic analyses. However, currently there are no practical statistical tests for gene clusters that model the influence of the number of homologs in each gene family on cluster significance. In this work, we demonstrate empirically that failure to incorporate gene family size in gene cluster statistics results in overestimation of significance, leading to incorrect conclusions. We further present novel analytical methods for estimating gene cluster significance that take gene family size into account. Our methods do not require complete genome data and are suitable for testing individual clusters found in local regions, such as contigs in an unfinished assembly. We consider pairs of regions drawn from the same genome (paralogous clusters), as well as regions drawn from two different genomes (orthologous clusters). Determining cluster significance under general models of gene family size is computationally intractable. By assuming that all gene families are of equal size, we obtain analytical expressions that allow fast approximation of cluster probabilities. We evaluate the accuracy of this approximation by comparing the resulting gene cluster probabilities with cluster probabilities obtained by simulating a realistic, power-law distributed model of gene family size, with parameters inferred from genomic data. Surprisingly, despite the simplicity of the underlying assumption, our method accurately approximates the true cluster probabilities. It slightly overestimates these probabilities, yielding a conservative test. We present additional simulation results indicating the best choice of parameter values for data

  13. Essential Bacillus subtilis genes

    NARCIS (Netherlands)

    Kobayashi, K.; Ehrlich, S.D.; Albertini, A.; Amati, G.; Andersen, K.K.; Arnaud, M.; Asai, K.; Ashikaga, S.; Aymerich, S.; Bessieres, P.; Boland, F.; Brignell, S.C.; Bron, S; Bunai, K.; Chapuis, J; Christiansen, L.C.; Danchin, A.; Debarbouille, M.; Dervyn, E.; Deuerling, E.; Devine, K.; Devine, S.K.; Dreesen, O.; Errington, J.; Fillinger, S.; Foster, S.J.; Fujita, Y.; Galizzi, A.; Gardan, R.; Eschevins, C.; Fukushima, T.; Haga, K.; Harwood, C.R; Hecker, M.; Hosoya, D.; Hullo, M.F.; Kakeshita, H.; Karamata, D.; Kasahara, Y.; Kawamura, F.; Koga, K.; Koski, P.; Kuwana, R.; Imamura, D.; Ishimaru, M.; Ishikawa, S.; Ishio, I.; Le Coq, D.; Masson, A.; Mauel, C.; Meima, Roelf; Mellado, R.P.; Moir, A.; Moriya, S.; Nagakawa, E.; Nanamiya, H.; Nakai, S.; Nygaard, P.; Ogura, M.; Ohanan, T.; O'Reilly, M.; O'Rourke, M.; Pragai, Z.; Pooley, H.M.; Rapoport, G.; Rawlins, J.P.; Rivas, L.A.; Rivolta, C.; Sadaie, A.; Sadaie, Y.; Sarvas, M; Sato, T.; Saxild, H.H.; Scanlan, E.; Schumann, W; Seegers, J.F. M. L.; Sekiguchi, J.; Sekowska, A.; Seror, S.J.; Simon, M.; Stragier, P.; Studer, R.; Takamatsu, H.; Tanaka, T.; Takeuchi, M.; Thomaides, H.B.; Vagner, V.; van Dijl, J.M.; Watabe, K.; Wipat, A; Yamamoto, H.; Yamamoto, M.; Yamamoto, Y.; Yamane, K.; Yata, K.; Yoshida, K.; Yoshikawa, H.; Zuber, U.; Ogasawara, N.; Ishio, [No Value

    2003-01-01

    To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximate to4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were

  14. Silence of the Genes

    Indian Academy of Sciences (India)

    Srimath

    The human genome codes for ~35,000 genes and all these genes are not expressed in every cell. The time and site of gene expression is very precisely regulated. In any cell, only. Silence of the Genes. 2006 Nobel Prize in Physiology or Medicine. Utpal Nath and Saumitra Das. Keywords. RNA interference, siRNA,.

  15. Gene Ontology annotation of the rice blast fungus, Magnaporthe oryzae

    Directory of Open Access Journals (Sweden)

    Deng Jixin

    2009-02-01

    Full Text Available Abstract Background Magnaporthe oryzae, the causal agent of blast disease of rice, is the most destructive disease of rice worldwide. The genome of this fungal pathogen has been sequenced and an automated annotation has recently been updated to Version 6 http://www.broad.mit.edu/annotation/genome/magnaporthe_grisea/MultiDownloads.html. However, a comprehensive manual curation remains to be performed. Gene Ontology (GO annotation is a valuable means of assigning functional information using standardized vocabulary. We report an overview of the GO annotation for Version 5 of M. oryzae genome assembly. Methods A similarity-based (i.e., computational GO annotation with manual review was conducted, which was then integrated with a literature-based GO annotation with computational assistance. For similarity-based GO annotation a stringent reciprocal best hits method was used to identify similarity between predicted proteins of M. oryzae and GO proteins from multiple organisms with published associations to GO terms. Significant alignment pairs were manually reviewed. Functional assignments were further cross-validated with manually reviewed data, conserved domains, or data determined by wet lab experiments. Additionally, biological appropriateness of the functional assignments was manually checked. Results In total, 6,286 proteins received GO term assignment via the homology-based annotation, including 2,870 hypothetical proteins. Literature-based experimental evidence, such as microarray, MPSS, T-DNA insertion mutation, or gene knockout mutation, resulted in 2,810 proteins being annotated with GO terms. Of these, 1,673 proteins were annotated with new terms developed for Plant-Associated Microbe Gene Ontology (PAMGO. In addition, 67 experiment-determined secreted proteins were annotated with PAMGO terms. Integration of the two data sets resulted in 7,412 proteins (57% being annotated with 1,957 distinct and specific GO terms. Unannotated proteins

  16. Over-expression of snakin-2 and extensin-like protein genes restricts pathogen invasiveness and enhances tolerance to Clavibacter michiganensis subsp. michiganensis in transgenic tomato (Solanum lycopersicum).

    Science.gov (United States)

    Balaji, Vasudevan; Smart, Christine D

    2012-02-01

    Two tomato proteins were evaluated by over-expression in transgenic tomato for their ability to confer resistance to Clavibacter michiganensis subsp. michiganensis (Cmm). Snakin-2 (SN2) is a cysteine-rich peptide with broad-spectrum antimicrobial activity in vitro while extensin-like protein (ELP) is a major cell-wall hydroxyproline-rich glycoprotein linked with plant response to pathogen attack and wounding. Tomato plants, cultivar Mountain Fresh, were transformed via Agrobacterium tumefaciens harboring a binary vector for expression of the full-length SN2 gene or ELP cDNA under the regulation of the CaMV 35S promoter. Molecular characterization of PCR-positive putative T(0) transgenic plants by Northern analysis revealed constitutive over-expression of SN2 and ELP mRNA. Junction fragment analysis by Southern blot showed that three of the four SN2 over-expressing T(0) lines had single copies of complete T-DNAs while the other line had two complete T-DNA copies. All four ELP over-expressing T(0) lines had a single copy T-DNA insertion. Semi-quantitative RT-PCR analysis of T(1) plants revealed constitutive over-expression of SN2 and ELP. Transgenic lines that accumulated high levels of SN2 or ELP mRNA showed enhanced tolerance to Cmm resulting in a significant delay in the development of wilt symptoms and a reduction in the size of canker lesions compared to non-transformed control plants. Furthermore, in transgenic lines over-expressing SN2 or ELP bacterial populations were significantly lower (100-10,000-fold) than in non-transformed control plants. These results demonstrate that SN2 and ELP over-expression limits Cmm invasiveness suggesting potential in vivo antibacterial activity and possible biotechnological application for these two defense proteins.

  17. Null mutants of individual RABA genes impact the proportion of different cell wall components in stem tissue of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Daniel Lunn

    Full Text Available In Arabidopsis, and other plants, the RABA GTPases (orthologous to the Rab11a of mammals have expanded in number and diversity and have been shown to belong to eight sub clades, some of which have been implicated in controlling vesicles that traffic cell wall polymers and enzymes that synthesise or modify them to the cell wall. In order to investigate this, we have investigated whether T-DNA insertion knockouts of individual RABA genes belonging to different sub clades, impact on the composition of the plant cell wall. Single gene knockouts of the RABA1, RABA2 and RABA4 sub clades primarily affected the percentage composition of pectin, cellulose and hemicellulose within the cell wall, respectively, despite having no obvious phenotype in the whole plant. We hypothesise that vesicles carrying specific types of cargoes from the Golgi to the cell surface may be regulated by particular sub types of RABA proteins, a finding that could have wider implications for how trafficking systems work and could be a useful tool in cell wall research and other fields of plant biology.

  18. Molecular and functional characterization of a human ATM gene analogue at Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Garcia, V.

    2001-12-01

    The human ATM gene, whose inactivation is responsible for the human disease ataxia telangiectasia is conserved throughout the Eukaryotes and plays an important role in the cellular responses to DNA damage, in particular to DNA double-strand breaks (DSBs). Here we describe the identification of an Arabidopsis thaliana homologue of ATM (AtATM), and the molecular and cytological characterization of plants, hereafter called atm, carrying a disrupting T-DNA insertion in this gene. AtATM covers a 32 kb region on chromosome 3. The AtATM transcript has a complex structure, is 12 kb long and formed by 79 exons. The transcriptional level of AtATM is very low in all the tissues tested, and does not vary after exposure to ionizing radiations (IR). In atm plants, the protein is not detected suggesting the mutants are null. The atm mutants are partially sterile. Aberrant segregation of chromosomes during meiosis I on both male and female sides account for this sterility. However, meiotic recombination frequency is normal. Mutant plants are also hypersensitive to gamma rays and methyl methane sulfonate, but not to UV-B, pointing to a specific defect of atm mutants in the response to DNA DSBs. In plants, ionizing radiations induce a strong, rapid and transient transcriptional activation of genes involved in the cellular response to or the repair of DSBs. This transcriptional regulation of AtRAD51, AtPARP1, atGR1 and AtL1G4 is lost in the atm mutants . The absence of AtRAD51 induction associated with ionizing radiation sensitivity suggest that AtAtm play an important function in DSB repair by homologous recombination. In addition we show that homologous intra-chromosomal recombination frequency is elevated in the mutant comparing to wild-type, with or without gamma irradiation. These results show the implication of AtAtm in the genomic stability. (author)

  19. Human Gene Therapy: Genes without Frontiers?

    Science.gov (United States)

    Simon, Eric J.

    2002-01-01

    Describes the latest advancements and setbacks in human gene therapy to provide reference material for biology teachers to use in their science classes. Focuses on basic concepts such as recombinant DNA technology, and provides examples of human gene therapy such as severe combined immunodeficiency syndrome, familial hypercholesterolemia, and…

  20. Tumor targeted gene therapy

    International Nuclear Information System (INIS)

    Kang, Joo Hyun

    2006-01-01

    Knowledge of molecular mechanisms governing malignant transformation brings new opportunities for therapeutic intervention against cancer using novel approaches. One of them is gene therapy based on the transfer of genetic material to an organism with the aim of correcting a disease. The application of gene therapy to the cancer treatment had led to the development of new experimental approaches such as suicidal gene therapy, inhibition of oncogenes and restoration of tumor-suppressor genes. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a prodrug into a toxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1-tk) and cytosine deaminase (CD). Especially, physicians and scientists of nuclear medicine field take an interest in suicidal gene therapy because they can monitor the location and magnitude, and duration of expression of HSV1-tk and CD by PET scanner

  1. Essential Bacillus subtilis genes

    DEFF Research Database (Denmark)

    Kobayashi, K.; Ehrlich, S.D.; Albertini, A.

    2003-01-01

    To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximate to4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were...... predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related...... to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from...

  2. Epigenetics: beyond genes

    CSIR Research Space (South Africa)

    Fossey, A

    2009-06-01

    Full Text Available Gene regulatory processes lead to differential gene expression and are referred to as epigenetic phenomena; these are ubiquitous processes in the biological world. These reversible heritable changes concern DNA and RNA, their interactions...

  3. Evolution of gene expression after gene amplification.

    Science.gov (United States)

    Garcia, Nelson; Zhang, Wei; Wu, Yongrui; Messing, Joachim

    2015-04-24

    We took a rather unique approach to investigate the conservation of gene expression of prolamin storage protein genes across two different subfamilies of the Poaceae. We took advantage of oat plants carrying single maize chromosomes in different cultivars, called oat-maize addition (OMA) lines, which permitted us to determine whether regulation of gene expression was conserved between the two species. We found that γ-zeins are expressed in OMA7.06, which carries maize chromosome 7 even in the absence of the trans-acting maize prolamin-box-binding factor (PBF), which regulates their expression. This is likely because oat PBF can substitute for the function of maize PBF as shown in our transient expression data, using a γ-zein promoter fused to green fluorescent protein (GFP). Despite this conservation, the younger, recently amplified prolamin genes in maize, absent in oat, are not expressed in the corresponding OMAs. However, maize can express the oldest prolamin gene, the wheat high-molecular weight glutenin Dx5 gene, even when maize Pbf is knocked down (through PbfRNAi), and/or another maize transcription factor, Opaque-2 (O2) is knocked out (in maize o2 mutant). Therefore, older genes are conserved in their regulation, whereas younger ones diverged during evolution and eventually acquired a new repertoire of suitable transcriptional activators. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. MR REPORTER GENES

    OpenAIRE

    Gilad, Assaf A.; Ziv, Keren; McMahon, Michael T.; van Zijl, Peter C.M.; Neeman, Michal; Bulte, Jeff W.M.

    2008-01-01

    Non-invasive molecular imaging of dynamic processes has benefited tremendously from the use of reporter genes. These genes encode for proteins that emit light, bind radiolabeled probes or, as covered in this review, modulate magnetic resonance (MR) contrast. Reporter genes play a pivotal role in monitoring cell trafficking, gene replacement therapy, protein-protein interactions, neuronal plasticity and embryonic development. Several strategies exist for generating MR contrast: enzyme-catalyze...

  5. Enhancement of Ganoderic Acid Accumulation by Overexpression of an N-Terminally Truncated 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene in the Basidiomycete Ganoderma lucidum

    Science.gov (United States)

    Xu, Jun-Wei; Xu, Yi-Ning

    2012-01-01

    Ganoderic acids produced by Ganoderma lucidum, a well-known traditional Chinese medicinal mushroom, exhibit antitumor and antimetastasis activities. Genetic modification of G. lucidum is difficult but critical for the enhancement of cellular accumulation of ganoderic acids. In this study, a homologous genetic transformation system for G. lucidum was developed for the first time using mutated sdhB, encoding the iron-sulfur protein subunit of succinate dehydrogenase, as a selection marker. The truncated G. lucidum gene encoding the catalytic domain of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) was overexpressed by using the Agrobacterium tumefaciens-mediated transformation system. The results showed that the mutated sdhB successfully conferred carboxin resistance upon transformation. Most of the integrated transfer DNA (T-DNA) appeared as a single copy in the genome. Moreover, deregulated constitutive overexpression of the HMGR gene led to a 2-fold increase in ganoderic acid content. It also increased the accumulation of intermediates (squalene and lanosterol) and the upregulation of downstream genes such as those of farnesyl pyrophosphate synthase, squalene synthase, and lanosterol synthase. This study demonstrates that transgenic basidiomycete G. lucidum is a promising system to achieve metabolic engineering of the ganoderic acid pathway. PMID:22941092

  6. Radiotechnologies and gene therapy

    International Nuclear Information System (INIS)

    Xia Jinsong

    2001-01-01

    Gene therapy is an exciting frontier in medicine today. Radiologist will make an uniquely contribution to these exciting new technologies at every level by choosing sites for targeting therapy, perfecting and establishing routes of delivery, developing imaging strategies to monitor therapy and assess gene expression, developing radiotherapeutic used of gene therapy

  7. Silence of the Genes

    Indian Academy of Sciences (India)

    Srimath

    tary to the endogenous sense mRNA produced by the normal gene. The antisense strand binds to the sense strand and blocks protein synthesis. This method of gene inhibition was termed antisense technology. The antisense technology soon became a. RNA interference. (RNAi) is a novel mechanism for controlling gene.

  8. Discovering genes underlying QTL

    Energy Technology Data Exchange (ETDEWEB)

    Vanavichit, Apichart [Kasetsart University, Kamphaengsaen, Nakorn Pathom (Thailand)

    2002-02-01

    A map-based approach has allowed scientists to discover few genes at a time. In addition, the reproductive barrier between cultivated rice and wild relatives has prevented us from utilizing the germ plasm by a map-based approach. Most genetic traits important to agriculture or human diseases are manifested as observable, quantitative phenotypes called Quantitative Trait Loci (QTL). In many instances, the complexity of the phenotype/genotype interaction and the general lack of clearly identifiable gene products render the direct molecular cloning approach ineffective, thus additional strategies like genome mapping are required to identify the QTL in question. Genome mapping requires no prior knowledge of the gene function, but utilizes statistical methods to identify the most likely gene location. To completely characterize genes of interest, the initially mapped region of a gene location will have to be narrowed down to a size that is suitable for cloning and sequencing. Strategies for gene identification within the critical region have to be applied after the sequencing of a potentially large clone or set of clones that contains this gene(s). Tremendous success of positional cloning has been shown for cloning many genes responsible for human diseases, including cystic fibrosis and muscular dystrophy as well as plant disease resistance genes. Genome and QTL mapping, positional cloning: the pre-genomics era, comparative approaches to gene identification, and positional cloning: the genomics era are discussed in the report. (M. Suetake)

  9. Discovering genes underlying QTL

    International Nuclear Information System (INIS)

    Vanavichit, Apichart

    2002-01-01

    A map-based approach has allowed scientists to discover few genes at a time. In addition, the reproductive barrier between cultivated rice and wild relatives has prevented us from utilizing the germ plasm by a map-based approach. Most genetic traits important to agriculture or human diseases are manifested as observable, quantitative phenotypes called Quantitative Trait Loci (QTL). In many instances, the complexity of the phenotype/genotype interaction and the general lack of clearly identifiable gene products render the direct molecular cloning approach ineffective, thus additional strategies like genome mapping are required to identify the QTL in question. Genome mapping requires no prior knowledge of the gene function, but utilizes statistical methods to identify the most likely gene location. To completely characterize genes of interest, the initially mapped region of a gene location will have to be narrowed down to a size that is suitable for cloning and sequencing. Strategies for gene identification within the critical region have to be applied after the sequencing of a potentially large clone or set of clones that contains this gene(s). Tremendous success of positional cloning has been shown for cloning many genes responsible for human diseases, including cystic fibrosis and muscular dystrophy as well as plant disease resistance genes. Genome and QTL mapping, positional cloning: the pre-genomics era, comparative approaches to gene identification, and positional cloning: the genomics era are discussed in the report. (M. Suetake)

  10. Carboxylesterase 1 genes

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Madsen, Majbritt Busk

    2018-01-01

    The carboxylesterase 1 gene (CES1) encodes a hydrolase that metabolizes commonly used drugs. The CES1-related pseudogene, carboxylesterase 1 pseudogene 1 (CES1P1), has been implicated in gene exchange with CES1 and in the formation of hybrid genes including the carboxylesterase 1A2 gene (CES1A2...... region was revealed. In conclusion, many procedures for CES1, CES1A2 and CES1P1 genotyping appear to lack specificity. Knowledge about the segmental duplications may improve the typing of these genes....

  11. Gene therapy: An overview

    Directory of Open Access Journals (Sweden)

    Sudip Indu

    2013-01-01

    Full Text Available Gene therapy "the use of genes as medicine" involves the transfer of a therapeutic or working copy of a gene into specific cells of an individual in order to repair a faulty gene copy. The technique may be used to replace a faulty gene, or to introduce a new gene whose function is to cure or to favorably modify the clinical course of a condition. The objective of gene therapy is to introduce new genetic material into target cells while causing no damage to the surrounding healthy cells and tissues, hence the treatment related morbidity is decreased. The delivery system includes a vector that delivers a therapeutic gene into the patient′s target cell. Functional proteins are created from the therapeutic gene causing the cell to return to a normal stage. The vectors used in gene therapy can be viral and non-viral. Gene therapy, an emerging field of biomedicine, is still at infancy and much research remains to be done before this approach to the treatment of condition will realize its full potential.

  12. Human gene essentiality.

    Science.gov (United States)

    Bartha, István; di Iulio, Julia; Venter, J Craig; Telenti, Amalio

    2018-01-01

    A gene can be defined as essential when loss of its function compromises viability of the individual (for example, embryonic lethality) or results in profound loss of fitness. At the population level, identification of essential genes is accomplished by observing intolerance to loss-of-function variants. Several computational methods are available to score gene essentiality, and recent progress has been made in defining essentiality in the non-coding genome. Haploinsufficiency is emerging as a critical aspect of gene essentiality: approximately 3,000 human genes cannot tolerate loss of one of the two alleles. Genes identified as essential in human cell lines or knockout mice may be distinct from those in living humans. Reconciling these discrepancies in how we evaluate gene essentiality has applications in clinical genetics and may offer insights for drug development.

  13. Do Housekeeping Genes Exist?

    Science.gov (United States)

    Sun, Bingyun

    2015-01-01

    The searching of human housekeeping (HK) genes has been a long quest since the emergence of transcriptomics, and is instrumental for us to understand the structure of genome and the fundamentals of biological processes. The resolved genes are frequently used in evolution studies and as normalization standards in quantitative gene-expression analysis. Within the past 20 years, more than a dozen HK-gene studies have been conducted, yet none of them sampled human tissues completely. We believe an integration of these results will help remove false positive genes owing to the inadequate sampling. Surprisingly, we only find one common gene across 15 examined HK-gene datasets comprising 187 different tissue and cell types. Our subsequent analyses suggest that it might not be appropriate to rigidly define HK genes as expressed in all tissue types that have diverse developmental, physiological, and pathological states. It might be beneficial to use more robustly identified HK functions for filtering criteria, in which the representing genes can be a subset of genome. These genes are not necessarily the same, and perhaps need not to be the same, everywhere in our body. PMID:25970694

  14. Primetime for Learning Genes.

    Science.gov (United States)

    Keifer, Joyce

    2017-02-11

    Learning genes in mature neurons are uniquely suited to respond rapidly to specific environmental stimuli. Expression of individual learning genes, therefore, requires regulatory mechanisms that have the flexibility to respond with transcriptional activation or repression to select appropriate physiological and behavioral responses. Among the mechanisms that equip genes to respond adaptively are bivalent domains. These are specific histone modifications localized to gene promoters that are characteristic of both gene activation and repression, and have been studied primarily for developmental genes in embryonic stem cells. In this review, studies of the epigenetic regulation of learning genes in neurons, particularly the brain-derived neurotrophic factor gene ( BDNF ), by methylation/demethylation and chromatin modifications in the context of learning and memory will be highlighted. Because of the unique function of learning genes in the mature brain, it is proposed that bivalent domains are a characteristic feature of the chromatin landscape surrounding their promoters. This allows them to be "poised" for rapid response to activate or repress gene expression depending on environmental stimuli.

  15. Genes and Social Behavior

    OpenAIRE

    Robinson, Gene E.; Fernald, Russell D.; Clayton, David F.

    2008-01-01

    What specific genes and regulatory sequences contribute to the organization and functioning of brain circuits that support social behavior? How does social experience interact with information in the genome to modulate these brain circuits? Here we address these questions by highlighting progress that has been made in identifying and understanding two key “vectors of influence” that link genes, brain, and social behavior: 1) social information alters gene readout in the brain to influence beh...

  16. History of gene therapy.

    Science.gov (United States)

    Wirth, Thomas; Parker, Nigel; Ylä-Herttuala, Seppo

    2013-08-10

    Two decades after the initial gene therapy trials and more than 1700 approved clinical trials worldwide we not only have gained much new information and knowledge regarding gene therapy in general, but also learned to understand the concern that has persisted in society. Despite the setbacks gene therapy has faced, success stories have increasingly emerged. Examples for these are the positive recommendation for a gene therapy product (Glybera) by the EMA for approval in the European Union and the positive trials for the treatment of ADA deficiency, SCID-X1 and adrenoleukodystrophy. Nevertheless, our knowledge continues to grow and during the course of time more safety data has become available that helps us to develop better gene therapy approaches. Also, with the increased understanding of molecular medicine, we have been able to develop more specific and efficient gene transfer vectors which are now producing clinical results. In this review, we will take a historical view and highlight some of the milestones that had an important impact on the development of gene therapy. We will also discuss briefly the safety and ethical aspects of gene therapy and address some concerns that have been connected with gene therapy as an important therapeutic modality. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Expression of kenaf mitochondrial chimeric genes HM184 causes male sterility in transgenic tobacco plants.

    Science.gov (United States)

    Zhao, Yanhong; Liao, Xiaofang; Huang, Zhipeng; Chen, Peng; Zhou, Bujin; Liu, Dongmei; Kong, Xiangjun; Zhou, Ruiyang

    2015-08-01

    Chimeric genes resulting from the rearrangement of a mitochondrial genome were generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). In the study, earlier we reported that identifying a 47 bp deletion at 3'- flanking of atp9 that was linked to male sterile cytoplasm in kenaf. The truncated fragment was fused with atp9, a mitochondrial transit signal (MTS) and/or GFP, comprised two chimeric genes MTS-HM184-GFP and MTS-HM184. The plant expression vector pBI121 containing chimeric genes were then introduced to tobacco plants by Agrobacterium-mediated T-DNA transformation. The result showed that certain transgenic plants were male sterility or semi-sterility, while some were not. The expression analysis further demonstrated that higher level of expression were showed in the sterility plants, while no expression or less expression in fertility plants, the levels of expression of semi-sterility were in between. And the sterile plant (containing MTS-HM184-GFP) had abnormal anther produced malformed/shriveled pollen grains stained negative that failed to germinate (0%), the corresponding fruits was shrunken, the semi-sterile plants having normal anther shape produced about 10-50% normal pollen grains, the corresponding fruits were not full, and the germination rate was 58%. Meanwhile these transgenic plants which altered on fertility were further analyzed in phenotype. As a result, the metamorphosis leaves were observed in the seedling stage, the plant height of transgenic plants was shorter than wild type. The growth duration of transgenic tobacco was delayed 30-45 days compared to the wild type. The copy numbers of target genes of transgenic tobacco were analyzed using the real-time quantitative method. The results showed that these transgenic plants targeting-expression in mitochondrial containing MTS-HM184-GFP had 1 copy and 2 copies, the other two plants containing MTS-HM184 both had 3 copies, but 0 copy in wild type. In

  18. Self-entanglement of long linear DNA vectors using transient non-B-DNA attachment points: a new concept for improvement of non-viral therapeutic gene delivery.

    Science.gov (United States)

    Tolmachov, Oleg E

    2012-05-01

    The cell-specific and long-term expression of therapeutic transgenes often requires a full array of native gene control elements including distal enhancers, regulatory introns and chromatin organisation sequences. The delivery of such extended gene expression modules to human cells can be accomplished with non-viral high-molecular-weight DNA vectors, in particular with several classes of linear DNA vectors. All high-molecular-weight DNA vectors are susceptible to damage by shear stress, and while for some of the vectors the harmful impact of shear stress can be minimised through the transformation of the vectors to compact topological configurations by supercoiling and/or knotting, linear DNA vectors with terminal loops or covalently attached terminal proteins cannot be self-compacted in this way. In this case, the only available self-compacting option is self-entangling, which can be defined as the folding of single DNA molecules into a configuration with mutual restriction of molecular motion by the individual segments of bent DNA. A negatively charged phosphate backbone makes DNA self-repulsive, so it is reasonable to assume that a certain number of 'sticky points' dispersed within DNA could facilitate the entangling by bringing DNA segments into proximity and by interfering with the DNA slipping away from the entanglement. I propose that the spontaneous entanglement of vector DNA can be enhanced by the interlacing of the DNA with sites capable of mutual transient attachment through the formation of non-B-DNA forms, such as interacting cruciform structures, inter-segment triplexes, slipped-strand DNA, left-handed duplexes (Z-forms) or G-quadruplexes. It is expected that the non-B-DNA based entanglement of the linear DNA vectors would consist of the initial transient and co-operative non-B-DNA mediated binding events followed by tight self-ensnarement of the vector DNA. Once in the nucleoplasm of the target human cells, the DNA can be disentangled by type II

  19. An artificial intelligence approach fit for tRNA gene studies in the era of big sequence data.

    Science.gov (United States)

    Iwasaki, Yuki; Abe, Takashi; Wada, Kennosuke; Wada, Yoshiko; Ikemura, Toshimichi

    2017-09-12

    Unsupervised data mining capable of extracting a wide range of knowledge from big data without prior knowledge or particular models is a timely application in the era of big sequence data accumulation in genome research. By handling oligonucleotide compositions as high-dimensional data, we have previously modified the conventional self-organizing map (SOM) for genome informatics and established BLSOM, which can analyze more than ten million sequences simultaneously. Here, we develop BLSOM specialized for tRNA genes (tDNAs) that can cluster (self-organize) more than one million microbial tDNAs according to their cognate amino acid solely depending on tetra- and pentanucleotide compositions. This unsupervised clustering can reveal combinatorial oligonucleotide motifs that are responsible for the amino acid-dependent clustering, as well as other functionally and structurally important consensus motifs, which have been evolutionarily conserved. BLSOM is also useful for identifying tDNAs as phylogenetic markers for special phylotypes. When we constructed BLSOM with 'species-unknown' tDNAs from metagenomic sequences plus 'species-known' microbial tDNAs, a large portion of metagenomic tDNAs self-organized with species-known tDNAs, yielding information on microbial communities in environmental samples. BLSOM can also enhance accuracy in the tDNA database obtained from big sequence data. This unsupervised data mining should become important for studying numerous functionally unclear RNAs obtained from a wide range of organisms.

  20. Role of the plant-specific endoplasmic reticulum stress-inducible gene TIN1 in the formation of pollen surface structure in Arabidopsis thaliana

    KAUST Repository

    Iwata, Yuji

    2012-01-01

    Accumulation of unfolded proteins in the endoplasmic reticulum (ER) of eukaryotic cells triggers the transcriptional activation of ER-resident molecular chaperones and folding enzymes to maintain cellular homeostasis. This process is known as the ER stress response or the unfolded protein response. We have identified tunicamycin induced 1 (TIN1), a plant-specific ER stress-inducible Arabidopsis thaliana gene. The TIN1 protein is localized in the ER; however, its molecular function has yet to be clarified. In this study, we performed functional analysis of TIN1 in planta. RT-PCR analysis showed that TIN1 is highly expressed in pollen. Analysis using the β-glucuronidase reporter gene demonstrated that the TIN1 promoter is active throughout pollen development, peaking at the time of flowering and in an ovule of an open flower. Although a T-DNA insertion mutant of TIN1 grows normally under ambient laboratory conditions, abnormal pollen surface morphology was observed under a scanning electron microscope. Based on the current and previous observations, a possible physiological function of TIN1 during pollen development is discussed. © 2012 The Japanese Society for Plant Cell and Molecular Biology.

  1. The Agrobacterium tumefaciens virulence protein VirE3 is a transcriptional activator of the F-box gene VBF.

    Science.gov (United States)

    Niu, Xiaolei; Zhou, Meiliang; Henkel, Christiaan V; van Heusden, G Paul H; Hooykaas, Paul J J

    2015-12-01

    During Agrobacterium tumefaciens-mediated transformation of plant cells a part of the tumour-inducing plasmid, T-DNA, is integrated into the host genome. In addition, a number of virulence proteins are translocated into the host cell. The virulence protein VirE3 binds to the Arabidopsis thaliana pBrp protein, a plant-specific general transcription factor of the TFIIB family. To study a possible role for VirE3 in transcriptional regulation, we stably expressed virE3 in A. thaliana under control of a tamoxifen-inducible promoter. By RNA sequencing we showed that upon expression of virE3 the RNA levels of 607 genes were increased more than three-fold and those of 132 genes decreased more than three-fold. One of the strongly activated genes was that encoding VBF (At1G56250), an F-box protein that may affect the levels of the VirE2 and VIP1 proteins. Using Arabidopsis cell suspension protoplasts we showed that VirE3 stimulates the VBF promoter, especially when co-expressed with pBrp. Although pBrp is localized at the external surface of plastids, co-expression of VirE3 and pBrp in Arabidopsis cell suspension protoplasts resulted in the accumulation of pBrp in the nucleus. Our results suggest that VirE3 affects the transcriptional machinery of the host cell to favour the transformation process. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  2. Production of artemisinin and its derivatives in hairy roots of Artemisia dubia induced by rolA gene transformation

    International Nuclear Information System (INIS)

    Amanullah, M.; Mirza, B.; Zia, M.

    2016-01-01

    Artemisinin and its derivatives are phytochemical constituents of genus Artemisia. Demand of these plant secondary metabolitesis increasing due to their immense therapeutic significance. Besides their established antimalarial role, recent studies have also disclosed their anticancer potentials. It has made imperative to develop new and efficient sources of these compounds. Inherent synthetic challenges give biological sources preference over chemical synthesis of artemisinin and its derivatives. Therefore, genetic improvement of plants and, rather less preferentially, microbes is focus of current research to gain increase productivity of these valuable drugs. This study has analyzed A. dubiaas potential source of artemisinin and its derivatives. Transformation of Artemisia dubia was carried out using A. tumefaciens strain LBA 4404 containing rolA gene constructed on pRB 29. Healthy and acclimatizable transgenic plants were produced using optimized concentrations of BAP and NAA. Previously acclimatized rol ABC transgenic plants were also In vitro regenerated for comparative analysis of artemisinin and its derivatives. PCR amplification of rolA gene was done to confirm the integration of T-DNA in transgenic plants.TLC analysis was performed to evaluate comparative production of artemisinin and derivatives in rolA and rol ABC transgenic A. dubia. It revealed that rolA transgenic plants contain comparable amounts of these metabolites. Both type of transgenic plants manifested the enhancement of other uncharacterized compounds as well. Besides systematic optimization of In vitro regenerative protocol for Artemisia dubia, relative regeneration ability of rol transgenic and controlplants was also assessed at four regenerative stages. It was observed that unlike control, rol transgenic plants showed best root induction only on combination of auxins and cytokines. It was concluded that rol genes transformation of plants is an efficient tool to enhance their secondary

  3. Human housekeeping genes, revisited.

    Science.gov (United States)

    Eisenberg, Eli; Levanon, Erez Y

    2013-10-01

    Housekeeping genes are involved in basic cell maintenance and, therefore, are expected to maintain constant expression levels in all cells and conditions. Identification of these genes facilitates exposure of the underlying cellular infrastructure and increases understanding of various structural genomic features. In addition, housekeeping genes are instrumental for calibration in many biotechnological applications and genomic studies. Advances in our ability to measure RNA expression have resulted in a gradual increase in the number of identified housekeeping genes. Here, we describe housekeeping gene detection in the era of massive parallel sequencing and RNA-seq. We emphasize the importance of expression at a constant level and provide a list of 3804 human genes that are expressed uniformly across a panel of tissues. Several exceptionally uniform genes are singled out for future experimental use, such as RT-PCR control genes. Finally, we discuss both ways in which current technology can meet some of past obstacles encountered, and several as yet unmet challenges. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Recombinant gene expression protocols

    National Research Council Canada - National Science Library

    Tuan, Rocky S

    1997-01-01

    .... A fundamental requirement for successful recombinant gene expression is the design of the cloning vector and the choice of the host organism for expression. Recombinant Gene Expression Protocols grows out of the need for a laboratory manual that provides the reader the background and rationale, as well as the practical protocols for the preparation of...

  5. One gene's shattering effects.

    Science.gov (United States)

    Olsen, Kenneth M

    2012-05-29

    A new study shows that three independent mutations in the Sh1 gene, which encodes a YABBY transcription factor, gave rise to the non-shattering seed phenotype in domesticated sorghum. This same gene may have also had a role in the domestication of other cereals, including maize and rice.

  6. Your Genes, Your Choices

    Science.gov (United States)

    Table of Contents Your Genes, Your Choices describes the Human Genome Project, the science behind it, and the ethical, legal, and social issues that are ... Nothing could be further from the truth. Your Genes, Your Choices points out how the progress of ...

  7. Novel pGreen/pSoup dual-binary vector system in multiple T-DNA ...

    African Journals Online (AJOL)

    Both the pGreen and pSoup plasmids were transformed into E. coli strain DH5α using the PEG-transformation technique and into Agrobacterium strains AGL1using a freeze-thaw method. AGL1 was then used to transform embryogenic nodular units (ENU), derived from mature seeds of the model rice genotype Nipponbare.

  8. Radionuclide reporter gene imaging

    International Nuclear Information System (INIS)

    Min, Jung Joon

    2004-01-01

    Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene expression. This article reviews the principles, characteristics, categories and the use of radionuclide reporter gene imaging technologies as they have been used in imaging cell trafficking, imaging gene therapy, imaging endogenous gene expression and imaging molecular interactions. The studies published to date demonstrate that reporter gene imaging technologies will help to accelerate model validation as well as allow for clinical monitoring of human diseases

  9. Third party annotation gene data set of eutherian lysozyme genes

    Directory of Open Access Journals (Sweden)

    Marko Premzl

    2014-12-01

    Full Text Available The eutherian comparative genomic analysis protocol annotated most comprehensive eutherian lysozyme gene data set. Among 209 potential coding sequences, the third party annotation gene data set of eutherian lysozyme genes included 116 complete coding sequences that first described seven major gene clusters. As one new framework of future experiments, the present integrated gene annotations, phylogenetic analysis and protein molecular evolution analysis proposed new classification and nomenclature of eutherian lysozyme genes.

  10. Gene amplification in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Lucimari Bizari

    2006-01-01

    Full Text Available Gene amplification increases the number of genes in a genome and can give rise to karyotype abnormalities called double minutes (DM and homogeneously staining regions (HSR, both of which have been widely observed in human tumors but are also known to play a major role during embryonic development due to the fact that they are responsible for the programmed increase of gene expression. The etiology of gene amplification during carcinogenesis is not yet completely understood but can be considered a result of genetic instability. Gene amplification leads to an increase in protein expression and provides a selective advantage during cell growth. Oncogenes such as CCND1, c-MET, c-MYC, ERBB2, EGFR and MDM2 are amplified in human tumors and can be associated with increased expression of their respective proteins or not. In general, gene amplification is associated with more aggressive tumors, metastases, resistance to chemotherapy and a decrease in the period during which the patient stays free of the disease. This review discusses the major role of gene amplification in the progression of carcinomas, formation of genetic markers and as possible therapeutic targets for the development of drugs for the treatment of some types of tumors.

  11. Genes and hypertension.

    Science.gov (United States)

    Garcia, E A; Newhouse, S; Caulfield, M J; Munroe, P B

    2003-01-01

    The combination of investigation of rare Mendelian forms of hypertension, candidate gene studies, comparative mapping and genome-wide screening in both animal models and man has led to significant progress in determining new mechanisms of blood pressure control. In this review, the newly discovered blood pressure/cardiovascular genes, WNK kinases and angiotensin converting enzyme 2 and the development of a new anti-hypertensive agent PST2238 are discussed. Major genes causing essential hypertension have yet to be discovered, however, there are now over 20 published genome-wide screens for blood pressure controlling genes. Several regions demonstrate suggestive linkage to the trait and there is some overlap of regions between the different studies. It is hoped that new blood pressure genes will ultimately be discovered using this method. Pharmacogenetic studies in hypertension have only been initiated recently, some are described in this paper. Small studies upon single candidate genes, suggest that the contribution of genetics to the inter-individual variation in blood pressure response to anti-hypertensive therapy, is small, approximately 3-5%. Recently micro-arrays with multiple polymorphisms in multiple genes have been used. After accounting for the additive affects of multiple blood pressure loci, an individual's genetic profile appeared to explain up to 50% of the variation in blood pressure response to therapy. Knowledge of the genetic variants that cause hypertension and influence response to anti-hypertensive therapy will ultimately provide a greater understanding of the molecular mechanisms underlying blood pressure control.

  12. [Agrobacterium-mediated sunflower transformation (Helianthus annuus L.) in vitro and in Planta using strain of LBA4404 harboring binary vector pBi2E with dsRNA-suppressor proline dehydrogenase gene].

    Science.gov (United States)

    Tishchenko, E N; Komisarenko, A G; Mikhal'skaia, S I; Sergeeva, L E; Adamenko, N I; Morgun, B V; Kochetov, A V

    2014-01-01

    To estimate the efficiency of proline dehydrogenase gene suppression towards increasing of sunflower (Helianthus annuus L.) tolerance level to water deficit and salinity, we employed strain LBA4404 harboring pBi2E with double-stranded RNA-suppressor, which were prepared on basis arabidopsis ProDH1 gene. The techniques of Agrobacterium-mediated transformation in vitro and in planta during fertilization sunflower have been proposed. There was shown the genotype-depended integration of T-DNA in sunflower genome. PCR-analysis showed that ProDH1 presents in genome of inbred lines transformed in planta, as well as in T1- and T2-generations. In trans-genic regenerants the essential accumulation of free L-proline during early stages of in vitro cultivation under normal conditions was shown. There was established the essential accumulation of free proline in transgenic regenerants during cultivation under lethal stress pressure (0.4 M mannitol and 2.0% sea water salts) and its decline upon the recovery period. These data are declared about effectiveness of suppression of sunflower ProDH and gene participation in processes connected with osmotolerance.

  13. Antisense gene silencing

    DEFF Research Database (Denmark)

    Nielsen, Troels T; Nielsen, Jørgen E

    2013-01-01

    Since the first reports that double-stranded RNAs can efficiently silence gene expression in C. elegans, the technology of RNA interference (RNAi) has been intensively exploited as an experimental tool to study gene function. With the subsequent discovery that RNAi could also be applied...... to mammalian cells, the technology of RNAi expanded from being a valuable experimental tool to being an applicable method for gene-specific therapeutic regulation, and much effort has been put into further refinement of the technique. This review will focus on how RNAi has developed over the years and how...

  14. Rice Genomics: Gene discovery

    Indian Academy of Sciences (India)

    There is a need for discovering candidate genes( a lot of them all over the genome indeed ) and the unlimited allelic variation that can productively take over rice metabolism when cellular water content falls below threshold levels.

  15. Gene Expression Omnibus (GEO)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene Expression Omnibus is a public functional genomics data repository supporting MIAME-compliant submissions of array- and sequence-based data. Tools are provided...

  16. Què hi fa un androgin com tu en un planeta com aquest? Alteritat, ciència-ficció i gènere a The Left Hand of Darkness, d'Ursula K. Le Guin

    Directory of Open Access Journals (Sweden)

    Pau Pitarch Fernández

    2005-01-01

    Full Text Available This paper discusses Le Guin's classic novel as an example of the creative use of popular fiction codes and motifs to deal with gender issues. The use of androginy in the text is read as a thematization of the bisexualist bias in dealing with gendered bodies in our culture.Through the experiences of the main character, the novel reworks the classic science-fiction motif of the "alien encounter" in order to tackle the importance of otherness in the cultural understanding of gender. Far from offering an escapist utopia of unified androginy, the text sets free the multiplicity of identity options that exist behind the naturalized bisexual model.

  17. Evidence for Hoogsteen GC Base Pairs in the Proton-Induced Transition from Right-Handed to Left-Handed Poly(dG-dC) . Poly(dG-dC)

    NARCIS (Netherlands)

    Segers-Nolten, Gezina M.J.; Sijtsema, N.M.; Otto, Cornelis

    1997-01-01

    The structure of double-helical poly(dG-dC)·poly(dG-dC) is investigated at various pH values with Raman spectroscopy, absorption spectroscopy, and circular dichroism. A comparison is made between the B-form with Watson−Crick base pairing at 1 mM [Na+] and pH 7.2, the Z-form with Watson−Crick base

  18. Characterization of host-dependent mutations of apple fruit crinkle viroid replicating in newly identified experimental hosts suggests maintenance of stem-loop structures in the left-hand half of the molecule is important for replication

    Czech Academy of Sciences Publication Activity Database

    Suzuki, T.; Fujibayashi, M.; Hataya, T.; Taneda, A.; He, Y.-H.; Tsushima, T.; Duraisamy, Ganesh Selvaraj; Siglová, Kristýna; Matoušek, Jaroslav; Sano, T.

    2017-01-01

    Roč. 98, č. 3 (2017), s. 506-516 ISSN 0022-1317 R&D Projects: GA MŠk(CZ) LH14255 Institutional support: RVO:60077344 Keywords : scar-skin * plants * populations * grapevines Subject RIV: EE - Microbiology, Virology OBOR OECD: Biochemistry and molecular biology Impact factor: 2.838, year: 2016

  19. Solution of Volterra and Fredholm Classes of Equations via Triangular Orthogonal Function (A Combination of Right Hand Triangular Function and Left Hand Triangular Function) and Hybrid Orthogonal Function (A Combination of Sample Hold Function and Right Hand Triangular Function)

    Science.gov (United States)

    Mukhopadhyay, Anirban; Ganguly, Anindita; Chatterjee, Saumya Deep

    2018-01-01

    In this paper the authors have dealt with seven kinds of non-linear Volterra and Fredholm classes of equations. The authors have formulated an algorithm for solving the aforementioned equation types via Hybrid Function (HF) and Triangular Function (TF) piecewise-linear orthogonal approach. In this approach the authors have reduced integral equation or integro-differential equation into equivalent system of simultaneous non-linear equation and have employed either Newton's method or Broyden's method to solve the simultaneous non-linear equations. The authors have calculated the L2-norm error and the max-norm error for both HF and TF method for each kind of equations. Through the illustrated examples, the authors have shown that the HF based algorithm produces stable result, on the contrary TF-computational method yields either stable, anomalous or unstable results.

  20. Radiosensitivity and genes

    International Nuclear Information System (INIS)

    Hu Qiyue; Lun Mingyue

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G 1 phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM 9 cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation

  1. Evidence for homosexuality gene

    Energy Technology Data Exchange (ETDEWEB)

    Pool, R.

    1993-07-16

    A genetic analysis of 40 pairs of homosexual brothers has uncovered a region on the X chromosome that appears to contain a gene or genes for homosexuality. When analyzing the pedigrees of homosexual males, the researcheres found evidence that the trait has a higher likelihood of being passed through maternal genes. This led them to search the X chromosome for genes predisposing to homosexuality. The researchers examined the X chromosomes of pairs of homosexual brothers for regions of DNA that most or all had in common. Of the 40 sets of brothers, 33 shared a set of five markers in the q28 region of the long arm of the X chromosome. The linkage has a LOD score of 4.0, which translates into a 99.5% certainty that there is a gene or genes in this area that predispose males to homosexuality. The chief researcher warns, however, that this one site cannot explain all instances of homosexuality, since there were some cases where the trait seemed to be passed paternally. And even among those brothers where there was no evidence that the trait was passed paternally, seven sets of brothers did not share the Xq28 markers. It seems likely that homosexuality arises from a variety of causes.

  2. Gene-Gene and Gene-Environment Interactions in the Etiology of Breast Cancer

    National Research Council Canada - National Science Library

    Adegoke, Olufemi

    2003-01-01

    The objective of this CDA is to evaluate the gene-gene and gene-environment interactions in the etiology of breast cancer in two ongoing case-control studies, the Shanghai Breast Cancer Study (SBCS...

  3. Identification of Cell Wall Synthesis Regulatory Genes Controlling Biomass Characteristics and Yield in Rice (Oryza Sativa)

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Zhaohua PEng [Mississippi State University; Ronald, Palmela [UC-Davis; Wang, Guo-Liang [The Ohio State University

    2013-04-26

    This project aims to identify the regulatory genes of rice cell wall synthesis pathways using a cell wall removal and regeneration system. We completed the gene expression profiling studies following the time course from cell wall removal to cell wall regeneration in rice suspension cells. We also completed, total proteome, nuclear subproteome and histone modification studies following the course from cell wall removal and cell wall regeneration process. A large number of differentially expressed regulatory genes and proteins were identified. Meanwhile, we generated RNAi and over-expression transgenic rice for 45 genes with at least 10 independent transgenic lines for each gene. In addition, we ordered T-DNA and transposon insertion mutants for 60 genes from Korea, Japan, and France and characterized the mutants. Overall, we have mutants and transgenic lines for over 90 genes, exceeded our proposed goal of generating mutants for 50 genes. Interesting Discoveries a) Cell wall re-synthesis in protoplasts may involve a novel cell wall synthesis mechanism. The synthesis of the primary cell wall is initiated in late cytokinesis with further modification during cell expansion. Phragmoplast plays an essential role in cell wall synthesis. It services as a scaffold for building the cell plate and formation of a new cell wall. Only one phragmoplast and one new cell wall is produced for each dividing cell. When the cell wall was removed enzymatically, we found that cell wall re-synthesis started from multiple locations simultaneously, suggesting that a novel mechanism is involved in cell wall re-synthesis. This observation raised many interesting questions, such as how the starting sites of cell wall synthesis are determined, whether phragmoplast and cell plate like structures are involved in cell wall re-synthesis, and more importantly whether the same set of enzymes and apparatus are used in cell wall re-synthesis as during cytokinesis. Given that many known cell wall

  4. Optimisation of tomato Micro-tom regeneration and selection on glufosinate/Basta and dependency of gene silencing on transgene copy number.

    Science.gov (United States)

    Khuong, Thi Thu Huong; Crété, Patrice; Robaglia, Christophe; Caffarri, Stefano

    2013-09-01

    An efficient protocol of transformation and selection of transgenic lines of Micro-tom, a widespread model cultivar for tomato, is reported. RNA interference silencing efficiency and stability have been investigated and correlated with the number of insertions. Given its small size and ease of cultivation, the tomato (Solanum lycopersicon) cultivar Micro-tom is of widespread use as a model tomato plant. To create and screen transgenic plants, different selectable markers are commonly used. The bar marker carrying the resistance to the herbicide glufosinate/Basta, has many advantages, but it has been little utilised and with low efficiency for identification of tomato transgenic plants. Here we describe a procedure for accurate selection of transgenic Micro-tom both in vitro and in soil. Immunoblot, Southern blot and phenotypic analyses showed that 100 % of herbicide-resistant plants were transgenic. In addition, regeneration improvement has been obtained by using 2 mg/l Gibberellic acid in the shoot elongation medium; rooting optimisation on medium containing 1 mg/l IAA allowed up to 97 % of shoots developing strong and very healthy roots after only 10 days. Stable transformation frequency by infection of leaf explants with Agrobacterium reached 12 %. Shoots have been induced by combination of 1 mg/l zeatin-trans and 0.1 mg/l IAA. Somatic embryogenesis of cotyledon on medium containing 1 mg/l zeatin + 2 mg/l IAA is described in Micro-tom. The photosynthetic psbS gene has been used as reporter gene for RNA silencing studies. The efficiency of gene silencing has been found equivalent using three different target gene fragments of 519, 398 and 328 bp. Interestingly, silencing efficiency decreased from T0 to the T3 generation in plants containing multiple copies of the inserted T-DNA, while it was stable in plants containing a single insertion.

  5. Agrobacterium rhizogenes-dependent production of transformed roots from foliar explants of pepper (Capsicum annuum): a new and efficient tool for functional analysis of genes.

    Science.gov (United States)

    Aarrouf, J; Castro-Quezada, P; Mallard, S; Caromel, B; Lizzi, Y; Lefebvre, V

    2012-02-01

    Pepper is known to be a recalcitrant species to genetic transformation via Agrobacterium tumefaciens. A. rhizogenes-mediated transformation offers an alternative and rapid possibility to study gene functions in roots. In our study, we developed a new and efficient system for A. rhizogenes transformation of the cultivated species Capsicum annuum. Hypocotyls and foliar organs (true leaves and cotyledons) of Yolo Wonder (YW) and Criollo de Morelos 334 (CM334) pepper cultivars were inoculated with the two constructs pBIN-gus and pHKN29-gfp of A. rhizogenes strain A4RS. Foliar explants of both pepper genotypes infected by A4RS-pBIN-gus or A4RS-pHKN29-gfp produced transformed roots. Optimal results were obtained using the combination of the foliar explants with A4RS-pHKN29-gfp. 20.5% of YW foliar explants and 14.6% of CM334 foliar explants inoculated with A4RS-pHKN29-gfp produced at least one root expressing uniform green fluorescent protein. We confirmed by polymerase chain reaction the presence of the rolB and gfp genes in the co-transformed roots ensuring that they integrated both the T-DNA from the Ri plasmid and the reporter gene. We also demonstrated that co-transformed roots of YW and CM334 displayed the same resistance response to Phytophthora capsici than the corresponding untransformed roots. Our novel procedure to produce C. annuum hairy roots will thus support the functional analysis of potential resistance genes involved in pepper P. capsici interaction.

  6. Impact of AtNHX1, a vacuolar Na+/H+ antiporter, upon gene expression during short- and long-term salt stress in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Blumwald Eduardo

    2007-04-01

    Full Text Available Abstract Background AtNHX1, the most abundant vacuolar Na+/H+ antiporter in Arabidopsis thaliana, mediates the transport of Na+ and K+ into the vacuole, influencing plant development and contributing to salt tolerance. In this report, microarray expression profiles of wild type plants, a T-DNA insertion knockout mutant of AtNHX1 (nhx1, and a 'rescued' line (NHX1::nhx1 were exposed to both short (12 h and 48 h and long (one and two weeks durations of a non-lethal salt stress to identify key gene transcripts associated with the salt response that are influenced by AtNHX1. Results 147 transcripts showed both salt responsiveness and a significant influence of AtNHX1. Fifty-seven of these genes showed an influence of the antiporter across all salt treatments, while the remaining genes were influenced as a result of a particular duration of salt stress. Most (69% of the genes were up-regulated in the absence of AtNHX1, with the exception of transcripts encoding proteins involved with metabolic and energy processes that were mostly down-regulated. Conclusion While part of the AtNHX1-influenced transcripts were unclassified, other transcripts with known or putative roles showed the importance of AtNHX1 to key cellular processes that were not necessarily limited to the salt stress response; namely calcium signaling, sulfur metabolism, cell structure and cell growth, as well as vesicular trafficking and protein processing. Only a small number of other salt-responsive membrane transporter transcripts appeared significantly influenced by AtNHX1.

  7. Harnessing gene expression networks to prioritize candidate epileptic encephalopathy genes.

    Science.gov (United States)

    Oliver, Karen L; Lukic, Vesna; Thorne, Natalie P; Berkovic, Samuel F; Scheffer, Ingrid E; Bahlo, Melanie

    2014-01-01

    We apply a novel gene expression network analysis to a cohort of 182 recently reported candidate Epileptic Encephalopathy genes to identify those most likely to be true Epileptic Encephalopathy genes. These candidate genes were identified as having single variants of likely pathogenic significance discovered in a large-scale massively parallel sequencing study. Candidate Epileptic Encephalopathy genes were prioritized according to their co-expression with 29 known Epileptic Encephalopathy genes. We utilized developing brain and adult brain gene expression data from the Allen Human Brain Atlas (AHBA) and compared this to data from Celsius: a large, heterogeneous gene expression data warehouse. We show replicable prioritization results using these three independent gene expression resources, two of which are brain-specific, with small sample size, and the third derived from a heterogeneous collection of tissues with large sample size. Of the nineteen genes that we predicted with the highest likelihood to be true Epileptic Encephalopathy genes, two (GNAO1 and GRIN2B) have recently been independently reported and confirmed. We compare our results to those produced by an established in silico prioritization approach called Endeavour, and finally present gene expression networks for the known and candidate Epileptic Encephalopathy genes. This highlights sub-networks of gene expression, particularly in the network derived from the adult AHBA gene expression dataset. These networks give clues to the likely biological interactions between Epileptic Encephalopathy genes, potentially highlighting underlying mechanisms and avenues for therapeutic targets.

  8. Third party annotation gene data set of eutherian lysozyme genes

    OpenAIRE

    Premzl, Marko

    2014-01-01

    The eutherian comparative genomic analysis protocol annotated most comprehensive eutherian lysozyme gene data set. Among 209 potential coding sequences, the third party annotation gene data set of eutherian lysozyme genes included 116 complete coding sequences that first described seven major gene clusters. As one new framework of future experiments, the present integrated gene annotations, phylogenetic analysis and protein molecular evolution analysis proposed new classification and nomencla...

  9. [Telomere length and phylogenetic relationship of Baikal and Siberian planarians (Turbellaria, Tricladida)].

    Science.gov (United States)

    Koroleva, A G; Evtushenko, E V; Timoshkin, O A; Vershinin, A V; Kiril'chik, S V

    2013-01-01

    Dynamics of the telomeric DNA (tDNA) and the phylogeny of the Baikal and Siberian planarians have been studied based on the analysis of the 18S rDNA and beta-actin gene fragments. A relationship between tDNA and the planarians size has been demonstrated. Giant planarians with a minor exception have longer tDNA than little planarians. Phylogenetic affinity between the species that have the stretched tracks of tDNA, big size and similar habitats may indicate possible role of tDNA in the development of the indefinite regenerative capacity of planarians.

  10. Gene therapy prospects--intranasal delivery of therapeutic genes.

    Science.gov (United States)

    Podolska, Karolina; Stachurska, Anna; Hajdukiewicz, Karolina; Małecki, Maciej

    2012-01-01

    Gene therapy is recognized to be a novel method for the treatment of various disorders. Gene therapy strategies involve gene manipulation on broad biological processes responsible for the spreading of diseases. Cancer, monogenic diseases, vascular and infectious diseases are the main targets of gene therapy. In order to obtain valuable experimental and clinical results, sufficient gene transfer methods are required. Therapeutic genes can be administered into target tissues via gene carriers commonly defined as vectors. The retroviral, adenoviral and adeno-associated virus based vectors are most frequently used in the clinic. So far, gene preparations may be administered directly into target organs or by intravenous, intramuscular, intratumor or intranasal injections. It is common knowledge that the number of gene therapy clinical trials has rapidly increased. However, some limitations such as transfection efficiency and stable and long-term gene expression are still not resolved. Consequently, great effort is focused on the evaluation of new strategies of gene delivery. There are many expectations associated with intranasal delivery of gene preparations for the treatment of diseases. Intranasal delivery of therapeutic genes is regarded as one of the most promising forms of pulmonary gene therapy research. Gene therapy based on inhalation of gene preparations offers an alternative way for the treatment of patients suffering from such lung diseases as cystic fibrosis, alpha-1-antitrypsin defect, or cancer. Experimental and first clinical trials based on plasmid vectors or recombinant viruses have revealed that gene preparations can effectively deliver therapeutic or marker genes to the cells of the respiratory tract. The noninvasive intranasal delivery of gene preparations or conventional drugs seems to be very encouraging, although basic scientific research still has to continue.

  11. Radionuclide reporter gene imaging for cardiac gene therapy

    International Nuclear Information System (INIS)

    Inubushi, Masayuki; Tamaki, Nagara

    2007-01-01

    In the field of cardiac gene therapy, angiogenic gene therapy has been most extensively investigated. The first clinical trial of cardiac angiogenic gene therapy was reported in 1998, and at the peak, more than 20 clinical trial protocols were under evaluation. However, most trials have ceased owing to the lack of decisive proof of therapeutic effects and the potential risks of viral vectors. In order to further advance cardiac angiogenic gene therapy, remaining open issues need to be resolved: there needs to be improvement of gene transfer methods, regulation of gene expression, development of much safer vectors and optimisation of therapeutic genes. For these purposes, imaging of gene expression in living organisms is of great importance. In radionuclide reporter gene imaging, ''reporter genes'' transferred into cell nuclei encode for a protein that retains a complementary ''reporter probe'' of a positron or single-photon emitter; thus expression of the reporter genes can be imaged with positron emission tomography or single-photon emission computed tomography. Accordingly, in the setting of gene therapy, the location, magnitude and duration of the therapeutic gene co-expression with the reporter genes can be monitored non-invasively. In the near future, gene therapy may evolve into combination therapy with stem/progenitor cell transplantation, so-called cell-based gene therapy or gene-modified cell therapy. Radionuclide reporter gene imaging is now expected to contribute in providing evidence on the usefulness of this novel therapeutic approach, as well as in investigating the molecular mechanisms underlying neovascularisation and safety issues relevant to further progress in conventional gene therapy. (orig.)

  12. [Gene therapy in cardiology].

    Science.gov (United States)

    Jay, David

    2002-01-01

    The modification of genetic material of living cells for therapeutic purposes have been regarded by many as an unrealized promise. However, recent successful achievements in the field have contributed to vanish this perception and have reopened the possibility to use gene therapy as a medical intervention in humans. In the case of cardiovascular diseases, and despite its high prevalence, the number of approved human gene therapy protocols has remained low. This may be due, at least in part, to the availability of effective alternative therapies for some of the most common vasculopathies. However, recent advances in the understanding of the genetic and molecular bases of the cardiovascular system have opened the possibility to introduce gene therapy in the management of a great variety of cardiovascular disorders. The purpose of this communication is to briefly summarize the progress in this area.

  13. Gene decay in archaea

    Directory of Open Access Journals (Sweden)

    M. W. J. van Passel

    2007-01-01

    Full Text Available The gene-dense chromosomes of archaea and bacteria were long thought to be devoid of pseudogenes, but with the massive increase in available genome sequences, whole genome comparisons between closely related species have identified mutations that have rendered numerous genes inactive. Comparative analyses of sequenced archaeal genomes revealed numerous pseudogenes, which can constitute up to 8.6% of the annotated coding sequences in some genomes. The largest proportion of pseudogenes is created by gene truncations, followed by frameshift mutations. Within archaeal genomes, large numbers of pseudogenes contain more than one inactivating mutation, suggesting that pseudogenes are deleted from the genome more slowly in archaea than in bacteria. Although archaea seem to retain pseudogenes longer than do bacteria, most archaeal genomes have unique repertoires of pseudogenes.

  14. Neighboring Genes Show Correlated Evolution in Gene Expression

    Science.gov (United States)

    Ghanbarian, Avazeh T.; Hurst, Laurence D.

    2015-01-01

    When considering the evolution of a gene’s expression profile, we commonly assume that this is unaffected by its genomic neighborhood. This is, however, in contrast to what we know about the lack of autonomy between neighboring genes in gene expression profiles in extant taxa. Indeed, in all eukaryotic genomes genes of similar expression-profile tend to cluster, reflecting chromatin level dynamics. Does it follow that if a gene increases expression in a particular lineage then the genomic neighbors will also increase in their expression or is gene expression evolution autonomous? To address this here we consider evolution of human gene expression since the human-chimp common ancestor, allowing for both variation in estimation of current expression level and error in Bayesian estimation of the ancestral state. We find that in all tissues and both sexes, the change in gene expression of a focal gene on average predicts the change in gene expression of neighbors. The effect is highly pronounced in the immediate vicinity (genes increasing their expression in humans tend to avoid nuclear lamina domains and be enriched for the gene activator 5-hydroxymethylcytosine, we conclude that, most probably owing to chromatin level control of gene expression, a change in gene expression of one gene likely affects the expression evolution of neighbors, what we term expression piggybacking, an analog of hitchhiking. PMID:25743543

  15. Characterization of Soybean mosaic virus resistance derived from inverted repeat-SMV-HC-Pro genes in multiple soybean cultivars.

    Science.gov (United States)

    Gao, Le; Ding, Xueni; Li, Kai; Liao, Wenlin; Zhong, Yongkun; Ren, Rui; Liu, Zhitao; Adhimoolam, Karthikeyan; Zhi, Haijian

    2015-08-01

    Soybean mosaic virus resistance was significantly improved in multiple soybean cultivars through genetic transformation induced by inverted repeat-SMV- HC - Pro genes based on RNAi and post-transcriptional gene silencing. Here, we demonstrate Soybean mosaic virus (SMV) resistance in transgenic soybean plants. Transformation of five soybean genotypes with a construct containing inverted repeat-SMV-HC-Pro genes-induced high-level SMV resistance. Through leaf-painting assays, polymerase chain reaction (PCR) verification and LibertyLink(®) strip detection, 105 T0 and 1059 T1 plants were confirmed as transgene-positive. Southern blotting confirmed insertion of the T-DNA into the genomic DNA and revealed a low-copy integration pattern. Most T0 plants were fertile and transmitted the exogenous genes to their progenies (ratios of 3:1 or 15:1). In the T1 generation, virus resistance was evaluated visually after inoculation with SMV (strain SC3) and 441 plants were highly resistant (HR). SMV disease rating was classified on a scale with 0 = symptomless and 4 = mosaic symptoms with severe leaf curl. In the positive T1 plants, the disease rating on average was 1.42 (range 0.45-2.14) versus 3.2 (range 2-4) for the nontransformed plants. With the T2 generation, 75 transgene-positive plants were inoculated with SC3, and 57 HR plants were identified. Virus-induced seed coat mottling was eliminated in the resistant lines. Analysis of SMV levels in the plants was performed using quantitative real-time PCR and double-antibody sandwich enzyme-linked immunosorbent assays; the results revealed no virus or a gradual reduction over time in the viral content, thereby supporting the visual examination results. This is the first report demonstrating pathogen-derived resistance to SMV induced by inverted repeat-SMV-HC-Pro genes in multiple soybean cultivars. Our findings contribute positively to the study of transgenic SMV-resistance using RNA interference.

  16. Inferring horizontal gene transfer.

    Directory of Open Access Journals (Sweden)

    Matt Ravenhall

    2015-05-01

    Full Text Available Horizontal or Lateral Gene Transfer (HGT or LGT is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages. Computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. Sequence composition-based ("parametric" methods search for deviations from the genomic average, whereas evolutionary history-based ("phylogenetic" approaches identify genes whose evolutionary history significantly differs from that of the host species. The evaluation and benchmarking of HGT inference methods typically rely upon simulated genomes, for which the true history is known. On real data, different methods tend to infer different HGT events, and as a result it can be difficult to ascertain all but simple and clear-cut HGT events.

  17. Genes in mammalian reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gwatkin, R.B.L. [ed.

    1996-11-01

    This is an informative book which deals mainly with genomic imprinting, the role of steroid hormones in development, the expression of a variety of genes during development and the link to hereditary diseases. It is an up-to-date review in a field that is quickly changing and provides valuable basic information and current research trends.

  18. Are there anxious genes?

    Science.gov (United States)

    Morris-Rosendahl, Deborah J.

    2002-01-01

    Anxiety comprises many clinical descriptions and phenotypes. A genetic predisposition to anxiety is undoubted; however, the nature and extent of that contribution is still unclear. Methods for the genetic analysis of such complex disorders is briefly reviewed, followed by a discussion of the comorbidity of anxiety with other psychiatric disorders and their possible common genetic etiology. Extensive genetic studies of the serotonin (5-hydroxytryptamine, 5-HT) transporter (5-HTT) gene have revealed how variation in gene expression can be correlated with anxiety phenotypes. Complete genome-wide linkage scans for panic disorder (PD) susceptibility genes have suggested a locus on chromosome arm 7p, and association studies have highlighted many candidate genes. A highly significant association between phobias, panic disorder, and a duplication at chromosomal region 15q24-26 is one of the most exciting findings to date. Emerging molecular genetic technologies and the use of increasingly sophisticated animal models of anxiety provide great promise for the future of the field. PMID:22033820

  19. Silence of the Genes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 4. Silence of the Genes - 2006 Nobel Prize in Physiology or Medicine. Utpal Nath Saumitra Das. General Article Volume 12 Issue 4 April 2007 pp 6-18. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Searching for speciation genes

    DEFF Research Database (Denmark)

    Holt, Benjamin George; Côté, Isabelle M; Emerson, Brent C

    2011-01-01

    Closely related species that show clear phenotypic divergence, but without obvious geographic barriers, can provide opportunities to study how diversification can occur when opportunities for allopatric speciation are limited. We examined genetic divergence in the coral reef fish genus Hypoplectr...... evidence for genes that may be associated with colour morphotype in the genus Hypoplectrus....

  1. How Genes Evolve

    Indian Academy of Sciences (India)

    Haemoglobin is a well known respiratory pigment which transports oxygen to various tissues of the body. Tetrameric haemoglo bin (Hb) molecules consist of two .... production of a tetramer that was more effective in oxygen transport and release as compared to the ancestral monomeric form of haemoglobin. Further, gene ...

  2. pyrophosphatase gene in rye

    Indian Academy of Sciences (India)

    photoperiod. Leaves, stems and roots were collected sepa- rately at 6-h intervals from the start (0 h) to the end (72 h) of each experiment. Each treatment was conducted in triplicate. All samples were immediately frozen in liquid nitrogen and were stored at −80. ◦. C until being used for analysis. Isolation of the ScHP1 gene.

  3. Hidden genes in birds

    Czech Academy of Sciences Publication Activity Database

    Hron, Tomáš; Pajer, Petr; Pačes, Jan; Bartůněk, Petr; Elleder, Daniel

    2015-01-01

    Roč. 16, August 18 (2015) ISSN 1465-6906 R&D Projects: GA MŠk(CZ) LK11215; GA MŠk LO1419 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:68378050 Keywords : REPETITIVE SEQUENCES * G/C stretches * avian genes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.313, year: 2015

  4. What is a Gene?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 4. What is a Gene? A Question With Variable Answers. S C Lakhotia. General Article Volume 2 Issue 4 April 1997 pp 38-47. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/04/0038-0047 ...

  5. What is a Gene?

    Indian Academy of Sciences (India)

    certain supra-genic aspects of biological information that we inherit through the generations and has a profound role in gene activity. Our understanding of the structure and organization of the genetic material has greatly increased in recent years: we have deciphered the total DNA base sequence of genomes of some.

  6. Suicide genes or p53 gene and p53 target genes as targets for cancer gene therapy by ionizing radiation

    International Nuclear Information System (INIS)

    Liu Bing; Chinese Academy of Sciences, Beijing; Zhang Hong

    2005-01-01

    Radiotherapy has some disadvantages due to the severe side-effect on the normal tissues at a curative dose of ionizing radiation (IR). Similarly, as a new developing approach, gene therapy also has some disadvantages, such as lack of specificity for tumors, limited expression of therapeutic gene, potential biological risk. To certain extent, above problems would be solved by the suicide genes or p53 gene and its target genes therapies targeted by ionizing radiation. This strategy not only makes up the disadvantage from radiotherapy or gene therapy alone, but also promotes success rate on the base of lower dose. By present, there have been several vectors measuring up to be reaching clinical trials. This review focused on the development of the cancer gene therapy through suicide genes or p53 and its target genes mediated by IR. (authors)

  7. Misexpression of AtTX12 encoding a Toll/interleukin-1 receptor domain induces growth defects and expression of defense-related genes partially independently of EDS1 in Arabidopsis.

    Science.gov (United States)

    Song, Sang-Kee

    2016-12-01

    In this study, a tissue-specific GAL4/UAS activation tagging system was used for the characterization of genes which could induce lethality when ubiquitously expressed. A dominant mutant exhibiting stunted growth was isolated and named defective root development 1-D (drd1-D). The T-DNA tag was located within the promoter region of AtTX12, which is predicted to encode a truncated nucleotide-binding leucinerich repeat (NLR) protein, containing a Toll/interleukin-1 receptor (TIR) domain. The transcript levels of AtTX12 and defense-related genes were elevated in drd1-D, and the misexpression of AtTX12 recapitulated the drd1-D phenotypes. In the presence of ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), a key transducer of signals triggered by TIR-type NLRs, a low-level of AtTX12 misexpression induced strong defective phenotypes including seedling lethality whereas, in the absence of EDS1, a high-level of AtTX12 misexpression induced weak growth defects like dwarfism, suggesting that AtTX12 might function mainly in an EDS1-dependent and partially in an EDS1-independent manner. [BMB Reports 2016; 49(12): 693-698].

  8. Genes2FANs: connecting genes through functional association networks

    Science.gov (United States)

    2012-01-01

    Background Protein-protein, cell signaling, metabolic, and transcriptional interaction networks are useful for identifying connections between lists of experimentally identified genes/proteins. However, besides physical or co-expression interactions there are many ways in which pairs of genes, or their protein products, can be associated. By systematically incorporating knowledge on shared properties of genes from diverse sources to build functional association networks (FANs), researchers may be able to identify additional functional interactions between groups of genes that are not readily apparent. Results Genes2FANs is a web based tool and a database that utilizes 14 carefully constructed FANs and a large-scale protein-protein interaction (PPI) network to build subnetworks that connect lists of human and mouse genes. The FANs are created from mammalian gene set libraries where mouse genes are converted to their human orthologs. The tool takes as input a list of human or mouse Entrez gene symbols to produce a subnetwork and a ranked list of intermediate genes that are used to connect the query input list. In addition, users can enter any PubMed search term and then the system automatically converts the returned results to gene lists using GeneRIF. This gene list is then used as input to generate a subnetwork from the user’s PubMed query. As a case study, we applied Genes2FANs to connect disease genes from 90 well-studied disorders. We find an inverse correlation between the counts of links connecting disease genes through PPI and links connecting diseases genes through FANs, separating diseases into two categories. Conclusions Genes2FANs is a useful tool for interpreting the relationships between gene/protein lists in the context of their various functions and networks. Combining functional association interactions with physical PPIs can be useful for revealing new biology and help form hypotheses for further experimentation. Our finding that disease genes in

  9. Industrial scale gene synthesis.

    Science.gov (United States)

    Notka, Frank; Liss, Michael; Wagner, Ralf

    2011-01-01

    The most recent developments in the area of deep DNA sequencing and downstream quantitative and functional analysis are rapidly adding a new dimension to understanding biochemical pathways and metabolic interdependencies. These increasing insights pave the way to designing new strategies that address public needs, including environmental applications and therapeutic inventions, or novel cell factories for sustainable and reconcilable energy or chemicals sources. Adding yet another level is building upon nonnaturally occurring networks and pathways. Recent developments in synthetic biology have created economic and reliable options for designing and synthesizing genes, operons, and eventually complete genomes. Meanwhile, high-throughput design and synthesis of extremely comprehensive DNA sequences have evolved into an enabling technology already indispensable in various life science sectors today. Here, we describe the industrial perspective of modern gene synthesis and its relationship with synthetic biology. Gene synthesis contributed significantly to the emergence of synthetic biology by not only providing the genetic material in high quality and quantity but also enabling its assembly, according to engineering design principles, in a standardized format. Synthetic biology on the other hand, added the need for assembling complex circuits and large complexes, thus fostering the development of appropriate methods and expanding the scope of applications. Synthetic biology has also stimulated interdisciplinary collaboration as well as integration of the broader public by addressing socioeconomic, philosophical, ethical, political, and legal opportunities and concerns. The demand-driven technological achievements of gene synthesis and the implemented processes are exemplified by an industrial setting of large-scale gene synthesis, describing production from order to delivery. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Genes contributing to prion pathogenesis

    DEFF Research Database (Denmark)

    Tamgüney, Gültekin; Giles, Kurt; Glidden, David V

    2008-01-01

    incubation times, indicating that the conversion reaction may be influenced by other gene products. To identify genes that contribute to prion pathogenesis, we analysed incubation times of prions in mice in which the gene product was inactivated, knocked out or overexpressed. We tested 20 candidate genes...... show that many genes previously implicated in prion replication have no discernible effect on the pathogenesis of prion disease. While most genes tested did not significantly affect survival times, ablation of the amyloid beta (A4) precursor protein (App) or interleukin-1 receptor, type I (Il1r1...

  11. Patenting human genes: Chinese academic articles' portrayal of gene patents.

    Science.gov (United States)

    Du, Li

    2018-04-24

    The patenting of human genes has been the subject of debate for decades. While China has gradually come to play an important role in the global genomics-based testing and treatment market, little is known about Chinese scholars' perspectives on patent protection for human genes. A content analysis of academic literature was conducted to identify Chinese scholars' concerns regarding gene patents, including benefits and risks of patenting human genes, attitudes that researchers hold towards gene patenting, and any legal and policy recommendations offered for the gene patent regime in China. 57.2% of articles were written by law professors, but scholars from health sciences, liberal arts, and ethics also participated in discussions on gene patent issues. While discussions of benefits and risks were relatively balanced in the articles, 63.5% of the articles favored gene patenting in general and, of the articles (n = 41) that explored gene patents in the Chinese context, 90.2% supported patent protections for human genes in China. The patentability of human genes was discussed in 33 articles, and 75.8% of these articles reached the conclusion that human genes are patentable. Chinese scholars view the patent regime as an important legal tool to protect the interests of inventors and inventions as well as the genetic resources of China. As such, many scholars support a gene patent system in China. These attitudes towards gene patents remain unchanged following the court ruling in the Myriad case in 2013, but arguments have been raised about the scope of gene patents, in particular that the increasing numbers of gene patents may negatively impact public health in China.

  12. Gene set analysis for longitudinal gene expression data

    Directory of Open Access Journals (Sweden)

    Piepho Hans-Peter

    2011-07-01

    Full Text Available Abstract Background Gene set analysis (GSA has become a successful tool to interpret gene expression profiles in terms of biological functions, molecular pathways, or genomic locations. GSA performs statistical tests for independent microarray samples at the level of gene sets rather than individual genes. Nowadays, an increasing number of microarray studies are conducted to explore the dynamic changes of gene expression in a variety of species and biological scenarios. In these longitudinal studies, gene expression is repeatedly measured over time such that a GSA needs to take into account the within-gene correlations in addition to possible between-gene correlations. Results We provide a robust nonparametric approach to compare the expressions of longitudinally measured sets of genes under multiple treatments or experimental conditions. The limiting distributions of our statistics are derived when the number of genes goes to infinity while the number of replications can be small. When the number of genes in a gene set is small, we recommend permutation tests based on our nonparametric test statistics to achieve reliable type I error and better power while incorporating unknown correlations between and within-genes. Simulation results demonstrate that the proposed method has a greater power than other methods for various data distributions and heteroscedastic correlation structures. This method was used for an IL-2 stimulation study and significantly altered gene sets were identified. Conclusions The simulation study and the real data application showed that the proposed gene set analysis provides a promising tool for longitudinal microarray analysis. R scripts for simulating longitudinal data and calculating the nonparametric statistics are posted on the North Dakota INBRE website http://ndinbre.org/programs/bioinformatics.php. Raw microarray data is available in Gene Expression Omnibus (National Center for Biotechnology Information with

  13. Optimal Reference Genes for Gene Expression Normalization in Trichomonas vaginalis.

    Science.gov (United States)

    dos Santos, Odelta; de Vargas Rigo, Graziela; Frasson, Amanda Piccoli; Macedo, Alexandre José; Tasca, Tiana

    2015-01-01

    Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR), one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis.

  14. Optimal Reference Genes for Gene Expression Normalization in Trichomonas vaginalis.

    Directory of Open Access Journals (Sweden)

    Odelta dos Santos

    Full Text Available Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR, one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis.

  15. Gene therapy in keratoconus

    Directory of Open Access Journals (Sweden)

    Mahgol Farjadnia

    2015-01-01

    Full Text Available Keratoconus (KC is the most common ectasia of the cornea and is a common reason for corneal transplant. Therapeutic strategies that can arrest the progression of this disease and modify the underlying pathogenesis are getting more and more popularity among scientists. Cumulating data represent strong evidence of a genetic role in the pathogenesis of KC. Different loci have been identified, and certain mutations have also been mapped for this disease. Moreover, Biophysical properties of the cornea create an appropriate candidate of this tissue for gene therapy. Immune privilege, transparency and ex vivo stability are among these properties. Recent advantage in vectors, besides the ability to modulate the corneal milieu for accepting the target gene for a longer period and fruitful translation, make a big hope for stupendous results reasonable.

  16. Graphene based gene transfection

    Science.gov (United States)

    Feng, Liangzhu; Zhang, Shuai; Liu, Zhuang

    2011-03-01

    Graphene as a star in materials research has been attracting tremendous attentions in the past few years in various fields including biomedicine. In this work, for the first time we successfully use graphene as a non-toxic nano-vehicle for efficient gene transfection. Graphene oxide (GO) is bound with cationic polymers, polyethyleneimine (PEI) with two different molecular weights at 1.2 kDa and 10 kDa, forming GO-PEI-1.2k and GO-PEG-10k complexes, respectively, both of which are stable in physiological solutions. Cellular toxicity tests reveal that our GO-PEI-10k complex exhibits significantly reduced toxicity to the treated cells compared to the bare PEI-10k polymer. The positively charged GO-PEI complexes are able to further bind with plasmid DNA (pDNA) for intracellular transfection of the enhanced green fluorescence protein (EGFP) gene in HeLa cells. While EGFP transfection with PEI-1.2k appears to be ineffective, high EGFP expression is observed using the corresponding GO-PEI-1.2k as the transfection agent. On the other hand, GO-PEI-10k shows similar EGFP transfection efficiency but lower toxicity compared with PEI-10k. Our results suggest graphene to be a novel gene delivery nano-vector with low cytotoxicity and high transfection efficiency, promising for future applications in non-viral based gene therapy.Graphene as a star in materials research has been attracting tremendous attentions in the past few years in various fields including biomedicine. In this work, for the first time we successfully use graphene as a non-toxic nano-vehicle for efficient gene transfection. Graphene oxide (GO) is bound with cationic polymers, polyethyleneimine (PEI) with two different molecular weights at 1.2 kDa and 10 kDa, forming GO-PEI-1.2k and GO-PEG-10k complexes, respectively, both of which are stable in physiological solutions. Cellular toxicity tests reveal that our GO-PEI-10k complex exhibits significantly reduced toxicity to the treated cells compared to the bare PEI

  17. Gene Expression in Bone

    Science.gov (United States)

    D'Ambrogio, A.

    Skeletal system has two main functions, to provide mechanical integrity for both locomotion and protection and to play an important role in mineral homeostasis. There is extensive evidence showing loss of bone mass during long-term Space-Flights. The loss is due to a break in the equilibrium between the activity of osteoblasts (the cells that forms bone) and the activity of osteoclasts (the cells that resorbs bone). Surprisingly, there is scanty information about the possible altered gene expression occurring in cells that form bone in microgravity.(Just 69 articles result from a "gene expression in microgravity" MedLine query.) Gene-chip or microarray technology allows to screen thousands of genes at the same time: the use of this technology on samples coming from cells exposed to microgravity could provide us with many important informations. For example, the identification of the molecules or structures which are the first sensors of the mechanical stress derived from lack of gravity, could help in understanding which is the first event leading to bone loss due to long-term exposure to microgravity. Consequently, this structure could become a target for a custom-designed drug. It is evident that bone mass loss, observed during long-time stay in Space, represents an accelerated model of what happens in aging osteoporosis. Therefore, the discovery and design of drugs able to interfere with the bone-loss process, could help also in preventing negative physiological processes normally observed on Earth. Considering the aims stated above, my research is designed to:

  18. Gene Porter Bridwell

    Science.gov (United States)

    1994-01-01

    Gene Porter Bridwell served as the director of the Marshall Space Flight Center from January 6, 1994 until February 3, 1996, when he retired from NASA after thirty-four years service. Bridwell, a Marshall employee since 1962, had been Marshall's Space Shuttle Projects Office Director and Space Station Redesign Team deputy manager. Under Bridwell, Marshall worked to develop its role as a Center of Excellence for propulsion and for providing access to space.

  19. 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

  20. Regulation of eucaryotic gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Brent, R.; Ptashne, M.S

    1989-05-23

    This patent describes a method of regulating the expression of a gene in a eucaryotic cell. The method consists of: providing in the eucaryotic cell, a peptide, derived from or substantially similar to a peptide of a procaryotic cell able to bind to DNA upstream from or within the gene, the amount of the peptide being sufficient to bind to the gene and thereby control expression of the gene.

  1. Genealogy and gene trees.

    Science.gov (United States)

    Rasmuson, Marianne

    2008-02-01

    Heredity can be followed in persons or in genes. Persons can be identified only a few generations back, but simplified models indicate that universal ancestors to all now living persons have occurred in the past. Genetic variability can be characterized as variants of DNA sequences. Data are available only from living persons, but from the pattern of variation gene trees can be inferred by means of coalescence models. The merging of lines backwards in time leads to a MRCA (most recent common ancestor). The time and place of living for this inferred person can give insights in human evolutionary history. Demographic processes are incorporated in the model, but since culture and customs are known to influence demography the models used ought to be tested against available genealogy. The Icelandic data base offers a possibility to do so and points to some discrepancies. Mitochondrial DNA and Y chromosome patterns give a rather consistent view of human evolutionary history during the latest 100 000 years but the earlier epochs of human evolution demand gene trees with longer branches. The results of such studies reveal as yet unsolved problems about the sources of our genome.

  2. Gene-gene and gene-environmental interactions of childhood asthma: a multifactor dimension reduction approach.

    Directory of Open Access Journals (Sweden)

    Ming-Wei Su

    Full Text Available BACKGROUND: The importance of gene-gene and gene-environment interactions on asthma is well documented in literature, but a systematic analysis on the interaction between various genetic and environmental factors is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a population-based, case-control study comprised of seventh-grade children from 14 Taiwanese communities. A total of 235 asthmatic cases and 1,310 non-asthmatic controls were selected for DNA collection and genotyping. We examined the gene-gene and gene-environment interactions between 17 single-nucleotide polymorphisms in antioxidative, inflammatory and obesity-related genes, and childhood asthma. Environmental exposures and disease status were obtained from parental questionnaires. The model-free and non-parametrical multifactor dimensionality reduction (MDR method was used for the analysis. A three-way gene-gene interaction was elucidated between the gene coding glutathione S-transferase P (GSTP1, the gene coding interleukin-4 receptor alpha chain (IL4Ra and the gene coding insulin induced gene 2 (INSIG2 on the risk of lifetime asthma. The testing-balanced accuracy on asthma was 57.83% with a cross-validation consistency of 10 out of 10. The interaction of preterm birth and indoor dampness had the highest training-balanced accuracy at 59.09%. Indoor dampness also interacted with many genes, including IL13, beta-2 adrenergic receptor (ADRB2, signal transducer and activator of transcription 6 (STAT6. We also used likelihood ratio tests for interaction and chi-square tests to validate our results and all tests showed statistical significance. CONCLUSIONS/SIGNIFICANCE: The results of this study suggest that GSTP1, INSIG2 and IL4Ra may influence the lifetime asthma susceptibility through gene-gene interactions in schoolchildren. Home dampness combined with each one of the genes STAT6, IL13 and ADRB2 could raise the asthma risk.

  3. Gene therapy of cancer and development of therapeutic target gene

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Min; Kwon, Hee Chung

    1998-04-01

    We applied HSV-tk/GCV strategy to orthotopic rat hepatoma model and showed anticancer effects of hepatoma. The increased expression of Lac Z gene after adenovirus-mediated gene delivery throughout hepatic artery was thought that is increased the possibility of gene therapy for curing hepatoma. With the construction of kGLP-laboratory, it is possible to produce a good quantity and quality of adenovirus in lage-scale production and purification of adenovirus vector. Also, the analysis of hepatoma related genes by PCR-LOH could be used for the diagnosis of patients and the development of therapeutic gene.

  4. Gene therapy of cancer and development of therapeutic target gene

    International Nuclear Information System (INIS)

    Kim, Chang Min; Kwon, Hee Chung

    1998-04-01

    We applied HSV-tk/GCV strategy to orthotopic rat hepatoma model and showed anticancer effects of hepatoma. The increased expression of Lac Z gene after adenovirus-mediated gene delivery throughout hepatic artery was thought that is increased the possibility of gene therapy for curing hepatoma. With the construction of kGLP-laboratory, it is possible to produce a good quantity and quality of adenovirus in lage-scale production and purification of adenovirus vector. Also, the analysis of hepatoma related genes by PCR-LOH could be used for the diagnosis of patients and the development of therapeutic gene

  5. Gene probes: principles and protocols

    National Research Council Canada - National Science Library

    Aquino de Muro, Marilena; Rapley, Ralph

    2002-01-01

    ... of labeled DNA has allowed genes to be mapped to single chromosomes and in many cases to a single chromosome band, promoting significant advance in human genome mapping. Gene Probes: Principles and Protocols presents the principles for gene probe design, labeling, detection, target format, and hybridization conditions together with detailed protocols, accom...

  6. Independent Gene Discovery and Testing

    Science.gov (United States)

    Palsule, Vrushalee; Coric, Dijana; Delancy, Russell; Dunham, Heather; Melancon, Caleb; Thompson, Dennis; Toms, Jamie; White, Ashley; Shultz, Jeffry

    2010-01-01

    A clear understanding of basic gene structure is critical when teaching molecular genetics, the central dogma and the biological sciences. We sought to create a gene-based teaching project to improve students' understanding of gene structure and to integrate this into a research project that can be implemented by instructors at the secondary level…

  7. Compositional gradients in Gramineae genes

    DEFF Research Database (Denmark)

    Wong, Gane Ka-Shu; Wang, Jun; Tao, Lin

    2002-01-01

    In this study, we describe a property of Gramineae genes, and perhaps all monocot genes, that is not observed in eudicot genes. Along the direction of transcription, beginning at the junction of the 5'-UTR and the coding region, there are gradients in GC content, codon usage, and amino-acid usage...

  8. Gene electrotransfer in clinical trials

    DEFF Research Database (Denmark)

    Gehl, Julie

    2014-01-01

    Electroporation is increasingly being used for delivery of chemotherapy to tumors. Likewise, gene delivery by electroporation is rapidly gaining momentum for both vaccination purposes and for delivery of genes coding for other therapeutic molecules, such as chronic diseases or cancer. This chapte...... describes how gene therapy may be performed using electric pulses to enhance uptake and expression.......Electroporation is increasingly being used for delivery of chemotherapy to tumors. Likewise, gene delivery by electroporation is rapidly gaining momentum for both vaccination purposes and for delivery of genes coding for other therapeutic molecules, such as chronic diseases or cancer. This chapter...

  9. The ethics of gene therapy.

    Science.gov (United States)

    Chan, Sarah; Harris, John

    2006-10-01

    Recent developments have progressed in areas of science that pertain to gene therapy and its ethical implications. This review discusses the current state of therapeutic gene technologies, including stem cell therapies and genetic modification, and identifies ethical issues of concern in relation to the science of gene therapy and its application, including the ethics of embryonic stem cell research and therapeutic cloning, the risks associated with gene therapy, and the ethics of clinical research in developing new therapeutic technologies. Additionally, ethical issues relating to genetic modification itself are considered: the significance of the human genome, the distinction between therapy and enhancement, and concerns regarding gene therapy as a eugenic practice.

  10. Exploring new gene integration sites for gene knock-in by gene-trapping strategy.

    Science.gov (United States)

    Nanchi, Isamu; Yoshimura, Yuki; Nakamura, Kazuomi; Masago, Yusaku; Ohbayashi, Tetsuya; Okuda, Tomohiko

    2015-06-01

    The knock-in mouse is a powerful tool for biological research, but the stability of expression of an integrated gene strongly depends on where it is integrated in the mouse genome. At present, there are an insufficient number of loci suitable for gene knock-in, such as the Rosa26 locus. Therefore, in this study, we developed an efficient strategy for identifying genome loci suitable for gene knock-in and characterized the properties of such loci for gene integration. For efficient discovery and characterization, we constructed a new gene-trapping vector that enables monitoring of the expression of both trapped and integrated genes using fluorescence. We successfully obtained fluorescent-positive mouse embryonic stem cell (mESC) clones with the vector. Thorough analysis of the expression of fluorescent proteins in chimera embryos generated with the obtained mESC clones, some of the gene-trapped chimera embryos showed stable and ubiquitous expression of the integrated gene. Furthermore, adult mice derived from one of the gene-trapped mESC clones showed ubiquitous expression of the integrated gene in various tissues without any unusual phenotype. This indicated that the identified locus possesses high potential for foreign gene integration. Our strategy allows for efficient discovery and characterization of mouse genome loci for gene integration.

  11. Radiopharmaceuticals to monitor gene transfer

    International Nuclear Information System (INIS)

    Wiebe, L. I.; Morin, K. W.; Knaus, E. E.

    1997-01-01

    Advances in genetic engineering and molecular biology have opened the door to disease treatment by transferring genes to cells that are responsible for the pathological condition being addressed. These genes can serve to supplement or introduce the function of indigenous genes that are either inadequately expressed or that are congenitally absent in the patient. They can introduce new functions such as drug sensitization to provide a unique therapeutic target. Gene transfer is readily monitored in vitro using a range of histochemical and biochemical tests that are ''built in'' to the therapeutic gene cassette. In vivo, in situ monitoring of the gene transfer and gene expression processes can be achieved with these tests only if biopsy is possible. Scintigraphic imaging can offer unique information on both the extent and location of gene expression, provided that an appropriate reporter gene is included in the therapeutic cassette. This overview includes a brief orientation to gene transfer therapy and is followed by a review of current approaches to gene therapy imaging. The concluding section deals with imaging based on radiolabelled nucleoside substrates for herpes simplex type-1 thymidine kinase, with emphasis on IVFRU, a stable potent and selective HSV-1 TK substrate developed in their laboratories

  12. Gene finding in novel genomes

    Directory of Open Access Journals (Sweden)

    Korf Ian

    2004-05-01

    Full Text Available Abstract Background Computational gene prediction continues to be an important problem, especially for genomes with little experimental data. Results I introduce the SNAP gene finder which has been designed to be easily adaptable to a variety of genomes. In novel genomes without an appropriate gene finder, I demonstrate that employing a foreign gene finder can produce highly inaccurate results, and that the most compatible parameters may not come from the nearest phylogenetic neighbor. I find that foreign gene finders are more usefully employed to bootstrap parameter estimation and that the resulting parameters can be highly accurate. Conclusion Since gene prediction is sensitive to species-specific parameters, every genome needs a dedicated gene finder.

  13. Gene circuit analysis of the terminal gap gene huckebein.

    Directory of Open Access Journals (Sweden)

    Maksat Ashyraliyev

    2009-10-01

    Full Text Available The early embryo of Drosophila melanogaster provides a powerful model system to study the role of genes in pattern formation. The gap gene network constitutes the first zygotic regulatory tier in the hierarchy of the segmentation genes involved in specifying the position of body segments. Here, we use an integrative, systems-level approach to investigate the regulatory effect of the terminal gap gene huckebein (hkb on gap gene expression. We present quantitative expression data for the Hkb protein, which enable us to include hkb in gap gene circuit models. Gap gene circuits are mathematical models of gene networks used as computational tools to extract regulatory information from spatial expression data. This is achieved by fitting the model to gap gene expression patterns, in order to obtain estimates for regulatory parameters which predict a specific network topology. We show how considering variability in the data combined with analysis of parameter determinability significantly improves the biological relevance and consistency of the approach. Our models are in agreement with earlier results, which they extend in two important respects: First, we show that Hkb is involved in the regulation of the posterior hunchback (hb domain, but does not have any other essential function. Specifically, Hkb is required for the anterior shift in the posterior border of this domain, which is now reproduced correctly in our models. Second, gap gene circuits presented here are able to reproduce mutants of terminal gap genes, while previously published models were unable to reproduce any null mutants correctly. As a consequence, our models now capture the expression dynamics of all posterior gap genes and some variational properties of the system correctly. This is an important step towards a better, quantitative understanding of the developmental and evolutionary dynamics of the gap gene network.

  14. Maximum Gene-Support Tree

    Directory of Open Access Journals (Sweden)

    Yunfeng Shan

    2008-01-01

    Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

  15. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder. The ...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  16. Genes and Disease: Prader-Willi Syndrome

    Science.gov (United States)

    ... MD): National Center for Biotechnology Information (US); 1998-. Genes and Disease [Internet]. Show details National Center for ... 45K) PDF version of this title (3.8M) Gene sequence Genome view see gene locations Entrez Gene ...

  17. Human AZU-1 gene, variants thereof and expressed gene products

    Science.gov (United States)

    Chen, Huei-Mei; Bissell, Mina

    2004-06-22

    A human AZU-1 gene, mutants, variants and fragments thereof. Protein products encoded by the AZU-1 gene and homologs encoded by the variants of AZU-1 gene acting as tumor suppressors or markers of malignancy progression and tumorigenicity reversion. Identification, isolation and characterization of AZU-1 and AZU-2 genes localized to a tumor suppressive locus at chromosome 10q26, highly expressed in nonmalignant and premalignant cells derived from a human breast tumor progression model. A recombinant full length protein sequences encoded by the AZU-1 gene and nucleotide sequences of AZU-1 and AZU-2 genes and variant and fragments thereof. Monoclonal or polyclonal antibodies specific to AZU-1, AZU-2 encoded protein and to AZU-1, or AZU-2 encoded protein homologs.

  18. One gene, many phenotypes

    Directory of Open Access Journals (Sweden)

    Prasun P

    2007-01-01

    Full Text Available "Phenotype" is the visible or quantifiable effect of the expression of a gene, whereas the specific genetic constitution responsible for a phenotype is called "genotype". It was hoped that phenotype could be accurately predicted if the genotype could be characterized. But, the relationship between the genotype and phenotype is not straightforward. Similar genetic lesions can have entirely different phenotypes. In recent years, there has been tremendous progress in the understanding of the genetic basis of diseases. The extent to which it will be possible to relate findings at the DNA level to the clinical phenotype is difficult to delineate on many occasions. The elucidation of mechanisms underlying genotype-phenotype discrepancies is important as it will influence the use of DNA-based tests in the diagnosis, therapy and counseling of individuals affected with genetic disorders. This issue is pertinent to almost every aspect of medical practice and research in this post-genome era. In this article, we have tried to summarize those factors which are responsible for varied manifestations of lesion(s in a single gene.

  19. Arabidopsis Raf-Like Mitogen-Activated Protein Kinase Kinase Kinase Gene Raf43 Is Required for Tolerance to Multiple Abiotic Stresses.

    Directory of Open Access Journals (Sweden)

    Nasar Virk

    Full Text Available Mitogen-activated protein kinase (MAPK cascades are critical signaling modules that mediate the transduction of extracellular stimuli into intracellular response. A relatively large number of MAPKKKs have been identified in a variety of plant genomes but only a few of them have been studied for their biological function. In the present study, we identified an Arabidopsis Raf-like MAPKKK gene Raf43 and studied its function in biotic and abiotic stress response using a T-DNA insertion mutant raf43-1 and two Raf43-overexpressing lines Raf43-OE#1 and Raf43-OE#13. Expression of Raf43 was induced by multiple abiotic and biotic stresses including treatments with drought, mannitol and oxidative stress or defense signaling molecule salicylic acid and infection with necrotrophic fungal pathogen Botrytis cinerea. Seed germination and seedling root growth of raf43-1 were significantly inhibited on MS medium containing mannitol, NaCl, H2O2 or methyl viologen (MV while seed germination and seedling root growth of the Raf43-OE#1 and Raf43-OE#13 lines was similar to wild type Col-0 under the above stress conditions. Soil-grown raf43-1 plants exhibited reduced tolerance to MV, drought and salt stress. Abscisic acid inhibited significantly seed germination and seedling root growth of the raf43-1 line but had no effect on the two Raf43-overexpressing lines. Expression of stress-responsive RD17 and DREB2A genes was significantly down-regulated in raf43-1 plants. However, the raf43-1 and Raf43-overexpressing plants showed similar disease phenotype to the wild type plants after infection with B. cinerea or Pseudomonas syringae pv. tomato DC3000. Our results demonstrate that Raf43, encoding for a Raf-like MAPKKK, is required for tolerance to multiple abiotic stresses in Arabidopsis.

  20. Reverse engineering transcriptional gene networks.

    Science.gov (United States)

    Belcastro, Vincenzo; di Bernardo, Diego

    2014-01-01

    The aim of this chapter is a step-by-step guide on how to infer gene networks from gene expression profiles. The definition of a gene network is given in Subheading 1, where the different types of networks are discussed. The chapter then guides the readers through a data-gathering process in order to build a compendium of gene expression profiles from a public repository. Gene expression profiles are then discretized and a statistical relationship between genes, called mutual information (MI), is computed. Gene pairs with insignificant MI scores are then discarded by applying one of the described pruning steps. The retained relationships are then used to build up a Boolean adjacency matrix used as input for a clustering algorithm to divide the network into modules (or communities). The gene network can then be used as a hypothesis generator for discovering gene function and analyzing gene signatures. Some case studies are presented, and an online web-tool called Netview is described.

  1. Bayesian assignment of gene ontology terms to gene expression experiments.

    Science.gov (United States)

    Sykacek, P

    2012-09-15

    Gene expression assays allow for genome scale analyses of molecular biological mechanisms. State-of-the-art data analysis provides lists of involved genes, either by calculating significance levels of mRNA abundance or by Bayesian assessments of gene activity. A common problem of such approaches is the difficulty of interpreting the biological implication of the resulting gene lists. This lead to an increased interest in methods for inferring high-level biological information. A common approach for representing high level information is by inferring gene ontology (GO) terms which may be attributed to the expression data experiment. This article proposes a probabilistic model for GO term inference. Modelling assumes that gene annotations to GO terms are available and gene involvement in an experiment is represented by a posterior probabilities over gene-specific indicator variables. Such probability measures result from many Bayesian approaches for expression data analysis. The proposed model combines these indicator probabilities in a probabilistic fashion and provides a probabilistic GO term assignment as a result. Experiments on synthetic and microarray data suggest that advantages of the proposed probabilistic GO term inference over statistical test-based approaches are in particular evident for sparsely annotated GO terms and in situations of large uncertainty about gene activity. Provided that appropriate annotations exist, the proposed approach is easily applied to inferring other high level assignments like pathways. Source code under GPL license is available from the author. peter.sykacek@boku.ac.at.

  2. Bayesian assignment of gene ontology terms to gene expression experiments

    Science.gov (United States)

    Sykacek, P.

    2012-01-01

    Motivation: Gene expression assays allow for genome scale analyses of molecular biological mechanisms. State-of-the-art data analysis provides lists of involved genes, either by calculating significance levels of mRNA abundance or by Bayesian assessments of gene activity. A common problem of such approaches is the difficulty of interpreting the biological implication of the resulting gene lists. This lead to an increased interest in methods for inferring high-level biological information. A common approach for representing high level information is by inferring gene ontology (GO) terms which may be attributed to the expression data experiment. Results: This article proposes a probabilistic model for GO term inference. Modelling assumes that gene annotations to GO terms are available and gene involvement in an experiment is represented by a posterior probabilities over gene-specific indicator variables. Such probability measures result from many Bayesian approaches for expression data analysis. The proposed model combines these indicator probabilities in a probabilistic fashion and provides a probabilistic GO term assignment as a result. Experiments on synthetic and microarray data suggest that advantages of the proposed probabilistic GO term inference over statistical test-based approaches are in particular evident for sparsely annotated GO terms and in situations of large uncertainty about gene activity. Provided that appropriate annotations exist, the proposed approach is easily applied to inferring other high level assignments like pathways. Availability: Source code under GPL license is available from the author. Contact: peter.sykacek@boku.ac.at PMID:22962488

  3. Generalist genes and learning disabilities.

    Science.gov (United States)

    Plomin, Robert; Kovas, Yulia

    2005-07-01

    The authors reviewed recent quantitative genetic research on learning disabilities that led to the conclusion that genetic diagnoses differ from traditional diagnoses in that the effects of relevant genes are largely general rather than specific. This research suggests that most genes associated with common learning disabilities--language impairment, reading disability, and mathematics disability--are generalists in 3 ways. First, genes that affect common learning disabilities are largely the same genes responsible for normal variation in learning abilities. Second, genes that affect any aspect of a learning disability affect other aspects of the disability. Third, genes that affect one learning disability are also likely to affect other learning disabilities. These quantitative genetic findings have far-reaching implications for molecular genetics and neuroscience as well as psychology. Copyright 2005 APA, all rights reserved.

  4. Differential Gene Expression and Aging

    Directory of Open Access Journals (Sweden)

    Laurent Seroude

    2002-01-01

    Full Text Available It has been established that an intricate program of gene expression controls progression through the different stages in development. The equally complex biological phenomenon known as aging is genetically determined and environmentally modulated. This review focuses on the genetic component of aging, with a special emphasis on differential gene expression. At least two genetic pathways regulating organism longevity act by modifying gene expression. Many genes are also subjected to age-dependent transcriptional regulation. Some age-related gene expression changes are prevented by caloric restriction, the most robust intervention that slows down the aging process. Manipulating the expression of some age-regulated genes can extend an organism's life span. Remarkably, the activity of many transcription regulatory elements is linked to physiological age as opposed to chronological age, indicating that orderly and tightly controlled regulatory pathways are active during aging.

  5. Gene Therapy for Cartilage Repair

    Science.gov (United States)

    Madry, Henning; Orth, Patrick; Cucchiarini, Magali

    2011-01-01

    The concept of using gene transfer strategies for cartilage repair originates from the idea of transferring genes encoding therapeutic factors into the repair tissue, resulting in a temporarily and spatially defined delivery of therapeutic molecules to sites of cartilage damage. This review focuses on the potential benefits of using gene therapy approaches for the repair of articular cartilage and meniscal fibrocartilage, including articular cartilage defects resulting from acute trauma, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Possible applications for meniscal repair comprise meniscal lesions, meniscal sutures, and meniscal transplantation. Recent studies in both small and large animal models have demonstrated the applicability of gene-based approaches for cartilage repair. Chondrogenic pathways were stimulated in the repair tissue and in osteoarthritic cartilage using genes for polypeptide growth factors and transcription factors. Although encouraging data have been generated, a successful translation of gene therapy for cartilage repair will require an ongoing combined effort of orthopedic surgeons and of basic scientists. PMID:26069580

  6. Gene Therapy for Fracture Repair

    Science.gov (United States)

    2007-05-01

    the periosteal tissues of healing fractures in small animals , and allow more accurate evaluation of the effects of the fracture therapy (Rundle et...X-ray fluoroscopy (Figure 7). Individual animals receiving the MLV-BMP-2/4 gene therapy by either the percutaneous injection or the intramedullary... animal subjects to understand gene expression in the healing response to bone injury and identify novel genes that might accelerate or delay the

  7. A genetic ensemble approach for gene-gene interaction identification

    Directory of Open Access Journals (Sweden)

    Ho Joshua WK

    2010-10-01

    Full Text Available Abstract Background It has now become clear that gene-gene interactions and gene-environment interactions are ubiquitous and fundamental mechanisms for the development of complex diseases. Though a considerable effort has been put into developing statistical models and algorithmic strategies for identifying such interactions, the accurate identification of those genetic interactions has been proven to be very challenging. Methods In this paper, we propose a new approach for identifying such gene-gene and gene-environment interactions underlying complex diseases. This is a hybrid algorithm and it combines genetic algorithm (GA and an ensemble of classifiers (called genetic ensemble. Using this approach, the original problem of SNP interaction identification is converted into a data mining problem of combinatorial feature selection. By collecting various single nucleotide polymorphisms (SNP subsets as well as environmental factors generated in multiple GA runs, patterns of gene-gene and gene-environment interactions can be extracted using a simple combinatorial ranking method. Also considered in this study is the idea of combining identification results obtained from multiple algorithms. A novel formula based on pairwise double fault is designed to quantify the degree of complementarity. Conclusions Our simulation study demonstrates that the proposed genetic ensemble algorithm has comparable identification power to Multifactor Dimensionality Reduction (MDR and is slightly better than Polymorphism Interaction Analysis (PIA, which are the two most popular methods for gene-gene interaction identification. More importantly, the identification results generated by using our genetic ensemble algorithm are highly complementary to those obtained by PIA and MDR. Experimental results from our simulation studies and real world data application also confirm the effectiveness of the proposed genetic ensemble algorithm, as well as the potential benefits of

  8. Genes, evolution and intelligence.

    Science.gov (United States)

    Bouchard, Thomas J

    2014-11-01

    I argue that the g factor meets the fundamental criteria of a scientific construct more fully than any other conception of intelligence. I briefly discuss the evidence regarding the relationship of brain size to intelligence. A review of a large body of evidence demonstrates that there is a g factor in a wide range of species and that, in the species studied, it relates to brain size and is heritable. These findings suggest that many species have evolved a general-purpose mechanism (a general biological intelligence) for dealing with the environments in which they evolved. In spite of numerous studies with considerable statistical power, we know of very few genes that influence g and the effects are very small. Nevertheless, g appears to be highly polygenic. Given the complexity of the human brain, it is not surprising that that one of its primary faculties-intelligence-is best explained by the near infinitesimal model of quantitative genetics.

  9. Gene therapy for hemophilia

    Science.gov (United States)

    Rogers, Geoffrey L.; Herzog, Roland W.

    2015-01-01

    Hemophilia is an X-linked inherited bleeding disorder consisting of two classifications, hemophilia A and hemophilia B, depending on the underlying mutation. Although the disease is currently treatable with intravenous delivery of replacement recombinant clotting factor, this approach represents a significant cost both monetarily and in terms of quality of life. Gene therapy is an attractive alternative approach to the treatment of hemophilia that would ideally provide life-long correction of clotting activity with a single injection. In this review, we will discuss the multitude of approaches that have been explored for the treatment of both hemophilia A and B, including both in vivo and ex vivo approaches with viral and nonviral delivery vectors. PMID:25553466

  10. Introduction: Cancer Gene Networks.

    Science.gov (United States)

    Clarke, Robert

    2017-01-01

    Constructing, evaluating, and interpreting gene networks generally sits within the broader field of systems biology, which continues to emerge rapidly, particular with respect to its application to understanding the complexity of signaling in the context of cancer biology. For the purposes of this volume, we take a broad definition of systems biology. Considering an organism or disease within an organism as a system, systems biology is the study of the integrated and coordinated interactions of the network(s) of genes, their variants both natural and mutated (e.g., polymorphisms, rearrangements, alternate splicing, mutations), their proteins and isoforms, and the organic and inorganic molecules with which they interact, to execute the biochemical reactions (e.g., as enzymes, substrates, products) that reflect the function of that system. Central to systems biology, and perhaps the only approach that can effectively manage the complexity of such systems, is the building of quantitative multiscale predictive models. The predictions of the models can vary substantially depending on the nature of the model and its inputoutput relationships. For example, a model may predict the outcome of a specific molecular reaction(s), a cellular phenotype (e.g., alive, dead, growth arrest, proliferation, and motility), a change in the respective prevalence of cell or subpopulations, a patient or patient subgroup outcome(s). Such models necessarily require computers. Computational modeling can be thought of as using machine learning and related tools to integrate the very high dimensional data generated from modern, high throughput omics technologies including genomics (next generation sequencing), transcriptomics (gene expression microarrays; RNAseq), metabolomics and proteomics (ultra high performance liquid chromatography, mass spectrometry), and "subomic" technologies to study the kinome, methylome, and others. Mathematical modeling can be thought of as the use of ordinary

  11. Gene expression in colorectal cancer

    DEFF Research Database (Denmark)

    Birkenkamp-Demtroder, Karin; Christensen, Lise Lotte; Olesen, Sanne Harder

    2002-01-01

    Understanding molecular alterations in colorectal cancer (CRC) is needed to define new biomarkers and treatment targets. We used oligonucleotide microarrays to monitor gene expression of about 6,800 known genes and 35,000 expressed sequence tags (ESTs) on five pools (four to six samples in each......' C, and clustered Dukes' D separately. Real-time PCR of 10 known genes and 5 ESTs demonstrated excellent reproducibility of the array-based findings. The most frequently altered genes belonged to functional categories of metabolism (22%), transcription and translation (11%), and cellular processes (9...

  12. Synthetic sustained gene delivery systems.

    Science.gov (United States)

    Agarwal, Ankit; Mallapragada, Surya K

    2008-01-01

    Gene therapy today is hampered by the need of a safe and efficient gene delivery system that can provide a sustained therapeutic effect without cytotoxicity or unwanted immune responses. Bolus gene delivery in solution results in the loss of delivered factors via lymphatic system and may cause undesired effects by the escape of bioactive molecules to distant sites. Controlled gene delivery systems, acting as localized depot of genes, provide an extended sustained release of genes, giving prolonged maintenance of the therapeutic level of encoded proteins. They also limit the DNA degradation in the nuclease rich extra-cellular environment. While attempts have been made to adapt existing controlled drug delivery technologies, more novel approaches are being investigated for controlled gene delivery. DNA encapsulated in nano/micro spheres of polymers have been administered systemically/orally to be taken up by the targeted tissues and provide sustained release once internalized. Alternatively, DNA entrapped in hydrogels or scaffolds have been injected/implanted in tissues/cavities as platforms for gene delivery. The present review examines these different modalities for sustained delivery of viral and non-viral gene-delivery vectors. Design parameters and release mechanisms of different systems made with synthetic or natural polymers are presented along with their prospective applications and opportunities for continuous development.

  13. Gene therapy and reproductive medicine.

    Science.gov (United States)

    Stribley, John M; Rehman, Khurram S; Niu, Hairong; Christman, Gregory M

    2002-04-01

    To review the literature on the principles of gene therapy and its potential application in reproductive medicine. Literature review. Gene therapy involves transfer of genetic material to target cells using a delivery system, or vector. Attention has primarily focused on viral vectors. Significant problems remain to be overcome including low efficacy of gene transfer, the transient expression of some vectors, safety issues with modified adenoviruses and retroviruses, and ethical concerns. If these issues can be resolved, gene therapy will be applicable to an increasing spectrum of single and multiple gene disorders, as the Human Genome Project data are analyzed, and the genetic component of human disease becomes better understood. Gynecologic gene therapy has advanced to human clinical trials for ovarian carcinoma, and shows potential for the treatment of uterine leiomyomata. Obstetric applications of gene therapy, including fetal gene therapy, remain more distant goals. Concerns about the safety of human gene therapy research are being actively addressed, and remarkable progress in improving DNA transfer has been made. The first treatment success for a genetic disease (severe combined immunodeficiency disease) has been achieved, and ongoing research efforts will eventually yield clinical applications in many spheres of reproductive medicine.

  14. Gene- and evidence-based candidate gene selection for schizophrenia and gene feature analysis.

    Science.gov (United States)

    Sun, Jingchun; Han, Leng; Zhao, Zhongming

    2010-01-01

    Schizophrenia is a chronic psychiatric disorder that affects about 1% of the population globally. A tremendous amount of effort has been expended in the past decade, including more than 2400 association studies, to identify genes influencing susceptibility to the disorder. However, few genes or markers have been reliably replicated. The wealth of this information calls for an integration of gene association data, evidence-based gene ranking, and follow-up replication in large sample. The objective of this study is to develop and evaluate evidence-based gene ranking methods and to examine the features of top-ranking candidate genes for schizophrenia. We proposed a gene-based approach for selecting and prioritizing candidate genes by combining odds ratios (ORs) of multiple markers in each association study and then combining ORs in multiple studies of a gene. We named it combination-combination OR method (CCOR). CCOR is similar to our recently published method, which first selects the largest OR of the markers in each study and then combines these ORs in multiple studies (i.e., selection-combination OR method, SCOR), but differs in selecting representative OR in each study. Features of top-ranking genes were examined by Gene Ontology terms and gene expression in tissues. Our evaluation suggested that the SCOR method overall outperforms the CCOR method. Using the SCOR, a list of 75 top-ranking genes was selected for schizophrenia candidate genes (SZGenes). We found that SZGenes had strong correlation with neuro-related functional terms and were highly expressed in brain-related tissues. The scientific landscape for schizophrenia genetics and other complex disease studies is expected to change dramatically in the next a few years, thus, the gene-based combined OR method is useful in candidate gene selection for follow-up association studies and in further artificial intelligence in medicine. This method for prioritization of candidate genes can be applied to other

  15. Gene therapy for meningioma: improved gene delivery with targeted adenoviruses

    NARCIS (Netherlands)

    Dirven, Clemens M. F.; Grill, Jacques; Lamfers, Martine L. M.; van der Valk, Paul; Leonhart, Angelique M.; van Beusechem, Victor W.; Haisma, Hidde J.; Pinedo, Herbert M.; Curiel, David T.; Vandertop, W. Peter; Gerritsen, Winald R.

    2002-01-01

    OBJECT: Due to their surgical inaccessibility or aggressive behavior, some meningiomas cannot be cured with current treatment strategies. Gene therapy is an emerging strategy for the treatment of brain tumors, which the authors investigated to determine whether adenoviruses could be used for gene

  16. Gene therapy for meningioma : improved gene delivery with targeted adenoviruses

    NARCIS (Netherlands)

    Dirven, CMF; Grill, J; Lamfers, MLM; Van der Valk, P; Leonhart, AM; Van Beusechem, VW; Haisma, HJ; Pinedo, HM; Curiel, DT; Vandertop, WP; Gerritsen, WR

    Object. Due to their surgical inaccessibility or aggressive behavior, some meningiomas cannot be cured with current treatment strategies. Gene therapy is an emerging strategy for the treatment of brain tumors, which the authors investigated to determine whether adenoviruses could be used for gene

  17. Evaluation of suitable reference genes for gene expression studies ...

    Indian Academy of Sciences (India)

    2011-12-14

    Dec 14, 2011 ... MADS family of TFs control floral organ identity within each whorl of the flower by activating downstream genes. Measuring gene expression in different tissue types and developmental stages is of fundamental importance in TFs functional research. In last few years, quantitative real-time. PCR (qRT-PCR) ...

  18. Are TMEM genes potential candidate genes for panic disorder?

    DEFF Research Database (Denmark)

    NO, Gregersen; Buttenschøn, Henriette Nørmølle; Hedemand, Anne

    2014-01-01

    We analysed single nucleotide polymorphisms in two transmembrane genes (TMEM98 and TMEM132E) in panic disorder (PD) patients and control individuals from the Faroe Islands, Denmark and Germany. The genes encode single-pass membrane proteins and are located within chromosome 17q11.2-q12...

  19. Genes Sufficient for Synthesizing Peptidoglycan are Retained in Gymnosperm Genomes, and MurE from Larix gmelinii can Rescue the Albino Phenotype of Arabidopsis MurE Mutation.

    Science.gov (United States)

    Lin, Xiaofei; Li, Ningning; Kudo, Hiromi; Zhang, Zhe; Li, Jinyu; Wang, Li; Zhang, Wenbo; Takechi, Katsuaki; Takano, Hiroyoshi

    2017-03-01

    The endosymbiotic theory states that plastids are derived from a single cyanobacterial ancestor that possessed a cell wall. Peptidoglycan (PG), the main component of the bacteria cell wall, gradually degraded during plastid evolution. PG-synthesizing Mur genes have been found to be retained in the genomes of basal streptophyte plants, although many of them have been lost from the genomes of angiosperms. The enzyme encoded by bacterial MurE genes catalyzes the formation of the UDP-N-acetylmuramic acid (UDP-MurNAc) tripeptide in bacterial PG biosynthesis. Knockout of the MurE gene in the moss Physcomitrella patens resulted in defects of chloroplast division, whereas T-DNA-tagged mutants of Arabidopsis thaliana for MurE revealed inhibition of chloroplast development but not of plastid division, suggesting that AtMurE is functionally divergent from the bacterial and moss MurE proteins. Here, we could identify 10 homologs of bacterial Mur genes, including MurE, in the recently sequenced genomes of Picea abies and Pinus taeda, suggesting the retention of the plastid PG system in gymnosperms. To investigate the function of gymnosperm MurE, we isolated an ortholog of MurE from the larch, Larix gmelinii (LgMurE) and confirmed its presence as a single copy per genome, as well as its abundant expression in the leaves of larch seedlings. Analysis with a fusion protein combining green fluorescent protein and LgMurE suggested that it localizes in chloroplasts. Cross-species complementation assay with MurE mutants of A. thaliana and P. patens showed that the expression of LgMurE cDNA completely rescued the albefaction defects in A. thaliana but did not rescue the macrochloroplast phenotype in P. patens. The evolution of plastid PG and the mechanism behind the functional divergence of MurE genes are discussed in the context of information about plant genomes at different evolutionary stages. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of

  20. Classifying genes to the correct Gene Ontology Slim term in Saccharomyces cerevisiae using neighbouring genes with classification learning

    Directory of Open Access Journals (Sweden)

    Tsatsoulis Costas

    2010-05-01

    Full Text Available Abstract Background There is increasing evidence that gene location and surrounding genes influence the functionality of genes in the eukaryotic genome. Knowing the Gene Ontology Slim terms associated with a gene gives us insight into a gene's functionality by informing us how its gene product behaves in a cellular context using three different ontologies: molecular function, biological process, and cellular component. In this study, we analyzed if we could classify a gene in Saccharomyces cerevisiae to its correct Gene Ontology Slim term using information about its location in the genome and information from its nearest-neighbouring genes using classification learning. Results We performed experiments to establish that the MultiBoostAB algorithm using the J48 classifier could correctly classify Gene Ontology Slim terms of a gene given information regarding the gene's location and information from its nearest-neighbouring genes for training. Different neighbourhood sizes were examined to determine how many nearest neighbours should be included around each gene to provide better classification rules. Our results show that by just incorporating neighbour information from each gene's two-nearest neighbours, the percentage of correctly classified genes to their correct Gene Ontology Slim term for each ontology reaches over 80% with high accuracy (reflected in F-measures over 0.80 of the classification rules produced. Conclusions We confirmed that in classifying genes to their correct Gene Ontology Slim term, the inclusion of neighbour information from those genes is beneficial. Knowing the location of a gene and the Gene Ontology Slim information from neighbouring genes gives us insight into that gene's functionality. This benefit is seen by just including information from a gene's two-nearest neighbouring genes.

  1. Genetic analysis of the regulation of TCH gene expression, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Braam, Janet

    2008-10-28

    investigation of CML24 function and regulation led to the finding that CML24 has a critical role in nitric oxide regulation. Distinct tilling mutant alleles demonstrated that CML24 can act as a switch in the response to day length perception. Because of potential redundancy with the related CML23 gene, CML23 T-DNA insertion mutants were identified and characterized. Together, CML23 and CML24 impact the autonomous regulatory pathway of the transition to flowering. Nitric oxide levels are elevated in cml23/cml24 double mutants. Therefore, CML23 and CML24 are potential calcium sensors regulate nitric oxide accumulation. In collaboration with Drs. McCann and Carpita, fourier transform infrared spectroscopy (FTIR) was used to assess, verify and classify wall architectural changes that occur as a result of single XTH insertion mutations. Thirty-four homozygous mutant lines of Arabidopsis representing 21 members of the xyloglucan endotransglucosylase/hydrolase gene family provided a set of mutants to characterize. Kohonen networks classified cell wall architectures of xth mutant lines and previously characterized cell wall mutants. The xth mutants were found to have chemical changes in their cell walls not detectable as phenotypic growth and development changes, consistent with the existence of feed-back loops that modify wall composition in response to a life-long deficiency of a cell wall enzyme. To gain insight into the potential physiological relevance of the distinct members of the XTH family, GUS reporter fusion genes were constructed, and plants expressing these transgenes were characterized to reveal spatial and temporal patterns of expression. In addition, Genevestigator sources were mined for comprehensive and comparative XTH expression regulation analysis. These data revealed that the Arabidopsis XTHs are likely expressed in every developmental stage from seed germination through flowering. All organs showed XTH::GUS expression and most, if not all, are found to express

  2. Gene Synthesis with HG Khorana

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 12. Gene Synthesis with H G Khorana. Marvin H Caruthers. General Article Volume 17 Issue 12 December 2012 pp ... Keywords. Chemical synthesis of genes for yeast alanine tRNA and E. coli supressor tRNA; Khorana's philosophy on science.

  3. Clock genes, ADHD and aggression.

    Science.gov (United States)

    Mogavero, Floriana; Jager, Amanda; Glennon, Jeffrey C

    2016-11-09

    Attention deficit/hyperactivity disorder (ADHD) is frequently associated with comorbid aggression and sleep disturbances. The sleep/wake cycle is under the control of the circadian system which is moderated by clock genes. Clock genes can regulate the transcription of monoamine oxidase A, which is involved in the degradation of monoamines. Disturbances in monoamine interaction with clock genes in those with monoamine gene polymorphisms may regulate susceptibility of ADHD and comorbid aggression/sleep disturbances. While monoamines influence circadian rhythm and clock gene expression, circadian rhythm components modulate aggressive behavior, and altered clock genes expression have been associated with ADHD. We propose a mechanism by which circadian rhythm and clock gene expression may influence ADHD and comorbid aggression through the modulation of neurotransmitters. The role of clock genes in ADHD patients with comorbid aggression awaits further research; therefore we also indicate directions for future studies to help increase understanding of the underlying mechanisms in ADHD with comorbid aggression and sleep disturbances. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. (vitamin B1) biosynthesis genes

    African Journals Online (AJOL)

    In this study, the gene transcripts of first two enzymes in thiamine biosynthesis pathway, THIC and THI1/THI4 were identified and amplified from oil palm tissues. Primers were designed based on sequence comparison of the genes from Arabidopsis thaliana, Zea mays, Oryza sativa and Alnus glutinosa. Oil palm's responses ...

  5. superoxide dismutase gene in sugarcane

    African Journals Online (AJOL)

    Yomi

    2012-01-10

    Jan 10, 2012 ... Superoxide dismutases (SODs) play an important role in stress-tolerance in plants. In this study, for the first time, a full-length cDNA sequence of MnSOD gene, termed as Sc-MnSOD (GenBank accession number: GQ246460), was obtained in sugarcane. Sequence analysis revealed that Sc-MnSOD gene ...

  6. Determining Semantically Related Significant Genes.

    Science.gov (United States)

    Taha, Kamal

    2014-01-01

    GO relation embodies some aspects of existence dependency. If GO term xis existence-dependent on GO term y, the presence of y implies the presence of x. Therefore, the genes annotated with the function of the GO term y are usually functionally and semantically related to the genes annotated with the function of the GO term x. A large number of gene set enrichment analysis methods have been developed in recent years for analyzing gene sets enrichment. However, most of these methods overlook the structural dependencies between GO terms in GO graph by not considering the concept of existence dependency. We propose in this paper a biological search engine called RSGSearch that identifies enriched sets of genes annotated with different functions using the concept of existence dependency. We observe that GO term xcannot be existence-dependent on GO term y, if x- and y- have the same specificity (biological characteristics). After encoding into a numeric format the contributions of GO terms annotating target genes to the semantics of their lowest common ancestors (LCAs), RSGSearch uses microarray experiment to identify the most significant LCA that annotates the result genes. We evaluated RSGSearch experimentally and compared it with five gene set enrichment systems. Results showed marked improvement.

  7. Imaging after vascular gene therapy

    International Nuclear Information System (INIS)

    Manninen, Hannu I.; Yang, Xiaoming

    2005-01-01

    Targets for cardiovascular gene therapy currently include limiting restenosis after balloon angioplasty and stent placement, inhibiting vein bypass graft intimal hyperplasia/stenosis, therapeutic angiogenesis for cardiac and lower-limb ischemia, and prevention of thrombus formation. While catheter angiography is still standard method to follow-up vascular gene transfer, other modern imaging techniques, especially intravascular ultrasound (IVUS), magnetic resonance (MR), and positron emission tomography (PET) imaging provide complementary information about the therapeutic effect of vascular gene transfer in humans. Although molecular imaging of therapeutic gene expression in the vasculatures is still in its technical development phase, it has already offered basic medical science an extremely useful in vivo evaluation tool for non- or minimally invasive imaging of vascular gene therapy

  8. Gene recognition by combination of several gene-finding programs.

    Science.gov (United States)

    Murakami, K; Takagi, T

    1998-01-01

    A number of programs have been developed to predict the eukaryotic gene structures in DNA sequences. However, gene finding is still a challenging problem. We have explored the effectiveness when the results of several gene-finding programs were re-analyzed and combined. We studied several methods with four programs (FEXH, GeneParser3, GEN-SCAN and GRAIL2). By HIGHEST-policy combination method or BOUNDARY method, approximate correlation (AC) improved by 3-5% in comparison with the best single gene-finding program. From another viewpoint, OR-based combination of the four programs is the most reliable to know whether a candidate exon overlaps with the real exon or not, although it is less sensitive than GENSCAN for exon-intron boundaries. Our methods can easily be extended to combine other programs. We have developed a server program (Shirokane System) and a client program (GeneScope) to use the methods. GeneScope is available through a WWW site (http://gf.genome.ad.jp/). (katsu,takagi)@ims.u-tokyo.ac.jp

  9. Targeting Aflatoxin Biosynthetic Genes.

    Science.gov (United States)

    Srour, Ali Y; Fakhoury, Ahmad M; Brown, Robert L

    2017-01-01

    Chemical detoxification and physical destruction of aflatoxins in foods and feed commodities are mostly unattainable in a way that preserves the edibility of the food. Therefore, preventing mycotoxins in general and aflatoxins in particular from entering the food chain is a better approach. This requires early detection of the aflatoxin-causing organisms. Detection and quantification of aflatoxin-producing fungi has always been a challenge, especially within species of Aspergillus and Penicillium. Culture-based methods require a high level of expertise and a list of sophisticated equipment. Furthermore, even for a trained taxonomist, species that are identical in morphology, physiology, and nutritional aspects can be challenging to classify. Fungal taxonomy has changed over the past few decades; more species are being reclassified, and new species are being described due to advances in sequencing and genome assembly. These developments make the use of PCR-based approaches practical, rapid, and more reliable for the identification of fungi to the species level. This chapter presents a variety of protocols to detect and quantify aflatoxin-producing fungi using mycotoxin biosynthesis pathway genes.

  10. Therapeutic genes for anti-HIV/AIDS gene therapy.

    Science.gov (United States)

    Bovolenta, Chiara; Porcellini, Simona; Alberici, Luca

    2013-01-01

    The multiple therapeutic approaches developed so far to cope HIV-1 infection, such as anti-retroviral drugs, germicides and several attempts of therapeutic vaccination have provided significant amelioration in terms of life-quality and survival rate of AIDS patients. Nevertheless, no approach has demonstrated efficacy in eradicating this lethal, if untreated, infection. The curative power of gene therapy has been proven for the treatment of monogenic immunodeficiensies, where permanent gene modification of host cells is sufficient to correct the defect for life-time. No doubt, a similar concept is not applicable for gene therapy of infectious immunodeficiensies as AIDS, where there is not a single gene to be corrected; rather engineered cells must gain immunotherapeutic or antiviral features to grant either short- or long-term efficacy mostly by acquisition of antiviral genes or payloads. Anti-HIV/AIDS gene therapy is one of the most promising strategy, although challenging, to eradicate HIV-1 infection. In fact, genetic modification of hematopoietic stem cells with one or multiple therapeutic genes is expected to originate blood cell progenies resistant to viral infection and thereby able to prevail on infected unprotected cells. Ultimately, protected cells will re-establish a functional immune system able to control HIV-1 replication. More than hundred gene therapy clinical trials against AIDS employing different viral vectors and transgenes have been approved or are currently ongoing worldwide. This review will overview anti-HIV-1 infection gene therapy field evaluating strength and weakness of the transgenes and payloads used in the past and of those potentially exploitable in the future.

  11. Evidence based selection of housekeeping genes

    NARCIS (Netherlands)

    de Jonge, Hendrik J. M.; Fehrmann, Rudolf S. N.; de Bont, Eveline S. J. M.; Hofstra, Robert M. W.; Gerbens, Frans; Kamps, Willem A.; de Vries, Elisabeth G. E.; van der Zee, Ate G. J.; te Meerman, Gerard J.; ter Elst, Arja

    2007-01-01

    For accurate and reliable gene expression analysis, normalization of gene expression data against housekeeping genes (reference or internal control genes) is required. It is known that commonly used housekeeping genes (e. g. ACTB, GAPDH, HPRT1, and B2M) vary considerably under different experimental

  12. Gene Therapy and Children (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Gene Therapy and Children KidsHealth / For Parents / Gene Therapy and ... caused by a "bad" gene. Two Types of Gene Therapy The two forms of gene therapy are: Somatic ...

  13. Human Lacrimal Gland Gene Expression.

    Directory of Open Access Journals (Sweden)

    Vinay Kumar Aakalu

    Full Text Available The study of human lacrimal gland biology and development is limited. Lacrimal gland tissue is damaged or poorly functional in a number of disease states including dry eye disease. Development of cell based therapies for lacrimal gland diseases requires a better understanding of the gene expression and signaling pathways in lacrimal gland. Differential gene expression analysis between lacrimal gland and other embryologically similar tissues may be helpful in furthering our understanding of lacrimal gland development.We performed global gene expression analysis of human lacrimal gland tissue using Affymetrix ® gene expression arrays. Primary data from our laboratory was compared with datasets available in the NLM GEO database for other surface ectodermal tissues including salivary gland, skin, conjunctiva and corneal epithelium.The analysis revealed statistically significant difference in the gene expression of lacrimal gland tissue compared to other ectodermal tissues. The lacrimal gland specific, cell surface secretory protein encoding genes and critical signaling pathways which distinguish lacrimal gland from other ectodermal tissues are described.Differential gene expression in human lacrimal gland compared with other ectodermal tissue types revealed interesting patterns which may serve as the basis for future studies in directed differentiation among other areas.

  14. Remote control of gene expression.

    Science.gov (United States)

    Long, Xiaochun; Miano, Joseph M

    2007-06-01

    The elucidation of a growing number of species' genomes heralds an unprecedented opportunity to ascertain functional attributes of non-coding sequences. In particular, cis regulatory modules (CRMs) controlling gene expression constitute a rich treasure trove of data to be defined and experimentally validated. Such information will provide insight into cell lineage determination and differentiation and the genetic basis of heritable diseases as well as the development of novel tools for restricting the inactivation of genes to specific cell types or conditions. Historically, the study of CRMs and their individual transcription factor binding sites has been limited to proximal regions around gene loci. Two important by-products of the genomics revolution, artificial chromosome vectors and comparative genomics, have fueled efforts to define an increasing number of CRMs acting remotely to control gene expression. Such regulation from a distance has challenged our perspectives of gene expression control and perhaps the very definition of a gene. This review summarizes current approaches to characterize remote control of gene expression in transgenic mice and inherent limitations for accurately interpreting the essential nature of CRM activity.

  15. Delimiting Coalescence Genes (C-Genes) in Phylogenomic Data Sets.

    Science.gov (United States)

    Springer, Mark S; Gatesy, John

    2018-02-26

    coalescence methods have emerged as a popular alternative for inferring species trees with large genomic datasets, because these methods explicitly account for incomplete lineage sorting. However, statistical consistency of summary coalescence methods is not guaranteed unless several model assumptions are true, including the critical assumption that recombination occurs freely among but not within coalescence genes (c-genes), which are the fundamental units of analysis for these methods. Each c-gene has a single branching history, and large sets of these independent gene histories should be the input for genome-scale coalescence estimates of phylogeny. By contrast, numerous studies have reported the results of coalescence analyses in which complete protein-coding sequences are treated as c-genes even though exons for these loci can span more than a megabase of DNA. Empirical estimates of recombination breakpoints suggest that c-genes may be much shorter, especially when large clades with many species are the focus of analysis. Although this idea has been challenged recently in the literature, the inverse relationship between c-gene size and increased taxon sampling in a dataset-the 'recombination ratchet'-is a fundamental property of c-genes. For taxonomic groups characterized by genes with long intron sequences, complete protein-coding sequences are likely not valid c-genes and are inappropriate units of analysis for summary coalescence methods unless they occur in recombination deserts that are devoid of incomplete lineage sorting (ILS). Finally, it has been argued that coalescence methods are robust when the no-recombination within loci assumption is violated, but recombination must matter at some scale because ILS, a by-product of recombination, is the raison d'etre for coalescence methods. That is, extensive recombination is required to yield the large number of independently segregating c-genes used to infer a species tree. If coalescent methods are powerful

  16. Identification of key player genes in gene regulatory networks.

    Science.gov (United States)

    Nazarieh, Maryam; Wiese, Andreas; Will, Thorsten; Hamed, Mohamed; Helms, Volkhard

    2016-09-06

    Identifying the gene regulatory networks governing the workings and identity of cells is one of the main challenges in understanding processes such as cellular differentiation, reprogramming or cancerogenesis. One particular challenge is to identify the main drivers and master regulatory genes that control such cell fate transitions. In this work, we reformulate this problem as the optimization problems of computing a Minimum Dominating Set and a Minimum Connected Dominating Set for directed graphs. Both MDS and MCDS are applied to the well-studied gene regulatory networks of the model organisms E. coli and S. cerevisiae and to a pluripotency network for mouse embryonic stem cells. The results show that MCDS can capture most of the known key player genes identified so far in the model organisms. Moreover, this method suggests an additional small set of transcription factors as novel key players for governing the cell-specific gene regulatory network which can also be investigated with regard to diseases. To this aim, we investigated the ability of MCDS to define key drivers in breast cancer. The method identified many known drug targets as members of the MDS and MCDS. This paper proposes a new method to identify key player genes in gene regulatory networks. The Java implementation of the heuristic algorithm explained in this paper is available as a Cytoscape plugin at http://apps.cytoscape.org/apps/mcds . The SageMath programs for solving integer linear programming formulations used in the paper are available at https://github.com/maryamNazarieh/KeyRegulatoryGenes and as supplementary material.

  17. Gene therapy of cancer by vaccines carrying inserted immunostimulatory genes

    Czech Academy of Sciences Publication Activity Database

    Bubeník, Jan

    2007-01-01

    Roč. 53, č. 3 (2007), s. 71-73 ISSN 0015-5500 Grant - others:EU-FP6 NoE Clinigene(XE) 018933; Liga proti rakovině, Praha(CZ) XX Institutional research plan: CEZ:AV0Z50520514 Keywords : gene therapy * immunostimulatory genes * vaccine Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.596, year: 2007

  18. Cloning and selection of reference genes for gene expression ...

    African Journals Online (AJOL)

    Full length mRNA sequences of Ac-β-actin and Ac-gapdh, and partial mRNA sequences of Ac-18SrRNA and Ac-ubiquitin were cloned from pineapple in this study. The four genes were tested as housekeeping genes in three experimental sets. GeNorm and NormFinder analysis revealed that β-actin was the most ...

  19. Gene expression in colorectal cancer

    DEFF Research Database (Denmark)

    Birkenkamp-Demtroder, Karin; Christensen, Lise Lotte; Olesen, Sanne Harder

    2002-01-01

    Understanding molecular alterations in colorectal cancer (CRC) is needed to define new biomarkers and treatment targets. We used oligonucleotide microarrays to monitor gene expression of about 6,800 known genes and 35,000 expressed sequence tags (ESTs) on five pools (four to six samples in each...... pool) of total RNA from left-sided sporadic colorectal carcinomas. We compared normal tissue to carcinoma tissue from Dukes' stages A-D (noninvasive to distant metastasis) and identified 908 known genes and 4,155 ESTs that changed remarkably from normal to tumor tissue. Based on intensive filtering 226...

  20. Gene Therapy Approaches to Hemoglobinopathies.

    Science.gov (United States)

    Ferrari, Giuliana; Cavazzana, Marina; Mavilio, Fulvio

    2017-10-01

    Gene therapy for hemoglobinopathies is currently based on transplantation of autologous hematopoietic stem cells genetically modified with a lentiviral vector expressing a globin gene under the control of globin transcriptional regulatory elements. Preclinical and early clinical studies showed the safety and potential efficacy of this therapeutic approach as well as the hurdles still limiting its general application. In addition, for both beta-thalassemia and sickle cell disease, an altered bone marrow microenvironment reduces the efficiency of stem cell harvesting as well as engraftment. These hurdles need be addressed for gene therapy for hemoglobinopathies to become a clinical reality. Copyright © 2017 Elsevier Inc. All rights reserved.