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Sample records for alleles multivalent pfama1

  1. Generation of humoral immune responses to multi-allele PfAMA1 vaccines; effect of adjuvant and number of component alleles on the breadth of response.

    Directory of Open Access Journals (Sweden)

    Kwadwo A Kusi

    Full Text Available There is increasing interest in multi-allele vaccines to overcome strain-specificity against polymorphic vaccine targets such as Apical Membrane Antigen 1 (AMA1. These have been shown to induce broad inhibitory antibodies in vitro and formed the basis for the design of three Diversity-Covering (DiCo proteins with similar immunological effects. The antibodies produced are to epitopes that are shared between vaccine alleles and theoretically, increasing the number of component AMA1 alleles is expected to broaden the antibody response. A plateau effect could however impose a limit on the number of alleles needed to achieve the broadest specificity. Moreover, production cost and the vaccine formulation process would limit the number of component alleles. In this paper, we compare rabbit antibody responses elicited with multi-allele vaccines incorporating seven (three DiCos and four natural AMA1 alleles and three (DiCo mix antigens for gains in broadened specificity. We also investigate the effect of three adjuvant platforms on antigen specificity and antibody functionality. Our data confirms a broadened response after immunisation with DiCo mix in all three adjuvants. Higher antibody titres were elicited with either CoVaccine HT™ or Montanide ISA 51, resulting in similar in vitro inhibition (65-82% of five out of six culture-adapted P. falciparum strains. The antigen binding specificities of elicited antibodies were also similar and independent of the adjuvant used or the number of vaccine component alleles. Thus neither the four extra antigens nor adjuvant had any observable benefits with respect to specificity broadening, although adjuvant choice influenced the absolute antibody levels and thus the extent of parasite inhibition. Our data confirms the feasibility and potential of multi-allele PfAMA1 formulations, and highlights the need for adjuvants with improved antibody potentiation properties for AMA1-based vaccines.

  2. Humoral immune responses to a single allele PfAMA1 vaccine in healthy malaria-naive adults.

    Directory of Open Access Journals (Sweden)

    Edmond J Remarque

    Full Text Available Plasmodium falciparum: apical membrane antigen 1 (AMA1 is a candidate malaria vaccine antigen expressed on merozoites and sporozoites. The polymorphic nature of AMA1 may compromise vaccine induced protection. The humoral response induced by two dosages (10 and 50 µg of a single allele AMA1 antigen (FVO formulated with Alhydrogel, Montanide ISA 720 or AS02 was investigated in 47 malaria-naïve adult volunteers. Volunteers were vaccinated 3 times at 4 weekly intervals and serum samples obtained four weeks after the third immunization were analysed for (i Antibody responses to various allelic variants, (ii Domain specificity, (iii Avidity, (iv IgG subclass levels, by ELISA and (v functionality of antibody responses by Growth Inhibition Assay (GIA. About half of the antibodies induced by vaccination cross reacted with heterologous AMA1 alleles. The choice of adjuvant determined the magnitude of the antibody response, but had only a marginal influence on specificity, avidity, domain recognition or subclass responses. The highest antibody responses were observed for AMA1 formulated with AS02. The Growth Inhibition Assay activity of the antibodies was proportional to the amount of antigen specific IgG and the functional capacity of the antibodies was similar for heterologous AMA1-expressing laboratory strains.ClinicalTrials.gov NCT00730782.

  3. Organizing multivalency in carbohydrate recognition.

    Science.gov (United States)

    Müller, Christian; Despras, Guillaume; Lindhorst, Thisbe K

    2016-06-01

    The interactions of cell surface carbohydrates as well as of soluble glycoconjugates with their receptor proteins rule fundamental processes in cell biology. One of the supramolecular principles underlying and regulating carbohydrate recognition is multivalency. Many multivalent glycoconjugates have therefore been synthesized to study multivalency effects operative in glycobiology. This review is focused on smaller multivalent structures such as glycoclusters emphasizing carbohydrate-centered and heteromultivalent glycoconjugates. We are discussing primary, secondary and tertiary structural aspects including approaches to organize multivalency. PMID:27146554

  4. Architecture effects on multivalent interactions by polypeptide-based multivalent ligands

    Science.gov (United States)

    Liu, Shuang

    Multivalent interactions are characterized by the simultaneous binding between multiple ligands and multiple binding sites, either in solutions or at interfaces. In biological systems, most multivalent interactions occur between protein receptors and carbohydrate ligands through hydrogen-bonding and hydrophobic interactions. Compared with weak affinity binding between one ligand and one binding site, i.e. monovalent interaction, multivalent interactioins provide greater avidity and specificity, and therefore play unique roles in a broad range of biological activities. Moreover, the studies of multivalent interactions are also essential for producing effective inhibitors and effectors of biological processes that could have important therapeutic applications. Synthetic multivalent ligands have been designed to mimic the biological functions of natural multivalent interactions, and various types of scaffolds have been used to display multiple ligands, including small molecules, linear polymers, dendrimers, nanoparticle surfaces, monolayer surfaces and liposomes. Studies have shown that multivalent interactions can be highly affected by various architectural parameters of these multivalent ligands, including ligand identities, valencies, spacing, ligand densities, nature of linker arms, scaffold length and scaffold conformation. Most of these multivalent ligands are chemically synthesized and have limitations of controlling over sequence and conformation, which is a barrier for mimicking ordered and controlled natural biological systems. Therefore, multivalent ligands with precisely controlled architecture are required for improved structure-function relationship studies. Protein engineering methods with subsequent chemical coupling of ligands provide significant advantages of controlling over backbone conformation and functional group placement, and therefore have been used to synthesize recombinant protein-based materials with desired properties similar to natural

  5. EM Algorithm for Mapping Quantitative Trait Loci in Multivalent Tetraploids

    Science.gov (United States)

    Multivalent tetraploids that include many plant species, such as potato, sugarcane and rose, are of paramount importance to agricultural production and biological research. Quantitative trait locus (QTL) mapping in multivalent tetraploids is challenged by their unique cytogenetic properties, such ...

  6. Predicting hydration energies for multivalent ions

    DEFF Research Database (Denmark)

    Andersson, Martin Peter; Stipp, Susan Louise Svane

    2014-01-01

    We have predicted the free energy of hydration for 40 monovalent and multivalent cations and anions using density functional theory and the implicit solvent model COnductor like Screening MOdel for Real Solvents (COSMO-RS) at the Becke-Perdew (BP)/Triple zeta valence with polarization functions...... (TZVP) level. Agreement with experimental data for monovalent and divalent ions is good and shows no significant systematic errors. Predictions are noticeably better than with standard COSMO. The agreement with experimental data for trivalent and tetravalent ions is slightly worse and shows systematic...... errors. Our results indicate that quantum chemical calculations combined with COSMO-RS solvent treatment is a reliable method for treating multivalent ions in solution, provided one hydration shell of explicit water molecules is included for metal cations. The accuracy is not high enough to allow...

  7. EM Algorithm for Mapping Quantitative Trait Loci in Multivalent Tetraploids

    OpenAIRE

    2010-01-01

    Multivalent tetraploids that include many plant species, such as potato, sugarcane, and rose, are of paramount importance to agricultural production and biological research. Quantitative trait locus (QTL) mapping in multivalent tetraploids is challenged by their unique cytogenetic properties, such as double reduction. We develop a statistical method for mapping multivalent tetraploid QTLs by considering these cytogenetic properties. This method is built in the mixture model-based framework an...

  8. Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency.

    Science.gov (United States)

    Ciuk, Anna K; Lindhorst, Thisbe K

    2015-01-01

    Multivalency effects are essential in carbohydrate recognition processes as occurring on the cell surface. Thus many synthetic multivalent glycoconjugates have been developed as important tools for glycobiological research. We are expanding this collection of molecules by the introduction of carbohydrate-scaffolded divalent glycothymine derivatives that can be intramolecularily dimerized by [2 + 2] photocycloaddition. Thus, thymine functions as a control element that allows to restrict the conformational flexibility of the scaffolded sugar ligands and thus to "organize" multivalency. With this work we add a parameter to multivalency studies additional to valency. PMID:26124869

  9. Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency

    OpenAIRE

    Anna K. Ciuk; Lindhorst, Thisbe K

    2015-01-01

    Multivalency effects are essential in carbohydrate recognition processes as occurring on the cell surface. Thus many synthetic multivalent glycoconjugates have been developed as important tools for glycobiological research. We are expanding this collection of molecules by the introduction of carbohydrate-scaffolded divalent glycothymine derivatives that can be intramolecularily dimerized by [2 + 2] photocycloaddition. Thus, thymine functions as a control element that allows to restrict the co...

  10. Hydrogen-multivalent acceptor complexes in high-purity germanium

    International Nuclear Information System (INIS)

    Using copper (a fast diffusing, multivalent acceptor impurity in Ge) it was shown that hydrogen can form complexes with multivalent acceptors. Hydrogen is incorporated in the Ge single crystal during its growth from a melt in a H2 atmosphere. By analogy with the interaction between lithium and multivalent acceptors two acceptor like complexes (Cu-H and Cu-H2) were found. Using Photothermal Ionization Spectroscopy and Hall effect the following energy levels are assigned: Cu-H: E/sub V/ + 17.5 meV and E/sub V/ + 170 +- 20 meV and Cu-H2: E/sub V/ + 17.0 meV. According to the model the Cu-H3 complex is neutral. Consequences for the performance of large volume radiation detectors are discussed

  11. Binding effects in multivalent Gibbs-Donnan equilibrium

    CERN Document Server

    Castelnovo, M; Castelnovo, Martin; Evilevitch, Alex

    2005-01-01

    The classical Gibbs-Donnan equilibrium describes excess osmotic pressure associated with confined colloidal charges embedded in an electrolyte solution. In this work, we extend this approach to describe the influence of multivalent ion binding on the equilibrium force acting on a charged rod translocating between two compartments, thereby mimicking ionic effects on force balance during in vitro DNA ejection from bacteriophage. The subtle interplay between Gibbs-Donnan equilibrium and adsorption equilibrium leads to a non-monotonic variation of the ejection force as multivalent salt concentration is increased, in qualitative agreement with experimental observations.

  12. Strength and dynamics of multivalent complexes at surfaces

    OpenAIRE

    Gomez-Casado, Alberto

    2011-01-01

    The aim of the work described in this thesis is to study the role of multivalency in the dynamic behavior of multivalent supramolecular systems. Several supramolecular systems have been employed, ranging from π‐π charge‐transfer complexes to cucurbit[n]uril (CB[n]) and β‐cyclodextrin (βCD) host‐guest complexes. All these systems have been used before as building blocks to fabricate nanostructures. Understanding their kinetics potentially allows the design of more stable or fast‐responding dev...

  13. Multivalent glycobiomaterials for specific recognition and binding by lectins

    OpenAIRE

    Rosencrantz, Ruben R.

    2015-01-01

    Glycans are one of the most complex biomolecules and are used in nature for various tasks from cell-cell adhesions and communication to invasion or pathogenic processes. The most important term in protein-glycan interaction is the “multivalent effect”. This describes the boost in avidity as soon as the number of presented glycans in close proximity to each other is increased. In this work, we aimed for the design and evaluation of multivalent scaffolds based on polymers for the specific recog...

  14. Mono and Multivalency In Tethered Protein-Carbohydrate Bonds

    Energy Technology Data Exchange (ETDEWEB)

    Ratto, T V; Langry, K C; Rudd, R E; Balhorn, R L; McElfresh, M W

    2004-01-29

    Molecular recognition in biological systems typically involves large numbers of interactions simultaneously. By using a multivalent approach, weak interactions with fairly low specificity can become strong highly specific interactions. Additionally, this allows an organism to control the strength and specificity of an interaction simply by controlling the number of binding molecules (or binding sites), which in turn can be controlled through transcriptional regulation.

  15. Architectures of Multivalent Glycomimetics for Probing Carbohydrate-Lectin Interactions

    Science.gov (United States)

    Lahmann, Martina

    Well-defined multivalent glycoconjugates are valued tools in glycoscience and they are particularly valuable for the investigation of carbohydrate-lectin interactions. In addition to the relatively globularly shaped glycodendrimers many other designs have been realized. This chapter gives an overview on the common different architectures and their chemical synthesis by focussing on the achievements made since 2001.

  16. An array-based method to identify multivalent inhibitors.

    Science.gov (United States)

    Zhang, Yalong; Li, Qian; Rodriguez, Luis G; Gildersleeve, Jeffrey C

    2010-07-21

    Carbohydrate-protein interactions play a critical role in a variety of biological processes, and agonists/antagonists of these interactions are useful as biological probes and therapeutic agents. Most carbohydrate-binding proteins achieve tight binding through formation of a multivalent complex. Therefore, both ligand structure and presentation contribute to recognition. Since there are many potential combinations of structure, spacing, and orientation to consider and the optimal one cannot be predicted, high-throughput approaches for analyzing carbohydrate-protein interactions and designing inhibitors are appealing. In this report, we develop a strategy to vary neoglycoprotein density on a surface of a glycan array. This feature of presentation was combined with variations in glycan structure and glycan density to produce an array with approximately 600 combinations of glycan structure and presentation. The unique array platform allows one to distinguish between different types of multivalent complexes on the array surface. To illustrate the advantages of this format, it was used to rapidly identify multivalent probes for various lectins. The new array was first tested with several plant lectins, including concanavalin A (conA), Vicia villosa isolectin B4 (VVL-B(4)), and Ricinus communis agglutinin (RCA120). Next, it was used to rapidly identify potent multivalent inhibitors of Pseudomonas aeruginosa lectin I (PA-IL), a key protein involved in opportunistic infections of P. aeruginosa , and mouse macrophage galactose-type lectin (mMGL-2), a protein expressed on antigen presenting cells that may be useful as a vaccine targeting receptor. An advantage of the approach is that structural information about the lectin/receptor is not required to obtain a multivalent inhibitor/probe. PMID:20583754

  17. Glycodendrimers: tools to explore multivalent galectin-1 interactions

    Directory of Open Access Journals (Sweden)

    Jonathan M. Cousin

    2015-05-01

    Full Text Available Four generations of lactose-functionalized polyamidoamine (PAMAM were employed to further the understanding of multivalent galectin-1 mediated interactions. Dynamic light scattering and fluorescence microscopy were used to study the multivalent interaction of galectin-1 with the glycodendrimers in solution, and glycodendrimers were observed to organize galectin-1 into nanoparticles. In the presence of a large excess of galectin-1, glycodendrimers nucleated galectin-1 into nanoparticles that were remarkably homologous in size (400–500 nm. To understand augmentation of oncologic cellular aggregation by galectin-1, glycodendrimers were used in cell-based assays with human prostate carcinoma cells (DU145. The results revealed that glycodendrimers provided competitive binding sites for galectin-1, which diverted galectin-1 from its typical function in cellular aggregation of DU145 cells.

  18. Colloidal stability of iron oxide nanoparticles with multivalent polymer surfactants.

    Science.gov (United States)

    Choi, Young-Wook; Lee, Hoik; Song, Youngjun; Sohn, Daewon

    2015-04-01

    This paper introduces a new approach for preparing magnetic colloidal suspensions with electrostatic repulsion between particles and polyelectrolyte surfactants. The surface charge of the iron oxide particles was positive in acidic aqueous conditions; however the surface charge of the colloid was negative in basic aqueous conditions due to the amphoteric property of Fe2O3. The long-term colloidal stability and particle distribution of the multivalent charged polymers, Poly(4-vinylbenzenesulfonate sodium salt) (PSS), Poly(acrylic acid) (PAA), and Poly(allylamine hydrochloride) (PAH) were compared with the monovalent surfactant sodium dodecyl sulfate (SDS). Both mono- and multivalent surfactant molecules showed good colloidal stability for extended periods of time. However, the particle distribution was dependent on the hydrophobicity of the surfactants' functional groups. Polyelectrolytes with a negatively charged functional group showed good long-term stability of particles and a narrow particle distribution regardless of the acid dissociation constant (pKa) of the polymer. PMID:25526296

  19. Multivalent Protein Assembly Using Monovalent Self-Assembling Building Blocks

    Directory of Open Access Journals (Sweden)

    Katja Petkau-Milroy

    2013-10-01

    Full Text Available Discotic molecules, which self-assemble in water into columnar supramolecular polymers, emerged as an alternative platform for the organization of proteins. Here, a monovalent discotic decorated with one single biotin was synthesized to study the self-assembling multivalency of this system in regard to streptavidin. Next to tetravalent streptavidin, monovalent streptavidin was used to study the protein assembly along the supramolecular polymer in detail without the interference of cross-linking. Upon self-assembly of the monovalent biotinylated discotics, multivalent proteins can be assembled along the supramolecular polymer. The concentration of discotics, which influences the length of the final polymers at the same time dictates the amount of assembled proteins.

  20. Design and synthesis of multivalent neoglycoconjugates by click conjugations

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    Feiqing Ding

    2014-06-01

    Full Text Available A highly stereoselective BF3∙OEt2-promoted tandem hydroamination/glycosylation on glycal scaffolds has been developed to form propargyl 3-tosylamino-2,3-dideoxysugars in a one-pot manner. Subsequent construction of multivalent 3-tosylamino-2,3-dideoxyneoglycoconjugates with potential biochemical applications was presented herein involving click conjugations as the key reaction step. The copper-catalyzed regioselective click reaction was tremendously accelerated with assistance of microwave irradiation.

  1. An Array-Based Method to Identify Multivalent Inhibitors

    OpenAIRE

    Zhang, Yalong; Li, Qian; Rodriguez, Luis G.; Gildersleeve, Jeffrey C.

    2010-01-01

    Carbohydrate-protein interactions play a critical role in a variety of biological processes, and agonists/antagonists of these interactions are useful as biological probes and therapeutic agents. Most carbohydrate-binding proteins achieve tight binding through formation of a multivalent complex. Therefore, both ligand structure and presentation contribute to recognition. Since there are many potential combinations of structure, spacing, and orientation to consider and the optimal one cannot b...

  2. Specific Enrichment of Phosphoproteins Using Functionalized Multivalent Nanoparticles

    OpenAIRE

    Hwang, Leekyoung; Ayaz-Guner, Serife; Gregorich, Zachery R.; Cai, Wenxuan; Valeja, Santosh G.; Jin, Song; Ge, Ying

    2015-01-01

    Analysis of protein phosphorylation remains a significant challenge due to the low abundance of phosphoproteins and the low stoichiometry of phosphorylation, which requires effective enrichment of phosphoproteins. Here we have developed superparamagnetic nanoparticles (NPs) whose surface is functionalized by multivalent ligand molecules that specifically bind to the phosphate groups on any phosphoproteins. These NPs enrich phosphoproteins from complex cell and tissue lysates with high specifi...

  3. Secondary batteries with multivalent ions for energy storage

    OpenAIRE

    Chengjun Xu; Yanyi Chen; Shan Shi; Jia Li; Feiyu Kang; Dangsheng Su

    2015-01-01

    The use of electricity generated from clean and renewable sources, such as water, wind, or sunlight, requires efficiently distributed electrical energy storage by high-power and high-energy secondary batteries using abundant, low-cost materials in sustainable processes. American Science Policy Reports state that the next-generation “beyond-lithium” battery chemistry is one feasible solution for such goals. Here we discover new “multivalent ion” battery chemistry beyond lithium battery chemist...

  4. Polyelectrolytes in the presence of multivalent ions: gelation versus segregation

    OpenAIRE

    Ermoshkin, A. V.; de la Cruz, M. Olvera

    2002-01-01

    We analyze solutions of strongly charged chains bridged by linkers such as multivalent ions. The gelation induced by the strong short range electrostatic attractions is dramatically suppressed by the long range electrostatic correlations due to the charge along the uncrosslinked monomers and ions. A modified Debye-Huckel approach of crosslinked clusters of charged chains is used to determined the mean field gelation transition self-consistently. Highly dilute polyelectrolyte solutions tend to...

  5. Multivalent nanoparticles for the treatment of ocular diseases

    OpenAIRE

    Hennig, Robert

    2016-01-01

    The present work investigated the multivalent binding of nanoparticles towards cells and how they can be utilized for treating severe ocular diseases. It was more than 100 years ago when Paul Ehrlich coined the idea of the ‘Magic Bullet’, a personalized and tailored drug that precisely targets diseased cells in the human body and leaves healthy cells untouched. Among many examples that resemble this concept, targeted delivery of nanoparticles to specific tissues is often designated as the ...

  6. Evaluation of Multivalent, Functional Polymeric Nanoparticles for Imaging Applications

    OpenAIRE

    Shokeen, Monica; Pressly, Eric D.; Hagooly, Aviv; Zheleznyak, Alexander; Ramos, Nicholas; Fiamengo, Ashley L.; Welch, Michael J.; Hawker, Craig J.; Anderson, Carolyn J.

    2011-01-01

    A series of multivalent, functional polymer nanoparticles with diagnostic/imaging units and targeting ligands for molecular targeting were synthesized with the loading of the chain end functionalized, GRGDS peptide targeting sequence (model system based on integrin αvβ3) ranging from 0 to 50%. Accurate structural and functional group control in these systems was achieved through a modular approach involving the use of multiple functionalized macromonomer/monomer units combined with living fre...

  7. Potent Glycosidase Inhibition with Heterovalent Fullerenes: Unveiling the Binding Modes Triggering Multivalent Inhibition.

    Science.gov (United States)

    Abellán Flos, Marta; García Moreno, M Isabel; Ortiz Mellet, Carmen; García Fernández, Jose Manuel; Nierengarten, Jean-Francois; Vincent, Stéphane P

    2016-08-01

    Glycosidases are key enzymes in metabolism, pathogenic/antipathogenic mechanisms and normal cellular functions. Recently, a novel approach for glycosidase inhibition that conveys multivalent glycomimetic conjugates has emerged. Many questions regarding the mechanism(s) of multivalent enzyme inhibition remain unanswered. Herein we report the synthesis of a collection of novel homo- and heterovalent glyco(mimetic)-fullerenes purposely conceived for probing the contribution of non-catalytic pockets in glysosidases to the multivalent inhibitory effect. Their affinities towards selected glycosidases were compared with data from homovalent fullerene conjugates. An original competitive glycosidase-lectin binding assay demonstrated that the multivalent derivatives and the substrate compete for low affinity non-glycone binding sites of the enzyme, leading to inhibition by a "recognition and blockage" mechanism. Most notably, this work provides evidence for enzyme inhibition by multivalent glycosystems, which will likely have a strong impact in the glycosciences given the utmost relevance of multivalency in Nature. PMID:27374430

  8. Resonant energy transfer based biosensor for detection of multivalent proteins.

    Energy Technology Data Exchange (ETDEWEB)

    Song, X. (Xuedong); Swanson, Basil I.

    2001-01-01

    We have developed a new fluorescence-based biosensor for sensitive detection of species involved in a multivslent interaction. The biosensor system utilizes specific interactions between proteins and cell surface receptors, which trigger a receptor aggregation process. Distance-dependent fluorescence self-quenching and resonant energy transfer mechanisms were coupled with a multivalent interaction to probe the receptor aggregation process, providing a sensitive and specific signal transduction method for such a binding event. The fluorescence change induced by the aggregation process can be monitored by different instrument platforms, e.g. fluorimetry and flow cytometry. In this article, a sensitive detection of pentavalent cholera toxin which recognizes ganglioside GM1 has been demonstrated through the resonant energy transfer scheme, which can achieve a double color change simultaneously. A detection sensitivity as high as 10 pM has been achieved within a few minutes (c.a. 5 minutes). The simultaneous double color change (an increase of acceptor fluorescence and a decrease of donor fluorescence intensity) of two similar fluorescent probes provides particularly high detection reliability owing to the fact that they act as each other's internal reference. Any external perturbation such as environmental temperature change causes no significant change in signal generation. Besides the application for biological sensing, the method also provides a useful tool for investigation of kinetics and thermodynamics of a multivalent interaction. Keywords: Biosensor, Fluorescence resonant energy transfer, Multivalent interaction, Cholera Toxin, Ganglioside GM1, Signal Transduction

  9. Secondary batteries with multivalent ions for energy storage

    Science.gov (United States)

    Xu, Chengjun; Chen, Yanyi; Shi, Shan; Li, Jia; Kang, Feiyu; Su, Dangsheng

    2015-09-01

    The use of electricity generated from clean and renewable sources, such as water, wind, or sunlight, requires efficiently distributed electrical energy storage by high-power and high-energy secondary batteries using abundant, low-cost materials in sustainable processes. American Science Policy Reports state that the next-generation “beyond-lithium” battery chemistry is one feasible solution for such goals. Here we discover new “multivalent ion” battery chemistry beyond lithium battery chemistry. Through theoretic calculation and experiment confirmation, stable thermodynamics and fast kinetics are presented during the storage of multivalent ions (Ni2+, Zn2+, Mg2+, Ca2+, Ba2+, or La3+ ions) in alpha type manganese dioxide. Apart from zinc ion battery, we further use multivalent Ni2+ ion to invent another rechargeable battery, named as nickel ion battery for the first time. The nickel ion battery generally uses an alpha type manganese dioxide cathode, an electrolyte containing Ni2+ ions, and Ni anode. The nickel ion battery delivers a high energy density (340 Wh kg-1, close to lithium ion batteries), fast charge ability (1 minute), and long cycle life (over 2200 times).

  10. Self-organization of multivalent counterions in polyelectrolyte brushes

    Science.gov (United States)

    Wu, Jianzhong

    2013-03-01

    The structure and interfacial properties of a polyelectrolyte brush (PEB) depend on a broad range of parameters such as the polymer charge and grafting density, counterion valence, salt concentration, and solvent conditions. These properties are of fundamental importance in technological applications of PEBs including colloid stabilization, surface modification and lubrication, and in functioning of biological systems such as genome packaging in single-strand DNA/RNA viruses. Despite intensive studies by experiments, molecular simulations, and myriad analytical methods including scaling analyses, self-consistent-field theory, and most recently density functional theory, the behavior of PEBs in the presence of multivalent counterions remains poorly understood. In this talk, I will present a density functional method for polyelectrolyte brushes and discuss self-organization of multivalent counterions within highly charged polyelectrolyte brushes. The counterion-mediated attraction between polyions leads to a first-order phase transition similar to that for a neutral brush in a poor solvent. The self-organization of multivalent counterions results in a wavelike electrostatic potential and charge density that oscillate between positive and negative values.

  11. Effect of Mono- and Multivalent Salts on Angle-dependent Attractions between Charged Rods

    OpenAIRE

    Lee, Kun-Chun; Borukhov, Itamar; Gelbart, William M.; Liu, Andrea J.; Stevens, Mark J.

    2003-01-01

    Using molecular dynamics simulations we examine the effective interactions between two like-charged rods as a function of angle and separation. In particular, we determine how the competing electrostatic repulsions and multivalent-ion-induced attractions depend upon concentrations of simple and multivalent salt. We find that with increasing multivalent salt the stable configuration of two rods evolves from isolated rods to aggregated perpendicular rods to aggregated parallel rods; at sufficie...

  12. Single-incubation immunoassay for a multivalent ligand

    International Nuclear Information System (INIS)

    In a two-site immunoassay method for a multivalent ligand using a single incubation, the ligand, labelled receptor for the ligand and unlabelled receptor for the ligand covalently bound to a solid-phase support are incubated as a stable suspension to produce a solid and liquid phase. The solid and liquid phases are separated from each other and the labelled receptor in either phase is quantified. The method has particular application as an assay for human thyroid stimulating hormone using purified, radioactively labelled antibodies and unlabelled antibodies covalently bound to hydrolyzed polyacrylamide particles. (author)

  13. Phase transitions in the assembly of multivalent signalling proteins

    Energy Technology Data Exchange (ETDEWEB)

    Li, Pilong; Banjade, Sudeep; Cheng, Hui-Chun; Kim, Soyeon; Chen, Baoyu; Guo, Liang; Llaguno, Marc; Hollingsworth, Javoris V.; King, David S.; Banani, Salman F.; Russo, Paul S.; Jiang, Qiu-Xing; Nixon, B. Tracy; Rosen, Michael K. (IIT); (UCB); (LSU); (UTSMC); (Penn)

    2013-04-08

    Cells are organized on length scales ranging from angstrom to micrometers. However, the mechanisms by which angstrom-scale molecular properties are translated to micrometer-scale macroscopic properties are not well understood. Here we show that interactions between diverse synthetic, multivalent macromolecules (including multi-domain proteins and RNA) produce sharp liquid-liquid-demixing phase separations, generating micrometer-sized liquid droplets in aqueous solution. This macroscopic transition corresponds to a molecular transition between small complexes and large, dynamic supramolecular polymers. The concentrations needed for phase transition are directly related to the valency of the interacting species. In the case of the actin-regulatory protein called neural Wiskott-Aldrich syndrome protein (N-WASP) interacting with its established biological partners NCK and phosphorylated nephrin1, the phase transition corresponds to a sharp increase in activity towards an actin nucleation factor, the Arp2/3 complex. The transition is governed by the degree of phosphorylation of nephrin, explaining how this property of the system can be controlled to regulatory effect by kinases. The widespread occurrence of multivalent systems suggests that phase transitions may be used to spatially organize and biochemically regulate information throughout biology.

  14. Adding Mono- and Multivalent Ions to Lyotropic Chromonic Liquid Crystals

    Science.gov (United States)

    Tortora, Luana; Park, Heung-Shik; Antion, Kelly; Woolwerton, Chris; Finotello, Daniele; Lavrentovich, Oleg

    2006-03-01

    Lyotropic Chromonic Liquid Crystals (LCLCs) are a distinct class of liquid crystals formed in aqueous solutions by molecules with rigid polyaromatic cores and ionic groups at the periphery [1-4]. The phase diagrams of these materials should depend on entropic factors (as in the Onsager model) and electrostatic interactions. Using optical polarizing microscopy, we studied the effects of mono- and multivalent ions on the phase diagrams of Blue 27 [3] and Sunset Yellow [2]. The monovalent ions change the temperatures of phase transitions, as described in [4], while the effect of multivalent ions is more dramatic and, in addition to the changed temperatures of phase transitions by tens of degrees, it often involves condensation of LCLC aggregates into domains with birefringence much higher than that in a normal nematic phase. Work supported by OBR B-7844. [1]J. Lydon, Current Opin. Colloid & Interface Sci. 3, 458 (1998);8, 480-489 (2004); [2]V. R. Horowitz, L. A. Janowitz, A. L. Modic, P. J. Heiney, and P. J. Collings, 2005, Phys. Rew. E 72, 041710; [3]Yu. A. Nastishin, H. Liu, T. Schneider, T., V. Nazarenko, R. Vasyuta, S. V. Shiyanovskii, and O. D. Lavrentovich, 2005, Phys. Rev. E 72, 041711; [4]A.F. Kostko, B. H. Cipriano, O. A. Pinchuk, L. Ziserman, M. A. Anisimov, D. Danino, and S. R. Raghavan. J. Phys. Chem. B 109, 19126-19133 (2005)

  15. Is a multivalent hand, foot, and mouth disease vaccine feasible?

    Science.gov (United States)

    Klein, Michel; Chong, Pele

    2015-01-01

    Enterovirus A infections are the primary cause of hand, foot and mouth disease (HFMD) in infants and young children. Although enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) are the predominant causes of HFMD epidemics worldwide, EV-A71 has emerged as a major neurovirulent virus responsible for severe neurological complications and fatal outcomes. HFMD is a serious health threat and economic burden across the Asia-Pacific region. Inactivated EV-A71 vaccines have elicited protection against EV-A71 but not against CV-A16 infections in large efficacy trials. The current development of a bivalent inactivated EV-A71/CV-A16 vaccine is the next step toward that of multivalent HFMD vaccines. These vaccines should ultimately include other prevalent pathogenic coxsackieviruses A (CV-A6 and CV-A10), coxsackieviruses B (B3 and B5) and echovirus 30 that often co-circulate during HFMD epidemics and can cause severe HFMD, aseptic meningitis and acute viral myocarditis. The prospect and challenges for the development of such multivalent vaccines are discussed. PMID:26009802

  16. Multivalent protein polymers with controlled chemical and physical properties.

    Science.gov (United States)

    Top, Ayben; Kiick, Kristi L

    2010-12-30

    In this review, we describe our work on the design, characterization, and modification of a series of alanine-rich helical polypeptides with novel functions. Glycosylation of the polypeptides has permitted investigation of polymer architecture effects on multivalent interactions. One of the members of this polypeptide family exhibits polymorphological behavior that is easily manipulated via simple changes in solution pH and temperature. Polypeptide-based fibrils formed at acidic pH and high temperature were shown to direct the one-dimensional organization of gold nanoparticles via electrostatic interactions. As a precursor to fibrils, aggregates likely comprising alanine-rich cores form at low temperatures and acidic pH and reversibly dissociate into monomers upon deprotonation. PEGylation of these polypeptides does not alter the self-association or conformational behavior of the polypeptide, suggesting potential applications in the development of assembled delivery vehicles, as modification of the polypeptides should be a useful strategy for controlling assembly. PMID:20562016

  17. Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

    Directory of Open Access Journals (Sweden)

    Candace K. Goodman

    2014-07-01

    Full Text Available Galectin-3 meditates cell surface glycoprotein clustering, cross linking, and lattice formation. In cancer biology, galectin-3 has been reported to play a role in aggregation processes that lead to tumor embolization and survival. Here, we show that lactose-functionalized dendrimers interact with galectin-3 in a multivalent fashion to form aggregates. The glycodendrimer–galectin aggregates were characterized by dynamic light scattering and fluorescence microscopy methodologies and were found to be discrete particles that increased in size as the dendrimer generation was increased. These results show that nucleated aggregation of galectin-3 can be regulated by the nucleating polymer and provide insights that improve the general understanding of the binding and function of sugar-binding proteins.

  18. Protecting Ligands Enhance Selective Targeting of Multivalent Nanoparticles

    CERN Document Server

    Angioletti-Uberti, Stefano

    2016-01-01

    Nanoparticles functionalized with multiple ligands can be programmed to bind biological targets, e.g. cells, depending on the receptors they express, providing a general platform for the development of different technologies, from selective drug-delivery to biosensing. In order to be highly selective ligands should exclusively bind to specific targeted receptors, since formation of bonds with other, untargeted ones would lead to non-specific binding and potentially harmful behaviour. This poses a particular problem for multivalent nanoparticles, because even very weak bonds can collectively lead to strong binding. A statistical mechanical model is presented here to describe the extent to which bond strength and nanoparticle valency can induce non-selective adsorption. The same model is used to describe a possible solution: functionalization of the nanoparticles with "protective" receptors. The latter compete with cell receptors for the targeting ligands, and can be optimized to strongly reduce the effect of u...

  19. Forces between silica particles in the presence of multivalent cations.

    Science.gov (United States)

    Valmacco, Valentina; Elzbieciak-Wodka, Magdalena; Herman, David; Trefalt, Gregor; Maroni, Plinio; Borkovec, Michal

    2016-06-15

    Forces between negatively charged silica particles in aqueous electrolyte solutions were measured with the colloidal probe technique based on the atomic force microscope (AFM). The present study focuses on the comparison of monovalent and multivalent counterions, namely K(+), Mg(2+), and La(3+). The force profiles can be well described with the theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO) down to distances of about 4nm. At smaller distances, the forces become strongly repulsive due to additional non-DLVO repulsion. In the presence of La(3+), one observes an additional attractive force with a range of about 1nm at intermediate salt concentrations. This force is probably related to ion-ion correlations, but could also be influenced by surface charge heterogeneities or charge fluctuation forces. PMID:27016916

  20. SUBORDINATION PROPERTIES OF MULTIVALENT FUNCTIONS INVOLVING AN EXTENDED FRACTIONAL DIFFERINTEGRAL OPERATOR

    Institute of Scientific and Technical Information of China (English)

    Mohamed K. AOUF; Teodor BULBOACÂ; ; Rabha M. EL-ASHWASH

    2014-01-01

    The object of this article is to investigate inclusion, radius, and other various properties of subclasses of multivalent analytic functions, which are defined by using an extended version of the Owa-Srivastava fractional differintegral operator Ω(λ,p).

  1. Single multivalent vaccination boosted by trickle larval infection confers protection against experimental lymphatic filariasis

    OpenAIRE

    Joseph, SK; Ramaswamy, K.

    2013-01-01

    The multivalent vaccine BmHAT, consisting of the Brugia malayi infective larval (L3) antigens heat shock protein12.6 (HSP12.6), abundant larval transcript-2 (ALT-2) and tetraspanin large extra cellular loop (TSP-LEL), was shown to be protective in rodent models from our laboratory. We hypothesize that since these antigens were identified using protective antibodies from immune endemic normal individuals, the multivalent vaccine can be augmented by natural L3 infections providing protection to...

  2. Competition between condensation of monovalent and multivalent ions in DNA aggregation

    OpenAIRE

    Burak, Yoram; Ariel, Gil; Andelman, David

    2004-01-01

    We discuss the distribution of ions around highly charged PEs when there is competition between monovalent and multivalent ions, pointing out that in this case the number of condensed ions is sensitive to short-range interactions, salt, and model-dependent approximations. This sensitivity is discussed in the context of recent experiments on DNA aggregation, induced by multivalent counterions such as spermine and spermidine.

  3. Double-degradable responsive self-assembled multivalent arrays-temporary nanoscale recognition between dendrons and DNA

    OpenAIRE

    Barnard, A.; Posocco, P.; Fermeglia, M.; Tschiche, A.; Calderon, Marcelo; Pricl, S.; Smith, D. K.

    2014-01-01

    This article reports self-assembling dendrons which bind DNA in a multivalent manner. The molecular design directly impacts on self-assembly which subsequently controls the way these multivalent nanostructures bind DNA-this can be simulated by multiscale modelling. Incorporation of an S-S linkage between the multivalent hydrophilic dendron and the hydrophobic units responsible for self-assembly allows these structures to undergo triggered reductive cleavage, with dithiothreitol (DTT) inducing...

  4. Dendritic polyglycerol sulfates as multivalent inhibitors of inflammation

    Science.gov (United States)

    Dernedde, Jens; Rausch, Alexandra; Weinhart, Marie; Enders, Sven; Tauber, Rudolf; Licha, Kai; Schirner, Michael; Zügel, Ulrich; von Bonin, Arne; Haag, Rainer

    2010-01-01

    Adhesive interactions of leukocytes and endothelial cells initiate leukocyte migration to inflamed tissue and are important for immune surveillance. Acute and chronic inflammatory diseases show a dysregulated immune response and result in a massive efflux of leukocytes that contributes to further tissue damage. Therefore, targeting leukocyte trafficking may provide a potent form of anti-inflammatory therapy. Leukocyte migration is initiated by interactions of the cell adhesion molecules E-, L-, and P-selectin and their corresponding carbohydrate ligands. Compounds that efficiently address these interactions are therefore of high therapeutic interest. Based on this rationale we investigated synthetic dendritic polyglycerol sulfates (dPGS) as macromolecular inhibitors that operate via a multivalent binding mechanism mimicking naturally occurring ligands. dPGS inhibited both leukocytic L-selectin and endothelial P-selectin with high efficacy. Size and degree of sulfation of the polymer core determined selectin binding affinity. Administration of dPGS in a contact dermatitis mouse model dampened leukocyte extravasation as effectively as glucocorticoids did and edema formation was significantly reduced. In addition, dPGS interacted with the complement factors C3 and C5 as was shown in vitro and reduced C5a levels in a mouse model of complement activation. Thus, dPGS represent an innovative class of a fully synthetic polymer therapeutics that may be used for the treatment of inflammatory diseases. PMID:21041668

  5. Allele coding in genomic evaluation

    Directory of Open Access Journals (Sweden)

    Christensen Ole F

    2011-06-01

    Full Text Available Abstract Background Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous genotype of the first allele, one for the heterozygote, and two for the homozygous genotype for the other allele. Another common allele coding changes these regression coefficients by subtracting a value from each marker such that the mean of regression coefficients is zero within each marker. We call this centered allele coding. This study considered effects of different allele coding methods on inference. Both marker-based and equivalent models were considered, and restricted maximum likelihood and Bayesian methods were used in inference. Results Theoretical derivations showed that parameter estimates and estimated marker effects in marker-based models are the same irrespective of the allele coding, provided that the model has a fixed general mean. For the equivalent models, the same results hold, even though different allele coding methods lead to different genomic relationship matrices. Calculated genomic breeding values are independent of allele coding when the estimate of the general mean is included into the values. Reliabilities of estimated genomic breeding values calculated using elements of the inverse of the coefficient matrix depend on the allele coding because different allele coding methods imply different models. Finally, allele coding affects the mixing of Markov chain Monte Carlo algorithms, with the centered coding being

  6. Genetic diversity of the Plasmodium falciparum apical membrane antigen I gene in parasite population from the China-Myanmar border area.

    Science.gov (United States)

    Zhu, Xiaotong; Zhao, Zhenjun; Feng, Yonghui; Li, Peipei; Liu, Fei; Liu, Jun; Yang, Zhaoqing; Yan, Guiyun; Fan, Qi; Cao, Yaming; Cui, Liwang

    2016-04-01

    To investigate the genetic diversity of the Plasmodium falciparum apical membrane antigen 1 (PfAMA1) gene in Southeast Asia, we determined PfAMA1 sequences from 135 field isolates collected from the China-Myanmar border area and compared them with 956 publically available PfAMA1 sequences from seven global P. falciparum populations. This analysis revealed high genetic diversity of PfAMA1 in global P. falciparum populations with a total of 229 haplotypes identified. The genetic diversity of PfAMA1 gene from the China-Myanmar border is not evenly distributed in the different domains of this gene. Sequence diversity in PfAMA1 from the China-Myanmar border is lower than that observed in Thai, African and Oceanian populations, but higher than that in the South American population. This appeared to correlate well with the levels of endemicity of different malaria-endemic regions, where hyperendemic regions favor genetic cross of the parasite isolates and generation of higher genetic diversity. Neutrality tests show significant departure from neutrality in the entire ectodomain and Domain I of PfAMA1 in the China-Myanmar border parasite population. We found evidence supporting a substantial continent-wise genetic structure among P. falciparum populations, with the highest genetic differentiation detected between the China-Myanmar border and the South American populations. Whereas no alleles were unique to a specific region, there were considerable geographical differences in major alleles and their frequencies, highlighting further necessity to include more PfAMA1 alleles in vaccine designs. PMID:26825252

  7. Controlled multivalent interactions in the inhibition of toxins via well-designed glycopolypeptides

    Science.gov (United States)

    Maheshwari, Ronak

    Many critical recognition events in biology are mediated via multivalent interactions between multiple saccharide ligands and their protein receptors. These proteincarbohydrate interactions are therefore important and being extensively investigated as they play a crucial role in several processes including pathogen recognition, inflammation, cell signaling, differentiation, and adhesion of various bacterial toxins. Multiple research groups have investigated these interactions by developing multivalent polymeric antagonists for carbohydrate binding proteins. In our work, we have selected cholera toxin (CT) as a model example to study these multivalent bindings by developing multivalent inhibitors. Various investigations have employed diverse guidelines that are believed to govern multivalency in the design of inhibitors for CT-GM1 interactions. Although successful in many respects, they are limited by certain architectural features such as a lack of synthetic versatility, significant polydispersity, and uncontrolled density and arrangement of saccharide ligands. Thus the mechanism by which multivalency is functioning in these systems is impractical to analyze and control. A more detailed understanding of multivalent binding by polymeric materials therefore requires the development of well-designed glycopolymers in which architectural features are well defined and controlled. Our approach aims to develop polymers via protein engineering methods and to equip these polypeptides with multivalent sugar ligands via chemical methods, to competitively bind with such toxins and neutralize them. This method allows control over architectural features such as number and spacing of saccharide ligands on the polymer, precise placement of charges and conformation of the polymer backbone. Such control over the architectural features allows for more purposeful design of polymers for inhibition of the multivalent binding event. Polypeptides with chemically reactive natural or non

  8. Cyclic Peptide-Decorated Self-Assembled Nanohybrids for Selective Recognition and Detection of Multivalent RNAs.

    Science.gov (United States)

    Choi, Jun Shik; Han, So-hee; Kim, Hyoseok; Lim, Yong-Beom

    2016-03-16

    Although there has been substantial advancement in the development of nanostructures, the development of self-assembled nanostructures that can selectively recognize multivalent targets has been very difficult. Here we show the proof of concept that topology-controlled peptide nanoassemblies can selectively recognize and detect a multivalent RNA target. We compared the differential behaviors of peptides in a linear or cyclic topology in terms of peptide-gold nanoparticle hybrid nanostructure formation, conformational stabilization, monovalent and multivalent RNA binding in vitro, and multivalent RNA recognition in live cells. When the topology-dependent selectivity amplification of the cyclic peptide hybrids is combined with the noninvasive nature of dark-field microscopy, the cellular localization of the viral Rev response element (RRE) RNA can be monitored in situ. Because intracellular interactions are often mediated by overlapping binding partners with weak affinity, the topology-controlled peptide assemblies can provide a versatile means to convert weak ligands into multivalent ligands with high affinity and selectivity. PMID:26886413

  9. Immobilization of multivalent glycoprobes on gold surfaces for sensing proteins and macrophages.

    Science.gov (United States)

    Gade, Madhuri; Khandelwal, Puneet; Sangabathuni, Sivakoti; Bavireddi, Harikrishna; Murthy, Raghavendra Vasudeva; Poddar, Pankaj; Kikkeri, Raghavendra

    2016-04-01

    The multivalent display of carbohydrates on the cell surface provides cooperative binding to improve the specific biological events. In addition to multivalency, the spatial arrangement and orientation of sugars with respect to external stimuli also trigger carbohydrate-protein interactions. Herein, we report a non-covalent host-guest strategy to immobilize heptavalent glyco-β-cyclodextrin on gold-coated glass slides to study multivalent carbohydrate-protein interactions. We have found that the localization of sugar entities on surfaces using β-cyclodextrin (β-CD) chemistry increased the avidity of carbohydrate-protein and carbohydrate-macrophage interactions compared to monovalent-β-CD sugar coated surfaces. This platform is expected to be a promising tool to amplify the avidity of sugar-mediated interactions on surfaces and contribute to the development of next generation bio-medical products. PMID:26934683

  10. Opposing Effects of Multivalent Ions on the Flexibility of DNA and RNA

    Science.gov (United States)

    Drozdetski, Aleksander V.; Tolokh, Igor S.; Pollack, Lois; Baker, Nathan; Onufriev, Alexey V.

    2016-07-01

    Increasing the concentration of counterions (salt) is known to reduce the bending persistence length of DNA. Here we use atomistic molecular dynamics simulations to predict that multivalent counterions have the opposite effect on double-stranded RNA, increasing its bending rigidity by at least 30%. This counterintuitive effect is observed for various tri- and tetravalent ions alike, and is robust to methodological details and the RNA sequence. In contrast to DNA, multivalent counterions bind inside the RNA major groove, causing significant contraction of the molecule along its helical axis—as a result, its further deformation due to bending becomes energetically more expensive compared to bending without bound multivalent ions. Thus, the relationship between mechanical properties of a charged polymer and its ionic atmosphere may be richer than previously thought.

  11. Families of Meromorphic Multivalent Functions Associated with the Dziok-Raina Operator

    Directory of Open Access Journals (Sweden)

    G. Murugusundaramoorthy

    2013-07-01

    Full Text Available Making use a linear operator, which is defined here by means of the Hadamard product (or convolution, involving the Wright’s generalized hypergeometric function , we introduce two novel subclassesP p(q,s,α1;A,B,λ andP+p(q,s,α1;A,B,λ of meromorphically multivalent functions oforder λ(0 ≤ λ < p in the punctured disc U∗. In this paper we investigate the various important properties and characteristics of these subclasses of meromorphically multivalent functions. We extend the familiar concept of neighborhoods of analytic functions to these subclasses of meromorphically multivalent functions . We also derive many interesting results for the Hadamard products of functions belonging to the classP+p(q,s,α1;A,B,λ.

  12. Tunable Graphitic Carbon Nano-Onions Development in Carbon Nanofibers for Multivalent Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Haiqing L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    We developed a novel porous graphitic carbon nanofiber material using a synthesis strategy combining electrospinning and catalytic graphitization. RF hydrogel was used as carbon precursors, transition metal ions were successfully introduced into the carbon matrix by binding to the carboxylate groups of a resorcinol derivative. Transition metal particles were homogeneously distributed throughout the carbon matrix, which are used as in-situ catalysts to produce graphitic fullerene-like nanostructures surrounding the metals. The success design of graphitic carbons with enlarged interlayer spacing will enable the multivalent ion intercalation for the development of multivalent rechargeable batteries.

  13. Allele coding in genomic evaluation

    DEFF Research Database (Denmark)

    Standen, Ismo; Christensen, Ole Fredslund

    2011-01-01

    Genomic data are used in animal breeding to assist genetic evaluation. Several models to estimate genomic breeding values have been studied. In general, two approaches have been used. One approach estimates the marker effects first and then, genomic breeding values are obtained by summing marker...... effects. In the second approach, genomic breeding values are estimated directly using an equivalent model with a genomic relationship matrix. Allele coding is the method chosen to assign values to the regression coefficients in the statistical model. A common allele coding is zero for the homozygous...... estimates and estimated marker effects in marker-based models are the same irrespective of the allele coding, provided that the model has a fixed general mean. For the equivalent models, the same results hold, even though different allele coding methods lead to different genomic relationship matrices...

  14. Genetically engineered multivalent single chain antibody constructs for cancer therapy

    International Nuclear Information System (INIS)

    increase its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

  15. Genetically engineered multivalent single chain antibody constructs for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Surinder Batra, Ph D

    2006-02-27

    its tumor: normal tissue ratio for improved therapeutic index, we engineered a variety antibody constructs. These constructs were evaluated using novel approaches like special radionuclides, pretargeting and optimization. Due to the smaller size, the engineered antibody molecules should penetrate better throughout a tumor mass, with less dose heterogeneity, than is the case with intact IgG. Multivalent scFvs with an appropriate radionuclide, therefore, hold promising prospects for cancer therapy and clinical imaging in MAb-based radiopharmaceuticals. In addition, the human anti-mouse antibodies (HAMA) responses in patients against antibody-based therapy are usually directed against the immunoglobulin constant regions; however, anti-idiotypic responses can also be detected. The HAMA responses reduce the efficacy of treatment by removing the circulating antibody molecules, fragments, and possibly scFvs by altering the pharmacokinetic properties of the antibody. HAMA responses against divalent IgG, divalent Ig fragments, and possibly multimeric scFvs could cause immune complex formation with hypersensitivity or allergic reactions that could be harmful to patients. The use of small molecules, such as scFvs (monomeric as well as multimeric), with their shorter biological half-lives and the lack of the constant regions and humanized variable (binding regions) performed in our studies should reduce the development of HAMA. The generation of humanized and fully human scFvs should further reduce the development of HAMA. Specific accomplishments on the project are the production of large amounts of recombinant antibodies as they are required in large amounts for cancer diagnosis and therapy. A variety of single-chain Fv (scFv) constructs were engineered for the desired pharmacokinetic properties. Tetrameric and dimeric scFvs showed a two-fold advantage: (1) there was a considerable gain in avidity as compared to smaller fragments, and (2) the biological half-life was more

  16. Coarse-grained molecular dynamics simulations of nanopatterning with multivalent inks

    Science.gov (United States)

    Cieplak, Marek; Thompson, Damien

    2008-06-01

    A coarse-grained molecular dynamics (MD) model is developed to study the multivalent, or multisite, binding of small functionalized dendrimer molecules to β-cyclodextrin-terminated self-assembled monolayers, the so-called ``molecular printboards'' used to print ``ink'' molecules on surfaces with a high degree of positional control and specificity. Some current and future bionanotechnology applications are in the creation of nanoparticle assemblies, directed protein assembly, platforms for biosensing, and cell:surface attachment. The coarse-grained model allows us to probe up to microsecond timescales and model ink diffusion, crucial for the application of the printboard in, for example, medical diagnostics. Recent all-atom MD simulations identified and quantified the molecular strain limiting the stability of nanopatterns created with small dendrimer inks, and explained the different patterns obtained experimentally with different dendrimer inks. In the present work, the all-atom simulations are ``scaled up'' to longer timescales via coarse graining, without incurring significant additional computational expense, and, crucially, without significant loss in atom-scale detail, the coarse-grained MD simulations yielding properties similar to those obtained from the all-atom simulations. The anchoring of the ink molecules to the monolayer is of multivalent nature and the degree of multivalency shows a sharp dependence on temperature, control of temperature thus providing a further operational ``switch'' for directed molecular assembly. The computational protocol developed can, in principle, be extended to model any multivalent assembly, for example, virus-cell complexation.

  17. Double-degradable responsive self-assembled multivalent arrays--temporary nanoscale recognition between dendrons and DNA.

    Science.gov (United States)

    Barnard, Anna; Posocco, Paola; Fermeglia, Maurizio; Tschiche, Ariane; Calderon, Marcelo; Pricl, Sabrina; Smith, David K

    2014-01-21

    This article reports self-assembling dendrons which bind DNA in a multivalent manner. The molecular design directly impacts on self-assembly which subsequently controls the way these multivalent nanostructures bind DNA--this can be simulated by multiscale modelling. Incorporation of an S-S linkage between the multivalent hydrophilic dendron and the hydrophobic units responsible for self-assembly allows these structures to undergo triggered reductive cleavage, with dithiothreitol (DTT) inducing controlled breakdown, enabling the release of bound DNA. As such, the high-affinity self-assembled multivalent binding is temporary. Furthermore, because the multivalent dendrons are constructed from esters, a second slow degradation step causes further breakdown of these structures. This two-step double-degradation mechanism converts a large self-assembling unit with high affinity for DNA into small units with no measurable binding affinity--demonstrating the advantage of self-assembled multivalency (SAMul) in achieving highly responsive nanoscale binding of biological targets. PMID:24263553

  18. The effect of multivalent ions on the thermal transition of hydrated polyelectrolyte multilayers

    Science.gov (United States)

    Reid, Dariya; Lutkenhaus, Jodie

    2015-03-01

    Layer-by-layer (LbL) assembly is a commonly studied technique in the production of uniform thin films. Hydrate LbL assemblies made of model polyelectrolytes, poly(diallyldimethylammonium chloride) (PDAC) and poly(styrene sulfonate) (PSS), exhibit a thermal transition with features of a glass transition and a lower critical solution temperature transition when assembled in the presence of sodium chloride. The question remains as to how multivalent cations affect the nature of the transition. Here, we present results on the thermal transition of PDAC/PSS LbL assemblies exposed to various multivalent salts. Quartz crystal microbalance (QCM-D) and modulated differential scanning calorimetry (MDSC) is used to assess the transition.

  19. Compact, Polyvalent Mannose Quantum Dots as Sensitive, Ratiometric FRET Probes for Multivalent Protein-Ligand Interactions.

    Science.gov (United States)

    Guo, Yuan; Sakonsinsiri, Chadamas; Nehlmeier, Inga; Fascione, Martin A; Zhang, Haiyan; Wang, Weili; Pöhlmann, Stefan; Turnbull, W Bruce; Zhou, Dejian

    2016-04-01

    A highly efficient cap-exchange approach for preparing compact, dense polyvalent mannose-capped quantum dots (QDs) has been developed. The resulting QDs have been successfully used to probe multivalent interactions of HIV/Ebola receptors DC-SIGN and DC-SIGNR (collectively termed as DC-SIGN/R) using a sensitive, ratiometric Förster resonance energy transfer (FRET) assay. The QD probes specifically bind DC-SIGN, but not its closely related receptor DC-SIGNR, which is further confirmed by its specific blocking of DC-SIGN engagement with the Ebola virus glycoprotein. Tuning the QD surface mannose valency reveals that DC-SIGN binds more efficiently to densely packed mannosides. A FRET-based thermodynamic study reveals that the binding is enthalpy-driven. This work establishes QD FRET as a rapid, sensitive technique for probing structure and thermodynamics of multivalent protein-ligand interactions. PMID:26990806

  20. Compact, Polyvalent Mannose Quantum Dots as Sensitive, Ratiometric FRET Probes for Multivalent Protein–Ligand Interactions

    Science.gov (United States)

    Sakonsinsiri, Chadamas; Nehlmeier, Inga; Fascione, Martin A.; Zhang, Haiyan; Wang, Weili; Pöhlmann, Stefan; Turnbull, W. Bruce

    2016-01-01

    Abstract A highly efficient cap‐exchange approach for preparing compact, dense polyvalent mannose‐capped quantum dots (QDs) has been developed. The resulting QDs have been successfully used to probe multivalent interactions of HIV/Ebola receptors DC‐SIGN and DC‐SIGNR (collectively termed as DC‐SIGN/R) using a sensitive, ratiometric Förster resonance energy transfer (FRET) assay. The QD probes specifically bind DC‐SIGN, but not its closely related receptor DC‐SIGNR, which is further confirmed by its specific blocking of DC‐SIGN engagement with the Ebola virus glycoprotein. Tuning the QD surface mannose valency reveals that DC‐SIGN binds more efficiently to densely packed mannosides. A FRET‐based thermodynamic study reveals that the binding is enthalpy‐driven. This work establishes QD FRET as a rapid, sensitive technique for probing structure and thermodynamics of multivalent protein–ligand interactions.

  1. Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald Timothy [Los Alamos National Laboratory; Borkowski, Marian [Los Alamos National Laboratory; Lucchini, Jean - Francois [Los Alamos National Laboratory; Ams, David [Los Alamos National Laboratory; Richmann, M. K. [Los Alamos National Laboratory; Khaing, H. [Los Alamos National Laboratory; Swanson, J. S. [Los Alamos National Laboratory

    2010-12-10

    The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.

  2. Anti-CD20 multivalent HPMA copolymer-Fab′ conjugates for the direct induction of apoptosis

    OpenAIRE

    Chu, Te-Wei; Yang, Jiyuan; Kopeček, Jindřich

    2012-01-01

    A hybrid biomimetic system comprising high-molecular-weight, linear copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) grafted with multiple Fab′ fragments of anti-CD20 monoclonal antibody (mAb) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization followed by attachment of Fab′ fragments via thioether bonds. Exposure of human non-Hodgkin’s lymphoma (NHL) Raji B cells to the multivalent conjugates resulted in crosslinking of CD20 receptors and commenceme...

  3. Broadly protective adenovirus-based multivalent vaccines against highly pathogenic avian influenza viruses for pandemic preparedness.

    Science.gov (United States)

    Vemula, Sai V; Ahi, Yadvinder S; Swaim, Anne-Marie; Katz, Jacqueline M; Donis, Ruben; Sambhara, Suryaprakash; Mittal, Suresh K

    2013-01-01

    Recurrent outbreaks of H5, H7 and H9 avian influenza viruses in domestic poultry accompanied by their occasional transmission to humans have highlighted the public health threat posed by these viruses. Newer vaccine approaches for pandemic preparedness against these viruses are needed, given the limitations of vaccines currently approved for H5N1 viruses in terms of their production timelines and the ability to induce protective immune responses in the absence of adjuvants. In this study, we evaluated the feasibility of an adenovirus (AdV)-based multivalent vaccine approach for pandemic preparedness against H5, H7 and H9 avian influenza viruses in a mouse model. Replication-defective AdV vectors expressing hemagglutinin (HA) from different subtypes and nucleoprotein (NP) from one subtype induced high levels of humoral and cellular immune responses and conferred protection against virus replication following challenge with H5, H7 and H9 avian influenza virus subtypes. Inclusion of HA from the 2009 H1N1 pandemic virus in the vaccine formulation further broadened the vaccine coverage. Significantly high levels of HA stalk-specific antibodies were observed following immunization with the multivalent vaccine. Inclusion of NP into the multivalent HA vaccine formulation resulted in the induction of CD8 T cell responses. These results suggest that a multivalent vaccine strategy may provide reasonable protection in the event of a pandemic caused by H5, H7, or H9 avian influenza virus before a strain-matched vaccine can be produced. PMID:23638099

  4. Evaluation of a Multivalent Vaccine against Lymphatic Filariasis in Rhesus macaque Model

    OpenAIRE

    Gajalakshmi Dakshinamoorthy; Agneta von Gegerfelt; Hanne Andersen; Mark Lewis; Ramaswamy Kalyanasundaram

    2014-01-01

    Lymphatic filariasis affects 120 million people worldwide and another 1.2 billion people are at risk of acquiring the infection. Chemotherapy with mass drug administration is substantially reducing the incidence of the infection. Nevertheless, an effective vaccine is needed to prevent the infection and eradicate the disease. Previously we reported that a multivalent fusion protein vaccine (rBmHAT) composed of small heat shock proteins 12.6 (HSP12.6), abundant larval transcript-2 (ALT-2) and l...

  5. Pentacyclic triterpenes grafted on CD cores to interfere with influenza virus entry: A dramatic multivalent effect.

    Science.gov (United States)

    Xiao, Sulong; Si, Longlong; Tian, Zhenyu; Jiao, Pingxuan; Fan, Zibo; Meng, Kun; Zhou, Xiaoshu; Wang, Han; Xu, Renyang; Han, Xu; Fu, Ge; Zhang, Yongmin; Zhang, Lihe; Zhou, Demin

    2016-02-01

    Multivalent effect plays an important role in biological processes, particularly in the specific recognition of virus with its host cell during the first step of infection. Here we report the synthesis of multivalent pentacyclic triterpene grafted on cyclodextrin core and potency of against influenza entry activity. Nine star-shaped compounds containing six, seven and eight pentacyclic triterpene pharmacophore on cyclodextrin scaffold were prepared by way of copper-catalyzed azide-alkyl cycloaddition reaction under microwave activation. Some of the multimers exhibited much potent antiviral activity against H1N1 virus (A/WSN/33), even equivalent or superior to oseltamivir. The most active compound 31, a heptavalent oleanolic acid-β-cyclodextrin conjugate, shows an up to 125-fold potency enhancement by its IC50 value over the corresponding monovalent conjugate and oleanolic acid, disclosing a clear multivalent effect. Further studies show that three compounds 31-33 exhibited broad spectrum inhibitory activity against other two human influenza A/JX/312 (H3N2) and A/HN/1222 (H3N2) viruses with the IC50 values at 2.47-14.90 μM. Most importantly, we found that compound 31, one of the best representative conjugate, binds tightly to the viral envelope hemagglutinin with a dissociation constant of KD = 2.08 μM, disrupting the interaction of hemagglutinin with the sialic acid receptor and thus the attachment of viruses to host cells. Our study might establish a strategy for the design of new pharmaceutical agents based on multivalency so as to block influenza virus entry into host cells. PMID:26686050

  6. Multilocus Inherited Neoplasia Alleles Syndrome

    DEFF Research Database (Denmark)

    Whitworth, James; Skytte, Anne-Bine; Sunde, Lone; Lim, Derek H; Arends, Mark J; Happerfield, Lisa; Frayling, Ian M; van Minkelen, Rick; Woodward, Emma R; Tischkowitz, Marc D; Maher, Eamonn R

    Mendelian causes of inherited cancer susceptibility are mostly rare and characterized by variable expression and incomplete penetrance. Phenotypic variability may result from a range of causes including locus heterogeneity, allelic heterogeneity, genetic and environmental modifier effects, or...... chance. Another potential cause is the presence of 2 or more inherited cancer predisposition alleles in the same individual. Although the frequency of such occurrences might be predicted to be low, such cases have probably been underascertained because standard clinical practice has been to test...... candidate inherited cancer genes sequentially until a pathogenic mutation is detected. However, recent advances in next-generation sequencing technologies now provide the opportunity to perform simultaneous parallel testing of large numbers of inherited cancer genes. Herein we provide examples of patients...

  7. Novel Approach to Prepare {sup 99m}Tc-Based Multivalent RGD Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Shuang Liu

    2012-10-24

    This project presents a novel approach to prepare the {sup 99m}Tc-bridged multivalent RGD (arginine-glycine-aspartate) peptides. This project will focus on fundamentals of {sup 99m}Tc radiochemistry. The main objective of this project is to demonstrate the proof-of-principle for the proposed radiotracers. Once a kit formulation is developed for preparation of the {sup 99m}Tc-bridged multivalent RGD peptides, various tumor-bearing animal models will be used to evaluate their potential for SPECT (single photon-emission computed tomography) imaging of cancer. We have demonstrated that (1) multimerization of cyclic RGD peptides enhances the integrin {alpha}{sub v}{beta}{sub 3} bonding affinity and radiotracer tumor uptake; (2) addition of G{sub 3} or PEG{sub 4} linkers makes it possible for two RGD motifs in 3P-RGD{sub 2} and 3G-RGD{sub 2} to achieve simultaneous integrin {alpha}{sub v}{beta}{sub 3} binding; and (3) multimers are actually bivalent (not multivalent), the presence of extra RGD motifs can enhance the tumor retention time of the radiotracer.

  8. Synthesis of giant globular multivalent glycofullerenes as potent inhibitors in a model of Ebola virus infection

    Science.gov (United States)

    Muñoz, Antonio; Sigwalt, David; Illescas, Beatriz M.; Luczkowiak, Joanna; Rodríguez-Pérez, Laura; Nierengarten, Iwona; Holler, Michel; Remy, Jean-Serge; Buffet, Kevin; Vincent, Stéphane P.; Rojo, Javier; Delgado, Rafael; Nierengarten, Jean-François; Martín, Nazario

    2016-01-01

    The use of multivalent carbohydrate compounds to block cell-surface lectin receptors is a promising strategy to inhibit the entry of pathogens into cells and could lead to the discovery of novel antiviral agents. One of the main problems with this approach, however, is that it is difficult to make compounds of an adequate size and multivalency to mimic natural systems such as viruses. Hexakis adducts of [60]fullerene are useful building blocks in this regard because they maintain a globular shape at the same time as allowing control over the size and multivalency. Here we report water-soluble tridecafullerenes decorated with 120 peripheral carbohydrate subunits, so-called ‘superballs’, that can be synthesized efficiently from hexakis adducts of [60]fullerene in one step by using copper-catalysed azide-alkyne cycloaddition click chemistry. Infection assays show that these superballs are potent inhibitors of cell infection by an artificial Ebola virus with half-maximum inhibitory concentrations in the subnanomolar range.

  9. Invasive Allele Spread under Preemptive Competition

    OpenAIRE

    Yasi, J. A.; Korniss, G.; Caraco, T.

    2005-01-01

    We study a discrete spatial model for invasive allele spread in which two alleles compete preemptively, initially only the "residents" (weaker competitors) being present. We find that the spread of the advantageous mutation is well described by homogeneous nucleation; in particular, in large systems the time-dependent global density of the resident allele is well approximated by Avrami's law.

  10. RHD allele distribution in Africans of Mali

    Directory of Open Access Journals (Sweden)

    Moulds Joann M

    2003-09-01

    Full Text Available Abstract Background Aberrant and non-functional RHD alleles are much more frequent in Africans than in Europeans. The DAU cluster of RHD alleles exemplifies that the alleles frequent in Africans have evaded recognition until recently. A comprehensive survey of RHD alleles in any African population was lacking. Results We surveyed the molecular structure and frequency of RHD alleles in Mali (West Africa by evaluating 116 haplotypes. Only 69% could be attributed to standard RHD (55% or the RHD deletion (14%. The aberrant RHD allele DAU-0 was predicted for 19%, RHDΨ for 7% and Ccdes for 4% of all haplotypes. DAU-3 and the new RHD allele RHD(L207F, dubbed DMA, were found in one haplotype each. A PCR-RFLP for the detection of the hybrid Rhesus box diagnostic for the RHD deletion in Europeans was false positive in 9 individuals, including all carriers of RHDΨ . Including two silent mutations and the RHD deletion, a total of 9 alleles could be differentiated. Conclusion Besides standard RHD and the RHD deletion, DAU-0, RHDΨ and Ccdes are major alleles in Mali. Our survey proved that the most frequent alleles of West Africans have been recognized allowing to devise reliable genotyping and phenotyping strategies.

  11. Evaluation of monovalent and multivalent iminosugars to modulate Candida albicans β-1,2-mannosyltransferase activities.

    Science.gov (United States)

    Hurtaux, Thomas; Sfihi-Loualia, Ghenima; Brissonnet, Yoan; Bouckaert, Julie; Mallet, Jean-Maurice; Sendid, Boualem; Delplace, Florence; Fabre, Emeline; Gouin, Sébastien G; Guérardel, Yann

    2016-06-24

    β-1,2-Linked oligomannosides substitute the cell wall of numerous yeast species. Several of those including Candida albicans may cause severe infections associated with high rates of morbidity and mortality, especially in immunocompromised patients. β-1,2-Mannosides are known to be involved in the pathogenic process and to elicit an immune response from the host. In C. albicans, the synthesis of β-mannosides is under the control of a family of nine genes coding for putative β-mannosyltransferases. Two of them, CaBmt1 and CaBmt3, have been shown to initiate and prime the elongation of the β-mannosides on the cell-wall mannan core. In the present study, we have assessed the modulating activities of monovalent and multivalent iminosugar analogs on these enzymes in order to control the enzymatic bio-synthesis of β-mannosides. We have identified a monovalent deoxynojirimycin (DNJ) derivative that inhibits the CaBmt1-catalyzed initiating activity, and mono-, tetra- and polyvalent deoxymannojirimycin (DMJ) that modulate the CaBmt1 activity toward the formation of a single major product. Analysis of the aggregating properties of the multivalent iminosugars showed their ability to elicit clusterization of both CaBmt1 and CaBmt3, without affecting their activity. These results suggest promising roles for multivalent iminosugars as controlling agents for the biosynthesis of β-1,2 mannosides and for monovalent DNJ derivative as a first target for the design of future β-mannosyltransferase inhibitors. PMID:26852253

  12. The Significance of Multivalent Bonding Motifs and “Bond Order” in DNA-Directed Nanoparticle Crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Thaner, Ryan V.; Eryazici, Ibrahim; Macfarlane, Robert J.; Brown, Keith A.; Lee, Byeongdu; Nguyen, SonBinh T.; Mirkin, Chad A.

    2016-05-18

    Multivalent oligonucleotide-based bonding elements have been synthesized and studied for the assembly and crystallization of gold nanoparticles. Through the use of organic branching points, divalent and trivalent DNA linkers were readily incorporated into the oligonucleotide shells that define DNA-nanoparticles and compared to monovalent linker systems. These multivalent bonding motifs enable the change of "bond strength" between particles and therefore modulate the effective "bond order." In addition, the improved accessibility of strands between neighboring particles, either due to multivalency or modifications to increase strand flexibility, gives rise to superlattices with less strain in the crystallites compared to traditional designs. Furthermore, the increased availability and number of binding modes also provide a new variable that allows previously unobserved crystal structures to be synthesized, as evidenced by the formation of a thorium phosphide superlattice.

  13. Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

    Directory of Open Access Journals (Sweden)

    Christian Benkhäuser

    2015-05-01

    Full Text Available A Tröger's base-derived racemic bis(1,10-phenanthroline ligand (rac-1 and a bis(2,2'-bipyridine ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry.

  14. Design, synthesis, and testing of multivalent compounds targeted to melanocortin receptors

    Science.gov (United States)

    Dehigaspitiya, Dilani Chathurika

    Our focus is on developing non-invasive molecular imaging reagents, which target human cancers that presently are difficult to detect, such as melanoma. We wish to apply the multivalency concept to differentiate between healthy cells and melanoma cells. Melanoma cells are known to over-express alpha melanocyte stimulating hormone receptors. A successful multivalent construct should show greater avidity towards melanoma cells than healthy cells due to the synergistic effects arising from multivalency. Both oligomeric and shorter linear constructs bearing the minimum active sequence of melanocyte stimulating hormone, His-DPhe-Arg-Trp-NH2(MSH4), which binds with low micromolar affinity to alpha melanocyte stimulating hormone receptors, were synthesized. Binding affinities of these constructs were evaluated in a competitive binding assay by competing with labeled ligands, Eu-DTPA-PEGO-MSH7 and/or Eu-DTPA-PEGO-NDP-alpha-MSH on the engineered cell line HEK293 CCK2R/hMC4R, which is genetically modified to over-express both the cholecystokinin 2 receptor (CCK2R) and human melanocortin 4 receptor (hMC4R). The oligomers were rapidly assembled using microwave-assisted copper catalyzed azide-alkyne cycloaddition between a dialkyne derivative of MSH4 and a diazide derivative of (Pro-Gly)3 as co-monomers. Three oligomer mixtures were further analyzed based on their degree of oligomerization and the route by which the MSH4 monomers were oligomerized, protected vs deprotected. Completive binding assay against Eu-DTPA-PEGO-MSH7 showed only a statistical enhancement of binding when calculated based on the total MSH4 concentration. However, when the calculation of avidity is based on an estimation of the particles numbers, there was a seven times enhancement of binding compared to a monovalent MSH4 control. The shorter linear multivalent MSH4 constructs were synthesized using ethylene glycol, glycerol, and mannitol as core scaffolds with maximum inter-ligand distances ranging from 27

  15. Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting.

    Science.gov (United States)

    Benkhäuser, Christian; Lützen, Arne

    2015-01-01

    A Tröger's base-derived racemic bis(1,10-phenanthroline) ligand (rac)-1 and a bis(2,2'-bipyridine) ligand with a central 1,3-diethynylbenzene unit 2 were synthesized. Each of these ligands acts as a multivalent entity for the binding of two copper(I) ions. Upon coordination to the metal ions these two ligands undergo selective self-assembly into heteroleptic dinuclear metallosupramolecular kites in a high-fidelity social self-sorting manner as evidenced by NMR spectroscopy and mass spectrometry. PMID:26124873

  16. Multivalent display of minimal Clostridium difficile glycan epitopes mimics antigenic properties of larger glycans

    Science.gov (United States)

    Broecker, Felix; Hanske, Jonas; Martin, Christopher E.; Baek, Ju Yuel; Wahlbrink, Annette; Wojcik, Felix; Hartmann, Laura; Rademacher, Christoph; Anish, Chakkumkal; Seeberger, Peter H.

    2016-01-01

    Synthetic cell-surface glycans are promising vaccine candidates against Clostridium difficile. The complexity of large, highly antigenic and immunogenic glycans is a synthetic challenge. Less complex antigens providing similar immune responses are desirable for vaccine development. Based on molecular-level glycan–antibody interaction analyses, we here demonstrate that the C. difficile surface polysaccharide-I (PS-I) can be resembled by multivalent display of minimal disaccharide epitopes on a synthetic scaffold that does not participate in binding. We show that antibody avidity as a measure of antigenicity increases by about five orders of magnitude when disaccharides are compared with constructs containing five disaccharides. The synthetic, pentavalent vaccine candidate containing a peptide T-cell epitope elicits weak but highly specific antibody responses to larger PS-I glycans in mice. This study highlights the potential of multivalently displaying small oligosaccharides to achieve antigenicity characteristic of larger glycans. The approach may result in more cost-efficient carbohydrate vaccines with reduced synthetic effort. PMID:27091615

  17. Suppression of Cocaine-Evoked Hyperactivity by Self-Adjuvanting and Multivalent Peptide Nanofiber Vaccines.

    Science.gov (United States)

    Rudra, Jai S; Ding, Ye; Neelakantan, Harshini; Ding, Chunyong; Appavu, Rajagopal; Stutz, Sonja; Snook, Joshua D; Chen, Haiying; Cunningham, Kathryn A; Zhou, Jia

    2016-05-18

    The development of anti-cocaine vaccines that counteract the rewarding effects of the drug are currently being investigated as adjunct therapies for prevention of relapse in abstinent users. However, cocaine is weakly immunogenic and requires conjugation to carrier proteins and coadministration with strong adjuvants, which carry the risk of local reactogenicity and systemic toxicity. Here we report synthetic and multivalent self-assembling peptide nanofibers as adjuvant-free carriers for cocaine vaccines. A novel cocaine hapten modified at the P3 site was conjugated to the N-terminus of an amphipathic self-assembling domain KFE8. In aqueous buffers the cocaine-KFE8 conjugate assembled into β-sheet rich nanofibers, which raised anti-cocaine antibodies without the need for added adjuvants in mice. Vaccinated mice were treated with cocaine and a significant negative correlation was observed between antibody levels and cocaine-evoked hyperactivity. These totally synthetic and multivalent nanofibers with well-defined chemical composition represent the first generation of adjuvant-free cocaine vaccines. PMID:26926328

  18. Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

    Directory of Open Access Journals (Sweden)

    Lisa Maria Henning

    2015-05-01

    Full Text Available The coupling of peptides to polyglycerol carriers represents an important route towards the multivalent display of protein ligands. In particular, the inhibition of low affinity intracellular protein–protein interactions can be addressed by this design. We have applied this strategy to develop binding partners for FBP21, a protein which is important for the splicing of pre-mRNA in the nucleus of eukaryotic cells. Firstly, by using phage display the optimized sequence WPPPPRVPR was derived which binds with KDs of 80 μM and 150 µM to the individual WW domains and with a KD of 150 μM to the tandem-WW1–WW2 construct. Secondly, this sequence was coupled to a hyperbranched polyglycerol (hPG that allowed for the multivalent display on the surface of the dendritic polymer. This novel multifunctional hPG-peptide conjugate displayed a KD of 17.6 µM which demonstrates that the new carrier provides a venue for the future inhibition of proline-rich sequence recognition by FBP21 during assembly of the spliceosome.

  19. Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

    Science.gov (United States)

    Bertazzon, Miriam; Marczynke, Michaela; Seitz, Oliver; Volkmer, Rudolf; Haag, Rainer

    2015-01-01

    Summary The coupling of peptides to polyglycerol carriers represents an important route towards the multivalent display of protein ligands. In particular, the inhibition of low affinity intracellular protein–protein interactions can be addressed by this design. We have applied this strategy to develop binding partners for FBP21, a protein which is important for the splicing of pre-mRNA in the nucleus of eukaryotic cells. Firstly, by using phage display the optimized sequence WPPPPRVPR was derived which binds with K Ds of 80 μM and 150 µM to the individual WW domains and with a K D of 150 μM to the tandem-WW1–WW2 construct. Secondly, this sequence was coupled to a hyperbranched polyglycerol (hPG) that allowed for the multivalent display on the surface of the dendritic polymer. This novel multifunctional hPG-peptide conjugate displayed a K D of 17.6 µM which demonstrates that the new carrier provides a venue for the future inhibition of proline-rich sequence recognition by FBP21 during assembly of the spliceosome. PMID:26124874

  20. DNA-based immunisation against rabies and rabies-related viruses: towards multivalent vaccines.

    Science.gov (United States)

    Perrin, P; Jacob, Y; Desmézières, E; Tordo, N

    2000-01-01

    Prototypes of multivalent DNA vaccines against lyssaviruses (LV: rabies and rabies-related viruses) and other viruses were developed using chimaeric LV glycoprotein (cLVG) DNA and cLVG DNA carrying foreign epitopes. cLVG is composed of the N-terminal half of an LV genotype (GT) containing antigenic site II, the C-terminal half of GT containing antigenic site III, as well as the transmembrane and cytoplasmic domains of the same or a different GT. Both antigenic sites induced virus neutralizing antibodies (VNAb). Foreign B and T cell epitopes inserted between the two halves of cLVG correspond to the B cell C3 neutralisation epitope of poliovirus VP1 protein and to the H2d CMH I restricted T cell epitope of the nucleoprotein of the lymphocytic choriomeningitis virus (LCMV). In mice and dogs homogenous rabies virus G DNA induced protection against wild-type rabies virus whereas cLVG protected against lyssaviruses. cLVG DNA carrying foreign epitopes induced VNAb against LV and poliovirus and protection against LCMV. The results obtained clearly demonstrate the potential usefulness of cLVG for the development of multivalent vaccines against viral diseases, including rabies and zoonoses. PMID:11713814

  1. Multivalent anchored and crosslinked hyperbranched polyglycerol monolayers as antifouling coating for titanium oxide surfaces.

    Science.gov (United States)

    Wei, Qiang; Krysiak, Stefanie; Achazi, Katharina; Becherer, Tobias; Noeske, Paul-Ludwig Michael; Paulus, Florian; Liebe, Hendrik; Grunwald, Ingo; Dernedde, Jens; Hartwig, Andreas; Hugel, Thorsten; Haag, Rainer

    2014-10-01

    A set of new catecholic monolayer coatings was developed to improve the antifouling performance of TiO2 surfaces. To solve the problem of the weak charge-transfer interaction between a single catechol anchor and TiO2, multiple catechol groups were combined with hyperbranched polyglycerol (hPG) which is a distinct dendritic scaffold that exposes its multivalent anchor groups on the surface. Thus, multivalent catecholic hPGs can be easily prepared for surface modification. The immobilization of the compounds was monitored by quartz crystal microbalance with dissipation monitoring. Surface properties of the coatings were analyzed by water contact angle, X-ray photoelectron spectroscopy, and atomic force microscopy. The antifouling ability and stability were investigated by protein adsorption and cell adhesion. By increasing the number of catechol groups on the hPG scaffold, the stability and surface coverage could be significantly enhanced. Moreover, the inner-layer crosslinking of the coatings by grafting and initiating vinyl groups clearly improved their long-term stability. As a result, hPG with a catecholic functional degree of 10% (hPG-Cat10) and hPG with both catecholic and vinylic functional degree of 5% (hPG-Cat5-V5) were identified as the best catecholic hPGs to prepare bioinert and stable monolayer coatings on TiO2. PMID:25189471

  2. Multivalent IDP assemblies: Unique properties of LC8-associated, IDP duplex scaffolds.

    Science.gov (United States)

    Clark, Sarah A; Jespersen, Nathan; Woodward, Clare; Barbar, Elisar

    2015-09-14

    A wide variety of subcellular complexes are composed of one or more intrinsically disordered proteins (IDPs) that are multivalent, flexible, and characterized by dynamic binding of diverse partner proteins. These multivalent IDP assemblies, of broad functional diversity, are classified here into five categories distinguished by the number of IDP chains and the arrangement of partner proteins in the functional complex. Examples of each category are summarized in the context of the exceptional molecular and biological properties of IDPs. One type - IDP duplex scaffolds - is considered in detail. Its unique features include parallel alignment of two IDP chains, formation of new self-associated domains, enhanced affinity for additional bivalent ligands, and ubiquitous binding of the hub protein LC8. For two IDP duplex scaffolds, dynein intermediate chain IC and nucleoporin Nup159, these duplex features, together with the inherent flexibility of IDPs, are central to their assembly and function. A new type of IDP-LC8 interaction, distributed binding of LC8 among multiple IDP recognition sites, is described for Nup159 assembly. PMID:26226419

  3. Estimating the probability of allelic drop-out of STR alleles in forensic genetics

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Mogensen, Helle Smidt;

    2009-01-01

    In crime cases with available DNA evidence, the amount of DNA is often sparse due to the setting of the crime. In such cases, allelic drop-out of one or more true alleles in STR typing is possible. We present a statistical model for estimating the per locus and overall probability of allelic drop...

  4. Efficient Inhibition of Germination of Coat-Deficient Bacterial Spores by Multivalent Metal Cations, Including Terbium (Tb3+) ▿

    OpenAIRE

    Yi, Xuan; Bond, Colton; Sarker, Mahfuzur R.; Setlow, Peter

    2011-01-01

    Release of dipicolinic acid (DPA) and its fluorescence with terbium (Tb3+) allow rapid measurement of the germination and viability of spores of Bacillus and Clostridium species. However, germination of coat-deficient Bacillus spores was strongly inhibited by Tb3+ and some other multivalent cations. Tb3+ also inhibited germination of coat-deficient Clostridium perfringens spores.

  5. Adjusted system technology provides for perfect teamwork. Multivalent heating systems; Abgestimmte Systemtechnik sorgt fuer perfektes Teamwork. Multivalente Heizungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Rogatty, Wolfgang [Viessmann Werke GmbH, Allendorf (Germany)

    2011-07-01

    Multivalent heating systems offer several advantages: these systems reduce the dependence from petroleum and natural gas, reduce fuel consumption and help to protect the climate. The author of the contribution under consideration reports on the latest technical trends in this area.

  6. EV71 vaccines: a first step towards multivalent hand, foot and mouth disease vaccines.

    Science.gov (United States)

    Klein, Michel H

    2015-03-01

    Enterovirus A infections are the primary cause of hand, foot and mouth disease in infants and young children. Enterovirus 71 (EV71) and coxsackievirus A16 have emerged as neurotropic viruses responsible for severe neurological complications and a serious public health threat across the Asia-Pacific region. Formalin-inactivated EV71 vaccines have elicited protection against EV71 but not against coxsackievirus A16 infections. The development of a bivalent formalin-inactivated EV71/FI coxsackievirus A16 vaccine should be the next step towards that of multivalent hand, foot and mouth disease vaccines which should ultimately include other prevalent pathogenic coxsackieviruses and echovirus 30. This editorial summarizes the major challenges faced by the development of hand, foot and mouth disease vaccines. PMID:25536888

  7. The Effect of Oxygen Potential on the Sulfide Capacity for Slags Containing Multivalent Species

    Science.gov (United States)

    Allertz, Carl; Selleby, Malin; Sichen, Du

    2016-06-01

    The dependence of sulfide capacity on the oxygen partial pressure for slags containing multivalent species was investigated experimentally using a slag containing vanadium oxide. Copper-slag equilibration experiments were carried out at 1873 K (1600 °C) in the approximate oxygen partial pressure range 10-15.4 to 10-9 atm. The sulfide capacity was found to be strongly dependent on the oxygen potential in this slag system, increasing with the oxygen partial pressure. The sulfide capacity changed by more than two orders of magnitude over the oxygen partial pressure range. The effect of changing oxygen partial pressure was found to be much greater than the effect of changing slag composition at a fixed oxygen partial pressure.

  8. Orthogonal dual-modification of proteins for the engineering of multivalent protein scaffolds

    Directory of Open Access Journals (Sweden)

    Michaela Mühlberg

    2015-05-01

    Full Text Available To add new tools to the repertoire of protein-based multivalent scaffold design, we have developed a novel dual-labeling strategy for proteins that combines residue-specific incorporation of unnatural amino acids with chemical oxidative aldehyde formation at the N-terminus of a protein. Our approach relies on the selective introduction of two different functional moieties in a protein by mutually orthogonal copper-catalyzed azide–alkyne cycloaddition (CuAAC and oxime ligation. This method was applied to the conjugation of biotin and β-linked galactose residues to yield an enzymatically active thermophilic lipase, which revealed specific binding to Erythrina cristagalli lectin by SPR binding studies.

  9. Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

    Directory of Open Access Journals (Sweden)

    Tommaso Pecchioli

    2015-05-01

    Full Text Available The first immobilization of a MacMillan’s first generation organocatalyst onto dendritic support is described. A modified tyrosine-based imidazolidin-4-one was grafted to a soluble high-loading hyperbranched polyglycerol via a copper-catalyzed alkyne–azide cycloaddition (CuAAC reaction and readily purified by dialysis. The efficiency of differently functionalized multivalent organocatalysts 4a–c was tested in the asymmetric Friedel–Crafts alkylation of N-methylpyrrole with α,β-unsaturated aldehydes. A variety of substituted enals was investigated to explore the activity of the catalytic system which was also compared with monovalent analogues. The catalyst 4b showed excellent turnover rates and no loss of activity due to immobilization, albeit moderate enantioselectivities were observed. Moreover, easy recovery by selective precipitation allowed the reuse of the catalyst for three cycles.

  10. Structural Insight into Multivalent Galactoside Binding to Pseudomonas aeruginosa Lectin LecA.

    Science.gov (United States)

    Visini, Ricardo; Jin, Xian; Bergmann, Myriam; Michaud, Gaelle; Pertici, Francesca; Fu, Ou; Pukin, Aliaksei; Branson, Thomas R; Thies-Weesie, Dominique M E; Kemmink, Johan; Gillon, Emilie; Imberty, Anne; Stocker, Achim; Darbre, Tamis; Pieters, Roland J; Reymond, Jean-Louis

    2015-11-20

    Multivalent galactosides inhibiting Pseudomonas aeruginosa biofilms may help control this problematic pathogen. To understand the binding mode of tetravalent glycopeptide dendrimer GalAG2 [(Gal-β-OC6H4CO-Lys-Pro-Leu)4(Lys-Phe-Lys-Ile)2Lys-His-Ile-NH2] to its target lectin LecA, crystal structures of LecA complexes with divalent analog GalAG1 [(Gal-β-OC6H4CO-Lys-Pro-Leu)2Lys-Phe-Lys-Ile-NH2] and related glucose-triazole linked bis-galactosides 3u3 [Gal-β-O(CH2)n-(C2HN3)-4-Glc-β-(C2HN3)-[β-Glc-4-(N3HC2)]2-(CH2)n-O-β-Gal (n = 1)] and 5u3 (n = 3) were obtained, revealing a chelate bound 3u3, cross-linked 5u3, and monovalently bound GalAG1. Nevertheless, a chelate bound model better explaining their strong LecA binding and the absence of lectin aggregation was obtained by modeling for all three ligands. A model of the chelate bound GalAG2·LecA complex was also obtained rationalizing its unusually tight LecA binding (KD = 2.5 nM) and aggregation by lectin cross-linking. The very weak biofilm inhibition with divalent LecA inhibitors suggests that lectin aggregation is necessary for biofilm inhibition by GalAG2, pointing to multivalent glycoclusters as a unique opportunity to control P. aeruginosa biofilms. PMID:26295304

  11. Multivalent hyaluronic acid bioconjugates improve sFlt-1 activity in vitro.

    Science.gov (United States)

    Altiok, Eda I; Santiago-Ortiz, Jorge L; Svedlund, Felicia L; Zbinden, Aline; Jha, Amit K; Bhatnagar, Deepika; Loskill, Peter; Jackson, Wesley M; Schaffer, David V; Healy, Kevin E

    2016-07-01

    Anti-VEGF drugs that are used in conjunction with laser ablation to treat patients with diabetic retinopathy suffer from short half-lives in the vitreous of the eye resulting in the need for frequent intravitreal injections. To improve the intravitreal half-life of anti-VEGF drugs, such as the VEGF decoy receptor sFlt-1, we developed multivalent bioconjugates of sFlt-1 grafted to linear hyaluronic acid (HyA) chains termed mvsFlt. Using size exclusion chromatography with multiangle light scattering (SEC-MALS), SDS-PAGE, and dynamic light scattering (DLS), we characterized the mvsFlt with a focus on the molecular weight contribution of protein and HyA components to the overall bioconjugate size. We found that mvsFlt activity was independent of HyA conjugation using a sandwich ELISA and in vitro angiogenesis assays including cell survival, migration and tube formation. Using an in vitro model of the vitreous with crosslinked HyA gels, we demonstrated that larger mvsFlt bioconjugates showed slowed release and mobility in these hydrogels compared to low molecular weight mvsFlt and unconjugated sFlt-1. Finally, we used an enzyme specific to sFlt-1 to show that conjugation to HyA shields sFlt-1 from protein degradation. Taken together, our findings suggest that mvsFlt bioconjugates retain VEGF binding affinity, shield sFlt-1 from enzymatic degradation, and their movement in hydrogel networks (in vitro model of the vitreous) is controlled by both bioconjugate size and hydrogel network mesh size. These results suggest that a strategy of multivalent conjugation could substantially improve drug residence time in the eye and potentially improve therapeutics for the treatment of diabetic retinopathy. PMID:27086270

  12. Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

    Directory of Open Access Journals (Sweden)

    Stephan Schmidt

    2015-05-01

    Full Text Available Many biological functions at cell level are mediated by the glycocalyx, a dense carbohydrate-presenting layer. In this layer specific interactions between carbohydrate ligands and protein receptors are formed to control cell–cell recognition, cell adhesion and related processes. The aim of this work is to shed light on the principles of complex formation between surface anchored carbohydrates and receptor surfaces by measuring the specific adhesion between surface bound mannose on a concanavalin A (ConA layer via poly(ethylene glycol-(PEG-based soft colloidal probes (SCPs. Special emphasis is on the dependence of multivalent presentation and density of carbohydrate units on specific adhesion. Consequently, we first present a synthetic strategy that allows for controlled density variation of functional groups on the PEG scaffold using unsaturated carboxylic acids (crotonic acid, acrylic acid, methacrylic acid as grafting units for mannose conjugation. We showed by a range of analytic techniques (ATR–FTIR, Raman microscopy, zeta potential and titration that this synthetic strategy allows for straightforward variation in grafting density and grafting length enabling the controlled presentation of mannose units on the PEG network. Finally we determined the specific adhesion of PEG-network-conjugated mannose units on ConA surfaces as a function of density and grafting type. Remarkably, the results indicated the absence of a molecular-level enhancement of mannose/ConA interaction due to chelate- or subsite-binding. The results seem to support the fact that weak carbohydrate interactions at mechanically flexible interfaces hardly undergo multivalent binding but are simply mediated by the high number of ligand–receptor interactions.

  13. sFlt Multivalent Conjugates Inhibit Angiogenesis and Improve Half-Life In Vivo

    Science.gov (United States)

    Altiok, Eda I.; Browne, Shane; Khuc, Emily; Moran, Elizabeth P.; Qiu, Fangfang; Zhou, Kelu; Santiago-Ortiz, Jorge L.; Ma, Jian-xing; Chan, Matilda F.; Healy, Kevin E.

    2016-01-01

    Current anti-VEGF drugs for patients with diabetic retinopathy suffer from short residence time in the vitreous of the eye. In order to maintain biologically effective doses of drug for inhibiting retinal neovascularization, patients are required to receive regular monthly injections of drug, which often results in low patient compliance and progression of the disease. To improve the intravitreal residence time of anti-VEGF drugs, we have synthesized multivalent bioconjugates of an anti-VEGF protein, soluble fms-like tyrosine kinase-1 (sFlt) that is covalently grafted to chains of hyaluronic acid (HyA), conjugates that are termed mvsFlt. Using a mouse corneal angiogenesis assay, we demonstrate that covalent conjugation to HyA chains does not decrease the bioactivity of sFlt and that mvsFlt is equivalent to sFlt at inhibiting corneal angiogenesis. In a rat vitreous model, we observed that mvsFlt had significantly increased intravitreal residence time compared to the unconjugated sFlt after 2 days. The calculated intravitreal half-lives for sFlt and mvsFlt were 3.3 and 35 hours, respectively. Furthermore, we show that mvsFlt is more effective than the unconjugated form at inhibiting retinal neovascularization in an oxygen-induced retinopathy model, an effect that is most likely due to the longer half-life of mvsFlt in the vitreous. Taken together, our results indicate that conjugation of sFlt to HyA does not affect its affinity for VEGF and this conjugation significantly improves drug half-life. These in vivo results suggest that our strategy of multivalent conjugation could substantially improve upon drug half-life, and thus the efficacy of currently available drugs that are used in diseases such as diabetic retinopathy, thereby improving patient quality of life. PMID:27257918

  14. Dexamethasone treatment differentially alters viral shedding and the antibody and acute phase protein response after multivalent respiratory vaccination in beef steers

    Science.gov (United States)

    Our objective was to examine immunosuppression induced by dexamethasone (DEX) administration in cattle upon immunological responses to a multivalent respiratory vaccine containing replicating and non-replicating agents. Steers ( n = 32; 209 +/- 8 kg) seronegative to infectious bovine rhinotracheitis...

  15. Design of different strategies of multivalent DNA-based vaccination against rabies and canine distemper in mice and dogs

    Directory of Open Access Journals (Sweden)

    Touihri Leila

    2012-12-01

    Full Text Available Abstract Background During the vaccination campaigns, puppies younger than 3 months old are not targeted and remain unvaccinated for at least the first year of their lives. Almost half of the reported rabid dogs are 6 months or younger. Hence, we should recommend the vaccination against rabies of young puppies. Unfortunately, owing to the exposure of puppies to infections with either canine parvovirus (CPV or distemper virus (CDV after the intervention of the vaccinators, owners are reluctant to vaccinate puppies against rabies. Therefore, it is necessary to include the CPV and CDV valences in the vaccine against rabies. Multivalent DNA-based vaccination in dogs, including rabies and distemper valences, could help in raising vaccine coverage. Methods We have designed monovalent and multivalent DNA-based vaccine candidates for in vitro and in vivo assays. These plasmids encode to the rabies virus glycoprotein and/or the canine distemper virus hemagglutinin. The first strategy of multivalent DNA-based vaccination is by mixing plasmids encoding to a single antigen each. The second is by simply fusing the genes of the antigens together. The third is by adding the foot and mouth disease virus (FMDV 2A oligopeptide gene into the antigen genes. The last strategy is by the design and use of a bicistronic plasmid with an “Internal Ribosome Entry Site” (IRES domain. Results The monovalent construct against canine distemper was efficiently validated by inducing higher humoral immune responses compared to cell-culture-derived vaccine both in mice and dogs. All multivalent plasmids efficiently expressed both valences after in vitro transfection of BHK-21 cells. In BALB/c mice, the bicistronic IRES-dependant construct was the most efficient inducer of virus-neutralizing antibodies against both valences. It was able to induce better humoral immune responses compared to the administration of either cell-culture-derived vaccines or monovalent plasmids. The

  16. Allele Workbench: transcriptome pipeline and interactive graphics for allele-specific expression.

    Directory of Open Access Journals (Sweden)

    Carol A Soderlund

    Full Text Available Sequencing the transcriptome can answer various questions such as determining the transcripts expressed in a given species for a specific tissue or condition, evaluating differential expression, discovering variants, and evaluating allele-specific expression. Differential expression evaluates the expression differences between different strains, tissues, and conditions. Allele-specific expression evaluates expression differences between parental alleles. Both differential expression and allele-specific expression have been studied for heterosis (hybrid vigor, where the hybrid has improved performance over the parents for one or more traits. The Allele Workbench software was developed for a heterosis study that evaluated allele-specific expression for a mouse F1 hybrid using libraries from multiple tissues with biological replicates. This software has been made into a distributable package, which includes a pipeline, a Java interface to build the database, and a Java interface for query and display of the results. The required input is a reference genome, annotation file, and one or more RNA-Seq libraries with optional replicates. It evaluates allelic imbalance at the SNP and transcript level and flags transcripts with significant opposite directional allele-specific expression. The Java interface allows the user to view data from libraries, replicates, genes, transcripts, exons, and variants, including queries on allele imbalance for selected libraries. To determine the impact of allele-specific SNPs on protein folding, variants are annotated with their effect (e.g., missense, and the parental protein sequences may be exported for protein folding analysis. The Allele Workbench processing results in transcript files and read counts that can be used as input to the previously published Transcriptome Computational Workbench, which has a new algorithm for determining a trimmed set of gene ontology terms. The software with demo files is available

  17. Multivalent co-ions reduce DNA$-$DNA like-charge attraction and enhance DNA overcharging by mutivalent counterions

    CERN Document Server

    Duc, Nguyen Viet; Duc, Nguyen Huu

    2016-01-01

    Strongly correlated electrostatics of DNA systems has drawn the interest of many groups, especially the condensation and overcharging of DNA by multivalent counterions. By adding counterions of different valencies and shapes, one can enhance or reduce DNA overcharging. In this letter, we focus on the effect of multivalent co-ions, specifically divalent coion such as SO$_4^{2-}$, on the strongly correlated electrostatics of DNA condensation problem. A computational experiment of DNA condensation using Monte$-$Carlo simulation in grand canonical ensemble is carried out where DNA system is in equilibirium with a bulk solution containing a mixture of salt of different valency of co-ions. Compared to system with purely monovalent co-ions, the influence of divalent co-ions shows up in multiple aspects. Divalent co-ions lead to an increase of monovalent salt in the DNA condensate. Because monovalent salts mostly participate in linear screening of electrostatic interactions in the system, more monovalent salt molecul...

  18. Multivalent system for therapy of non-Hod king lymphomas based on Anti-CD20 conjugated to gold nanoparticles

    International Nuclear Information System (INIS)

    In recent publications has been reported that gold nanoparticles have an effect in reducing the expression of the oncogene Bcl -2 and have a high biocompatibility , this is the importance for using gold nanoparticles for this work. The antibody CD20 is an antibody that specifically binds to that over expressed CD20 antigen on the cell membrane of B lymphoma cell non- Hodgkin (cell line Raji) behold the importance of combining this bio molecule to gold nanoparticles since they have a high specificity with CD20 positive cells , also to carry out the antigen- antibody immunological reactions triggered mediating cell lysis, possibly by cytotoxicity and apoptosis. Therefore, this system must have characteristics of both components to eliminate B cell non- Hodgkin lymphoma.In this work it was studied a multivalent system composed of gold nanoparticles and anti-CD20 antibody, the term multi valency refers to the number of biomolecules attached to the surface of the gold nanoparticle. The synthesis and characterization of the gold nanoparticles and the multivalent system was performed and the effect of the multivalent system on the expression of oncogene Bcl-2 (group of proteins associated with the apoptotic pathway) was evaluated. Characterization of raw materials and the multivalent system was performed using spectroscopic and microscopic techniques, this to verify structural changes in raw materials and thus confirm the formation of CD20 binding to the surface of the nanoparticle gold by the bond between gold and sulfur in the cysteines of CD20. Taking advantage that the metal nanoparticles have the optical property of surface plasmon resonance, the absorption of gold nanoparticles was measured on the UV-Vis as it is affected by the surface molecules bind to it, showing a bathochromic displacement effected. The hydrodynamic diameter of the gold nanoparticles was measured to verify that the antibody is bound to the surface; this evidence was complemented by micrographs

  19. Transport Properties of Multivalent Cations in Nafion-117 Membrane with Mixed Ionic Composition.

    Science.gov (United States)

    Chaudhury, Sanhita; Agarwal, Chhavi; Goswami, A

    2015-08-20

    The transport characteristics of multivalent cations like Ba(2+) and Eu(3+) have been studied in bi-ionic form of the Nafion-117 membrane. The membranes have been prepared by loading different proportions of H(+)-Ba(2+)/Mg(2+)-Ba(2+)/Ba(2+)-Eu(3+)/H(+)-Eu(3+)/Na(+)-Eu(3+). The cationic compositions of the membranes have been determined from the measured ion exchange isotherms. Results show that the self-diffusion coefficient of Ba(2+) (D(Ba)) in H-Ba/Mg-Ba systems as well as the self-diffusion coefficient of Eu(3+) (D(Eu)) in H-Eu/Na-Eu systems are strongly dependent on the membrane ionic compositions and decreased continuously with increasing concentration of the highly hydrated ions (H(+)/Na(+)/Mg(2+)) in the membrane. Increase in the proportion of H(+)/Na(+)/Mg(2+) ions in the membrane increases the effective charge on the membrane matrix. This causes stronger electrostatic interaction of the less hydrated multivalent ions (Ba(2+)/Eu(3+)) with the membrane matrix charges, which ultimately results in their slower self-diffusion coefficients. The higher the valence, the stronger the electrostatic interaction is with the fixed ionic charges; hence, in general, D(Eu) is affected more as compared to D(Ba). On the basis of the free-volume theory for polymers, the effective interaction potential (Φ) of the Ba(2+) with the fixed ionic sites in the membrane has been calculated and found to be on the order of approximately millivolts. The higher the proportion of hydrated ion in the membrane, the higher the Φ is and the stronger the ion pair formation is with the fixed ionic sites in the membrane. However, in the Ba-Eu system, as the electrostatic interactions of the two ions with the membrane matrix are close, D(Ba) and D(Eu) are independent of the membrane ionic composition. The ionic composition dependence of D(Ba) in the H-Ba system is reflected in the transport rate of Ba(2+), showing the importance of such measurements in understanding the transport

  20. Multivalent linkers for improved covalent binding of oligonucleotides to dye-doped silica nanoparticles

    Science.gov (United States)

    Kelleher, S. M.; Nooney, R. I.; Flynn, S. P.; Clancy, E.; Burke, M.; Daly, S.; Smith, T. J.; Daniels, S.; McDonagh, C.

    2015-09-01

    This paper describes the fabrication of oligonucleotide-coated Cy5-doped silica nanoparticles using a combination of multivalent linkers and their use in surface-based DNA sandwich hybridization assays. Dipodal silane is introduced as a means to fabricate amine-coated silica nanoparticles and its advantages compared to monopodal silanes are discussed. The use of dipodal silane in conjunction with three different polymer linkers (oxidized dextran, linear and 8-arm polyethylene glycol (PEG)) to immobilize single-stranded DNA to Cy5-doped nanoparticles is investigated and dynamic light scattering measurements and Fourier transform infrared spectroscopy are used to follow the progression of the functionalization of the nanoparticles. We observe a significant improvement in the binding stability of the single-stranded DNA when the dipodal silane and 8-arm PEG are used in combination, when compared to alternative conjugation strategies. Both 8mer and 22mer oligonucleotides are securely conjugated to the high-brightness nanoparticles and their availability to hybridize with a complementary strand is confirmed using solution-based DNA hybridization experiments. In addition, a full surface-based sandwich assay demonstrates the potential these nanoparticles have in the detection of less than 500 femtomolar of a DNA analogue of micro RNA, miR-451.

  1. Modeling multivalent ligand-receptor interactions with steric constraints on configurations of cell surface receptor aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Monine, Michael [Los Alamos National Laboratory; Posner, Richard [TRANSLATION GENOMICS RESAEARCH INSTITUTE; Savage, Paul [BYU; Faeder, James [UNIV OF PITTSBURGH; Hlavacek, William S [UNM

    2008-01-01

    Signal transduction generally involves multivalent protein-protein interactions, which can produce various protein complexes and post-translational modifications. The reaction networks that characterize these interactions tend to be so large as to challenge conventional simulation procedures. To address this challenge, a kinetic Monte Carlo (KMC) method has been developed that can take advantage of a model specification in terms of reaction rules for molecular interactions. A set of rules implicitly defines the reactions that can occur as a result of the interactions represented by the rules. With the rule-based KMC method, explicit generation of the underlying chemical reaction network implied by rules is avoided. Here, we apply and extend this method to characterize the interactions of a trivalent ligand with a bivalent cell-surface receptor. This system is also studied experimentally. We consider the following kinetic models: an equivalent-site model, an extension of this model, which takes into account steric constraints on the configurations of receptor aggregates, and finally, a model that accounts for cyclic receptor aggregates. Simulation results for the equivalent-site model are consistent with an equilibrium continuum model. Using these models, we investigate the effects of steric constraints and the formation of cyclic aggregates on the kinetics and equilibria of small and large aggregate formation and the percolation phase transition that occurs in this system.

  2. Approaching rational epitope vaccine design for hepatitis C virus with meta-server and multivalent scaffolding

    Science.gov (United States)

    He, Linling; Cheng, Yushao; Kong, Leopold; Azadnia, Parisa; Giang, Erick; Kim, Justin; Wood, Malcolm R.; Wilson, Ian A.; Law, Mansun; Zhu, Jiang

    2015-08-01

    Development of a prophylactic vaccine against hepatitis C virus (HCV) has been hampered by the extraordinary viral diversity and the poor host immune response. Scaffolding, by grafting an epitope onto a heterologous protein scaffold, offers a possible solution to epitope vaccine design. In this study, we designed and characterized epitope vaccine antigens for the antigenic sites of HCV envelope glycoproteins E1 (residues 314-324) and E2 (residues 412-423), for which neutralizing antibody-bound structures are available. We first combined six structural alignment algorithms in a “scaffolding meta-server” to search for diverse scaffolds that can structurally accommodate the HCV epitopes. For each antigenic site, ten scaffolds were selected for computational design, and the resulting epitope scaffolds were analyzed using structure-scoring functions and molecular dynamics simulation. We experimentally confirmed that three E1 and five E2 epitope scaffolds bound to their respective neutralizing antibodies, but with different kinetics. We then investigated a “multivalent scaffolding” approach by displaying 24 copies of an epitope scaffold on a self-assembling nanoparticle, which markedly increased the avidity of antibody binding. Our study thus demonstrates the utility of a multi-scale scaffolding strategy in epitope vaccine design and provides promising HCV immunogens for further assessment in vivo.

  3. Scaling analysis of the optimized effective potentials for the multiplet states of multivalent 3d ions

    International Nuclear Information System (INIS)

    We apply the optimized effective potential method (OPM) to the multivalent 3dn (n = 2, ..., 8) ions; Mν+ (ν = 2, ..., 8). The total energy functional is approximated by the single-configuration Hartree-Fock. The exchange potential for the average energy configuration is decomposed into the potentials derived from F2(3d, 3d) and F4(3d, 3d) Slater integrals. To investigate properties of the density-functional potential, we have checked the scaling properties of several physical quantities such as the density, the 3d orbital and these potentials. We find that the potentials of the Slater integrals do not have the scaling property. Instead, the weighted potential Vi(r) of an ion i, which is the potential of the Slater integrals times the 3d-orbital density, satisfies the scaling property q3diVi(r) ∼ q3djλ4Vj(λr) where qi3d is the occupation number of the 3d-orbital R3d(r) for ion i. Furthermore, the weighted potential can be approximated by the ion-independent functional of the 3d-orbital density ckR8/33d(r)/q3d where c2 = 0.366 and c4 0.223. This suggests that the weighted potential can be expressed as a functional of the 3d-orbital density

  4. Multivalent ion-mediated nucleic acid helix-helix interactions: RNA versus DNA

    CERN Document Server

    Wu, Yuan-Yan; Zhang, Jin-Si; Zhu, Xiao-Long; Tan, Zhi-Jie

    2015-01-01

    Ion-mediated interaction is critical to the structure and stability of nucleic acids. Recent experiments suggest that the multivalent ion-induced aggregation of double-stranded (ds) RNAs and DNAs may strongly depend on the topological nature of helices, while there is still lack of an understanding on the relevant ion-mediated interactions at atomistic level. In this work, we have directly calculated the potentials of mean force (PMF) between two dsRNAs and between two dsDNAs in Cobalt Hexammine ion (Co-Hex) solutions by the atomistic molecular dynamics simulations. Our calculations show that at low [Co-Hex], the PMFs between B-DNAs and between A-RNAs are both (strongly) repulsive.However, at high [Co-Hex], the PMF between B-DNAs is strongly attractive, while those between A-RNAs and between A-DNAs are still (weakly) repulsive. The microscopic analyses show that for A-form helices, Co-Hex would become internal binding into the deep major groove and consequently cannot form the evident ion-bridge between adjac...

  5. Diversity of Lactase Persistence Alleles in Ethiopia

    DEFF Research Database (Denmark)

    Jones, BL; Raga, TO; Liebert, Anke;

    2013-01-01

    The persistent expression of lactase into adulthood in humans is a recent genetic adaptation that allows the consumption of milk from other mammals after weaning. In Europe, a single allele (−13910∗T, rs4988235) in an upstream region that acts as an enhancer to the expression of the lactase gene ...

  6. RHD alleles in the Tunisian population

    Directory of Open Access Journals (Sweden)

    Mouna Ouchari

    2013-01-01

    Full Text Available Background: A comprehensive survey of RHD alleles in Tunisia population was lacking. The aim of this study was to use a multiplex RHD typing assay for simultaneous detection of partial D especially with RHD/RHCE deoxyribonucleic acid (DNA sequence exchange mechanism and some weak D alleles. Materials and Methods: Six RHD specific primer sets were designed to amplify RHD exons 3, 4, 5, 6, 7 and 9. DNA from 2000 blood donors (1777 D+ and 223 D- from several regions was selected for RHD genotyping using a PCR multiplex assay. Further molecular investigations were done to characterize the RHD variants that were identified by the PCR multiplex assay. Results: In the 1777 D+ samples, only 10 individuals showed the absence of amplification of exons 4 and 5 that were subsequently identified by PCR-SSP as weak D type 4 variants. No hybrid allele was detected. In the 223 D-, RHD amplification of some exons was observed only in 5 samples: 4 individuals expressed only RHD exon 9, and one subject lacking exons 4 and 5. These samples were then screened by PCR-SSPs on d(C ce s and weak D type 4, respectively. Conclusion: The weak D type 4 appears to be the most common D variant allele. We have not found any partial D variant. Findings also indicated that RHD gene deletion is the most prevalent cause of the D- phenotype in the Tunisian population.

  7. Schizophrenia susceptibility alleles are enriched for alleles that affect gene expression in adult human brain

    OpenAIRE

    Richards, Alexander L.; Jones, Lesley; Moskvina, Valentina; Kirov, George; Gejman, Pablo V.; Levinson, Douglas F.; Sanders, Alan R; Purcell, Shaun; Visscher, Peter M.; Craddock, Nick; Owen, Michael J.; Holmans, Peter; O’Donovan, Michael C

    2011-01-01

    It is widely thought that alleles that influence susceptibility to common diseases, including schizophrenia, will frequently do so through effects on gene expression. Since only a small proportion of the genetic variance for schizophrenia has been attributed to specific loci, this remains an unproven hypothesis. The International Schizophrenia Consortium (ISC) recently reported a substantial polygenic contribution to that disorder, and that schizophrenia risk alleles are enriched among SNPs s...

  8. Microsatellite allele frequencies in humans and chimpanzees, with implications for constraints on allele size.

    Science.gov (United States)

    Garza, J C; Slatkin, M; Freimer, N B

    1995-07-01

    The distributions of allele sizes at eight simple-sequence repeat (SSR) or microsatellite loci in chimpanzees are found and compared with the distributions previously obtained from several human populations. At several loci, the differences in average allele size between chimpanzees and humans are sufficiently small that there might be a constraint on the evolution of average allele size. Furthermore, a model that allows for a bias in the mutation process shows that for some loci a weak bias can account for the observations. Several alleles at one of the loci (Mfd 59) were sequenced. Differences between alleles of different lengths were found to be more complex than previously assumed. An 8-base-pair deletion was present in the nonvariable region of the chimpanzee locus. This locus contains a previously unrecognized repeated region, which is imperfect in humans and perfect in chimpanzees. The apparently greater opportunity for mutation conferred by the two perfect repeat regions in chimpanzees is reflected in the higher variance in repeat number at Mfd 59 in chimpanzees than in humans. These data indicate that interspecific differences in allele length are not always attributable to simple changes in the number of repeats. PMID:7659015

  9. The effect of multivalent cations and Tau on paclitaxel-stabilized microtubule assembly, disassembly, and structure.

    Science.gov (United States)

    Safinya, Cyrus R; Chung, Peter J; Song, Chaeyeon; Li, Youli; Ewert, Kai K; Choi, Myung Chul

    2016-06-01

    In this review we describe recent studies directed at understanding the formation of novel nanoscale assemblies in biological materials systems. In particular, we focus on the effects of multivalent cations, and separately, of microtubule-associated protein (MAP) Tau, on microtubule (MT) ordering (bundling), MT disassembly, and MT structure. Counter-ion directed bundling of paclitaxel-stabilized MTs is a model electrostatic system, which parallels efforts to understand MT bundling by intrinsically disordered proteins (typically biological polyampholytes) expressed in neurons. We describe studies, which reveal an unexpected transition from tightly spaced MT bundles to loose bundles consisting of strings of MTs as the valence of the cationic counter-ion decreases from Z=3 to Z=2. This transition is not predicted by any current theories of polyelectrolytes. Notably, studies of a larger series of divalent counter-ions reveal strong ion specific effects. Divalent counter-ions may either bundle or depolymerize paclitaxel-stabilized MTs. The ion concentration required for depolymerization decreases with increasing atomic number. In a more biologically related system we review synchrotron small angle x-ray scattering (SAXS) studies on the effect of the Tau on the structure of paclitaxel-stabilized MTs. The electrostatic binding of MAP Tau isoforms leads to an increase in the average radius of microtubules with increasing Tau coverage (i.e. a re-distribution of protofilament numbers in MTs). Finally, inspired by MTs as model nanotubes, we briefly describe other more robust lipid-based cylindrical nanostructures, which may have technological applications, for example, in drug encapsulation and delivery. PMID:26684364

  10. Low energy cyclotron production of multivalent transition metals for PET imaging and therapy

    Science.gov (United States)

    Avila-Rodriguez, Miguel Angel

    Recent advances in high-resolution tomographs for small animals require the production of nonconventional long-lived positron emitters to label novel radiopharmaceuticals for PET-based molecular imaging. Radioisotopes with an appropriate half life to match the kinetics of slow biological processes will allow to researchers to study the phamacokinetics of PET ligands over several hours, or even days, on the same animal, with the injection of a single dose. In addition, radionuclides with a suitable half life can potentially be distributed from a central production site making them available in PET facilities that lack an in-house cyclotron. In the last few years there has been a growing interest in the use of PET ligands labeled with radiometals, particularly isotopes of copper, yttrium and zirconium. Future clinical applications of these tracers will require them to be produced reliably and efficiently. This thesis work deals with implementing and optimizing the production of the multivalent transition metals 61,64Cu, 86Y and 89Zr for molecular PET imaging and therapy. Our findings in the production of these radionuclides at high specific activity on an 11 MeV proton-only cyclotron are presented. Local applications of these tracers, including Cu-ATSM for in vivo quantification of hypoxia, synthesis of targeted radiopharmaceuticals using activated esters of DOTA, and a novel development of positron emitting resin microspheres, are also be discussed. As a result of this thesis work, metallic radionuclides are now efficiently produced on a weekly basis in sufficient quality and quantity for collaborating scientists at UW-Madison and external users in other Universities across the country.

  11. Effects of multivalent cations on cell wall-associated acid phosphatase activity

    Energy Technology Data Exchange (ETDEWEB)

    Tu, S.I.; Brouillette, J.N.; Nagahashi, G.; Kumosinski, T.F.

    1988-09-01

    Primary cell walls, free from cytoplasmic contamination were prepared from corn (Zea mays L.) roots and potato (Solanum tuberosum) tubers. After EDTA treatment, the bound acid phosphatase activities were measured in the presence of various multivalent cations. Under the conditions of minimized Donnan effect and at pH 4.2, the bound enzyme activity of potato tuber cell walls (PCW) was stimulated by Cu/sup 2 +/, Mg/sup 2 +/, Za/sup 2 +/, and Mn/sup 2 +/; unaffected by Ba/sup 2 +/, Cd/sup 2 +/, and Pb/sup 2 +/; and inhibited by Al/sup 3 +/. The bound acid phosphatase of PCW was stimulated by a low concentration but inhibited by a higher concentration of Hg/sup 2 +/. On the other hand, in the case of corn root cells walls (CCW), only inhibition of the bound acid phosphatase by Al/sup 3 +/ and Hg/sup 2 +/ was observed. Kinetic analyses revealed that PCW acid phosphatase exhibited a negative cooperativity under all employed experimental conditions except in the presence of Mg/sup 2 +/. In contrast, CCW acid phosphatase showed no cooperative behavior. The presence of Ca/sup 2 +/ significantly reduced the effects of Hg/sup 2 +/ or Al/sup 3 +/, but not Mg/sup 2 +/, to the bound cell wall acid phosphatases. The salt solubilized (free) acid phosphatases from both PCW and CCW were not affected by the presence of tested cations except for Hg/sup 2 +/ or Al/sup 3 +/ which caused a Ca/sup 2 +/-insensitive inhibition of the enzymes. The induced stimulation or inhibition of bound acid phosphatases was quantitatively related to cation binding in the cell wall structure.

  12. Construction of multivalent DNA vaccines for Mycobacte-rium tuberculosis and its immunogenicity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The coding regions of Ag85B MPT-64, and ESAT-6 secreted proteins were cloned initially into the eukaryotic expression vector pJW4303, then transformed to E. coli Top 10 strain for plasmid DNA extraction and further analysis. Plasmids containing the right insertion were sequenced to confirm their identity. COS7 cells were transfected with a mixture containing serially diluted plasmid DNA encoding three secreted proteins and Lipofectin (Gibco). The supernatants and pellets prepared from various cell lines were run on SDS-PAGE gel and the expression of these proteins in COS7 cells were demonstrated by immunoblot using polyclonal or monoclonal antiserum of M.TBH37Rv. 21 days after first vaccination of C57BL-6 mice by all three recombinant eukaryotic expressing vectors, antibody titer for Ag85B reached 1∶3200. 21 days after second vaccination, the antibody titer reached 1∶102400. The highest antibody levels induced by multivalent vaccines after the second injection were equal to or even greater than the highest antibody levels of single DNA vaccine reported in literature after third injections. Antibody titer of MPT-64 was 1∶50 after the first injection and it reached 1∶200 after the second injection. No antigen-specific antibody against ESAT-6 was detected in sera harvested from immunized mice 21 days after both injections. Antigen-specific IFN-g level of Ag85B was 110 pg/mL while no antigen-specific IFN- g level of ESAT-6 and MPT-64 was detected even after third injections. To our knowledge, it is the first time that studies of polyvalent recombinant DNA vaccines against TB were carried out in C57BL-6 mice. Our results indicated that multiple DNA vaccines could be used to enhance protective responses against M.TB.

  13. Evaluation of the impact of multivalent metal ions on the permeation behavior of Dolutegravir sodium.

    Science.gov (United States)

    Grießinger, Julia Anita; Hauptstein, Sabine; Laffleur, Flavia; Netsomboon, Kesinee; Bernkop-Schnürch, Andreas

    2016-07-01

    Interactions between active pharmaceutical ingredients (APIs) and polyvalent cations are an important factor within drug absorption in the gastrointestinal tract. Dolutegravir sodium, as a second-generation integrase stand transfer inhibitor for the treatment of HIV was investigated regarding chelation with Al(3+), Ca(2+), Fe(3+), Mg(2+ )and Zn(2+) ions at three different molar ratios. Furthermore, the influence of drug-ion chelates on the permeability of the drug across two intestinal membrane models was analyzed. For this purpose, Caco-2 monolayer model and Ussing chamber technique utilizing freshly excited rat intestinal mucosa were chosen and a buffer system without additional Mg(2+) and Ca(2+) ions was tested regarding cell detachment. The addition of polyvalent cations in an equal molar ratio to the drug solution decreased the dissolved drug by at least 11%. An increased multivalent cation concentration in a ratio of 1:10 afforded an API drop in the solution of at least 88% with the exception of Mg(2+). In particular, Dolutegravir sodium was chelated with iron ions to nearly 100%. Overall, the higher the amount of metal ions in the solution, the lower was the detected amount of the drug. The permeation experiments across the Caco-2 monolayer and the rat intestinal mucosa pointed out that the addition of AlCl3, CaCl2 and ZnCl2 in a molar ratio of 10:1 to the drug led to significantly decreased drug permeation. According to these results the co-administration of Al(3+), Ca(2+ )or Zn(2+ )as well as of supplementary medications containing these polyvalent ions is in case of oral Dolutegravir delivery not recommended. PMID:26552713

  14. Microfluidic biofunctionalisation protocols to form multi-valent interactions for cell rolling and phenotype modification investigations

    KAUST Repository

    Perozziello, Gerardo

    2013-07-01

    In this study, we propose a fast, simple method to biofunctionalise microfluidic systems for cellomic investigations based on micro-fluidic protocols. Many available processes either require expensive and time-consuming protocols or are incompatible with the fabrication of microfluidic systems. Our method differs from the existing since it is applicable to an assembled system, uses few microlitres of reagents and it is based on the use of microbeads. The microbeads have specific surface moieties to link the biomolecules and couple cell receptors. Furthermore, the microbeads serve as arm spacer and offer the benefit of the multi-valent interaction. Microfluidics was adapted together with topology and biochemistry surface modifications to offer the microenvironment for cellomic studies. Based on this principle, we exploit the streptavidin-biotin interaction to couple antibodies to the biofunctionalised microfluidic environment within 5 h using 200 μL of reagents and biomolecules. We selected the antibodies able to form complexes with the MHC class I (MHC-I) molecules present on the cell membrane and involved in the immune surveillance. To test the microfluidic system, tumour cell lines (RMA) were rolled across the coupled antibodies to recognise and strip MHC-I molecules. As result, we show that cell rolling performed inside a microfluidic chamber functionalised with beads and the opportune antibody facilitate the removal of MHC class I molecules. We showed that the level of median fluorescent intensity of the MHC-I molecules is 300 for cells treated in a not biofunctionalised surface. It decreased to 275 for cells treated in a flat biofunctionalised surface and to 250 for cells treated on a surface where biofunctionalised microbeads were immobilised. The cells with reduced expression of MHC-I molecules showed, after cytotoxicity tests, susceptibility 3.5 times higher than normal cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Estimation of allele frequencies for VNTR loci.

    OpenAIRE

    Devlin, B; Risch, N; Roeder, K

    1991-01-01

    VNTR loci provide valuable information for a number of fields of study involving human genetics, ranging from forensics (DNA fingerprinting and paternity testing) to linkage analysis and population genetics. Alleles of a VNTR locus are simply fragments obtained from a particular portion of the DNA molecule and are defined in terms of their length. The essential element of a VNTR fragment is the repeat, which is a short sequence of basepairs. The core of the fragment is composed of a variable ...

  16. Charge Inversion Effects in Electrophoresis of Polyelectrolytes in the Presence of Multivalent Counterions and Transversal Electric Fields

    Directory of Open Access Journals (Sweden)

    Sorin Nedelcu

    2014-12-01

    Full Text Available By molecular dynamics simulations we investigate the transport of charged polymers in confinement, under externally applied electric fields, in straight cylinders of uniform diameter and in the presence of monovalent or multivalent counterions. The applied electric field has two components; a longitudinal component along the axis of the cylinder and a transversal component perpendicular to the cylinder axis. The direction of electrophoretic velocity depends on the polyelectrolyte length, valency of the counterions present in solution and transversal electric field value. A statistical model is put forward in order to explain these observations.

  17. Phase II studies to select the formulation of a multivalent HPV L1 virus-like particle (VLP) vaccine

    OpenAIRE

    Luxembourg, Alain; Brown, Darron; Bouchard, Celine; Giuliano, Anna R.; Iversen, Ole-Erik; Joura, Elmar A; Penny, Mary E; Restrepo, Jaime A; Romaguera, Josefina; Maansson, Roger; Moeller, Erin; Ritter, Michael; Chen, Joshua

    2015-01-01

    Our objective was to develop a multivalent prophylactic HPV vaccine that protects against infection and disease caused by HPV16/18 (oncogenic types in existing prophylactic vaccines) plus additional oncogenic types by conducting 3 Phase II studies comparing the immunogenicity (i.e., anti-HPV6/11/16/18 geometric mean titers [GMT]) and safety of 7 vaccine candidates with the licensed quadrivalent HPV6/11/16/18 vaccine (qHPV vaccine) in young women ages 16–26. In the first study (Study 1), subje...

  18. Construction and Immunological Evaluation of Multivalent Hepatitis B Virus (HBV) Core Virus-Like Particles Carrying HBV and HCV Epitopes▿

    OpenAIRE

    Sominskaya, Irina; Skrastina, Dace; Dislers, Andris; Vasiljev, Denis; Mihailova, Marija; Ose, Velta; Dreilina, Dzidra; Pumpens, Paul

    2010-01-01

    A multivalent vaccine candidate against hepatitis B virus (HBV) and hepatitis C virus (HCV) infections was constructed on the basis of HBV core (HBc) virus-like particles (VLPs) as carriers. Chimeric VLPs that carried a virus-neutralizing HBV pre-S1 epitope corresponding to amino acids (aa) 20 to 47 in the major immunodominant region (MIR) and a highly conserved N-terminal HCV core epitope corresponding to aa 1 to 60 at the C terminus of the truncated HBcΔ protein (N-terminal aa 1 to 144 of f...

  19. Optimized Solid Phase-Assisted Synthesis of Dendrons Applicable as Scaffolds for Radiolabeled Bioactive Multivalent Compounds Intended for Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Gabriel Fischer

    2014-05-01

    Full Text Available Dendritic structures, being highly homogeneous and symmetric, represent ideal scaffolds for the multimerization of bioactive molecules and thus enable the synthesis of compounds of high valency which are e.g., applicable in radiolabeled form as multivalent radiotracers for in vivo imaging. As the commonly applied solution phase synthesis of dendritic scaffolds is cumbersome and time-consuming, a synthesis strategy was developed that allows for the efficient assembly of acid amide bond-based highly modular dendrons on solid support via standard Fmoc solid phase peptide synthesis protocols. The obtained dendritic structures comprised up to 16 maleimide functionalities and were derivatized on solid support with the chelating agent DOTA. The functionalized dendrons furthermore could be efficiently reacted with structurally variable model thiol-bearing bioactive molecules via click chemistry and finally radiolabeled with 68Ga. Thus, this solid phase-assisted dendron synthesis approach enables the fast and straightforward assembly of bioactive multivalent constructs for example applicable as radiotracers for in vivo imaging with Positron Emission Tomography (PET.

  20. Effect of Ionic Correlations on the Surface Forces in Thin Liquid Films: Influence of Multivalent Coions and Extended Theory

    Directory of Open Access Journals (Sweden)

    Krassimir D. Danov

    2016-03-01

    Full Text Available Experimental data for the disjoining pressure of foam films stabilized by anionic surfactant in the presence of 1:1, 1:2, 1:3, and 2:2 electrolytes: NaCl, Na2SO4, Na3Citrate, and MgSO4 are reported. The disjoining pressure predicted by the Derjaguin-Landau-Verwey-Overbeek (DLVO theory coincides with the experimental data in the case of a 1:1 electrolyte, but it is considerably greater than the measured pressure in all other cases. The theory is extended to account for the effects of ionic correlations and finite ionic radii. Original analytical expressions are derived for the local activity coefficient, electrostatic disjoining pressure, and asymptotic screening parameter. With the same parameter of counterion binding as for a 1:1 electrolyte, the curves predicted by the extended theory are in perfect agreement with the experimental data for 1:2 and 1:3 electrolytes. In comparison with the DLVO theory, the effect of ionic correlations leads to more effective screening of electrostatic interactions, and lower electric potential and counterion concentrations in the film’s midplane, resulting in lower disjoining pressure, as experimentally observed. The developed theory is applicable to both multivalent coions and multivalent counterions. Its application could remove some discrepancies between theory and experiment observed in studies with liquid films from electrolyte solutions.

  1. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    Science.gov (United States)

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  2. Multivalent dendrimeric compounds containing carbohydrates expressed on immune cells inhibit infection by primary isolates of HIV-1

    International Nuclear Information System (INIS)

    Specific glycosphingolipids (GSL), found on the surface of target immune cells, are recognized as alternate cell surface receptors by the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein. In this study, the globotriose and 3'-sialyllactose carbohydrate head groups found on two GSL were covalently attached to a dendrimer core to produce two types of unique multivalent carbohydrates (MVC). These MVC inhibited HIV-1 infection of T cell lines and primary peripheral blood mononuclear cells (PBMC) by T cell line-adapted viruses or primary isolates, with IC50s ranging from 0.1 to 7.4 μg/ml. Inhibition of Env-mediated membrane fusion by MVC was also observed using a dye-transfer assay. These carbohydrate compounds warrant further investigation as a potential new class of HIV-1 entry inhibitors. The data presented also shed light on the role of carbohydrate moieties in HIV-1 virus-host cell interactions. -- Research Highlights: →Multivalent carbohydrates (MVCs) inhibited infection of PBMCs by HIV-1. →MVCs inhibited infection by T cell line-adapted viruses. →MVCs inhibited infection by primary isolates of HIV-1. →MVCs inhibited Env-mediated membrane fusion.

  3. Evaluation of a Multivalent Vaccine against Lymphatic Filariasis in Rhesus macaque Model

    Science.gov (United States)

    Dakshinamoorthy, Gajalakshmi; von Gegerfelt, Agneta; Andersen, Hanne; Lewis, Mark; Kalyanasundaram, Ramaswamy

    2014-01-01

    Lymphatic filariasis affects 120 million people worldwide and another 1.2 billion people are at risk of acquiring the infection. Chemotherapy with mass drug administration is substantially reducing the incidence of the infection. Nevertheless, an effective vaccine is needed to prevent the infection and eradicate the disease. Previously we reported that a multivalent fusion protein vaccine (rBmHAT) composed of small heat shock proteins 12.6 (HSP12.6), abundant larval transcript-2 (ALT-2) and large extracellular domain of tetraspanin (TSP LEL) could confer >95% protection against the challenge infection with Brugia malayi infective larvae (L3) in mouse and gerbil models. In this study we evaluated the immunogenicity and efficacy of rBmHAT fusion protein vaccine in a rhesus macaque model. Our results show that rBmHAT is highly immunogenic in rhesus macaques. All the vaccinated monkeys developed significant titers of antigen-specific IgG antibodies against each of the component antigens (16,000 for rBmHSP12.6), (24,000 for rBmALT-2) and (16,000 for rBmTSP-LEL). An in vitro antibody dependent cellular cytotoxicity (ADCC) assay performed using the sera samples from vaccinated monkeys showed that the anti-rBmHAT antibodies are functional with 35% killing of B. malayi L3s. Vaccinated monkeys also had antigen responding cells in the peripheral blood. Vaccine-induced protection was determined after challenging the monkeys with 500 B. malayi L3. Following challenge infection, 3 out of 5 vaccinated macaques failed to develop the infection. These three protected macaques had high titers of IgG1 antibodies and their PBMC secreted significantly high levels of IFN-γ in response to the vaccine antigens. The two vaccinated macaques that picked the infection had slightly low titers of antibodies and their PBMC secreted high levels of IL-10. Based on these findings we conclude that the rBmHAT vaccine is highly immunogenic and safe and can confer significant protection against

  4. Multivalency and polaronic hole trapping in BaBiO3

    Science.gov (United States)

    Franchini, Cesare

    2010-03-01

    The phase diagrams of hole-doped oxides have been one of the central issues of condensed-matter physics in the last 20 years. Whereas transition metal oxides are now fairly well understood, the physics of the conceivably ``simpler'' sp bonded oxides is less clear. How is it possible that some of these oxides remain insulating upon doping? By adopting hybrid density functional theory and self-consistent GW we show that the multivalency of the metal cations and the formation of polaronic lattice distortions (i.e the coupling between holes/electrons trapping on specific lattice sites and the accompanying polarization field) can explain this puzzling experimental observation. The example we have chosen is BaBiO3, which remains an insulator upon moderate hole doping and undergoes an insulator to superconductor transition around a hole concentration of 0.35. Pure BaBiO3 is characterized by a charge disproportionation (CD) with half of the Bi atoms possessing a valence 3+ and half a valence 5+. The CD goes in hand with significant structural and electronic changes from the ideal metallic cubic perovskite crystal (BaBi^4+O3) towards an insulating monoclinic structure (Ba2Bi^3+Bi^5+O6) characterized by a charge density wave state formed by alternating breathing-in/out distortions of oxygen octahedra around inequivalent Bi^5+/Bi^3+ ions [1]. Our results show that upon-hole doping Bi^3+ sites trap two holes from the valence band to form Bi^5+ cations, and that the trapping is accompanied by a distortion of the oxygen polarization field that surround the BiO6 octahedra. We show that the strong interaction between polarons ultimately causes an overlap between the polaronic band and the valence band resulting in a metallic non-disproportionated state [2]. [4pt] [1] C. Franchini, A. Sanna, M. Marsman & G. Kresse, arXiv:0803.0619v2 (2009).[0pt] [2] C. Franchini, G. Kresse & R. Podloucky, PRL 102, 256402 (2009).

  5. Borrowed alleles and convergence in serpentine adaptation.

    Science.gov (United States)

    Arnold, Brian J; Lahner, Brett; DaCosta, Jeffrey M; Weisman, Caroline M; Hollister, Jesse D; Salt, David E; Bomblies, Kirsten; Yant, Levi

    2016-07-19

    Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary genomic approach coupled with elemental profiling to assess how autotetraploid Arabidopsis arenosa adapted to a multichallenge serpentine habitat in the Austrian Alps. We first demonstrate that serpentine-adapted plants exhibit dramatically altered elemental accumulation levels in common conditions, and then resequence 24 autotetraploid individuals from three populations to perform a genome scan. We find evidence for highly localized selective sweeps that point to a polygenic, multitrait basis for serpentine adaptation. Comparing our results to a previous study of independent serpentine colonizations in the closely related diploid Arabidopsis lyrata in the United Kingdom and United States, we find the highest levels of differentiation in 11 of the same loci, providing candidate alleles for mediating convergent evolution. This overlap between independent colonizations in different species suggests that a limited number of evolutionary strategies are suited to overcome the multiple challenges of serpentine adaptation. Interestingly, we detect footprints of selection in A. arenosa in the context of substantial gene flow from nearby off-serpentine populations of A. arenosa, as well as from A. lyrata In several cases, quantitative tests of introgression indicate that some alleles exhibiting strong selective sweep signatures appear to have been introgressed from A. lyrata This finding suggests that migrant alleles may have facilitated adaptation of A. arenosa to this multihazard environment. PMID:27357660

  6. DQB1*06:02 allele-specific expression varies by allelic dosage, not narcolepsy status

    DEFF Research Database (Denmark)

    Weiner Lachmi, Karin; Lin, Ling; Kornum, Birgitte Rahbek;

    2012-01-01

    The association of narcolepsy-cataplexy, a sleep disorder caused by the loss of hypocretin/orexin neurons in the hypothalamus, with DQA1*01:02-DQB1*06:02 is one of the tightest known single-allele human leukocyte antigen (HLA) associations. In this study, we explored genome-wide expression in per...

  7. SNP GENOTYPING BY TAQMAN ALLELE DISCRIMINATION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Lucian Negura

    2015-07-01

    Full Text Available Breast cancer is the most frequent neoplasm in women worldwide and the principal cause of deaths by cancer, the majority being by metastatic disease. About half of breast tumors are hormone dependent, and in post-menopause women the preferred first line treatment uses third generation aromatase inhibitors. Aromatase is encoded by CYP19 gene on 15q21.1, and there is strong evidence that mutations in this gene affect its expression, with directconsequences on cancer phenotype and response to treatment. Several single nucleotide polymorphisms have beenstudied on CYP19A1 transcription variant, notably rs727479, rs10046, rs4646 and rs700518. We implemented a Taqman-based allele discrimination assay for the rapid investigation of the 4 SNPs in CYP19A1. We genotyped 22 metastaticbreast cancer patients by the technique described.

  8. Self-adjuvanting influenza candidate vaccine presenting epitopes for cell-mediated immunity on a proteinaceous multivalent nanoplatform.

    Science.gov (United States)

    Szurgot, Inga; Szolajska, Ewa; Laurin, David; Lambrecht, Benedicte; Chaperot, Laurence; Schoehn, Guy; Chroboczek, Jadwiga

    2013-09-13

    We exploit the features of a virus-like particle, adenoviral dodecahedron (Ad Dd), for engineering a multivalent vaccination platform carrying influenza epitopes for cell-mediated immunity. The delivery platform, Ad Dd, is a proteinaceous, polyvalent, and biodegradable nanoparticle endowed with remarkable endocytosis activity that can be engineered to carry 60 copies of a peptide. Influenza M1 is the most abundant influenza internal protein with the conserved primary structure. Two different M1 immunodominant epitopes were separately inserted in Dd external positions without destroying the particles' dodecahedric structure. Both kinds of DdFluM1 obtained through expression in baculovirus system were properly presented by human dendritic cells triggering efficient activation of antigen-specific T cells responses. Importantly, the candidate vaccine was able to induce cellular immunity in vivo in chickens. These results warrant further investigation of Dd as a platform for candidate vaccine, able to stimulate cellular immune responses. PMID:23880363

  9. The role of multivalent metal cations and organic complexing agents in bitumen-mineral interactions in aqueous solutions

    Science.gov (United States)

    Gan, Weibing

    A systematic investigation was carried out to study the interactions between bitumen (or hexadecane) and minerals (quartz, kaolinite and illite) in aqueous solutions containing multivalent metal cations Ca2+, Mg2+ and Fe2+/Fe3+, in the absence and presence of organic complexing agents (oxalic acid, EDTA and citric acid). A range of experimental techniques, including coagulation measurement, visualization of bitumen-mineral attachment, metal ion adsorption measurement, zeta potential measurement, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopic analyses, were employed in the investigation. Free energy changes of adsorption of metal cations on the minerals and bitumen were evaluated using the James & Healy thermodynamic model. Total interaction energies between the minerals and bitumen were calculated using classical DLVO theory. It was observed that while the tested minerals showed varying degrees of mutual-coagulation with bitumen (or hexadecane), the presence of the multivalent metal cations could prominently increase the mutual coagulation. It was also found that such enhancement of the mutual coagulation was only significant when the metal cations formed first-order hydroxyl complexes (such as CaOH +, MgOH+, etc.) or metal hydroxides (such as Fe(OH) 3, Mg(OH)2, etc.). Therefore, the increase of the bitumen-mineral mutual coagulation by the metal cations was strongly pH dependent. Organic complexing agents (oxalic acid, citric acid and EDTA) used in this study, citric acid in particular, significantly reduced or virtually eliminated the mutual coagulation between bitumen (or hexadecane) and minerals caused by metal cations Ca2+, Mg2+, Fe 2+ and Fe3+. Due to its ability to substantially lower the mutual coagulation between bitumen and mineral particles, citric acid was found the most effective in improving bitumen-mineral liberation in solutions containing the multivalent metal cations at pH 8--10. In small scale flotation experiments

  10. Effects of multivalent histamine supported on gold nanoparticles: activation of histamine receptors by derivatized histamine at subnanomolar concentrations.

    Science.gov (United States)

    Gasiorek, Friederike; Pouokam, Ervice; Diener, Martin; Schlecht, Sabine; Wickleder, Mathias S

    2015-10-21

    Colloidal gold nanoparticles with a functionalized ligand shell were synthesized and used as new histamine receptor agonists. Mercaptoundecanoic acid moieties were attached to the surface of the nanoparticles and derivatized with native histamine. The multivalent presentation of the immobilized ligands carried by the gold nanoparticles resulted in extremely low activation concentrations for histamine receptors on rat colonic epithelium. As a functional read-out system, chloride secretion resulting from stimulation of neuronal and epithelial histamine H1 and H2 receptors was measured in Ussing chamber experiments. These responses were strictly attributed to the histamine entities as histamine-free particles Au-MUDOLS or the monovalent ligand AcS-MUDA-HA proved to be ineffective. The vitality of the tissues used was not impaired by the nanoparticles. PMID:26289108

  11. Nomenclature for human CYP2D6 alleles.

    Science.gov (United States)

    Daly, A K; Brockmöller, J; Broly, F; Eichelbaum, M; Evans, W E; Gonzalez, F J; Huang, J D; Idle, J R; Ingelman-Sundberg, M; Ishizaki, T; Jacqz-Aigrain, E; Meyer, U A; Nebert, D W; Steen, V M; Wolf, C R; Zanger, U M

    1996-06-01

    To standardize CYP2D6 allele nomenclature, and to conform with international human gene nomenclature guidelines, an alternative to the current arbitrary system is described. Based on recommendations for human genome nomenclature, we propose that alleles be designated by CYP2D6 followed by an asterisk and a combination of roman letters and arabic numerals distinct for each allele with the number specifying the key mutation and, where appropriate, a letter specifying additional mutations. Criteria for classification as a separate allele and protein nomenclature are also presented. PMID:8807658

  12. Identification of Multiple Alleles at the Wx Locus and Development of Single Segment Substitution Lines for the Alleles in Rice

    Institute of Scientific and Technical Information of China (English)

    ZENG Rui-zhen; ZHANG Ze-min; HE Feng-hua; XI Zhang-ying; Akshay TALUKDAR; SHI Jun-qiong; QIN Li-jun; HUANG Chao-feng; ZHANG Gui-quan

    2006-01-01

    The microsatellite markers 484/485 and 484/W2R were used to identify the multiple alleles at the Wx locus in rice germplasm. Fifteen alleles were identified in 278 accessions by using microsatellite class and G-T polymorphism. Among these alleles, (CT)12-G, (CT)15-G, (CT)16-G, (CT)17-G, (CT)18-G and (CT)21-G have not been reported. Seventy-two single-segment substitution lines (SSSLs) carrying different alleles at the Wx locus were developed by using Huajingxian 74 with the (CT)11-G allele as a recipient and 20 accessions containing 12 different alleles at the Wx locus as donors. The estimated length of the substituted segments ranged from 2.2 to 77.3 cM with an average of 17.4 cM.

  13. Allelic imbalance metre (Allim), a new tool for measuring allele-specific gene expression with RNA-seq data

    OpenAIRE

    Pandey, Ram Vinay; Franssen, Susanne U.; Futschik, Andreas; Schlötterer, Christian

    2013-01-01

    Estimating differences in gene expression among alleles is of high interest for many areas in biology and medicine. Here, we present a user-friendly software tool, Allim, to estimate allele-specific gene expression. Because mapping bias is a major problem for reliable estimates of allele-specific gene expression using RNA-seq, Allim combines two different strategies to account for the mapping biases. In order to reduce the mapping bias, Allim first generates a polymorphism-aware reference gen...

  14. Ultrasensitive detection of cancer cells and glycan expression profiling based on a multivalent recognition and alkaline phosphatase-responsive electrogenerated chemiluminescence biosensor

    Science.gov (United States)

    Chen, Xiaojiao; He, Yao; Zhang, Youyu; Liu, Meiling; Liu, Yang; Li, Jinghong

    2014-09-01

    A multivalent recognition and alkaline phosphatase (ALP)-responsive electrogenerated chemiluminescence (ECL) biosensor for cancer cell detection and in situ evaluation of cell surface glycan expression was developed on a poly(amidoamine) (PAMAM) dendrimer-conjugated, chemically reduced graphene oxide (rGO) electrode interface. In this strategy, the multivalency and high affinity of the cell-targeted aptamers on rGO provided a highly efficient cell recognition platform on the electrode. The ALP and concanavalin A (Con A) coated gold nanoparticles (Au NPs) nanoprobes allowed the ALP enzyme-catalyzed production of phenols that inhibited the ECL reaction of Ru(bpy)32+ on the rGO electrode interface, affording fast and highly sensitive ECL cytosensing and cell surface glycan evaluation. Combining the multivalent aptamer interface and ALP nanoprobes, the ECL cytosensor showed a detection limit of 38 CCRF-CEM cells per mL in human serum samples, broad dynamic range and excellent selectivity. In addition, the proposed biosensor provided a valuable insight into dynamic profiling of the expression of different glycans on cell surfaces, based on the carbohydrates recognized by lectins applied to the nanoprobes. This biosensor exhibits great promise in clinical diagnosis and drug screening.A multivalent recognition and alkaline phosphatase (ALP)-responsive electrogenerated chemiluminescence (ECL) biosensor for cancer cell detection and in situ evaluation of cell surface glycan expression was developed on a poly(amidoamine) (PAMAM) dendrimer-conjugated, chemically reduced graphene oxide (rGO) electrode interface. In this strategy, the multivalency and high affinity of the cell-targeted aptamers on rGO provided a highly efficient cell recognition platform on the electrode. The ALP and concanavalin A (Con A) coated gold nanoparticles (Au NPs) nanoprobes allowed the ALP enzyme-catalyzed production of phenols that inhibited the ECL reaction of Ru(bpy)32+ on the rGO electrode

  15. Drop-out probabilities of IrisPlex SNP alleles

    DEFF Research Database (Denmark)

    Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt;

    2013-01-01

    true alleles is possible. As part of the validation of the IrisPlex assay in our ISO17025 accredited, forensic genetic laboratory, we estimated the probability of drop-out of specific SNP alleles using 29 and 30 PCR cycles and 25, 50 and 100 Single Base Extension (SBE) cycles. We observed no drop...

  16. Rescue of progeria in trichothiodystrophy by homozygous lethal Xpd alleles.

    Directory of Open Access Journals (Sweden)

    Jaan-Olle Andressoo

    2006-10-01

    Full Text Available Although compound heterozygosity, or the presence of two different mutant alleles of the same gene, is common in human recessive disease, its potential to impact disease outcome has not been well documented. This is most likely because of the inherent difficulty in distinguishing specific biallelic effects from differences in environment or genetic background. We addressed the potential of different recessive alleles to contribute to the enigmatic pleiotropy associated with XPD recessive disorders in compound heterozygous mouse models. Alterations in this essential helicase, with functions in both DNA repair and basal transcription, result in diverse pathologies ranging from elevated UV sensitivity and cancer predisposition to accelerated segmental progeria. We report a variety of biallelic effects on organismal phenotype attributable to combinations of recessive Xpd alleles, including the following: (i the ability of homozygous lethal Xpd alleles to ameliorate a variety of disease symptoms when their essential basal transcription function is supplied by a different disease-causing allele, (ii differential developmental and tissue-specific functions of distinct Xpd allele products, and (iii interallelic complementation, a phenomenon rarely reported at clinically relevant loci in mammals. Our data suggest a re-evaluation of the contribution of "null" alleles to XPD disorders and highlight the potential of combinations of recessive alleles to affect both normal and pathological phenotypic plasticity in mammals.

  17. A Risk Allele for Nicotine Dependence in CHRNA5 Is a Protective Allele for Cocaine Dependence

    Science.gov (United States)

    Grucza, Richard A; Wang, Jen C.; Stitzel, Jerry A.; Hinrichs, Anthony L.; Saccone, Scott F.; Saccone, Nancy L.; Bucholz, Kathleen K.; Cloninger, C. Robert; Neuman, Rosalind J.; Budde, John P.; Fox, Louis; Bertelsen, Sarah; Kramer, John; Hesselbrock, Victor; Tischfield, Jay; Nurnberger, John. I.; Almasy, Laura; Porjesz, Bernice; Kuperman, Samuel; Schuckit, Marc A.; Edenberg, Howard J.; Rice, John P.; Goate, Alison M.; Bierut, Laura J.

    2008-01-01

    Background A non-synonymous coding polymorphism, rs16969968, of the CHRNA5 gene which encodes the alpha-5 subunit of the nicotinic acetylcholine receptor (nAChR) has been found to be associated with nicotine dependence (20). The goal of the present study is to examine the association of this variant with cocaine dependence. Methods Genetic association analysis in two, independent samples of unrelated cases and controls; 1.) 504 European-American participating in the Family Study on Cocaine Dependence (FSCD); 2.) 814 European Americans participating in the Collaborative Study on the Genetics of Alcoholsim (COGA). Results In the FSCD, there was a significant association between the CHRNA5 variant and cocaine dependence (OR = 0.67 per allele, p = 0.0045, assuming an additive genetic model), but in the reverse direction compared to that previously observed for nicotine dependence. In multivariate analyses that controlled for the effects of nicotine dependence, both the protective effect for cocaine dependence and the previously documented risk effect for nicotine dependence were statistically significant. The protective effect for cocaine dependence was replicated in the COGA sample. In COGA, effect sizes for habitual smoking, a proxy phenotype for nicotine dependence, were consistent with those observed in FSCD. Conclusion The minor (A) allele of rs16969968, relative to the major G allele, appears to be both a risk factor for nicotine dependence and a protective factor for cocaine dependence. The biological plausibility of such a bidirectional association stems from the involvement of nAChRs with both excitatory and inhibitory modulation of dopamine-mediated reward pathways. PMID:18519132

  18. AllelicImbalance: An R/ bioconductor package for detecting, managing, and visualizing allele expression imbalance data from RNA sequencing

    DEFF Research Database (Denmark)

    Gådin, Jesper R.; van't Hooft, Ferdinand M.; Eriksson, Per;

    2015-01-01

    Background: One aspect in which RNA sequencing is more valuable than microarray-based methods is the ability to examine the allelic imbalance of the expression of a gene. This process is often a complex task that entails quality control, alignment, and the counting of reads over heterozygous single...... possible biases. Results: We present AllelicImblance, a software program that is designed to detect, manage, and visualize allelic imbalances comprehensively. The purpose of this software is to allow users to pose genetic questions in any RNA sequencing experiment quickly, enhancing the general utility of...... RNA sequencing. The visualization features can reveal notable, non-trivial allelic imbalance behavior over specific regions, such as exons. Conclusions: The software provides a complete framework to perform allelic imbalance analyses of aligned RNA sequencing data, from detection to visualization...

  19. Are ???Endurance??? Alleles ???Survival??? Alleles? Insights from the ACTN3 R577X Polymorphism

    OpenAIRE

    Fiuza-Luces, Carmen; Ruiz, Jonatan R.; Rodr??guez-Romo, Gabriel; Santiago, Catalina; G??mez-Gallego, F??lix; Yvert, Thomas; Cano-Nieto, Amalia; Garatechea, Nuria; Mor??n, Mar??a; Luc??a, Alejandro

    2011-01-01

    Exercise phenotypes have played a key role for ensuring survival over human evolution. We speculated that some genetic variants that influence exercise phenotypes could be associated with exceptional survival (i.e. reaching ???100years of age). Owing to its effects on muscle structure/function, a potential candidate is the Arg(R)577Ter(X) polymorphism (rs1815739) in ACTN3, the structural gene encoding the skeletal muscle protein ??-actinin-3. We compared the ACTN3 R577X genotype/allele freque...

  20. Common alleles contribute to schizophrenia in CNV carriers

    Science.gov (United States)

    Tansey, K E; Rees, E; Linden, D E; Ripke, S; Chambert, K D; Moran, J L; McCarroll, S A; Holmans, P; Kirov, G; Walters, J; Owen, M J; O'Donovan, M C

    2016-01-01

    The genetic architecture of schizophrenia is complex, involving risk alleles ranging from common alleles of weak effect to rare alleles of large effect, the best exemplar of the latter being large copy number variants (CNVs). It is currently unknown whether pathophysiology in those with defined rare mutations overlaps with that in other individuals with the disorder who do not share the same rare mutation. Under an extreme heterogeneity model, carriers of specific high-penetrance mutations form distinct subgroups. In contrast, under a polygenic threshold model, high-penetrance rare allele carriers possess many risk factors, of which the rare allele is the only one, albeit an important, factor. Under the latter model, cases with rare mutations can be expected to share some common risk alleles, and therefore pathophysiological mechanisms, with cases without the same mutation. Here we show that, compared with controls, individuals with schizophrenia who have known pathogenic CNVs carry an excess burden of common risk alleles (P=2.25 × 10−17) defined from a genome-wide association study largely based on individuals without known CNVs. Our finding is not consistent with an extreme heterogeneity model for CNV carriers, but does offer support for the polygenic threshold model of schizophrenia. That this is so provides support for the notion that studies aiming to model the effects of rare variation may uncover pathophysiological mechanisms of relevance to those with the disorder more widely. PMID:26390827

  1. Monomerization of viral entry inhibitor griffithsin elucidates the relationship between multivalent binding to carbohydrates and anti-HIV activity

    Energy Technology Data Exchange (ETDEWEB)

    Moulaei, Tinoush; Shenoy, Shilpa R.; Giomarelli, Barbara; Thomas, Cheryl; McMahon, James B.; Dauter, Zbigniew; O' Keefe, Barry R.; Wlodawer, Alexander (NCI)

    2010-10-28

    Mutations were introduced to the domain-swapped homodimer of the antiviral lectin griffithsin (GRFT). Whereas several single and double mutants remained dimeric, insertion of either two or four amino acids at the dimerization interface resulted in a monomeric form of the protein (mGRFT). Monomeric character of the modified proteins was confirmed by sedimentation equilibrium ultracentrifugation and by their high resolution X-ray crystal structures, whereas their binding to carbohydrates was assessed by isothermal titration calorimetry. Cell-based antiviral activity assays utilizing different variants of mGRFT indicated that the monomeric form of the lectin had greatly reduced activity against HIV-1, suggesting that the antiviral activity of GRFT stems from crosslinking and aggregation of viral particles via multivalent interactions between GRFT and oligosaccharides present on HIV envelope glycoproteins. Atomic resolution crystal structure of a complex between mGRFT and nonamannoside revealed that a single mGRFT molecule binds to two different nonamannoside molecules through all three carbohydrate-binding sites present on the monomer.

  2. A New Electrophoresis Technique to Seperate Microsatellite Alleles

    Science.gov (United States)

    Traditional agarose and polyacrylamide gel electrophoresis have been used commonly for microsatellite (simple sequence repeats, SSRs) analysis, but they are labor- intensive and not always able to provide accurate sizes for different alleles. Capillary sequencers provide automated analysis and accur...

  3. Are 'endurance' alleles 'survival' alleles? Insights from the ACTN3 R577X polymorphism.

    Directory of Open Access Journals (Sweden)

    Carmen Fiuza-Luces

    Full Text Available Exercise phenotypes have played a key role for ensuring survival over human evolution. We speculated that some genetic variants that influence exercise phenotypes could be associated with exceptional survival (i.e. reaching ≥100 years of age. Owing to its effects on muscle structure/function, a potential candidate is the Arg(R577Ter(X polymorphism (rs1815739 in ACTN3, the structural gene encoding the skeletal muscle protein α-actinin-3. We compared the ACTN3 R577X genotype/allele frequencies between the following groups of ethnically-matched (Spanish individuals: centenarians (cases, n = 64; 57 female; age range: 100-108 years, young healthy controls (n = 283, 67 females, 216 males; 21±2 years, and humans who are at the two end-points of exercise capacity phenotypes, i.e. muscle endurance (50 male professional road cyclists and muscle power (63 male jumpers/sprinters. Although there were no differences in genotype/allele frequencies between centenarians (RR:28.8%; RX:47.5%; XX:23.7%, and controls (RR:31.8%; RX:49.8%; XX:18.4% or endurance athletes (RR:28.0%; RX:46%; XX:26.0%, we observed a significantly higher frequency of the X allele (P = 0.019 and XX genotype (P = 0.011 in centenarians compared with power athletes (RR:47.6%; RX:36.5%;XX:15.9%. Notably, the frequency of the null XX (α-actinin-3 deficient genotype in centenarians was the highest ever reported in non-athletic Caucasian populations. In conclusion, despite there were no significant differences with the younger, control population, overall the ACTN3 genotype of centenarians resembles that of world-class elite endurance athletes and differs from that of elite power athletes. Our preliminary data would suggest a certain 'survival' advantage brought about by α-actinin-3 deficiency and the 'endurance'/oxidative muscle phenotype that is commonly associated with this condition.

  4. Random survey for RH allele polymorphism among 50 native Tibetans

    OpenAIRE

    Wei, Qing

    2006-01-01

    Rhesus D (RHD) allele distribution varied significantly among different population. However, no data are available for people, like Tibetans, living at extreme altitudes, where the oxygen density is decreased. A comprehensive study has been performed to define the Rhesus (RH) allele polymorphism and RH haplotype distribution in 50 native Tibetans. Nucleotide sequencing from genomic deoxyribonucleic acid (DNA) for 10 Rhesus D gene (RHD) exons in all of 50 samples plus 10 Rhesus CE gene (RHCE) ...

  5. DRD4 dopamine receptor allelic diversity in various primate species

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, M.; Higley, D. [NIAAA, Rockville, MD (United States); O`Brien, S. [NCI, Frederick, MD (United States)] [and others

    1994-09-01

    The DRD4 dopamine receptor is uniquely characterized by a 48 bp repeating segment within the coding region, located in exon III. Different DRD4 alleles are produced by the presence of additional 48 bp repeats, each of which adds 16 amino acids to the length of the 3rd intracytoplasmic loop of the receptor. The DRD4 receptor is therefore an intriguing candidate gene for behaviors which are influenced by dopamine function. In several human populations, DRD4 alleles with 2-8 and 10 repeats have previously been identified, and the 4 and 7 repeat alleles are the most abundant. We have determined DRD4 genotypes in the following nonhuman primate species: chimpanzee N=2, pygmy chimpanzee N=2, gorilla N=4, siamang N=2, Gelada baboon N=1, gibbon N=1, orangutan (Bornean and Sumatran) N=62, spider monkey N=4, owl monkey N=1, Colobus monkey N=1, Patas monkey N=1, ruffed lemur N=1, rhesus macaque N=8, and vervet monkey N=28. The degree of DRD4 polymorphism and which DRD4 alleles were present both showed considerable variation across primate species. In contrast to the human, rhesus macaque monkeys were monomorphic. The 4 and 7 repeat allels, highly abundant in the human, may not be present in certain other primates. For example, the four spider monkeys we studied showed the 7, 8 and 9 repeat length alleles and the only gibbon we analyzed was homozygous for the 9 repeat allele (thus far not observed in the human). Genotyping of other primate species and sequencing of the individual DRD4 repeat alleles in different species may help us determine the ancestral DRD4 repeat length and identify connections between DRD4 genotype and phenotype.

  6. MHC-DAB allele polymorphism in Japanese flounders Paralichthys olivaceus

    OpenAIRE

    XU Tian-Jun; Chen, Song-Lin; Tian, Yong-Sheng

    2008-01-01

    Polymorphism of the major histocompatibility complex DAB gene in Japanese flounder (Paralichthys olivaceus) was investigated using sequences analysis. In this study, 24 individuals were selected to amplify partial exon1 and intron2, complete intron1 and exon2 of DAB gene. 131 sequences were subsequently used to analyze genetic variation and revealed 31 different sequences, which presented 31 novel alleles belonging to 19 allele major types according to accepted nomenclature rules. Frequency o...

  7. ALLELIC POLYMORPHISM OF IFNγ GENE IN PATIENTS WITH PULMONARY TUBERCULOSIS

    OpenAIRE

    E. L. Nikulina; I. O. Naslednikova; Urazova, O. I.; O. V. Voronkova; V. V. Novitsky; E. V. Nekrasov; O. V. Filiniuk; E. G. Churina; K. O. Mikheyeva; R. R. Hasanova; V. A. Serebryakova; N. A. Sukhalentseva

    2014-01-01

    In present work, some immunogenetic aspects of pulmonary tuberculosis were studied, using modern techniques from molecular genetics and immunology. It is shown that carriage of Т allele and homozygous TT genotype in +874А/Т IFNγ gene polymorphism comprise a immunogenetic factor which correlated with a protective effect, regarding a susceptibility to pulmonary tuberculosis. Predisposition for tuberculosis infection is associated with A allele of this gene, as well as with АА and АТ genotypes o...

  8. Allele-specific MMP-3 transcription under in vivo conditions

    International Nuclear Information System (INIS)

    A common matrix metalloproteinases-3 (MMP-3) -1612 5A/6A promoter polymorphism is associated with risk for cardiovascular disease, rheumatoid arthritis, and other diseases. Here we used the haplotype chromatin immunoprecipitation method to study allele-specific MMP-3 expression under in vivo conditions in heterozygous THP-1 cells. Pyrosequencing was used to analyse the ratio of 5A-allele to 6A-allele after chromatin immunoprecipitation using an antibody against phosphorylated active RNA polymerase II. There was no allele-specific difference in transcriptional activity during basal conditions, i.e., in unstimulated monocytic THP-1 cells. However, after stimulation of MMP-3 expression by monocyte differentiation or incubation with IL-1β, the haplotype containing the 5A-allele was associated with higher transcriptional activity compared with the 6A-containing haplotype. Electromobility shift assay demonstrated increased binding of nuclear proteins to the 5A-allele after monocyte differentiation. In conclusion, the common MMP-3 5A/6A promoter polymorphism appears to be functional only during specific environmental conditions involving inflammation

  9. Allelic imbalance analysis by high-density single-nucleotide polymorphic allele (SNP) array with whole genome amplified DNA

    OpenAIRE

    Wong, Kwong-Kwok; Tsang, Yvonne T.M.; Shen, Jianhe; Cheng, Rita S.; Chang, Yi-Mieng; Man, Tsz-Kwong; Lau, Ching C.

    2004-01-01

    Besides their use in mRNA expression profiling, oligonucleotide microarrays have also been applied to single-nucleotide polymorphism (SNP) and loss of heterozygosity (LOH) or allelic imbalance studies. In this report, we evaluate the reliability of using whole genome amplified DNA for analysis with an oligonucleotide microarray containing 11 560 SNPs to detect allelic imbalance and chromosomal copy number abnormalities. Whole genome SNP analyses were performed with DNA extracted from osteosar...

  10. Impriniting of human H19: Allele-specific CpG methylation, loss of the active allele in Wilms tumor, and potential for somatic allele switching

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Shields, T.; Crenshaw, T.; Hao, Y.; Moulton, T.; Tycko, B. (Columbia Univ., New York (United States))

    1993-07-01

    Genomic imprinting and monoallelic gene expression appear to play a role in human genetic disease and tumorigenesis. The human H19 gene, at chromosome 11p15, has previously been shown to be monoallelically expressed. Since CpG methylation has been implicated in imprinting, the authors analyzed methylation of H19 DNA. In fetal and adult organs the transcriptionally silent H19 allele was extensively hypermethylated through the entire gene and its promoter, and, consistent with a functional role for DNA methylation, expression of an H19 promoter-reporter construct was inhibited by in vitro methylation. Gynogenetic ovarian teratomas were found to contain only hypomethylated H19 DNA, suggesting that the expressed H19 allele might be maternal. This was confirmed by analysis of 11p15 polymorphisms in a patient with Wilms tumor. The tumor had lost the maternal 11p15, and H19 expression in the normal kidney was exclusively from this allele. Imprinting of human H19 appears to be susceptible to tissue-specific modulation in somatic development; in one individual, cerebellar cells were found to express only the otherwise silent allele. Implications of these findings for the role of DNA methylation in imprinting and for H19 as a candidate imprinted tumor-suppressor gene are discussed. 57 refs., 7 figs.

  11. Immunisation with a multivalent, subunit vaccine reduces patent infection in a natural bovine model of onchocerciasis during intense field exposure.

    Directory of Open Access Journals (Sweden)

    Benjamin L Makepeace

    Full Text Available Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Naïve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund's adjuvant or alum. The selected antigens were orthologues of O. volvulus recombinant proteins that had previously been shown to confer protection against filarial larvae in rodent models and, in some cases, were recognised by serum antibodies from putatively immune humans. The vaccine was highly immunogenic, eliciting a mixed IgG isotype response. Four weeks after the final immunisation, vaccinated and adjuvant-treated control calves were exposed to natural parasite transmission by the blackfly vectors in an area of Cameroon hyperendemic for O. ochengi. After 22 months, all the control animals had patent infections (i.e., microfilaridermia, compared with only 58% of vaccinated cattle (P = 0.015. This study indicates that vaccination to prevent patent infection may be an achievable goal in onchocerciasis, reducing both the pathology and transmissibility of the infection. The cattle model has also demonstrated its utility for preclinical vaccine discovery, although much research will be required to achieve the requisite target product profile of a clinical candidate.

  12. ANAMNESTIC IMMUNE RESPONSE EIGHT YEARS AFTER IMMUNIZATION OF PRIMATES WITH A MULTIVALENT HIV-1 GP120 VARIABLE PEPTIDE VACCINE

    Directory of Open Access Journals (Sweden)

    Rebecca Rivera

    2013-01-01

    Full Text Available Successful development of an effective HIV vaccine hasn’t occurred yet partly as a consequence of the antigenic variation deployed by HIV-1 to escape the immune system. Our laboratory is dedicated to develop a single peptide synthesis approach to create multivalent peptides representing hypervariable epitopes of the gp120 envelope glycoprotein of HIV-1. Our previous study showed that our HIV HECs are potent immunogens that activate both humoral and cellular arms of the acquired immune response and that these responses are broadly reactive, recognizing epitopes from divergent strains of HIV-1. To detect the long term duration of memory response induced by HIV HECs, two rhesus macaques were immunized at weeks 0 and 8 and euthanized two weeks after a third immunization at week 393 (more than 8 years later. Antibody response to individual components of HIV HEC immunogens and HIV HEC-induced cross-reactive antibody response were determined by an Enzyme-Linked Immunosorbent Assay (ELISA. The antibody titer to individual HIV HEC components and a mixture of the five peptides was greater than 1:5000 dilution. Antibodies from HIV HEC-immunized macaques recognized HIV HEC analogs representing the monovalent epitopes of five variable regions of gp120 from subtype B HIV-1 MN, HIV-1 RF and HIV-1 SF2 isolates with an antibody titer greater than 1: 500 dilution. Moreover, lymphocytes from lymph nodes of HIV HEC-immunized macaques showed T cell proliferative responses specific to HIV HEC individual components and to the five HIV HEC peptides combined. Our results clearly show that in these two macaques, HIV HECs induced strong, long-lasting anamnestic immune responses 8 years after immunization.

  13. Affinity-controlled protein encapsulation into sub-30 nm telodendrimer nanocarriers by multivalent and synergistic interactions.

    Science.gov (United States)

    Wang, Xu; Shi, Changying; Zhang, Li; Bodman, Alexa; Guo, Dandan; Wang, Lili; Hall, Walter A; Wilkens, Stephan; Luo, Juntao

    2016-09-01

    Novel nanocarriers are highly demanded for the delivery of heterogeneous protein therapeutics for disease treatments. Conventional nanoparticles for protein delivery are mostly based on the diffusion-limiting mechanisms, e.g., physical trapping and entanglement. We develop herein a novel linear-dendritic copolymer (named telodendrimer) nanocarrier for efficient protein delivery by affinitive coating. This affinity-controlled encapsulation strategy provides nanoformulations with a small particle size (50% w/w) and maintained protein bioactivity. We integrate multivalent electrostatic and hydrophobic functionalities synergistically into the well-defined telodendrimer scaffold to fine-tune protein binding affinity and delivery properties. The ion strength and density of the charged groups as well as the structure of the hydrophobic segments are important and their combinations in telodendrimers are crucial for efficient protein encapsulation. We have conducted a series of studies to understand the mechanism and kinetic process of the protein loading and release, utilizing electrophoresis, isothermal titration calorimetry, Förster resonance energy transfer spectroscopy, bio-layer interferometry and computational methods. The optimized nanocarriers are able to deliver cell-impermeable therapeutic protein intracellularly to kill cancer cells efficiently. In vivo imaging studies revealed cargo proteins preferentially accumulate in subcutaneous tumors and retention of peptide therapeutics is improved in an orthotopic brain tumor, these properties are evidence of the improved pharmacokinetics and biodistributions of protein therapeutics delivered by telodendrimer nanoparticles. This study presents a bottom-up strategy to rationally design and fabricate versatile nanocarriers for encapsulation and delivery of proteins for numerous applications. PMID:27294543

  14. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios

    International Nuclear Information System (INIS)

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed

  15. Chloroplast genetics of chlamydomonas. I. Allelic segregation ratios. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sager, R.; Ramanis, Z.

    1976-06-01

    This paper presents allelic segregation data from a series of 16 crosses segregated for nuclear and chloroplast genes. By means of pedigree analysis, segregants of chloroplast genes. By means of pedigree analysis, segregants of chloroplast markers occurring in the zygote have been distinguished from those occurring in zoospore clones. The genes ac1, ac2, and tm1 showed little if any deviation from 1:1 either in zygotic segregation or in zoospore clones. The genes sm2, ery, and spc showed a significant excess of the allele from the mt+ parent in zygotes. However, in zoospores, mt+ excess was seen only when the allele was the mutant (resistant) form but not when it was wild type (sensitive). These results show that the extent of preferential segregation differs in zygotes and in zoospores, and that preferential segregation is influenced by map location and by allele specificity. A comparison of progeny from zygotes mated after 0, 15'', 30'', and 50'' uv irradiation of the mt+ gametes demonstrated the lack of an effect of uv upon allelic segregation ratios. In total, these results exclude the multi-copy model of chloroplast genome segregation suggested by Gillham. Boynton and Lee (1974) and support the diploid model we have previously proposed.

  16. Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

    Directory of Open Access Journals (Sweden)

    Katharina Koschek

    2015-05-01

    Full Text Available Three polymers, poly(N-(2-hydroxypropylmethacrylamide (pHPMA, hyperbranched polyglycerol (hPG, and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21. Polymer carriers were conjugated with 3–9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1. Binding of the obtained peptide–polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC to determine the binding affinity, the enthalpic and entropic contributions to free binding energy, and the stoichiometry of binding for all peptide–polymer conjugates. Binding affinities of all multivalent ligands were in the µM range, strongly amplified compared to the monovalent ligand P1 with a KD > 1 mM. In addition, concise differences were observed, pHPMA and hPG carriers showed moderate affinity and bound 2.3–2.8 peptides per protein binding site resulting in the formation of aggregates. Dextran-based conjugates displayed affinities down to 1.2 µM, forming complexes with low stoichiometry, and no precipitation. Experimental results were compared with parameters obtained from molecular dynamics simulations in order to understand the observed differences between the three carrier materials. In summary, the more rigid and condensed peptide–polymer conjugates based on the dextran scaffold seem to be superior to induce multivalent binding and to increase affinity, while the more flexible and dendritic polymers, pHPMA and hPG are suitable to induce crosslinking upon binding.

  17. Peptide-polymer ligands for a tandem WW-domain, an adaptive multivalent protein-protein interaction: lessons on the thermodynamic fitness of flexible ligands.

    Science.gov (United States)

    Koschek, Katharina; Durmaz, Vedat; Krylova, Oxana; Wieczorek, Marek; Gupta, Shilpi; Richter, Martin; Bujotzek, Alexander; Fischer, Christina; Haag, Rainer; Freund, Christian; Weber, Marcus; Rademann, Jörg

    2015-01-01

    Three polymers, poly(N-(2-hydroxypropyl)methacrylamide) (pHPMA), hyperbranched polyglycerol (hPG), and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21). Polymer carriers were conjugated with 3-9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1). Binding of the obtained peptide-polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC) to determine the binding affinity, the enthalpic and entropic contributions to free binding energy, and the stoichiometry of binding for all peptide-polymer conjugates. Binding affinities of all multivalent ligands were in the µM range, strongly amplified compared to the monovalent ligand P1 with a K D > 1 mM. In addition, concise differences were observed, pHPMA and hPG carriers showed moderate affinity and bound 2.3-2.8 peptides per protein binding site resulting in the formation of aggregates. Dextran-based conjugates displayed affinities down to 1.2 µM, forming complexes with low stoichiometry, and no precipitation. Experimental results were compared with parameters obtained from molecular dynamics simulations in order to understand the observed differences between the three carrier materials. In summary, the more rigid and condensed peptide-polymer conjugates based on the dextran scaffold seem to be superior to induce multivalent binding and to increase affinity, while the more flexible and dendritic polymers, pHPMA and hPG are suitable to induce crosslinking upon binding. PMID:26124884

  18. Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

    Science.gov (United States)

    Koschek, Katharina; Durmaz, Vedat; Krylova, Oxana; Wieczorek, Marek; Gupta, Shilpi; Richter, Martin; Bujotzek, Alexander; Fischer, Christina; Haag, Rainer; Freund, Christian; Weber, Marcus

    2015-01-01

    Summary Three polymers, poly(N-(2-hydroxypropyl)methacrylamide) (pHPMA), hyperbranched polyglycerol (hPG), and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21). Polymer carriers were conjugated with 3–9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1). Binding of the obtained peptide–polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC) to determine the binding affinity, the enthalpic and entropic contributions to free binding energy, and the stoichiometry of binding for all peptide–polymer conjugates. Binding affinities of all multivalent ligands were in the µM range, strongly amplified compared to the monovalent ligand P1 with a K D > 1 mM. In addition, concise differences were observed, pHPMA and hPG carriers showed moderate affinity and bound 2.3–2.8 peptides per protein binding site resulting in the formation of aggregates. Dextran-based conjugates displayed affinities down to 1.2 µM, forming complexes with low stoichiometry, and no precipitation. Experimental results were compared with parameters obtained from molecular dynamics simulations in order to understand the observed differences between the three carrier materials. In summary, the more rigid and condensed peptide–polymer conjugates based on the dextran scaffold seem to be superior to induce multivalent binding and to increase affinity, while the more flexible and dendritic polymers, pHPMA and hPG are suitable to induce crosslinking upon binding. PMID:26124884

  19. A strategy to discover genes that carry multi-allelic or mono-allelic risk for common diseases: A cohort allelic sums test (CAST)

    International Nuclear Information System (INIS)

    A method is described to discover if a gene carries one or more allelic mutations that confer risk for any specified common disease. The method does not depend upon genetic linkage of risk-conferring mutations to high frequency genetic markers such as single nucleotide polymorphisms. Instead, the sums of allelic mutation frequencies in case and control cohorts are determined and a statistical test is applied to discover if the difference in these sums is greater than would be expected by chance. A statistical model is presented that defines the ability of such tests to detect significant gene-disease relationships as a function of case and control cohort sizes and key confounding variables: zygosity and genicity, environmental risk factors, errors in diagnosis, limits to mutant detection, linkage of neutral and risk-conferring mutations, ethnic diversity in the general population and the expectation that among all exonic mutants in the human genome greater than 90% will be neutral with regard to any effect on disease risk. Means to test the null hypothesis for, and determine the statistical power of, each test are provided. For this 'cohort allelic sums test' or 'CAST', the statistical model and test are provided as an Excel (TM) program, CASTAT (C) at http://epidemiology.mit.edu. Based on genetics, technology and statistics, a strategy of enumerating the mutant alleles carried in the exons and splice sites of the estimated ∼25,000 human genes in case cohort samples of 10,000 persons for each of 100 common diseases is proposed and evaluated: A wide range of possible conditions of multi-allelic or mono-allelic and monogenic, multigenic or polygenic (including epistatic) risk are found to be detectable using the statistical criteria of 1 or 10 ''false positive'' gene associations per 25,000 gene-disease pair-wise trials and a statistical power of >0.8. Using estimates of the distribution of both neutral and gene-inactivating nondeleterious mutations in humans and

  20. Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

    OpenAIRE

    Katharina Koschek; Vedat Durmaz; Oxana Krylova; Marek Wieczorek; Shilpi Gupta; Martin Richter; Alexander Bujotzek; Christina Fischer; Rainer Haag; Christian Freund; Marcus Weber; Jörg Rademann

    2015-01-01

    Three polymers, poly(N-(2-hydroxypropyl)methacrylamide) (pHPMA), hyperbranched polyglycerol (hPG), and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21). Polymer carriers were conjugated with 3–9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1). Binding of the obtained peptide–polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC) to determine t...

  1. Implication of HLA-DMA Alleles in Corsican IDDM

    Directory of Open Access Journals (Sweden)

    P. Cucchi-Mouillot

    1998-01-01

    Full Text Available The HLA-DM molecule catalyses the CLIP/antigen peptide exchange in the classical class II peptide-binding groove. As such, DM is an antigen presentation regulator and may be linked to autoimmune diseases. Using PCR derived methods, a relationship was revealed between DM gene polymorphism and IDDM, in a Corsican population. The DMA*0101 allele was observed to confer a significant predisposition to this autoimmune disease while the DMA*0102 allele protected significantly. Experiments examining polymorphism of the HLA-DRB1 gene established that these relationships are not a consequence of linkage disequilibrium with HLA-DRB1 alleles implicated in this pathology. The study of the DMA gene could therefore be an additional tool for early IDDM diagnosis in the Corsican population.

  2. Genetic Diversity Based on Allozyme Alleles of Chinese Cultivated Rice

    Institute of Scientific and Technical Information of China (English)

    TANG Sheng-xiang; WEI Xing-hua; JIANG Yun-zhu; D S Brar; G S Khush

    2007-01-01

    Genetic diversity was analyzed with 6 632 core rice cultivars selected from 60 282 Chinese rice accessions on the basis of 12 allozyme loci, Pgil, Pgi2, Ampl, Amp2, Amp3, Amp4, Sdh1, Adh1, Est1, Est2, Est5 and Est9, by starch gel electrophoresis. Among the materials examined, 52 alleles at 12 polymorphic loci were identified, which occupied 96.3% of 54 alleles found in cultivated germplasm of O.sativa L. The number of alleles per locus ranged from 2 to 7 with an average of 4.33. The gene diversity (He) each locus varied considerably from 0.017 for Amp4 to 0.583 for Est2 with an average gene diversity (Ht) 0.271, and Shannon-Wiener index from 0.055 to 0.946 with an average of 0.468. The degree of polymorphism (DP) was in a range from 0.9 to 46.9% with an average of 21.4%. It was found that the genetic diversity in japonica (Keng) subspecies was lower in terms of allele's number, Ht and S-W index, being 91.8, 66.2 and 75.7% of indica (Hsien) one, respectively. Significant genetic differentiation between indica and japonica rice has been appeared in the loci Pgil, Amp2, Pgi2, and Est2, with higher average coefficient of genetic differentiation (Gst) 0.635, 0.626, 0.322 and 0.282, respectively. Except less allele number per locus (3.33) for modern cultivars, being 76.9% of landraces, the Ht and S-W index showed in similar between the modern cultivars and the landraces detected. In terms of allozyme, the rice cultivars in the Southwest Plateau and Central China have richer genetic diversity. The present study reveals again that Chinese cultivated rice germplasm has rich genetic diversity, showed by the allozyme allele variation.

  3. A common mutation associated with the Duarte galactosemia allele

    Energy Technology Data Exchange (ETDEWEB)

    Elsas, L.J.; Dembure, P.P.; Langley, S.; Paulk, E.M.; Hjelm, L.N.; Fridovich-Keil, J. (Emory Univ. School of Medicine, Atlanta, GA (United States))

    1994-06-01

    The human cDNA and gene for galactose-1-phosphate uridyl transferase (GALT) have been cloned and sequenced. A prevalant mutation (Q188R) is known to cause classic galactosemia (G/G). G/G galactosemia has an incidence of 1/38,886 in 1,396,766 Georgia live-born infants, but a more common variant of galactosemia, Duarte, has an unknown incidence. The proposed Duarte biochemical phenotypes of GALT are as follows: D/N, D/D, and D/G, which have [approximately]75%, 50%, and 25% of normal GALT activity, respectively. In addition, the D allele has isoforms of its enzyme that have more acidic pI than normal. Here the authors systematically determine (a) the prevalence of an A-to-G transition at base pair 2744 of exon 10 in the GALT gene, a transition that produces a codon change converting asparagine to aspartic acid at position 314 (N314D), and (b) the association of this mutation with the Duarte biochemical phenotype. The 2744G nucleotide change adds an AvaII (SinI) cut site, which was identified in PCR-amplified DNA. In 111 biochemically unphenotyped controls with no history of galactosemia, 13 N314D alleles were identified (prevalence 5.9%). In a prospective study, 40 D alleles were biochemically phenotyped, and 40 N314D alleles were found. By contrast, in 36 individuals known not to have the Duarte biochemical phenotype, no N314D alleles were found. The authors conclude that the N314D mutation is a common allele that probably causes the Duarte GALT biochemical phenotype and occurs in a predominantly Caucasian, nongalactosemic population, with a prevalence of 5.9%. 36 refs., 3 figs., 2 tabs.

  4. The inheritance of resistance alleles in multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Sreeram V Ramagopalan

    2007-09-01

    Full Text Available Multiple sclerosis (MS is a complex trait in which alleles at or near the class II loci HLA-DRB1 and HLA-DQB1 contribute significantly to genetic risk. HLA-DRB1*15 and HLA-DRB1*17-bearing haplotypes and interactions at the HLA-DRB1 locus increase risk of MS but it has taken large samples to identify resistance HLA-DRB1 alleles. In this investigation of 7,093 individuals from 1,432 MS families, we have assessed the validity, mode of inheritance, associated genotypes, and the interactions of HLA-DRB1 resistance alleles. HLA-DRB1*14-, HLA-DRB1*11-, HLA-DRB1*01-, and HLA-DRB1*10-bearing haplotypes are protective overall but they appear to operate by different mechanisms. The first type of resistance allele is characterised by HLA-DRB1*14 and HLA-DRB1*11. Each shows a multiplicative mode of inheritance indicating a broadly acting suppression of risk, but a different degree of protection. In contrast, a second type is exemplified by HLA-DRB1*10 and HLA-DRB1*01. These alleles are significantly protective when they interact specifically in trans with HLA-DRB1*15-bearing haplotypes. HLA-DRB1*01 and HLA-DRB1*10 do not interact with HLA-DRB1*17, implying that several mechanisms may be operative in major histocompatibility complex-associated MS susceptibility, perhaps analogous to the resistance alleles. There are major practical implications for risk and for the exploration of mechanisms in animal models. Restriction of antigen presentation by HLA-DRB1*15 seems an improbably simple mechanism of major histocompatibility complex-associated susceptibility.

  5. Allele-specific DNA methylation reinforces PEAR1 enhancer activity.

    Science.gov (United States)

    Izzi, Benedetta; Pistoni, Mariaelena; Cludts, Katrien; Akkor, Pinar; Lambrechts, Diether; Verfaillie, Catherine; Verhamme, Peter; Freson, Kathleen; Hoylaerts, Marc F

    2016-08-18

    Genetic variation in the PEAR1 locus is linked to platelet reactivity and cardiovascular disease. The major G allele of rs12041331, an intronic cytosine guanine dinucleotide-single-nucleotide polymorphism (CpG-SNP), is associated with higher PEAR1 expression in platelets and endothelial cells than the minor A allele. The molecular mechanism underlying this difference remains elusive. We have characterized the histone modification profiles of the intronic region surrounding rs12041331 and identified H3K4Me1 enhancer-specific enrichment for the region that covers the CpG-SNP. Interestingly, methylation studies revealed that the CpG site is fully methylated in leukocytes of GG carriers. Nuclear protein extracts from megakaryocytes, endothelial cells, vs control HEK-293 cells show a 3-fold higher affinity for the methylated G allele compared with nonmethylated G or A alleles in a gel electrophoretic mobility shift assay. To understand the positive relationship between methylation and gene expression, we studied DNA methylation at 4 different loci of PEAR1 during in vitro megakaryopoiesis. During differentiation, the CpG-SNP remained fully methylated, while we observed rapid methylation increases at the CpG-island overlapping the first 5'-untranslated region exon, paralleling the increased PEAR1 expression. In the same region, A-allele carriers of rs12041331 showed significantly lower DNA methylation at CGI1 compared with GG homozygote. This CpG-island contains binding sites for the methylation-sensitive transcription factor CTCF, whose binding is known to play a role in enhancer activation and/or repression. In conclusion, we report the molecular characterization of the first platelet function-related CpG-SNP, a genetic predisposition that reinforces PEAR1 enhancer activity through allele-specific DNA methylation. PMID:27313330

  6. Distribution of a pseudodeficiency allele among Tay-Sachs carriers

    Energy Technology Data Exchange (ETDEWEB)

    Tomczak, J.; Grebner, E.E. (Thomas Jefferson Univ., Philadelphia, PA (United States)); Boogen, C. (Univ. of Essen Medical School (Germany))

    1993-08-01

    Recently Triggs-Raine et al. (1992) identified a new mutation in the gene coding for the [alpha]-subunit of [beta]-hexosaminidase A (hex A), the enzyme whose deficiency causes Tay-Sachs disease. This mutation, a C[sub 739]-to-T transition in exon 7, results in an altered enzyme that is active (albeit at reduced levels) in cells but that has essentially no activity in serum. This so-called pseudodeficient allele was first detected in compound heterozygotes who also carried a Tay-Sachs disease allele and therefore had no detectable hex A in their serum but who were in good health. Carriers of this apparently benign mutation are generally indistinguishable from carriers of a lethal mutation by means of routine enzyme-based screening tests, because the product of the pseudodeficient allele is not detectable in serum and has decreased activity in cells. This suggests that some individuals who have been classified as Tay-Sachs carriers are actually carriers of the pseudodeficient allele and are not at risk to have a child affected with Tay-Sachs disease. The pseudodeficient allele may also be responsible for some inconclusive diagnoses, where leukocyte values fall below the normal range but are still above the carrier range. The fact that there are now two mutant alleles (the psuedodeficient and the adult) that are indistinguishable from the lethal infantile mutations by means of enzyme assay yet that are phenotypically very different and that together may account for as much as 12% of enzyme-defined carriers on the basis of the data here suggests that DNA analysis should be part of a comprehensive screening program. It will be particularly useful to identify the mutations in couples at risk, before they undergo prenatal diagnosis. DNA analysis will also resolve some inconclusive diagnoses.

  7. Platelet antigen allele frequencies in Australian aboriginal and Caucasian populations.

    Science.gov (United States)

    Chen, Z; Lester, S; Boettcher, B; McCluskey, J

    1997-11-01

    We have applied genotyping methods of PCR-SSOP and PCR-RFLP to three, bi-allelic platelet specific antigen systems HPA-1 (Pla), HPA-3 (Bak) and HPA-5 (Br). This combination of techniques offers flexibility for high volume or rapid typing. The phenotype and genotype frequencies of alleles from the three systems differ significantly between the Yuendumu Australian Aboriginals (Wailbri) and Australian Caucasians. The major differences are the very low frequencies of HPA-1b and HPA-3b in Yuendumu Aboriginals which are potentially relevant to platelet transfusion in patients of Australian Aboriginal descent. PMID:9423221

  8. A common allele on chromosome 9 associated with coronary heartdisease

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Ruth; Pertsemlidis, Alexander; Kavaslar, Nihan; Stewart, Alexandre; Roberts, Robert; Cox, David R.; Hinds, David; Pennachio, Len; Tybjaerg-Hansen, Anne; Folsom, Aaron R.; Boerwinkle,Eric; Hobbs, Helen H.; Cohen, Jonathan C.

    2007-03-01

    Coronary heart disease (CHD) is a major cause of death in Western countries. Here we used genome-wide association scanning to identify a 58 kb interval on chromosome 9 that was consistently associated with CHD in six independent samples. The interval contains no annotated genes and is not associated with established CHD risk factors such as plasma lipoproteins, hypertension or diabetes. Homozygotes for the risk allele comprise 20-25% of Caucasians and have a {approx}30-40% increased risk of CHD. These data indicate that the susceptibility allele acts through a novel mechanism to increase CHD risk in a large fraction of the population.

  9. What phylogeny and gene genealogy analyses reveal about homoplasy in citrus microsatellite alleles

    OpenAIRE

    Barkley, Noelle A.; Krueger, Robert R.; Federici, Claire T.; Roose, Mikeal L

    2009-01-01

    Sixty-five microsatellite alleles amplified from ancestral citrus accessions classified in three separate genera were evaluated for sequence polymorphism to establish the basis of inter- and intra-allelic genetic variation, evaluate the extent of size homoplasy, and determine an appropriate model (stepwise or infinite allele) for analysis of citrus microsatellite alleles. Sequences for each locus were aligned and subsequently used to determine relationships between alleles of different taxa v...

  10. An immunosensor based on magnetic relaxation switch and polystyrene microparticle-induced immune multivalency enrichment system for the detection of Pantoea stewartii subsp. Stewartii.

    Science.gov (United States)

    Chen, Yi ping; Zou, Ming qiang; Wang, Da ning; Li, Yong liang; Xue, Qiang; Xie, Meng xia; Qi, Cai

    2013-05-15

    A rapid, sensitive, and simple immunosensor has been developed for the detection of Pantoea stewartii subsp. Stewartii (Pss). This immunosensor combines magnetic relaxation switch (MRS) assay with polystyrene microparticle-induced immune multivalency enrichment system. Comparing to conventional enzyme-linked immunosorbent assay (ELISA), the immunosensor developed in this study provides higher sensitivity and requires less analysis time. The detection limit of Pss obtained by immunosensor was determined to be 10(3)cfu/mL, 50 times lower than that by ELISA (5×10(4)cfu/mL), while the analysis time required by immunosensor is 30min much shorter than that by ELISA. The average recoveries studied with Pss at various spiking levels ranged from 85.5% to 93.4% with a relative standard deviation (RSD) below 6.0%. No cross-reaction with the other five strains was found, demonstrating a good specificity of Pss detection. The results showed that the MRS immunosensor combined with PS-induced immune multivalency enhancement system is a promising platform for the determination of large biological molecules due to its high sensitivity, specificity, homogeneity, and speed. PMID:23274190

  11. Ion-Responsive Channels of Zwitterion-Carbon Nanotube Membrane for Rapid Water Permeation and Ultrahigh Mono-/Multivalent Ion Selectivity.

    Science.gov (United States)

    Liu, Tian-Yin; Yuan, Hao-Ge; Li, Qian; Tang, Yuan-Hui; Zhang, Qiang; Qian, Weizhong; Van der Bruggen, Bart; Wang, Xiaolin

    2015-07-28

    The rational combination of polymer matrix and nanostructured building blocks leads to the formation of composite membranes with unexpected capability of selectivity of monovalent electrolytes and water, which affords the feasibility to effeciently remove harmful ions and neutral molecules from the environment of concentrated salines. However, the multivalent ion rejection in salined water of routine nanocomposite membranes was less than 98% when ion strength is high, resulting in a poor ion selectivity far below the acceptable value. In this contribution, the ion-responsive membrane with zwitterion-carbon nanotube (ZCNT) entrances at the surface and nanochannels inside membrane has been proposed to obtain ultrahigh multivalent ion rejection. The mean effective pore diameter of ZCNT membrane was dedicated tuned from 1.24 to 0.54 nm with the rise in Na2SO4 concentration from 0 to 70 mol m(-3) as contrary to the conventional rejection drop in carbon nanotube (CNT) membrane. The ultrahigh selective permeabilities of monovalent anions against divalent anions of 93 and against glucose of 5.5 were obtained on ZCNT membrane, while such selectivities were only 20 and 1.6 for the pristine CNT membrane, respectively. The ZCNT membranes have potential applications in treatment of salined water with general NaCl concentration from 100 to 600 mol m(-3), which are widely applicable in desalination, food, and biological separation processes. PMID:26153719

  12. Multifragment alleles in DNA fingerprints of the parrot, Amazona ventralis

    Science.gov (United States)

    Brock, M.K.; White, B.N.

    1991-01-01

    Human DNA probes that identify variable numbers of tandem repeat loci are being used to generate DNA fingerprints in many animal and plant species. In most species the majority of the sc rable autoradiographic bands of the DNA fingerprint represent alleles from numerous unlinked loci. This study was initiated to use DNA fingerprints to determine the amount of band-sharing among captive Hispaniolan parrots (Amazona ventralis) with known genetic relationships. This would form the data base to examine DNA fingerprints of the closely related and endangered Puerto Rican parrot (A. vittata) and to estimate the degree of inbreeding in the relic population. We found by segregation analysis of the bands scored in the DNA fingerprints of the Hispaniolan parrots that there may be as few as two to five loci identified by the human 33.15 probe. Furthermore, at one locus we identified seven alleles, one of which is represented by as many as 19 cosegregating bands. It is unknown how common multiband alleles might be in natural populations, and their existence will cause problems in the assessment of relatedness by band-sharing analysis. We believe, therefore, that a pedigree analysis should be included in all DNA fingerprinting studies, where possible, in order to estimate the number of loci identified by a minisatellite DNA probe and to examine the nature of their alleles.

  13. Tissue-specific patterns of allelically-skewed DNA methylation

    Science.gov (United States)

    Marzi, Sarah J.; Meaburn, Emma L.; Dempster, Emma L.; Lunnon, Katie; Paya-Cano, Jose L.; Smith, Rebecca G.; Volta, Manuela; Troakes, Claire; Schalkwyk, Leonard C.; Mill, Jonathan

    2016-01-01

    ABSTRACT While DNA methylation is usually thought to be symmetrical across both alleles, there are some notable exceptions. Genomic imprinting and X chromosome inactivation are two well-studied sources of allele-specific methylation (ASM), but recent research has indicated a more complex pattern in which genotypic variation can be associated with allelically-skewed DNA methylation in cis. Given the known heterogeneity of DNA methylation across tissues and cell types we explored inter- and intra-individual variation in ASM across several regions of the human brain and whole blood from multiple individuals. Consistent with previous studies, we find widespread ASM with > 4% of the ∼220,000 loci interrogated showing evidence of allelically-skewed DNA methylation. We identify ASM flanking known imprinted regions, and show that ASM sites are enriched in DNase I hypersensitivity sites and often located in an extended genomic context of intermediate DNA methylation. We also detect examples of genotype-driven ASM, some of which are tissue-specific. These findings contribute to our understanding of the nature of differential DNA methylation across tissues and have important implications for genetic studies of complex disease. As a resource to the community, ASM patterns across each of the tissues studied are available in a searchable online database: http://epigenetics.essex.ac.uk/ASMBrainBlood. PMID:26786711

  14. Distribution of forensic marker allelic frequencies in Pernambuco, Northestern Brazil.

    Science.gov (United States)

    Santos, S M; Souza, C A; Rabelo, K C N; Souza, P R E; Moura, R R; Oliveira, T C; Crovella, S

    2015-01-01

    Pernambuco is one of the 27 federal units of Brazil, ranking seventh in the number of inhabitants. We examined the allele frequencies of 13 short tandem repeat loci (CFS1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, TH01, vWA, and TPOX), the minimum recommended by the Federal Bureau of Investigation and commonly used in forensic genetics laboratories in Brazil, in a sample of 609 unrelated individuals from all geographic regions of Pernambuco. The allele frequencies ranged from 5 to 47.2%. No significant differences for any loci analyzed were observed compared with other publications in other various regions of Brazil. Most of the markers observed were in Hardy-Weinberg equilibrium. The occurrence of the allele 47.2 (locus FGA) and alleles 35.1 and 39 (locus D21S11), also described in a single study of the Brazilian population, was observed. The other forensic parameters analyzed (matching probability, power of discrimination, polymorphic information content, paternity exclusion, complement factor I, observed heterozygosity, expected heterozygosity) indicated that the studied markers are very informative for human forensic identification purposes in the Pernambuco population. PMID:25966202

  15. Estimating the age of alleles by use of intraallelic variability

    Energy Technology Data Exchange (ETDEWEB)

    Slatkin, M.; Rannala, B. [Univ of California, Berkeley, CA (United States)

    1997-02-01

    A method is presented for estimating the age of an allele by use of its frequency and the extent of variation among different copies. The method uses the joint distribution of the number of copies in a population sample and the coalescence times of the intraallelic gene genealogy conditioned on the number of copies. The linear birth-death process is used to approximate the dynamics of a rare allele in a finite population. A maximum-likelihood estimate of the age of the allele is obtained by Monte Carlo integration over the coalescence times. The method is applied to two alleles at the cystic fibrosis (CFTR) locus, {Delta}F508 and G542X, for which intraallelic variability at three intronic microsatellite loci has been examined. Our results indicate that G542X is somewhat older than {Delta}F508. Although absolute estimates depend on the mutation rates at the microsatellite loci, our results support the hypothesis that {Delta}F508 arose <500 generations ({approx}10,000 years) ago. 32 refs., 4 figs.

  16. Disease-Causing Allele-Specific Silencing by RNA Interference

    Directory of Open Access Journals (Sweden)

    Hirohiko Hohjoh

    2013-04-01

    Full Text Available Small double-stranded RNAs (dsRNAs of approximately 21-nucleotides in size, referred to as small interfering RNA (siRNA duplexes, can induce sequence-specific posttranscriptional gene silencing, or RNA interference (RNAi. Since chemically synthesized siRNA duplexes were found to induce RNAi in mammalian cells, RNAi has become a powerful reverse genetic tool for suppressing the expression of a gene of interest in mammals, including human, and its application has been expanding to various fields. Recent studies further suggest that synthetic siRNA duplexes have the potential for specifically inhibiting the expression of an allele of interest without suppressing the expression of other alleles, i.e., siRNA duplexes likely confer allele-specific silencing. Such gene silencing by RNAi is an advanced technique with very promising applications. In this review, I would like to discuss the potential utility of allele-specific silencing by RNAi as a therapeutic method for dominantly inherited diseases, and describe possible improvements in siRNA duplexes for enhancing their efficacy.

  17. Short mucin 6 alleles are associated with H pylori infection

    Institute of Scientific and Technical Information of China (English)

    Thai V Nguyen; Marcel JR Janssen; Paulien Gritters; René HM te Morsche; Joost PH Drenth; Henri van Asten; Robert JF Laheij; Jan BMJ Jansen

    2006-01-01

    AIM: To investigate the relationship between mucin 6(MUC6) VNTR length and H pylori infection.METHODS: Blood samples were collected from patients visiting the Can Tho General Hospital for upper gastrointestinal endoscopy. DNA was isolated from whole blood, the repeated section was cut out using a restriction enzyme (Pvu Ⅱ) and the length of the allele fragments was determined by Southern blotting. H pylori infection was diagnosed by 14C urea breath test. For analysis, MUC6 allele fragment length was dichotomized as being either long (> 13.5 kbp) or short (≤ 13.5 kbp)and patients were classified according to genotype [long-long (LL), long-short (LS), short-short (SS)].RESULTS: 160 patients were studied (mean age 43years, 36% were males, 58% H pylori positive). MUC6Pvu Ⅱ-restricted allele fragment lengths ranged from 7 to 19 kbp. Of the patients with the LL, LS, SS MUC6genotype, 43% (24/56), 57% (25/58) and 76% (11/46)were infected with H pylori, respectively (P = 0.003).CONCLUSION: Short MUC6 alleles are associated with H pylori infection.

  18. Impact of autoimmune risk alleles on the immune system

    OpenAIRE

    Ray, John P.; Hacohen, Nir

    2015-01-01

    Genetic analyses of autoimmune diseases have revealed hundreds of disease-associated DNA variants, but the identity and function of the causal variants are understudied and warrant deeper mechanistic studies. Here, we highlight methods for deciphering how alleles that are associated with autoimmune disease alter the human immune system, and suggest strategies for future autoimmune genetic research.

  19. Effect of injectable trace minerals on the humoral immune response to multivalent vaccine administration in beef calves.

    Science.gov (United States)

    Arthington, J D; Havenga, L J

    2012-06-01

    The objective of this experiment was to investigate the effects of injectable trace minerals on humoral responses of calves receiving a viral vaccination. Beef steer calves (n = 99; average BW = 316 ± 4.2 kg), seronegative for bovine herpesvirus-1 (BHV-1) and bovine viral diarrhea virus, genotypes 1 and 2 (BVDV-1 and BVDV-2), were sourced from 2 locations. All calves, except 15 non-vaccinated (sentinel) calves, received a single dose of a multivalent modified live vaccine (Titanium 5; AgriLabs, St. Joseph, MO) containing BHV-1, BVDV-1, BVDV-2, bovine parainfluenza virus type 3, and bovine respiratory syncytial virus. Among the vaccinated calves, 2 treatments were concurrently and randomly applied on the basis of initial serum Se status and BW, including 1) injectable trace mineral supplement (ITM; n = 42; 7 mL subcutaneous.; MultiMin, Fort Collins, CO) containing 15, 40, 10, and 5 mg/mL of Cu, Zn, Mn (all as disodium EDTA salts), and Se (as Na selenite) or 2) saline-injected control (Control; n = 42). As a measure of humoral immunity, neutralizing antibody titers were measured on d 0, 14, 30, 60, and 90, relative to vaccine administration. All calves were seronegative for each of the 3 viruses on d 0, and sentinel calves remained seronegative throughout the study. Serum mineral concentrations were evaluated on d 0 and 14. No differences (P ≥ 0.30) in serum Cu, Zn, Mn, or Se were observed between treatments on d 0. Control steers experienced a decrease (P < 0.001) in serum Zn and Se, and ITM steers had an increase (P = 0.007) in serum Cu on d 14 relative to initial d 0 values. On d 14, serum Zn and Se concentrations were greater (P < 0.01) in ITM compared with Control steers. Vaccinated calves experienced marked increases in neutralizing antibody titers by d 30 following vaccine administration. Calves receiving ITM at the time of vaccination experienced greater (P ≤ 0.003) neutralizing antibody titers to BHV-1 on d 14, 30, and 60 compared with Control. These

  20. Allelic divergence and cultivar-specific SSR alleles revealed by capillary electrophoresis using fluorescence-labeled SSR markers in sugarcane

    Science.gov (United States)

    Though sugarcane cultivars (Saccharum spp. hybrids) are complex aneu-polyploid hybrids, genetic evaluation and tracking of clone- or cultivar-specific alleles become possible due to capillary electrophoregrams (CE) using fluorescence-labeled SSR primer pairs. Twenty-four sugarcane cultivars, 12 each...

  1. KIR2DL2/2DL3-E35 alleles are functionally stronger than -Q35 alleles

    Science.gov (United States)

    Bari, Rafijul; Thapa, Rajoo; Bao, Ju; Li, Ying; Zheng, Jie; Leung, Wing

    2016-03-01

    KIR2DL2 and KIR2DL3 segregate as alleles of a single locus in the centromeric motif of the killer cell immunoglobulin-like receptor (KIR) gene family. Although KIR2DL2/L3 polymorphism is known to be associated with many human diseases and is an important factor for donor selection in allogeneic hematopoietic stem cell transplantation, the molecular determinant of functional diversity among various alleles is unclear. In this study we found that KIR2DL2/L3 with glutamic acid at position 35 (E35) are functionally stronger than those with glutamine at the same position (Q35). Cytotoxicity assay showed that NK cells from HLA-C1 positive donors with KIR2DL2/L3-E35 could kill more target cells lacking their ligands than NK cells with the weaker -Q35 alleles, indicating better licensing of KIR2DL2/L3+ NK cells with the stronger alleles. Molecular modeling analysis reveals that the glutamic acid, which is negatively charged, interacts with positively charged histidine located at position 55, thereby stabilizing KIR2DL2/L3 dimer and reducing entropy loss when KIR2DL2/3 binds to HLA-C ligand. The results of this study will be important for future studies of KIR2DL2/L3-associated diseases as well as for donor selection in allogeneic stem cell transplantation.

  2. Mannose-binding lectin variant alleles and HLA-DR4 alleles are associated with giant cell arteritis

    DEFF Research Database (Denmark)

    Jacobsen, Soren; Baslund, Bo; Madsen, Hans Ole;

    2002-01-01

    To determine whether variant alleles of the mannose-binding lectin (MBL) gene causing low serum concentrations of MBL and/or polymorphisms of HLA-DRB1 are associated with increased susceptibility to polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) or particular clinical phenotypes of PMR/GCA....

  3. The administration of a single dose of a multivalent (DHPPiL4R vaccine prevents clinical signs and mortality following virulent challenge with canine distemper virus, canine adenovirus or canine parvovirus

    Directory of Open Access Journals (Sweden)

    Stephen Wilson

    2014-01-01

    In conclusion, we demonstrated that a single administration of a minimum titre, multivalent vaccine to dogs of six weeks of age is efficacious and prevents clinical signs and mortality caused by CAV-1 and CDV; prevents clinical signs and significantly reduces virus shedding caused by CAV-2; and prevents clinical signs, leucopoenia and viral excretion caused by CPV.

  4. Early allelic selection in maize as revealed by ancient DNA.

    Science.gov (United States)

    Jaenicke-Després, Viviane; Buckler, Ed S; Smith, Bruce D; Gilbert, M Thomas P; Cooper, Alan; Doebley, John; Pääbo, Svante

    2003-11-14

    Maize was domesticated from teosinte, a wild grass, by approximately 6300 years ago in Mexico. After initial domestication, early farmers continued to select for advantageous morphological and biochemical traits in this important crop. However, the timing and sequence of character selection are, thus far, known only for morphological features discernible in corn cobs. We have analyzed three genes involved in the control of plant architecture, storage protein synthesis, and starch production from archaeological maize samples from Mexico and the southwestern United States. The results reveal that the alleles typical of contemporary maize were present in Mexican maize by 4400 years ago. However, as recently as 2000 years ago, allelic selection at one of the genes may not yet have been complete. PMID:14615538

  5. Generating Novel Allelic Variation Through Activator Insertional Mutagenesis in Maize

    OpenAIRE

    Bai, Ling; Singh, Manjit; Pitt, Lauren; Sweeney, Meredith; Brutnell, Thomas P.

    2007-01-01

    The maize transposable element Activator (Ac) has been exploited as an insertional mutagen to disrupt, clone, and characterize genes in a number of plant species. To develop an Ac-based mutagenesis platform for maize, a large-scale mutagenesis was conducted targeting the pink scutellum1 locus. We selected 1092 Ac transposition events from a closely linked donor Ac, resulting in the recovery of 17 novel ps1 alleles. Multiple phenotypic classes were identified corresponding to Ac insertions in ...

  6. Allele-selective inhibition of trinucleotide repeat genes

    OpenAIRE

    Matsui, Masayuki; Corey, David R.

    2012-01-01

    Expanded trinucleotide repeats cause Huntington’s disease (HD) and many other neurodegenerative disorders. There are no cures for these devastating illnesses and treatments are urgently needed. Each trinucleotide repeat disorder is the result of the mutation of just one gene, and agents that block expression of the mutant gene offer a promising option for treatment. Therapies that block expression of both mutant and wild-type alleles can have adverse effects, challenging researchers to develo...

  7. Multiplex allele-specific target amplification based on PCR suppression

    OpenAIRE

    Broude, Natalia E.; Zhang, Lingang; Woodward, Karen; Englert, David; Cantor, Charles R.

    2001-01-01

    We have developed a strategy for multiplex PCR based on PCR suppression. PCR suppression allows DNA target amplification with only one sequence-specific primer per target and a second primer that is common for all targets. Therefore, an n-plex PCR would require only n + 1 primers. We have demonstrated uniform, efficient amplification of targeted sequences in 14-plex PCR. The high specificity of suppression PCR also provides multiplexed amplification with allele specifi...

  8. Effect of wheat puroindoline alleles on functional properties of starch

    OpenAIRE

    Brites, Carla Moita; Santos, Carla Alexandra Lourenço; Bagulho, Ana Sofia; Beirão-da-Costa, Maria Luisa

    2008-01-01

    Puroindoline a and b (Pina, Pinb) form the molecular basis of bread wheat grain hardness. Varieties with a softer endosperm and a wild genotype, in which both Pina and Pinb were present, seemed to produce less damaged starch Xour than hard varieties, where Pin mutations occurred and changed the starch rheological properties. The functional property of starch samples extracted from wheat varieties with diVerent Pin alleles was evaluated. Starch morphology was characteri...

  9. Allelic diversity of the population of Phytophthora infestans in China

    OpenAIRE

    Li, Y; Huang, S.; Lee; Kessel, G.J.T.; Jacobsen, E.; Zhang, R.; Jin, G.; Lan, C.; Zhao, Z.; Kamoun, S

    2009-01-01

    Introduction of resistance genes from wild Solanum species into potato cultivars is considered the most promising and environmentally safe approach to achieve late blight resistance. An R-gene stacking breeding program using cisgenesis is planning to trial its products in China. To adapt this approach to local conditions, we propose to assess the allelic diversity of known avirulent genes of P. infestans from the intended introduction regions of the GM-potatoes in China. So far, we have a lar...

  10. Allele-Specific DNA Methylation Detection by Pyrosequencing®

    DEFF Research Database (Denmark)

    Sommer Kristensen, Lasse; Johansen, Jens Vilstrup; Grønbæk, Kirsten

    2015-01-01

    DNA methylation is an epigenetic modification that plays important roles in healthy as well as diseased cells, by influencing the transcription of genes. In spite the fact that human somatic cells are diploid, most of the currently available methods for the study of DNA methylation do not provide......-effective protocol for allele-specific DNA methylation detection based on Pyrosequencing(®) of methylation-specific PCR (MSP) products including a single nucleotide polymorphism (SNP) within the amplicon....

  11. Multimer Formation Explains Allelic Suppression of PRDM9 Recombination Hotspots

    Czech Academy of Sciences Publication Activity Database

    Baker, C.L.; Petkova, P.; Walker, M.; Flachs, Petr; Mihola, Ondřej; Trachtulec, Zdeněk; Petkov, P.M.; Paigen, K.

    2015-01-01

    Roč. 11, č. 9 (2015), e1005512-e1005512. ISSN 1553-7390 R&D Projects: GA ČR GAP305/10/1931; GA ČR(CZ) GA14-20728S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : recombination * PRDM9 * allelic competition Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.528, year: 2014

  12. Demographic history and rare allele sharing among human populations

    OpenAIRE

    Henn, Brenna M.; Indap, Amit R.; Donnelly, Peter; Nickerson, Debbie A.; Peltonen, Leena; Deiros, David; Metzker, Mike; Li, Jingxiang; Jian, Min; Liang, Huiqing; Tian, Geng; Wang, Bo; Wang, Wei; Zhang, Xiuqing; Zheng, Huisong

    2011-01-01

    High-throughput sequencing technology enables population-level surveys of human genomic variation. Here, we examine the joint allele frequency distributions across continental human populations and present an approach for combining complementary aspects of whole-genome, low-coverage data and targeted high-coverage data. We apply this approach to data generated by the pilot phase of the Thousand Genomes Project, including whole-genome 2–4× coverage data for 179 samples from HapMap European, As...

  13. Gene identification and allele-specific marker development for two allelic low phytic acid mutations in rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate) is an important anti-nutritional component in cereal and legume grains. PA forms of phosphorus (P) and its salts with micronutrient cations, such as iron and zinc, are indigestible in humans and non-ruminant animals, and hence could affect food/feed nutritional value and cause P pollution of ground water from animal waste. We previously developed a set of low phytic acid (LPA) rice mutants with the aim to increase their nutritional quality. Among them, one line, i.e., Os-lpa -XQZ-1 (hereafter lpa 1-2), was identified to have a mutation allelic to the KBNT lpa 1-1 mutation (hereafter lpa 1-1), which was already delimited to a 47-kb region on chromosome 2. In this study, we searched the candidate gene for these two allelic LPA mutations using T-DNA insertion mutants, mutation detection by CEL I facilitated mismatch cleavage, and gene sequencing. The TIGR locus LOCOs02g57400 was revealed as the candidate gene hosting these two mutations. Sequence analysis showed that the lpa 1-1 is a single base pair substitution mutation, while lpa 1-2 involves a 1,475-bp fragment deletion. A CAPS marker (LPA1CAPS) was developed for distinguishing the lpa 1-1 allele from lpa 1-2 and WT alleles, and InDel marker (LPA1InDel) was developed for differentiating the lpa 1-2 allele from lpa 1-1 and WT ones. Analysis of two populations derived from the two mutants with wild-type varieties confirmed the complete co-segregation of these two markers and LPA phenotype. The LOCOs02g57400 is predicted to encode, through alternative splicing, four possible proteins that are homologous to the 2-phosphoglycerate kinase reported in hyperthermophilic and thermophilic bacteria. The identification of the LPA gene and development of allele-specific markers are of importance not only for breeding LPA varieties, but also for advancing genetics and genomics of phytic acid biosynthesis in rice and other plant species. (author)

  14. Tracing pastoralist migrations to southern Africa with lactase persistence alleles.

    Science.gov (United States)

    Macholdt, Enrico; Lede, Vera; Barbieri, Chiara; Mpoloka, Sununguko W; Chen, Hua; Slatkin, Montgomery; Pakendorf, Brigitte; Stoneking, Mark

    2014-04-14

    Although southern African Khoisan populations are often assumed to have remained largely isolated during prehistory, there is growing evidence for a migration of pastoralists from eastern Africa some 2,000 years ago, prior to the arrival of Bantu-speaking populations in southern Africa. Eastern Africa harbors distinctive lactase persistence (LP) alleles, and therefore LP alleles in southern African populations may be derived from this eastern African pastoralist migration. We sequenced the lactase enhancer region in 457 individuals from 18 Khoisan and seven Bantu-speaking groups from Botswana, Namibia, and Zambia and additionally genotyped four short tandem repeat (STR) loci that flank the lactase enhancer region. We found nine single-nucleotide polymorphisms, of which the most frequent is -14010(∗)C, which was previously found to be associated with LP in Kenya and Tanzania and to exhibit a strong signal of positive selection. This allele occurs in significantly higher frequency in pastoralist groups and in Khoe-speaking groups in our study, supporting the hypothesis of a migration of eastern African pastoralists that was primarily associated with Khoe speakers. Moreover, we find a signal of ongoing positive selection in all three pastoralist groups in our study, as well as (surprisingly) in two foraging groups. PMID:24704073

  15. The protease inhibitor PI*S allele and COPD

    DEFF Research Database (Denmark)

    Hersh, C P; Ly, N P; Berkey, C S; Silverman, E K; Nordestgaard, B G; Dahl, Morten; Dahl, M

    2005-01-01

    In many countries, the protease inhibitor (SERPINA1) PI*S allele is more common than PI*Z, the allele responsible for most cases of chronic obstructive pulmonary disease (COPD) due to severe alpha 1-antitrypsin deficiency. However, the risk of COPD due to the PI*S allele is not clear. The current...... authors located studies that addressed the risk of COPD or measured lung function in individuals with the PI SZ, PI MS and PI SS genotypes. A separate meta-analysis for each genotype was performed. Aggregating data from six studies, the odds ratio (OR) for COPD in PI SZ compound heterozygotes compared...... with PI MM (normal) individuals was significantly increased at 3.26 (95% confidence intervals (CI): 1.24-8.57). In 17 cross-sectional and case-control studies, the OR for COPD in PI MS heterozygotes was 1.19 (95%CI: 1.02-1.38). However, PI MS genotype was not associated with COPD risk after correcting...

  16. HLA- DR Alleles in Pakistani Patients of Pemphigus Vulgaris

    International Nuclear Information System (INIS)

    Objective: To determine frequency of HLA-DR alleles in Pakistani patients of pemphigus vulgaris in comparison with local healthy controls. Study Design: Cross-sectional, comparative study. Place and Duration of Study: Department of Immunology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from January 2011 to January 2014. Methodology: Twenty eight patients with biopsy proven diagnosis of pemphigus vulgaris referred from Department of Dermatology, Military Hospital, Rawalpindi were included. Patients were compared with a group of 150 unrelated local healthy subjects. DNA was extracted from peripheral blood collected in Tri-potassium EDTA. HLA-DRB1 typing was carried out on allele level (DRB1*01 - DRB1*16) using SSP (sequence specific primers). HLA type was determined by agarose gel electrophoresis and results recorded. Phenotype frequency of various alleles among patient group and control group was calculated by direct counting and significance of their association was determined by Fisher's exact test/ Chi square test. Results: A total of 12 male and 16 female patients, with age ranging from 21 to 34 (mean 23.4 years) were genotype for HLA-DRB1 loci. A statistically significant association of the disease with HLA-DRB1*04 was observed (50% versus 20.7% in controls, p < 0.05). Conclusion: There is a strong association of HLA-DRB1*04 with pemphigus vulgaris in Pakistani population. (author)

  17. Sporadic inclusion body myositis: HLA-DRB1 allele interactions influence disease risk and clinical phenotype.

    Science.gov (United States)

    Mastaglia, Frank L; Needham, Merrilee; Scott, Adrian; James, Ian; Zilko, Paul; Day, Timothy; Kiers, Lynette; Corbett, Alastair; Witt, Campbell S; Allcock, Richard; Laing, Nigel; Garlepp, Michael; Christiansen, Frank T

    2009-11-01

    Susceptibility to sIBM is strongly associated with the HLA-DRB1*03 allele and the 8.1 MHC ancestral haplotype (HLA-A1, B8, DRB1*03) but little is known about the effects of allelic interactions at the DRB1 locus or disease-modifying effects of HLA alleles. HLA-A, B and DRB1 genotyping was performed in 80 Australian sIBM cases and the frequencies of different alleles and allele combinations were compared with those in a group of 190 healthy controls. Genotype-phenotype correlations were also investigated. Amongst carriers of the HLA-DRB1*03 allele, DRB1*03/*01 heterozygotes were over-represented in the sIBM group (pHLA-DRB1*03 allele and other alleles at the DRB1 locus can influence disease susceptibility and the clinical phenotype in sIBM. PMID:19720533

  18. HLA Dr beta 1 alleles in Pakistani patients with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Objective: To determine frequencies of HLA DR beta 1 alleles in rheumatoid arthritis in Pakistani patients. Study Design: Cross sectional / analytical study. Place and Duration of Study: Department of Immunology, Armed Forces Institute of Pathology, Rawalpindi in collaboration with Rheumatology departments of Military Hospital, Rawalpindi and Fauji Foundation Hospital, Rawalpindi, from January 2009 to January 2010. Methodology: HLA DR beta 1 genotyping of one hundred Pakistani patients, diagnosed as having RA as per American College of Rheumatology revised criteria 1987, was done. HLA DR beta 1 genotyping was carried out at allele group level (DR beta 1*01-DR beta 1*16) by sequence specific primers in RA patients. Comparison of HLA DR beta 1 allele frequencies between patients and control groups was made using Pearson's chi-square test to find possible association of HLA DR?1 alleles with RA in Pakistani rheumatoid patients. Results: HLA DR beta 1*04 was expressed with significantly increased frequency in patients with rheumatoid arthritis (p <0.05). HLA DR?1*11 was expressed statistically significantly more in control group as compared to rheumatoid patients indicating a possible protective effect. There was no statistically significant difference observed in frequencies of HLA DR beta 1 allele *01, DR beta 1 allele *03, DR beta 1 allele *07, DR beta 1 allele *08, DR beta 1 allele *09, DR beta 1 allele *10, DR beta 1 allele *12, DR beta 1 allele *13, DR beta 1 allele *14, DR?1 allele *15 and DR beta 1 allele *16 between patients and control groups. Conclusion: The identification of susceptible HLA DR beta 1 alleles in Pakistani RA patients may help physicians to make early decisions regarding initiation of early intensive therapy with disease modifying anti rheumatic medicines and biological agents decreasing disability in RA patients. (author)

  19. Conditional Allele Mouse Planner (CAMP): software to facilitate the planning and design of breeding strategies involving mice with conditional alleles.

    Science.gov (United States)

    Hoffert, Jason D; Pisitkun, Trairak; Miller, R Lance

    2012-06-01

    Transgenic and conditional knockout mouse models play an important role in biomedical research and their use has grown exponentially in the last 5-10 years. Generating conditional knockouts often requires breeding multiple alleles onto the background of a single mouse or group of mice. Breeding these mice depends on parental genotype, litter size, transmission frequency, and the number of breeding rounds. Therefore, a well planned breeding strategy is critical for keeping costs to a minimum. However, designing a viable breeding strategy can be challenging. With so many different variables this would be an ideal task for a computer program. To facilitate this process, we created a Java-based program called Conditional Allele Mouse Planner (CAMP). CAMP is designed to provide an estimate of the number of breeders, amount of time, and costs associated with generating mice of a particular genotype. We provide a description of CAMP, how to use it, and offer it freely as an application. PMID:21870117

  20. Induction of protective anti-CTL epitope responses against HER-2-positive breast cancer based on multivalent T7 phage nanoparticles.

    Directory of Open Access Journals (Sweden)

    Somayeh Pouyanfard

    Full Text Available We report here the development of multivalent T7 bacteriophage nanoparticles displaying an immunodominant H-2k(d-restricted CTL epitope derived from the rat HER2/neu oncoprotein. The immunotherapeutic potential of the chimeric T7 nanoparticles as anti-cancer vaccine was investigated in BALB/c mice in an implantable breast tumor model. The results showed that T7 phage nanoparticles confer a high immunogenicity to the HER-2-derived minimal CTL epitope, as shown by inducing robust CTL responses. Furthermore, the chimeric nanoparticles protected mice against HER-2-positive tumor challenge in both prophylactic and therapeutic setting. In conclusion, these results suggest that CTL epitope-carrying T7 phage nanoparticles might be a promising approach for development of T cell epitope-based cancer vaccines.

  1. Thermodynamics of Binary and Ternary Solutions of Multivalent Electrolytes with Formation of 1: 1 and 1: 2 Complexes, within the Mean Spherical Approximation

    International Nuclear Information System (INIS)

    The mean activity (γ±) and osmotic (Φ) coefficients for binary and ternary aqueous solutions of trivalent electrolytes (mainly made up of lanthanide salts) are described in the framework of the primitive model of ionic solutions, using the binding mean spherical approximation (BiMSA). This model, based on the Wertheim formalism, accounts for (chemical or electrostatic) association of ions. In this work, the multivalent cation and the anion are allowed to form 1: 1 (pairs) and 1: 2 (trimers) complexes. Expressions for γ±) and Φ are given which satisfy the Gibbs-Duhem relation. The model involves concentration-dependent cation size and effective relative permittivity, variations that can be interpreted in terms of solvent effects. The theory is applied to aqueous solutions of binary and ternary mixtures at 25 C with common anion. (authors)

  2. Multivalency in the gas phase: H/D exchange reactions unravel the dynamic "rock 'n' roll" motion in dendrimer-dendrimer complexes.

    Science.gov (United States)

    Qi, Zhenhui; Schlaich, Christoph; Schalley, Christoph A

    2013-10-25

    Noncovalent dendrimer-dendrimer complexes were successfully ionized by electrospray ionization of partly protonated amino-terminated polypropylene amine (POPAM) and POPAM dendrimers fully functionalized with benzo[21]crown-7 on all branches. Hydrogen/deuterium exchange (HDX) experiments conducted on dendrimer-dendrimer complexes in the high vacuum of a mass spectrometer give rise to a complete exchange of all labile NH hydrogen atoms. As crown ethers represent noncovalent protective groups against HDX reactions on the ammonium group to which they are coordinated, this result provides evidence for a very dynamic binding situation: each crown is mobile enough to move from one ammonium binding site to another. Schematically, one might compare this motion with two rock 'n' roll dancers that swirl around each other without completely losing all contact at any time. Although the multivalent attachment certainly increases the overall affinity, the "microdynamics" of individual site binding and dissociation remains fast. PMID:24105808

  3. Novel method for analysis of allele specific expression in triploid Oryzias latipes reveals consistent pattern of allele exclusion.

    Directory of Open Access Journals (Sweden)

    Tzintzuni I Garcia

    Full Text Available Assessing allele-specific gene expression (ASE on a large scale continues to be a technically challenging problem. Certain biological phenomena, such as X chromosome inactivation and parental imprinting, affect ASE most drastically by completely shutting down the expression of a whole set of alleles. Other more subtle effects on ASE are likely to be much more complex and dependent on the genetic environment and are perhaps more important to understand since they may be responsible for a significant amount of biological diversity. Tools to assess ASE in a diploid biological system are becoming more reliable. Non-diploid systems are, however, not uncommon. In humans full or partial polyploid states are regularly found in both healthy (meiotic cells, polynucleated cell types and diseased tissues (trisomies, non-disjunction events, cancerous tissues. In this work we have studied ASE in the medaka fish model system. We have developed a method for determining ASE in polyploid organisms from RNAseq data and we have implemented this method in a software tool set. As a biological model system we have used nuclear transplantation to experimentally produce artificial triploid medaka composed of three different haplomes. We measured ASE in RNA isolated from the livers of two adult, triploid medaka fish that showed a high degree of similarity. The majority of genes examined (82% shared expression more or less evenly among the three alleles in both triploids. The rest of the genes (18% displayed a wide range of ASE levels. Interestingly the majority of genes (78% displayed generally consistent ASE levels in both triploid individuals. A large contingent of these genes had the same allele entirely suppressed in both triploids. When viewed in a chromosomal context, it is revealed that these genes are from large sections of 4 chromosomes and may be indicative of some broad scale suppression of gene expression.

  4. A high-throughput method for genotyping S-RNase alleles in apple

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian; Toldam-Andersen, Torben Bo; Pedersen, Carsten

    2016-01-01

    We present a new efficient screening tool for detection of S-alleles in apple. The protocol using general and multiplexed primers for PCR reaction and fragment detection on an automatized capillary DNA sequencer exposed a higher number of alleles than any previous studies. Analysis of alleles is...

  5. Electrical transport and EPR investigations: A comparative study for d.c. conduction mechanism in monovalent and multivalent ions doped polyaniline

    Indian Academy of Sciences (India)

    Suresh Kumar Gupta; Vandna Luthra; Ramadhar Singh

    2012-10-01

    A detailed comparative study of electron paramagnetic resonance (EPR) in conjunction with d.c. electrical conductivity has been undertaken to know about the charge transport mechanism in polyaniline (PANI) doped with monovalent and multivalent protonic acids. This work is in continuation of our previous work for further understanding the conduction mechanism in conducting polymers. The results reveal that the polarons and bipolarons are the main charge carriers formed during doping process and these cause increase in electrical conductivity not only by increase in their concentration but also because of their enhanced mobility due to increased inter-chain transport in polyaniline at high doping levels. EPR line asymmetry having Dysonian line shape for highly doped samples shows a marked deviation of amplitudes / ratio from values close to one to much high values as usually observed in metals, thereby support the idea of high conductivity at higher doping levels. The nature of dopant ions and their doping levels control the charge carriers concentration as well as electrical conductivity of polyaniline. The electrical conductivity has also been studied as a function of temperature to know the thermally assisted transport process of these charge carriers at different doping levels which has been found to follow the Mott’s variable range hopping (VRH) conduction model for all the three dopants used. The charge carriers show a change over from 3D VRH to quasi 1D VRH hopping process for multivalent ions at higher doping levels whereas 1D VRH has been followed by monovalent ion for full doping range. These studies collectively give evidence of inter-chain percolation at higher doping levels causing increase in effective mobility of the charge carriers which mainly seems to govern the electrical conduction behaviour in this system.

  6. Studies on recombination between allele in the ml-o locus of barley and on pleiotropic effects of the alleles

    International Nuclear Information System (INIS)

    Five independently arisen genes, which are functionally allelic in the m1-o locus and conditioning resistance to the powdery mildew fungus, were tested for structural allelism by recombination. Two heteroallelic crosses produced susceptible recombinants in F2 with a frequency of 8.6 and 2.0 x 10-4, respectively, showing that m1-o 1 is structurally non-allelic to m1-o 5 and to m1-o 9. Homozygous resistant populations derived from crossing different m1-o resistant barleys with susceptible varieties were exposed to two successive cycles of selection against necrotic leaf spotting. Field experiments with selected F5 lines and their parents showed that the m1-o resistant parents differed in severity of spotting, and that the spotting can be reduced or eliminated by crossing and subsequent selection. It appears that a reduction in the necrotic leaf spotting is accopanied by an increase in grain yield. Two new experiments designed to further elucidate the interallelic recombination in m1-o and the pleiotropic effects are briefly described. (author)

  7. Expression and loss of alleles in cultured mouse embryonic fibroblasts and stem cells carrying allelic fluorescent protein genes

    Directory of Open Access Journals (Sweden)

    Stringer Saundra L

    2006-10-01

    Full Text Available Abstract Background Loss of heterozygosity (LOH contributes to many cancers, but the rate at which these events occur in normal cells of the body is not clear. LOH would be detectable in diverse cell types in the body if this event were to confer an obvious cellular phenotype. Mice that carry two different fluorescent protein genes as alleles of a locus would seem to be a useful tool for addressing this issue because LOH would change a cell's phenotype from dichromatic to monochromatic. In addition, LOH caused by mitotic crossing over might be discernable in tissues because this event produces a pair of neighboring monochromatic cells that are different colors. Results As a step in assessing the utility of this approach, we derived primary embryonic fibroblast populations and embryonic stem cell lines from mice that carried two different fluorescent protein genes as alleles at the chromosome 6 locus, ROSA26. Fluorescence activated cell sorting (FACS showed that the vast majority of cells in each line expressed the two marker proteins at similar levels, and that populations exhibited expression noise similar to that seen in bacteria and yeast. Cells with a monochromatic phenotype were present at frequencies on the order of 10-4 and appeared to be produced at a rate of approximately 10-5 variant cells per mitosis. 45 of 45 stably monochromatic ES cell clones exhibited loss of the expected allele at the ROSA26 locus. More than half of these clones retained heterozygosity at a locus between ROSA26 and the centromere. Other clones exhibited LOH near the centromere, but were disomic for chromosome 6. Conclusion Allelic fluorescent markers allowed LOH at the ROSA26 locus to be detected by FACS. LOH at this locus was usually not accompanied by LOH near the centromere, suggesting that mitotic recombination was the major cause of ROSA26 LOH. Dichromatic mouse embryonic cells provide a novel system for studying genetic/karyotypic stability and factors

  8. HLA-DR alleles among Pakistani patients of coeliac disease

    International Nuclear Information System (INIS)

    Objectives: To investigate whether certain DR alleles might also contribute to the genetic susceptibility among Coeliac disease patients in Pakistan. Methods: The case-control study was conducted at the Military Hospital, Rawalpindi, from October 2011 to January 2012, and analysed 25 children diagnosed to have coeliac disease as per the criteria set by the European Society of Paediatric Gastroenterology and Nutrition, which included histopathological alterations in duodenal biopsies, clinical response to gluten withdrawal, and presence of anti-endomyseal antibodies. Patients were compared with a group of 150 healthy subjects. Dioxyribonucleic acid was extracted from peripheral blood collected in ethylenediaminetetraacetic acid.K3. Human leukocyte antigen DRB1 typing was carried out on allele level (DRB1*01 - DRB1*16) using sequence specific primers. Human leukocyte antigen type was determined by agarose gel electrophoresis and results were recorded. Phenotype frequency of various alleles among the patient group and the control group was calculated by direct counting, and significance of their association was determined by Fisher Exact Test. Results: A total of 11 (44%) female paediatric coeliac patients in age range 1-9 (mean 7.2+-4.8 years) and 14 (56%) male paediatric patients in the age range 6-14 (mean 8.6+-5.1 years) were genotyped for HLA-DRB1 loci. A statistically significant positive association of the disease with HLA-DRB1*03 (n=23; 92% versus n=31; 21% in controls, p <0.01) was observed. Conclusion: HLA-DRB1*03 is associated with increased risk of developing coeliac disease. (author)

  9. Modulation of allele leakiness and adaptive mutability in Escherichia coli

    Indian Academy of Sciences (India)

    R. Jayaraman

    2000-08-01

    It is shown that partial phenotypic suppression of two ochre mutations (argE3 and lacZU118) and an amber mutation (in argE) by sublethal concentrations of streptomycin in an rpsL+ (streptomycin-sensitive) derivative of the Escherichia coli strain AB1157 greatly enhances their adaptive mutability under selection. Streptomycin also increases adaptive mutability brought about by the ppm mutation described earlier. Inactivation of recA affects neither phenotypic suppression by streptomycin nor replication-associated mutagenesis but abolishes adaptive mutagenesis. These results indicate a causal relationship between allele leakiness and adaptive mutability.

  10. Allelic drop-out probabilities estimated by logistic regression

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Asplund, Maria;

    2012-01-01

    We discuss the model for estimating drop-out probabilities presented by Tvedebrink et al. [7] and the concerns, that have been raised. The criticism of the model has demonstrated that the model is not perfect. However, the model is very useful for advanced forensic genetic work, where allelic drop......-out is occurring. With this discussion, we hope to improve the drop-out model, so that it can be used for practical forensic genetics and stimulate further discussions. We discuss how to estimate drop-out probabilities when using a varying number of PCR cycles and other experimental conditions....

  11. Effects of the APOE ε2 Allele on Mortality and Cognitive Function in the Oldest Old

    DEFF Research Database (Denmark)

    Lindahl-Jacobsen, Rune; Tan, Qihua; Mengel-From, Jonas;

    2013-01-01

    Some studies indicate that the APOE ε2 allele may have a protective effect on mortality and mental health among the elderly adults. We investigated the effect of the APOE ε2 allele on cognitive function and mortality in 1651 members of the virtually extinct Danish 1905 birth cohort. We found...... no protective effect of the APOE ε2 allele on mortality compared with the APOE ε3 allele. The point estimates indicated an increased protection against cognitive decline over time for persons with the APOE ε2 allele. Cognitive score did not significantly modify the mortality risk of the various APOE genotypes....... We did not find a protective effect of the APOE ε2 allele on mortality among the oldest old, but in agreement with our previous findings, we found a 22% increased mortality risk for APOE ε4 carriers. The APOE ε2 allele may be protective on cognitive decline among the oldest old....

  12. Analysis of the distribution of HLA-A alleles in populations from five continents.

    Science.gov (United States)

    Middleton, D; Williams, F; Meenagh, A; Daar, A S; Gorodezky, C; Hammond, M; Nascimento, E; Briceno, I; Perez, M P

    2000-10-01

    The variation and frequency of HLA-A genotypes were established by PCR-SSOP typing in diverse geographically distributed populations: Brazilian, Colombian Kogui, Cuban, Mexican, Omani, Singapore Chinese, and South African Zulu. HLA-A allelic families with only one allele were identified for HLA-A*01, -A*23, -A*25, -A*31, -A*32, -A*36, -A*43, -A*69, -A*80; and with two alleles for HLA-A*03, -A*11, -A*26, -A*29, -A*33, -A*34, and -A*66. Greater variation was detected for HLA-A*02, -A*24, and -A*68 allele families. Colombian Kogui and Mexican Seris showed the least diversity with respect to HLA-A alleles, albeit with small numbers tested, with only four and five HLA-A alleles identified, respectively. It would appear by their presence in all populations studied, either rural or indigenous, that certain alleles are very important in pathogen peptide presentation. PMID:11082518

  13. Design and synthesis of multifunctional poly(ethylene glycol)s using enzymatic catalysis for multivalent cancer drug delivery

    Science.gov (United States)

    Seo, Kwang Su

    The objective of this research was to design and synthesize multifunctional poly(ethylene glycol)s (PEG)s using enzyme-catalyzed reactions for multivalent targeted drug delivery. Based on computer simulation for optimum folate binding, a four-arm PEG star topology with Mn = 1000 g/mol was proposed. First, a four-functional core based on tetraethylene glycol (TEG) was designed and synthesized using transesterification and Michael addition reactions in the presence of Candida antarctica lipase B (CALB) as a biocatalyst. The four-functional core (HO)2-TEG-(OH)2 core was successfully prepared by the CALB-catalyzed transesterification of vinyl acrylate (VA) with TEG and then Michael addition of diethanolamine to the resulting TEG diacrylate with/without the use of solvent. The functional PEG arms with fluorescein isothiocyanate (FITC) and folic acid (FA) were prepared using both traditional organic chemistry and enzyme-catalyzed reactions. FITC was reacted with the amine group of H2N-PEG-OH in the presence of triethylamine via nucleophilic addition onto the isothiocyanate group. Then, divinyl adipate (DVA) was transesterified with the FITC-PEG-OH product in the presence of CALB to produce the FITC-PEG vinyl ester that will be attached to the four-functional core via CALC-catalyzed transesterification. For the synthesis of FA-PEG vinyl ester arm, DVA was first reacted with PEG-monobenzyl ether (BzPEG-OH) in bulk in the presence of CALB. The BzPEG vinyl ester was then transesterified with 12-bromo-1-dodecanol in the presence of CALB. Finally, BzPEG-Br was attached to FA exclusively in the gamma position using a new method. The thesis also discusses fundamental studies that were carried out in order to get better understanding of enzyme catalyzed transesterification and Michael addition reactions. First, in an effort to investigate the effects of reagent and enzyme concentrations in transesterification, vinyl methacrylate (VMA) was reacted with 2-(hydroxyethyl) acrylate (2

  14. Low frequency of the scrapile resistance-associated allele and presence of lysine-171 allele of the prion protein gene in Italian Biellese ovine breed

    NARCIS (Netherlands)

    Acutis, P.L.; Sbaiz, L.; Verburg, F.J.; Riina, M.V.; Ru, G.; Moda, G.; Caramelli, M.; Bossers, A.

    2004-01-01

    Frequencies of polymorphisms at codons 136, 154 and 171 of the prion protein (PrP) gene were studied in 1207 pure-bred and cross-bred Italian Biellese rams, a small ovine breed of about 65 000 head in Italy. Aside from the five most common alleles (VRQ, ARQ, ARR, AHQ and ARH), the rare ARK allele wa

  15. Allele mining and enhanced genetic recombination for rice breeding.

    Science.gov (United States)

    Leung, Hei; Raghavan, Chitra; Zhou, Bo; Oliva, Ricardo; Choi, Il Ryong; Lacorte, Vanica; Jubay, Mona Liza; Cruz, Casiana Vera; Gregorio, Glenn; Singh, Rakesh Kumar; Ulat, Victor Jun; Borja, Frances Nikki; Mauleon, Ramil; Alexandrov, Nickolai N; McNally, Kenneth L; Sackville Hamilton, Ruaraidh

    2015-12-01

    Traditional rice varieties harbour a large store of genetic diversity with potential to accelerate rice improvement. For a long time, this diversity maintained in the International Rice Genebank has not been fully used because of a lack of genome information. The publication of the first reference genome of Nipponbare by the International Rice Genome Sequencing Project (IRGSP) marked the beginning of a systematic exploration and use of rice diversity for genetic research and breeding. Since then, the Nipponbare genome has served as the reference for the assembly of many additional genomes. The recently completed 3000 Rice Genomes Project together with the public database (SNP-Seek) provides a new genomic and data resource that enables the identification of useful accessions for breeding. Using disease resistance traits as case studies, we demonstrated the power of allele mining in the 3,000 genomes for extracting accessions from the GeneBank for targeted phenotyping. Although potentially useful landraces can now be identified, their use in breeding is often hindered by unfavourable linkages. Efficient breeding designs are much needed to transfer the useful diversity to breeding. Multi-parent Advanced Generation InterCross (MAGIC) is a breeding design to produce highly recombined populations. The MAGIC approach can be used to generate pre-breeding populations with increased genotypic diversity and reduced linkage drag. Allele mining combined with a multi-parent breeding design can help convert useful diversity into breeding-ready genetic resources. PMID:26606925

  16. Allele frequency of CODIS 13 in Indonesian population.

    Science.gov (United States)

    Untoro, Evi; Atmadja, Djaja Surya; Pu, Chang-En; Wu, Fang-Chi

    2009-04-01

    Since the first application of DNA technology in 1985 in forensic cases, and the acceptance of this technology in 1988 at court, the DNA typing is widely used in personal identification, parentage cases and tracing the source of biological samples found in the crime scene. The FBI on 1990 had recommended the forensic labs to used 13 loci of Short Tandem Repeats (STR), known as CODIS 13, as the loci of choice for forensic use. The research on the population DNA database on these loci is extremely important for calculating the Paternity Index as well as Matching Probability for forensic application of DNA technology. As many as 402 unrelated persons, consisted of 322 from western part of Indonesia and 80 from eastern part of Indonesia, were chosen as the respondents of this research, after signing the informed consent. The peripheral blood sample was taken using sterile lancets and dropped onto FTA classic cards. The DNA was extracted by FTA purification solution (3x) and TE(-1) (2x), and amplified by PCR mix, either Cofiler or Profiler Plus (Perkin Elmers), followed by sequencing using ABI Prism type 3100 Avant Genetic Analyzer. The analysis showed that the alleles frequencies of Indonesian is specific, different with the other Asian populations with some specific alleles and microvariant were found. PMID:19261522

  17. Cytochrome allelic variants and clopidogrel metabolism in cardiovascular diseases therapy.

    Science.gov (United States)

    Jarrar, Mohammed; Behl, Shalini; Manyam, Ganiraju; Ganah, Hany; Nazir, Mohammed; Nasab, Reem; Moustafa, Khaled

    2016-06-01

    Clopidogrel and aspirin are among the most prescribed dual antiplatelet therapies to treat the acute coronary syndrome and heart attacks. However, their potential clinical impacts are a subject of intense debates. The therapeutic efficiency of clopidogrel is controlled by the actions of hepatic cytochrome P450 (CYPs) enzymes and impacted by individual genetic variations. Inter-individual polymorphisms in CYPs enzymes affect the metabolism of clopidogrel into its active metabolites and, therefore, modify its turnover and clinical outcome. So far, clinical trials fail to confirm higher or lower adverse cardiovascular effects in patients treated with combinations of clopidogrel and proton pump inhibitors, compared with clopidogrel alone. Such inconclusive findings may be due to genetic variations in the cytochromes CYP2C19 and CYP3A4/5. To investigate potential interactions/effects of these cytochromes and their allele variants on the treatment of acute coronary syndrome with clopidogrel alone or in combination with proton pump inhibitors, we analyze recent literature and discuss the potential impact of the cytochrome allelic variants on cardiovascular events and stent thrombosis treated with clopidogrel. The diversity of CYP2C19 polymorphisms and prevalence span within various ethnic groups, subpopulations and demographic areas are also debated. PMID:27072373

  18. Expression and loss of alleles in cultured mouse embryonic fibroblasts and stem cells carrying allelic fluorescent protein genes

    OpenAIRE

    Stringer Saundra L; Fischer Jared M; Yin Moying; Larson Jon S; Stringer James R

    2006-01-01

    Abstract Background Loss of heterozygosity (LOH) contributes to many cancers, but the rate at which these events occur in normal cells of the body is not clear. LOH would be detectable in diverse cell types in the body if this event were to confer an obvious cellular phenotype. Mice that carry two different fluorescent protein genes as alleles of a locus would seem to be a useful tool for addressing this issue because LOH would change a cell's phenotype from dichromatic to monochromatic. In a...

  19. Tetra-allelic SNPs: Informative forensic markers compiled from public whole-genome sequence data.

    Science.gov (United States)

    Phillips, C; Amigo, J; Carracedo, Á; Lareu, M V

    2015-11-01

    Multiple-allele single nucleotide polymorphisms (SNPs) are potentially useful for forensic DNA analysis as they can provide more discrimination power than normal binary SNPs. In addition, the presence in a profile of more than two alleles per marker provides a clearer indication of mixed DNA than assessments of imbalanced signals in the peak pairs of binary SNPs. Using the 1000 Genomes Phase III human variant data release of 2014 as the starting point, this study collated 961 tetra-allelic SNPs that pass minimum sequence quality thresholds and where four separate nucleotide substitution alleles were detected. Although most of these loci had three of the four alleles in combined frequencies of 2% or less, 160 had high heterozygosities with 50 exceeding those of 'ideal' 0.5:0.5 binary SNPs. From this set of most polymorphic tetra-allelic SNPs, we identified markers most informative for forensic purposes and explored these loci in detail. Subsets of the most polymorphic tetra-allelic SNPs will make useful additions to current panels of forensic identification SNPs and ancestry-informative SNPs. The 24 most discriminatory tetra-allelic SNPs were estimated to detect more than two alleles in at least one marker per profile in 99.9% of mixtures of African contributors. In European contributor mixtures 99.4% of profiles would show multiple allele patterns, but this drops to 92.6% of East Asian contributor mixtures due to reduced levels of polymorphism for the 24 SNPs in this population group. PMID:26209763

  20. Multivalent system for therapy of non-Hod king lymphomas based on Anti-CD20 conjugated to gold nanoparticles; Sistema multivalente para terapia de linfomas no-Hodking basado en Anti-CD20 conjugado a nanoparticulas de oro

    Energy Technology Data Exchange (ETDEWEB)

    Miranda O, R. M.

    2014-07-01

    In recent publications has been reported that gold nanoparticles have an effect in reducing the expression of the oncogene Bcl -2 and have a high biocompatibility , this is the importance for using gold nanoparticles for this work. The antibody CD20 is an antibody that specifically binds to that over expressed CD20 antigen on the cell membrane of B lymphoma cell non- Hodgkin (cell line Raji) behold the importance of combining this bio molecule to gold nanoparticles since they have a high specificity with CD20 positive cells , also to carry out the antigen- antibody immunological reactions triggered mediating cell lysis, possibly by cytotoxicity and apoptosis. Therefore, this system must have characteristics of both components to eliminate B cell non- Hodgkin lymphoma.In this work it was studied a multivalent system composed of gold nanoparticles and anti-CD20 antibody, the term multi valency refers to the number of biomolecules attached to the surface of the gold nanoparticle. The synthesis and characterization of the gold nanoparticles and the multivalent system was performed and the effect of the multivalent system on the expression of oncogene Bcl-2 (group of proteins associated with the apoptotic pathway) was evaluated. Characterization of raw materials and the multivalent system was performed using spectroscopic and microscopic techniques, this to verify structural changes in raw materials and thus confirm the formation of CD20 binding to the surface of the nanoparticle gold by the bond between gold and sulfur in the cysteines of CD20. Taking advantage that the metal nanoparticles have the optical property of surface plasmon resonance, the absorption of gold nanoparticles was measured on the UV-Vis as it is affected by the surface molecules bind to it, showing a bathochromic displacement effected. The hydrodynamic diameter of the gold nanoparticles was measured to verify that the antibody is bound to the surface; this evidence was complemented by micrographs

  1. A new analysis tool for individual-level allele frequency for genomic studies

    Directory of Open Access Journals (Sweden)

    Pan Wen-Harn

    2010-07-01

    Full Text Available Abstract Background Allele frequency is one of the most important population indices and has been broadly applied to genetic/genomic studies. Estimation of allele frequency using genotypes is convenient but may lose data information and be sensitive to genotyping errors. Results This study utilizes a unified intensity-measuring approach to estimating individual-level allele frequencies for 1,104 and 1,270 samples genotyped with the single-nucleotide-polymorphism arrays of the Affymetrix Human Mapping 100K and 500K Sets, respectively. Allele frequencies of all samples are estimated and adjusted by coefficients of preferential amplification/hybridization (CPA, and large ethnicity-specific and cross-ethnicity databases of CPA and allele frequency are established. The results show that using the CPA significantly improves the accuracy of allele frequency estimates; moreover, this paramount factor is insensitive to the time of data acquisition, effect of laboratory site, type of gene chip, and phenotypic status. Based on accurate allele frequency estimates, analytic methods based on individual-level allele frequencies are developed and successfully applied to discover genomic patterns of allele frequencies, detect chromosomal abnormalities, classify sample groups, identify outlier samples, and estimate the purity of tumor samples. The methods are packaged into a new analysis tool, ALOHA (Allele-frequency/Loss-of-heterozygosity/Allele-imbalance. Conclusions This is the first time that these important genetic/genomic applications have been simultaneously conducted by the analyses of individual-level allele frequencies estimated by a unified intensity-measuring approach. We expect that additional practical applications for allele frequency analysis will be found. The developed databases and tools provide useful resources for human genome analysis via high-throughput single-nucleotide-polymorphism arrays. The ALOHA software was written in R and R GUI and

  2. Design and pre-clinical profiling of a Plasmodium falciparum MSP-3 derived component for a multi-valent virosomal malaria vaccine

    Directory of Open Access Journals (Sweden)

    Boato Francesca

    2009-12-01

    Full Text Available Abstract Background Clinical profiling of two components for a synthetic peptide-based virosomal malaria vaccine has yielded promising results, encouraging the search for additional components for inclusion in a final multi-valent vaccine formulation. This report describes the immunological characterization of linear and cyclized synthetic peptides comprising amino acids 211-237 of Plasmodium falciparum merozoite surface protein (MSP-3. Methods These peptides were coupled to phosphatidylethanolamine (PE; the conjugates were intercalated into immunopotentiating reconstituted influenza virosomes (IRIVs and then used for immunizations in mice to evaluate their capacity to elicit P. falciparum cross-reactive antibodies. Results While all MSP-3-derived peptides were able to elicit parasite-binding antibodies, stabilization of turn structures by cyclization had no immune-enhancing effect. Therefore, further pre-clinical profiling was focused on FB-12, a PE conjugate of the linear peptide. Consistent with the immunological results obtained in mice, all FB-12 immunized rabbits tested seroconverted and consistently elicited antibodies that interacted with blood stage parasites. It was observed that a dose of 50 μg was superior to a dose of 10 μg and that influenza pre-existing immunity improved the immunogenicity of FB-12 in rabbits. FB-12 production was successfully up-scaled and the immunogenicity of a vaccine formulation, produced according to the rules of Good Manufacturing Practice (GMP, was tested in mice and rabbits. All animals tested developed parasite-binding antibodies. Comparison of ELISA and IFA titers as well as the characterization of a panel of anti-FB-12 monoclonal antibodies indicated that at least the majority of antibodies specific for the virosomally formulated synthetic peptide were parasite cross-reactive. Conclusion These results reconfirm the suitability of IRIVs as a carrier/adjuvant system for the induction of strong humoral

  3. Targeting surface nucleolin with multivalent HB-19 and related Nucant pseudopeptides results in distinct inhibitory mechanisms depending on the malignant tumor cell type

    International Nuclear Information System (INIS)

    Nucleolin expressed at the cell surface is a binding protein for a variety of ligands implicated in tumorigenesis and angiogenesis. By using a specific antagonist that binds the C-terminal RGG domain of nucleolin, the HB-19 pseudopeptide, we recently reported that targeting surface nucleolin with HB-19 suppresses progression of established human breast tumor cells in the athymic nude mice, and delays development of spontaneous melanoma in the RET transgenic mice. By the capacity of HB-19 to bind stably surface nucleolin, we purified and identified nucleolin partners at the cell surface. HB-19 and related multivalent Nucant pseudopeptides, that present pentavalently or hexavalently the tripeptide Lysψ(CH2N)-Pro-Arg, were then used to show that targeting surface nucleolin results in distinct inhibitory mechanisms on breast, prostate, colon carcinoma and leukemia cells. Surface nucleolin exists in a 500-kDa protein complex including several other proteins, which we identified by microsequencing as two Wnt related proteins, Ku86 autoantigen, signal recognition particle subunits SRP68/72, the receptor for complement component gC1q-R, and ribosomal proteins S4/S6. Interestingly, some of the surface-nucleolin associated proteins are implicated in cell signaling, tumor cell adhesion, migration, invasion, cell death, autoimmunity, and bacterial infections. Surface nucleolin in the 500-kDa complex is highly stable. Surface nucleolin antagonists, HB-19 and related multivalent Nucant pseudopeptides, exert distinct inhibitory mechanisms depending on the malignant tumor cell type. For example, in epithelial tumor cells they inhibit cell adhesion or spreading and induce reversion of the malignant phenotype (BMC cancer 2010, 10:325) while in leukemia cells they trigger a rapid cell death associated with DNA fragmentation. The fact that these pseudopeptides do not cause cell death in epithelial tumor cells indicates that cell death in leukemia cells is triggered by a specific

  4. Pharmacokinetics and biodistribution of 177Lu-labeled multivalent single-chain Fv construct of the pancarcinoma monoclonal antibody CC49

    International Nuclear Information System (INIS)

    Lutetium-177 (177Lu) is a radionuclide of interest for radioimmunoimaging (RII) and radioimmunotherapy (RIT) on account of its short half-life (161 h) and the ability to emit both β and γ radiation. Single-chain Fv (scFv) constructs have shown advancement in cancer diagnosis and therapy due to the pharmacokinetics advantage and seem to be intriguing tools in oncology. The objective of this study was to evaluate the pharmacokinetics and biodistribution characteristics of the 177Lu-labeled tetravalent scFv of CC49 MAb and intact CC49 IgG in vivo. Conjugation and labeling conditions of multivalent scFv with 177Lu were optimized without affecting integrity and immunoreactivity. For this purpose, multivalent scFv constructs dimer, sc(Fv)2; tetramer, [sc(Fv)2]2 of the MAb CC49 were expressed as secretory proteins in Pichia pastoris. The purified scFv constructs and IgG form of CC49 were conjugated with a bifunctional chelating agent, ITCB-DTPA, and labeled with 177Lu. The comparative biodistribution, blood clearance, and tumor-targeting characteristics of 177Lu-labeled tetravalent [sc(Fv)2 ]2 construct of CC49 MAb and intact CC49 IgG were investigated in the athymic mice bearing LS-174T xenografts. Approximately, 90% of 177Lu incorporation was achieved using ITCB-DTPA chelator, and the labeled immunoconjugates maintained integrity and immunoreactivity. Blood clearance studies demonstrated an alpha half-life (t1/2 α) of 177Lu-labeled [sc(Fv)2 ]2 and IgG of CC49 at 4.40 and 9.50 min and a beta half-life (t1/2 β) at 375 and 2,193 min, respectively. At 8 h post administration, the percent of the injected dose accumulated/gram (%ID/g) of the LS-174T tumor was 6.4 ±1.3 and 8.9 ±0.6 for 177Lu-labeled [sc(Fv)2 ]2 and IgG of CC49, respectively, in the absence of l-lysine. The corresponding values were 8.0 ±0.6 and 8.4 ±1.2 in the presence of l-lysine. Renal accumulation of [sc(Fv)2 ]2 was significantly (p <0.005) reduced in the presence of l-lysine. (orig.)

  5. Pharmacokinetics and biodistribution of {sup 177}Lu-labeled multivalent single-chain Fv construct of the pancarcinoma monoclonal antibody CC49

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Subhash C.; Jain, Maneesh; Moore, Erik D.; Wittel, Uwe A.; Batra, Surinder K. [University of Nebraska Medical Center, Department of Biochemistry and Molecular Biology, Omaha, NE (United States); Li, Jing; Gwilt, Peter R. [University of Nebraska Medical Center, College of Pharmacy, Omaha, NE (United States); Colcher, David [Beckman Research Institute at City of Hope National Medical Center, Department of Radioimmunotherapy, Duarte, CA (United States)

    2005-03-01

    Lutetium-177 ({sup 177}Lu) is a radionuclide of interest for radioimmunoimaging (RII) and radioimmunotherapy (RIT) on account of its short half-life (161 h) and the ability to emit both {beta} and {gamma} radiation. Single-chain Fv (scFv) constructs have shown advancement in cancer diagnosis and therapy due to the pharmacokinetics advantage and seem to be intriguing tools in oncology. The objective of this study was to evaluate the pharmacokinetics and biodistribution characteristics of the {sup 177}Lu-labeled tetravalent scFv of CC49 MAb and intact CC49 IgG in vivo. Conjugation and labeling conditions of multivalent scFv with {sup 177}Lu were optimized without affecting integrity and immunoreactivity. For this purpose, multivalent scFv constructs dimer, sc(Fv){sub 2}; tetramer, [sc(Fv){sub 2}]{sub 2} of the MAb CC49 were expressed as secretory proteins in Pichia pastoris. The purified scFv constructs and IgG form of CC49 were conjugated with a bifunctional chelating agent, ITCB-DTPA, and labeled with {sup 177}Lu. The comparative biodistribution, blood clearance, and tumor-targeting characteristics of {sup 177}Lu-labeled tetravalent [sc(Fv){sub 2} ]{sub 2} construct of CC49 MAb and intact CC49 IgG were investigated in the athymic mice bearing LS-174T xenografts. Approximately, 90% of {sup 177}Lu incorporation was achieved using ITCB-DTPA chelator, and the labeled immunoconjugates maintained integrity and immunoreactivity. Blood clearance studies demonstrated an alpha half-life (t{sub 1/2} {alpha}) of {sup 177}Lu-labeled [sc(Fv){sub 2} ]{sub 2} and IgG of CC49 at 4.40 and 9.50 min and a beta half-life (t{sub 1/2} {beta}) at 375 and 2,193 min, respectively. At 8 h post administration, the percent of the injected dose accumulated/gram (%ID/g) of the LS-174T tumor was 6.4 {+-}1.3 and 8.9 {+-}0.6 for {sup 177}Lu-labeled [sc(Fv){sub 2} ]{sub 2} and IgG of CC49, respectively, in the absence of l-lysine. The corresponding values were 8.0 {+-}0.6 and 8.4 {+-}1.2 in the

  6. Targeting surface nucleolin with multivalent HB-19 and related Nucant pseudopeptides results in distinct inhibitory mechanisms depending on the malignant tumor cell type

    Directory of Open Access Journals (Sweden)

    Hovanessian Ara G

    2011-08-01

    Full Text Available Abstract Background Nucleolin expressed at the cell surface is a binding protein for a variety of ligands implicated in tumorigenesis and angiogenesis. By using a specific antagonist that binds the C-terminal RGG domain of nucleolin, the HB-19 pseudopeptide, we recently reported that targeting surface nucleolin with HB-19 suppresses progression of established human breast tumor cells in the athymic nude mice, and delays development of spontaneous melanoma in the RET transgenic mice. Methods By the capacity of HB-19 to bind stably surface nucleolin, we purified and identified nucleolin partners at the cell surface. HB-19 and related multivalent Nucant pseudopeptides, that present pentavalently or hexavalently the tripeptide Lysψ(CH2N-Pro-Arg, were then used to show that targeting surface nucleolin results in distinct inhibitory mechanisms on breast, prostate, colon carcinoma and leukemia cells. Results Surface nucleolin exists in a 500-kDa protein complex including several other proteins, which we identified by microsequencing as two Wnt related proteins, Ku86 autoantigen, signal recognition particle subunits SRP68/72, the receptor for complement component gC1q-R, and ribosomal proteins S4/S6. Interestingly, some of the surface-nucleolin associated proteins are implicated in cell signaling, tumor cell adhesion, migration, invasion, cell death, autoimmunity, and bacterial infections. Surface nucleolin in the 500-kDa complex is highly stable. Surface nucleolin antagonists, HB-19 and related multivalent Nucant pseudopeptides, exert distinct inhibitory mechanisms depending on the malignant tumor cell type. For example, in epithelial tumor cells they inhibit cell adhesion or spreading and induce reversion of the malignant phenotype (BMC cancer 2010, 10:325 while in leukemia cells they trigger a rapid cell death associated with DNA fragmentation. The fact that these pseudopeptides do not cause cell death in epithelial tumor cells indicates that cell

  7. An Allele Real-Coded Quantum Evolutionary Algorithm Based on Hybrid Updating Strategy

    Directory of Open Access Journals (Sweden)

    Yu-Xian Zhang

    2016-01-01

    Full Text Available For improving convergence rate and preventing prematurity in quantum evolutionary algorithm, an allele real-coded quantum evolutionary algorithm based on hybrid updating strategy is presented. The real variables are coded with probability superposition of allele. A hybrid updating strategy balancing the global search and local search is presented in which the superior allele is defined. On the basis of superior allele and inferior allele, a guided evolutionary process as well as updating allele with variable scale contraction is adopted. And Hε gate is introduced to prevent prematurity. Furthermore, the global convergence of proposed algorithm is proved by Markov chain. Finally, the proposed algorithm is compared with genetic algorithm, quantum evolutionary algorithm, and double chains quantum genetic algorithm in solving continuous optimization problem, and the experimental results verify the advantages on convergence rate and search accuracy.

  8. An Allele Real-Coded Quantum Evolutionary Algorithm Based on Hybrid Updating Strategy.

    Science.gov (United States)

    Zhang, Yu-Xian; Qian, Xiao-Yi; Peng, Hui-Deng; Wang, Jian-Hui

    2016-01-01

    For improving convergence rate and preventing prematurity in quantum evolutionary algorithm, an allele real-coded quantum evolutionary algorithm based on hybrid updating strategy is presented. The real variables are coded with probability superposition of allele. A hybrid updating strategy balancing the global search and local search is presented in which the superior allele is defined. On the basis of superior allele and inferior allele, a guided evolutionary process as well as updating allele with variable scale contraction is adopted. And H ε gate is introduced to prevent prematurity. Furthermore, the global convergence of proposed algorithm is proved by Markov chain. Finally, the proposed algorithm is compared with genetic algorithm, quantum evolutionary algorithm, and double chains quantum genetic algorithm in solving continuous optimization problem, and the experimental results verify the advantages on convergence rate and search accuracy. PMID:27057159

  9. Introgressive hybridization: brown bears as vectors for polar bear alleles.

    Science.gov (United States)

    Hailer, Frank

    2015-03-01

    The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. PMID:25775930

  10. Enhancement of allele discrimination by introduction of nucleotide mismatches into siRNA in allele-specific gene silencing by RNAi.

    Directory of Open Access Journals (Sweden)

    Yusuke Ohnishi

    Full Text Available Allele-specific gene silencing by RNA interference (RNAi is therapeutically useful for specifically inhibiting the expression of disease-associated alleles without suppressing the expression of corresponding wild-type alleles. To realize such allele-specific RNAi (ASP-RNAi, the design and assessment of small interfering RNA (siRNA duplexes conferring ASP-RNAi is vital; however, it is also difficult. In a previous study, we developed an assay system to assess ASP-RNAi with mutant and wild-type reporter alleles encoding the Photinus and Renilla luciferase genes. In line with experiments using the system, we realized that it is necessary and important to enhance allele discrimination between mutant and corresponding wild-type alleles. Here, we describe the improvement of ASP-RNAi against mutant alleles carrying single nucleotide variations by introducing base substitutions into siRNA sequences, where original variations are present in the central position. Artificially mismatched siRNAs or short-hairpin RNAs (shRNAs against mutant alleles of the human Prion Protein (PRNP gene, which appear to be associated with susceptibility to prion diseases, were examined using this assessment system. The data indicates that introduction of a one-base mismatch into the siRNAs and shRNAs was able to enhance discrimination between the mutant and wild-type alleles. Interestingly, the introduced mismatches that conferred marked improvement in ASP-RNAi, appeared to be largely present in the guide siRNA elements, corresponding to the 'seed region' of microRNAs. Due to the essential role of the 'seed region' of microRNAs in their association with target RNAs, it is conceivable that disruption of the base-pairing interactions in the corresponding seed region, as well as the central position (involved in cleavage of target RNAs, of guide siRNA elements could influence allele discrimination. In addition, we also suggest that nucleotide mismatches at the 3'-ends of sense

  11. Origins, distribution and expression of the Duarte-2 (D2) allele of galactose-1-phosphate uridylyltransferase

    OpenAIRE

    Carney, Amanda E.; Rebecca D Sanders; Garza, Kerry R.; McGaha, Lee Anne; Bean, Lora J. H.; Coffee, Bradford W.; Thomas, James W; Cutler, David J.; Kurtkaya, Natalie L.; Fridovich-Keil, Judith L.

    2009-01-01

    Duarte galactosemia is a mild to asymptomatic condition that results from partial impairment of galactose-1-phosphate uridylyltransferase (GALT). Patients with Duarte galactosemia demonstrate reduced GALT activity and carry one profoundly impaired GALT allele (G) along with a second, partially impaired GALT allele (Duarte-2, D2). Molecular studies reveal at least five sequence changes on D2 alleles: a p.N314D missense substitution, three intronic base changes and a 4 bp deletion in the 5′ pro...

  12. Association of apolipoprotein E allele {epsilon}4 with late-onset sporadic Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Lucotte, G.; David, F.; Berriche, S. [Regional Center of Neurogenetics, Reims (France)] [and others

    1994-09-15

    Apolipoprotein E, type {epsilon}4 allele (ApoE {epsilon}4), is associated with late-onset sporadic Alzheimer`s disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for {epsilon}4 allele frequencies). These data support the involvement of ApoE {epsilon}4 allele as a very important risk factor for the clinical expression of AD. 22 refs., 1 fig., 3 tabs.

  13. Identification of resistant carboxylesterase alleles in Culex pipiens complex via PCR-RFLP

    Directory of Open Access Journals (Sweden)

    Zhang Hanying

    2012-09-01

    Full Text Available Abstract Background Carboxylesterase overproduction is a frequently observed resistance mechanism of insects to organophosphate insecticides. As a major transmitter of human diseases, mosquitoes in the Culex pipiens complex have evolved 13 carboxylesterase alleles (Ester that confer organophosphate resistance. Six alleles, EsterB1, Ester2, Ester8, Ester9, EsterB10, and Ester11, have been observed in field populations in China, sometimes co-existing in one population. To differentiate the carboxylesterase alleles found in these field populations, PCR-RFLP was designed for use in resistance monitoring. Results Based on the DNA sequences of resistant and nonresistant carboxylesterase alleles, Ester B alleles were first amplified with PCR-specific primers and then digested with the restriction enzyme DraI. In this step, Ester2 and Ester11 were differentiated from the other Ester alleles. When the other Ester B alleles were digested with the restriction enzyme XbaI, EsterB1 and the susceptible C. p. pallens Ester were screened out. Ester8 and Ester9 were differentiated from EsterB10 and the susceptible C. p. quinquefasciatus esterase allele, respectively, by amplifying and digesting the Ester A alleles with the restriction enzyme ApaLI. The effectiveness of the custom-designed PCR-RFLP was verified in two field mosquito populations. Conclusions A PCR-RFLP based approach was developed to differentiate carboxylesterase alleles in Culex pipiens complex mosquitoes. These processes may be useful in monitoring the evolutionary dynamics of known carboxylesterase alleles as well as in the identification of new alleles in field populations.

  14. Age of an allele and gene genealogies of nested subsamples for populations admitting large offspring numbers

    OpenAIRE

    Eldon, Bjarki

    2012-01-01

    Coalescent processes, including mutation, are derived from Moran type population models admitting large offspring numbers. Including mutation in the coalescent process allows for quantifying the turnover of alleles by computing the distribution of the number of original alleles still segregating in the population at a given time in the past. The turnover of alleles is considered for specific classes of the Moran model admitting large offspring numbers. Versions of the Kingman coalescent are a...

  15. Allelic Spectra of Risk SNPs Are Different for Environment/Lifestyle Dependent versus Independent Diseases.

    Directory of Open Access Journals (Sweden)

    Ivan P Gorlov

    2015-07-01

    Full Text Available Genome-wide association studies (GWAS have generated sufficient data to assess the role of selection in shaping allelic diversity of disease-associated SNPs. Negative selection against disease risk variants is expected to reduce their frequencies making them overrepresented in the group of minor (<50% alleles. Indeed, we found that the overall proportion of risk alleles was higher among alleles with frequency <50% (minor alleles compared to that in the group of major alleles. We hypothesized that negative selection may have different effects on environment (or lifestyle-dependent versus environment (or lifestyle-independent diseases. We used an environment/lifestyle index (ELI to assess influence of environmental/lifestyle factors on disease etiology. ELI was defined as the number of publications mentioning "environment" or "lifestyle" AND disease per 1,000 disease-mentioning publications. We found that the frequency distributions of the risk alleles for the diseases with strong environmental/lifestyle components follow the distribution expected under a selectively neutral model, while frequency distributions of the risk alleles for the diseases with weak environmental/lifestyle influences is shifted to the lower values indicating effects of negative selection. We hypothesized that previously selectively neutral variants become risk alleles when environment changes. The hypothesis of ancestrally neutral, currently disadvantageous risk-associated alleles predicts that the distribution of risk alleles for the environment/lifestyle dependent diseases will follow a neutral model since natural selection has not had enough time to influence allele frequencies. The results of our analysis suggest that prediction of SNP functionality based on the level of evolutionary conservation may not be useful for SNPs associated with environment/lifestyle dependent diseases.

  16. Allele-specific enzymatic amplification of beta-globin genomic DNA for diagnosis of sickle cell anemia.

    OpenAIRE

    Wu, D Y; Ugozzoli, L; B..K. Pal; Wallace, R B

    1989-01-01

    A rapid nonradioactive approach to the diagnosis of sickle cell anemia is described based on an allele-specific polymerase chain reaction (ASPCR). This method allows direct detection of the normal or the sickle cell beta-globin allele in genomic DNA without additional steps of probe hybridization, ligation, or restriction enzyme cleavage. Two allele-specific oligonucleotide primers, one specific for the sickle cell allele and one specific for the normal allele, together with another primer co...

  17. Allele-specific enzymatic amplification of. beta. -globin genomic DNA for diagnosis of sickle cell anemia

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D.Y.; Ugozzoli, L.; Pal, B.K.; Wallace, B. (Beckman Research Institute of the City of Hope, Duarte, CA (USA))

    1989-04-01

    A rapid nonradioactive approach to the diagnosis of sickle cell anemia is described based on an allele-specific polymerase chain reaction (ASPCR). This method allows direct detection of the normal or the sickle cell {beta}-globin allele in genomic DNA without additional steps of probe hybridization, ligation, or restriction enzyme cleavage. Two allele-specific oligonucleotide primers, one specific for the sickle cell allele and one specific for the normal allele, together with another primer complementary to both alleles were used in the polymerase chain reaction with genomic DNA templates. The allele-specific primers differed from each other in their terminal 3{prime} nucleotide. Under the proper annealing temperature and polymerase chain reaction conditions, these primers only directed amplification on their complementary allele. In a single blind study of DNA samples from 12 individuals, this method correctly and unambiguously allowed for the determination of the genotypes with no false negatives or positives. If ASPCR is able to discriminate all allelic variation (both transition and transversion mutations), this method has the potential to be a powerful approach for genetic disease diagnosis, carrier screening, HLA typing, human gene mapping, forensics, and paternity testing.

  18. Persistence of the common Hartnup disease D173N allele in populations of European origin.

    Science.gov (United States)

    Azmanov, Dimitar N; Rodgers, Helen; Auray-Blais, Christiane; Giguère, Robert; Bailey, Charles; Bröer, Stefan; Rasko, John E J; Cavanaugh, Juleen A

    2007-11-01

    Hartnup disorder is an aminoaciduria that results from mutations in the recently described gene SLC6A19 on chromosome 5p15.33. The disease is inherited in a simple recessive manner and ten different mutations have been described to date. One mutation, the D173N allele, is present in 42% of Hartnup chromosomes from apparently unrelated families from both Australia and North America. We report an investigation of the origins of the D173N allele using a unique combination of variants including SNPs, microsatellites, and a VNTR across 211 Kb spanning the SLC6A19 locus. All individuals who carry the mutant allele share an identical core haplotype suggesting a single common ancestor, indicating that the elevated frequency of the D173N allele is not a result of recurrent mutation. Analyses of these data indicate that the allele is more than 1000 years old. We compare the reasons for survival of this allele with other major alleles in some other common autosomal recessive diseases occurring in European Caucasians. We postulate that survival of this allele may be a consequence of failure of the allele to completely inactivate the transport of neutral amino acids. PMID:17555458

  19. Overdispersion in allelic counts and θ-correction in forensic genetics

    DEFF Research Database (Denmark)

    Tvedebrink, Torben

    2010-01-01

    We present a statistical model for incorporating the extra variability in allelic counts due to subpopulation structures. In forensic genetics, this effect is modelled by the identical-by-descent parameter θ, which measures the relationship between pairs of alleles within a population relative to...... the relationship of alleles between populations (Weir, 2007). In our statistical approach, we demonstrate that θ may be defined as an overdispersion parameter capturing the subpopulation effects. This formulation allows derivation of maximum likelihood estimates of the allele probabilities and θ...

  20. Estimating allele age and selection coefficient from Time-serial data

    DEFF Research Database (Denmark)

    Malaspinas, Anna Sapfo; Malaspinas, Orestis; Evans, Steven N.;

    2012-01-01

    age of an allele from time-serial data. Our method can be used for allele frequencies sampled from a single diallelic locus. The transition probabilities are calculated by approximating the standard diffusion equation of the Wright–Fisher model with a one-step process. We show that our method...... the age of the allele, it is possible to gain traction on the important problem of distinguishing selection on new mutations from selection on standing variation. In this coat color example for instance, we estimate the age of this allele, which is found to predate domestication....

  1. Disagreement in genotyping results of drug resistance alleles of the Plasmodium falciparum dihydrofolate reductase (Pfdhfr) gene by allele-specific PCR (ASPCR) assays and Sanger sequencing.

    Science.gov (United States)

    Sharma, Divya; Lather, Manila; Dykes, Cherry L; Dang, Amita S; Adak, Tridibes; Singh, Om P

    2016-01-01

    The rapid spread of antimalarial drug resistance in Plasmodium falciparum over the past few decades has necessitated intensive monitoring of such resistance for an effective malaria control strategy. P. falciparum dihydropteroate synthase (Pfdhps) and P. falciparum dihydrofolate reductase (Pfdhfr) genes act as molecular markers for resistance against the antimalarial drugs sulphadoxine and pyrimethamine, respectively. Resistance to pyrimethamine which is used as a partner drug in artemisinin combination therapy (ACT) is associated with several mutations in the Pfdhfr gene, namely A16V, N51I, C59R, S108N/T and I164L. Therefore, routine monitoring of Pfdhfr-drug-resistant alleles in a population may help in effective drug resistance management. Allele-specific PCR (ASPCR) is one of the commonly used methods for molecular genotyping of these alleles. In this study, we genotyped 55 samples of P. falciparum for allele discrimination at four codons of Pfdhfr (N51, C59, S108 and I164) by ASPCR using published methods and by Sanger's DNA sequencing method. We found that the ASPCR identified a significantly higher number of mutant alleles as compared to the DNA sequencing method. Such discrepancies arise due to the non-specificity of some of the allele-specific primer sets and due to the lack of sensitivity of Sanger's DNA sequencing method to detect minor alleles present in multiple clone infections. This study reveals the need of a highly specific and sensitive method for genotyping and detecting minor drug-resistant alleles present in multiple clonal infections. PMID:26407876

  2. Dynamics of insecticide resistance alleles in house fly populations from New York and Florida.

    Science.gov (United States)

    Rinkevich, Frank D; Hamm, Ronda L; Geden, Christopher J; Scott, Jeffrey G

    2007-06-01

    The frequency of insecticide-resistance alleles for two genes (Vssc1 and CYP6D1) was studied in field collected populations of house flies from two different climates. While the frequency of these resistance alleles in flies at dairies from four states has recently been reported, there is no information on the relative change of these allele frequencies over time. House flies were collected during the 2003-2004 season from New York and Florida before the first application of permethrin, during the middle of the field season, after the final application, and again the following spring (following months without permethrin use). Bioassay results indicated that homozygous susceptible and extremely resistant flies were rare, while moderately and highly resistant individuals were relatively common at all times in both states. The frequency of resistance alleles at the New York dairy rose during the season and declined over the winter, suggesting an overwintering fitness cost associated with these alleles. The super-kdr allele was detected for the first time in North America at the end of 2003. In Florida the frequency of the resistance alleles did not increase during the spray season or decrease during the winter, suggesting there is substantial immigration of susceptible alleles to the Florida dairy and no overwintering fitness cost associated with resistance alleles in this climate. Resistance to permethrin correlated well with the frequency of the Vssc1 and CYP6D1 resistance alleles in flies from New York, but not as well in the population from Florida. This suggests there may be a new resistance mechanism or allele evolving in Florida. PMID:17517332

  3. Allele-mining and natural diversity in wheat powdery mildew resistance genes

    International Nuclear Information System (INIS)

    Using map-based cloning, we have isolated the Pm3b powdery mildew resistance gene from hexaploid bread wheat (Triticum aestivum L.). Based on haplotype studies, we have developed molecular tools to isolate all the 10 known Pm3 genes conferring resistance. We found that the Pm3 genes form a true allelic series and that they are highly conserved at the molecular level. The molecular work on Pm3 resistance genes has lead to very diagnostic tools for these genes which support the cloning of new functional alleles from this locus by allele-mining. We have used these tools to screen for new Pm3 alleles in the gene pools of (i) wild and domesticated tetraploid accessions and (ii) hexaploid wheat landraces. The Pm3 locus is conserved in tetraploid wheat, allowing a comparative evolutionary study of the same resistance locus in a domesticated species and one of its wild ancestors. We have identified 61 Pm3 allelic sequences from wild and domesticated tetraploid wheat subspecies. These alleles showed low sequence diversity, differing by few polymorphic sequence blocks that were further reshuffled between alleles by gene conversion and recombination. A new functional gene was identified in a wild wheat accession from Syria. This gene, Pm3k, conferred intermediate resistance to powdery mildew and consists of a mosaic of gene segments derived from non-functional alleles. From the hexaploid wheat gene pool, a set of 1320 landraces, mostly from Asia, was screened for powdery mildew resistance and the presence of a Pm3 haplotype. Most of these lines were found to contain a susceptible Pm3 allele which is closely related to the functional Pm3 resistance genes. We have also identified resistant lines with new types of Pm3 allelic sequences, resulting from point mutations, gene conversion and illegitimate recombination events. These new alleles are currently tested for resistance activity in a transient expression assay. (author)

  4. Cognitive and neural correlates of the 5-repeat allele of the dopamine D4 receptor gene in a population lacking the 7-repeat allele.

    Science.gov (United States)

    Takeuchi, Hikaru; Tomita, Hiroaki; Taki, Yasuyuki; Kikuchi, Yoshie; Ono, Chiaki; Yu, Zhiqian; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2015-04-15

    The 5-repeat allele of a common length polymorphism in the gene that encodes the dopamine D4 receptor (DRD4) is robustly associated with the risk of attention deficit hyperactivity disorder (ADHD) and substantially exists in Asian populations, which have a lower ADHD prevalence. In this study, we investigated the effect of this allele on microstructural properties of the brain and on its functional activity during externally directed attention-demanding tasks and creative performance in the 765 Asian subjects. For this purpose, we employed diffusion tensor imaging, N-back functional magnetic resonance imaging paradigms, and a test to measure creativity by divergent thinking. The 5-repeat allele was significantly associated with increased originality in the creative performance, increased mean diffusivity (the measure of how the tissue includes water molecules instead of neural and vessel components) in the widespread gray and white matter areas of extensive areas, particularly those where DRD4 is expressed, and reduced task-induced deactivation in the areas that are deactivated during the tasks in the course of both the attention-demanding working memory task and simple sensorimotor task. The observed neural characteristics of 5-repeat allele carriers may lead to an increased risk of ADHD and behavioral deficits. Furthermore, the increased originality of creative thinking observed in the 5-repeat allele carriers may support the notion of the side of adaptivity of the widespread risk allele of psychiatric diseases. PMID:25659462

  5. Molecular detection and identification of intimin alleles in pathogenic Escherichia coli by multiplex PCR.

    Science.gov (United States)

    Reid, S D; Betting, D J; Whittam, T S

    1999-08-01

    A multiplex PCR was designed to detect the eae gene and simultaneously identify specific alleles in pathogenic Escherichia coli. The method was tested on 87 strains representing the diarrheagenic E. coli clones. The results show that the PCR assay accurately detects eae and resolves alleles encoding the alpha, beta, and gamma intimin variants. PMID:10405431

  6. Revealing the Genetic Variation and Allele Heterozygote Javanese and Arab Families in Malang East Java Indonesia

    Directory of Open Access Journals (Sweden)

    Nila Kartika Sari

    2014-02-01

    Results: Our result showed that the genetic variability and heterozygote allele increasing by using the 13 CODIS markers from the first generation to the next generation with paternity testing from each family were matched. Conclusion: We can conclude that in a Javanese-Arab family ethnic seems stimulate the increasing genetic variation and allele heterozygote.

  7. Identification of novel alleles of the rice blast resistance gene Pi54

    Science.gov (United States)

    Vasudevan, Kumar; Gruissem, Wilhelm; Bhullar, Navreet K.

    2015-10-01

    Rice blast is one of the most devastating rice diseases and continuous resistance breeding is required to control the disease. The rice blast resistance gene Pi54 initially identified in an Indian cultivar confers broad-spectrum resistance in India. We explored the allelic diversity of the Pi54 gene among 885 Indian rice genotypes that were found resistant in our screening against field mixture of naturally existing M. oryzae strains as well as against five unique strains. These genotypes are also annotated as rice blast resistant in the International Rice Genebank database. Sequence-based allele mining was used to amplify and clone the Pi54 allelic variants. Nine new alleles of Pi54 were identified based on the nucleotide sequence comparison to the Pi54 reference sequence as well as to already known Pi54 alleles. DNA sequence analysis of the newly identified Pi54 alleles revealed several single polymorphic sites, three double deletions and an eight base pair deletion. A SNP-rich region was found between a tyrosine kinase phosphorylation site and the nucleotide binding site (NBS) domain. Together, the newly identified Pi54 alleles expand the allelic series and are candidates for rice blast resistance breeding programs.

  8. Mannose-binding lectin variant alleles and the risk of arterial thrombosis in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Øhlenschlaeger, Tommy; Garred, Peter; Madsen, Hans O;

    2004-01-01

    Cardiovascular disease is an important complication in patients with systemic lupus erythematosus (SLE). Variant alleles of the mannose-binding lectin gene are associated with SLE as well as with severe atherosclerosis. We determined whether mannose-binding lectin variant alleles were associated...

  9. An Updated Collection of Sequence Barcoded Temperature-Sensitive Alleles of Yeast Essential Genes.

    Science.gov (United States)

    Kofoed, Megan; Milbury, Karissa L; Chiang, Jennifer H; Sinha, Sunita; Ben-Aroya, Shay; Giaever, Guri; Nislow, Corey; Hieter, Philip; Stirling, Peter C

    2015-09-01

    Systematic analyses of essential gene function using mutant collections in Saccharomyces cerevisiae have been conducted using collections of heterozygous diploids, promoter shut-off alleles, through alleles with destabilized mRNA, destabilized protein, or bearing mutations that lead to a temperature-sensitive (ts) phenotype. We previously described a method for construction of barcoded ts alleles in a systematic fashion. Here we report the completion of this collection of alleles covering 600 essential yeast genes. This resource covers a larger gene repertoire than previous collections and provides a complementary set of strains suitable for single gene and genomic analyses. We use deep sequencing to characterize the amino acid changes leading to the ts phenotype in half of the alleles. We also use high-throughput approaches to describe the relative ts behavior of the alleles. Finally, we demonstrate the experimental usefulness of the collection in a high-content, functional genomic screen for ts alleles that increase spontaneous P-body formation. By increasing the number of alleles and improving the annotation, this ts collection will serve as a community resource for probing new aspects of biology for essential yeast genes. PMID:26175450

  10. HLA-DRB1 allele polymorphisms in genetic susceptibility to esophageal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jun Lin; Chang-Sheng Deng; Jie Sun; Xian-Gong Zheng; Xing Huang; Yan Zhou; Ping Xiong; Ya-Ping Wang

    2003-01-01

    AIM: To probe into the genetic susceptibility of HLA-DRB1 alleles to esophageal carcinoma in Han Chinese in Hubei Province.METHODS: HLA-DRB1 allele polymorphisms were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP) in 42 unrelated patients with esophageal cancer and 136 unrelated normal control subjects and the associated HLA-DRB1 allele was measured by nucleotide sequence analysis with PCR.SAS software was used in statistics.RESULTS: Allele frequency (AF) of HLA-DRB1·0901 was significantly higher in esophageal carcinoma patients than that in the normal controls (0.2500 vs0.1397, P=0.028, the odds ratio 2.053, etiologic fraction 0.1282). After analyzed the allele nucleotide sequence of HLA-DRB1·0901 which approachs to the corresponded exon 2 sequence of the allele in genebank. There was no association between patients and controls in the rested HLA-DRB1 alleles.CONCLUSION: HLA-DRB1·0901 allele is more common in the patients with esophageal carcinoma than in the healthy controls, which is positively associated with the patients of Hubei Han Chinese. Individuals carrying HLA-DRB1·0901may be susceptible to esophageal carcinoma.

  11. Correlation in chicken between the marker LEI0258 alleles and Major Histocompatibility Complex sequences

    DEFF Research Database (Denmark)

    Chazara, Olympe; Juul-Madsen, Helle Risdahl; Chang, Chi-Seng;

    Background The LEI0258 marker is located within the B region of the chicken Major Histocompatibility Complex (MHC), and is surprisingly well associated with serology. Therefore, the correlation between the LEI0258 alleles and the MHC class I and the class II alleles at the level of sequences is w...

  12. Salmonella Typhi shdA: pseudogene or allelic variant?

    Science.gov (United States)

    Urrutia, I M; Fuentes, J A; Valenzuela, L M; Ortega, A P; Hidalgo, A A; Mora, G C

    2014-08-01

    ShdA from Salmonella Typhimurium (ShdASTm) is a large outer membrane protein that specifically recognizes and binds to fibronectin. ShdASTm is involved in the colonization of the cecum and the Peyer's patches of terminal ileum in mice. On the other hand, shdA gene from Salmonella Typhi (shdASTy) has been considered a pseudogene (i.e. a nonfunctional sequence of genomic DNA) due to the presence of deletions and mutations that gave rise to premature stop codons. In this work we show that, despite the deletions and mutations, shdASTy is fully functional. S. Typhi ΔshdA mutants presented an impaired adherence and invasion of HEp-2 pre-treated with TGF-β1, an inducer of fibronectin production. Moreover, shdA from S. Typhi and S. Typhimurium seem to be equivalent since shdASTm restored the adherence and invasion of S. Typhi ΔshdA mutant to wild type levels. In addition, anti-FLAG mAbs interfered with the adherence and invasion of the S. Typhi shdA-3xFLAG strain. Finally, shdASTy encodes a detectable protein when heterologously expressed in Escherichia coli DH5α. The data presented here show that shdASTy is not a pseudogene, but a different functional allele compared with shdASTm. PMID:24859062

  13. The functional importance of sequence versus expression variability of MHC alleles in parasite resistance.

    Science.gov (United States)

    Axtner, Jan; Sommer, Simone

    2012-12-01

    Understanding selection processes driving the pronounced allelic polymorphism of the major histocompatibility complex (MHC) genes and its functional associations to parasite load have been the focus of many recent wildlife studies. Two main selection scenarios are currently debated which explain the susceptibility or resistance to parasite infections either by the effects of (1) specific MHC alleles which are selected frequency-dependent in space and time or (2) a heterozygote or divergent allele advantage. So far, most studies have focused only on structural variance in co-evolutionary processes although this might not be the only trait subject to natural selection. In the present study, we analysed structural variance stretching from exon1 through exon3 of MHC class II DRB genes as well as genotypic expression variance in relation to the gastrointestinal helminth prevalence and infection intensity in wild yellow-necked mice (Apodemus flavicollis). We found support for the functional importance of specific alleles both on the sequence and expression level. By resampling a previously investigated study population we identified specific MHC alleles affected by temporal shifts in parasite pressure and recorded associated changes in allele frequencies. The allele Apfl-DRB*23 was associated with resistance to infections by the oxyurid nematode Syphacia stroma and at the same time with susceptibility to cestode infection intensity. In line with our expectation, MHC mRNA transcript levels tended to be higher in cestode-infected animals carrying the allele Apfl-DRB*23. However, no support for a heterozygote or divergent allele advantage on the sequence or expression level was detected. The individual amino acid distance of genotypes did not explain individual differences in parasite loads and the genetic distance had no effect on MHC genotype expression. For ongoing studies on the functional importance of expression variance in parasite resistance, allele

  14. Solution behaviour of myo-inositol hexakisphosphate in the presence of multivalent cations. Prediction of a neutral pentamagnesium species under cytosolic/nuclear conditions.

    Science.gov (United States)

    Torres, Julia; Domínguez, Sixto; Cerdá, M Fernanda; Obal, Gonzalo; Mederos, Alfredo; Irvine, Robin F; Díaz, Alvaro; Kremer, Carlos

    2005-03-01

    myo-Inositol hexakisphosphate (InsP6) is an ubiquitous and abundant molecule in the cytosol and nucleus of eukaryotic cells whose biological functions are incompletely known. A major hurdle for studying the biology of InsP6 has been a deficiency of a full understanding of the chemistry of its interaction with divalent and trivalent cations. This deficiency has limited our appreciation of how it remains in solution within cells, and the likely degree to which it might interact in vivo with physiologically important cations such as Ca2+ and Fe3+. We report here the initial part of the description of the InsP6-multivalent cation chemistry, including its solution equilibria studied by high resolution potentiometry and (for the Fe(III)/Fe(II) couple) cyclic voltammetry. InsP6 forms anionic complexes of high affinities and 1:1 stoichiometry with Mg(II), Ca(II), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II). Of particular importance is the observation that, in the exceptional case of Mg(II), InsP6 forms the species [Mg5(H2L)] (L representing fully deprotonated InsP6); this soluble neutral species is predicted to be the predominant form of InsP6 under nuclear or cytosolic conditions in animal cells. Contrary to previous suggestions, InsP6 is predicted not to interact with cytosolic calcium even when calcium is increased during signalling events. In vitro, InsP6 also forms high affinity 1:1 complexes with Fe(III) and Al(III). However, our data predict that in the biological context of excess free Mg(II), neither Fe(III) nor Fe(II) are complexed by InsP6. PMID:15708805

  15. Confounded by sequencing depth in association studies of rare alleles.

    Science.gov (United States)

    Garner, Chad

    2011-05-01

    Next-generation DNA sequencing technologies are facilitating large-scale association studies of rare genetic variants. The depth of the sequence read coverage is an important experimental variable in the next-generation technologies and it is a major determinant of the quality of genotype calls generated from sequence data. When case and control samples are sequenced separately or in different proportions across batches, they are unlikely to be matched on sequencing read depth and a differential misclassification of genotypes can result, causing confounding and an increased false-positive rate. Data from Pilot Study 3 of the 1000 Genomes project was used to demonstrate that a difference between the mean sequencing read depth of case and control samples can result in false-positive association for rare and uncommon variants, even when the mean coverage depth exceeds 30× in both groups. The degree of the confounding and inflation in the false-positive rate depended on the extent to which the mean depth was different in the case and control groups. A logistic regression model was used to test for association between case-control status and the cumulative number of alleles in a collapsed set of rare and uncommon variants. Including each individual's mean sequence read depth across the variant sites in the logistic regression model nearly eliminated the confounding effect and the inflated false-positive rate. Furthermore, accounting for the potential error by modeling the probability of the heterozygote genotype calls in the regression analysis had a relatively minor but beneficial effect on the statistical results. PMID:21328616

  16. Naturally occurring allele diversity allows potato cultivation in northern latitudes.

    Science.gov (United States)

    Kloosterman, Bjorn; Abelenda, José A; Gomez, María del Mar Carretero; Oortwijn, Marian; de Boer, Jan M; Kowitwanich, Krissana; Horvath, Beatrix M; van Eck, Herman J; Smaczniak, Cezary; Prat, Salomé; Visser, Richard G F; Bachem, Christian W B

    2013-03-14

    Potato (Solanum tuberosum L.) originates from the Andes and evolved short-day-dependent tuber formation as a vegetative propagation strategy. Here we describe the identification of a central regulator underlying a major-effect quantitative trait locus for plant maturity and initiation of tuber development. We show that this gene belongs to the family of DOF (DNA-binding with one finger) transcription factors and regulates tuberization and plant life cycle length, by acting as a mediator between the circadian clock and the StSP6A mobile tuberization signal. We also show that natural allelic variants evade post-translational light regulation, allowing cultivation outside the geographical centre of origin of potato. Potato is a member of the Solanaceae family and is one of the world's most important food crops. This annual plant originates from the Andean regions of South America. Potato develops tubers from underground stems called stolons. Its equatorial origin makes potato essentially short-day dependent for tuberization and potato will not make tubers in the long-day conditions of spring and summer in the northern latitudes. When introduced in temperate zones, wild material will form tubers in the course of the autumnal shortening of day-length. Thus, one of the first selected traits in potato leading to a European potato type is likely to have been long-day acclimation for tuberization. Potato breeders can exploit the naturally occurring variation in tuberization onset and life cycle length, allowing varietal breeding for different latitudes, harvest times and markets. PMID:23467094

  17. Demographic history and rare allele sharing among human populations

    Science.gov (United States)

    Gravel, Simon; Henn, Brenna M.; Gutenkunst, Ryan N.; Indap, Amit R.; Marth, Gabor T.; Clark, Andrew G.; Yu, Fuli; Gibbs, Richard A.; Bustamante, Carlos D.; Altshuler, David L.; Durbin, Richard M.; Abecasis, Gonçalo R.; Bentley, David R.; Chakravarti, Aravinda; Clark, Andrew G.; Collins, Francis S.; De La Vega, Francisco M.; Donnelly, Peter; Egholm, Michael; Flicek, Paul; Gabriel, Stacey B.; Gibbs, Richard A.; Knoppers, Bartha M.; Lander, Eric S.; Lehrach, Hans; Mardis, Elaine R.; McVean, Gil A.; Nickerson, Debbie A.; Peltonen, Leena; Schafer, Alan J.; Sherry, Stephen T.; Wang, Jun; Wilson, Richard K.; Gibbs, Richard A.; Deiros, David; Metzker, Mike; Muzny, Donna; Reid, Jeff; Wheeler, David; Wang, Jun; Li, Jingxiang; Jian, Min; Li, Guoqing; Li, Ruiqiang; Liang, Huiqing; Tian, Geng; Wang, Bo; Wang, Jian; Wang, Wei; Yang, Huanming; Zhang, Xiuqing; Zheng, Huisong; Lander, Eric S.; Altshuler, David L.; Ambrogio, Lauren; Bloom, Toby; Cibulskis, Kristian; Fennell, Tim J.; Gabriel, Stacey B.; Jaffe, David B.; Shefler, Erica; Sougnez, Carrie L.; Bentley, David R.; Gormley, Niall; Humphray, Sean; Kingsbury, Zoya; Koko-Gonzales, Paula; Stone, Jennifer; McKernan, Kevin J.; Costa, Gina L.; Ichikawa, Jeffry K.; Lee, Clarence C.; Sudbrak, Ralf; Lehrach, Hans; Borodina, Tatiana A.; Dahl, Andreas; Davydov, Alexey N.; Marquardt, Peter; Mertes, Florian; Nietfeld, Wilfiried; Rosenstiel, Philip; Schreiber, Stefan; Soldatov, Aleksey V.; Timmermann, Bernd; Tolzmann, Marius; Egholm, Michael; Affourtit, Jason; Ashworth, Dana; Attiya, Said; Bachorski, Melissa; Buglione, Eli; Burke, Adam; Caprio, Amanda; Celone, Christopher; Clark, Shauna; Conners, David; Desany, Brian; Gu, Lisa; Guccione, Lorri; Kao, Kalvin; Kebbel, Andrew; Knowlton, Jennifer; Labrecque, Matthew; McDade, Louise; Mealmaker, Craig; Minderman, Melissa; Nawrocki, Anne; Niazi, Faheem; Pareja, Kristen; Ramenani, Ravi; Riches, David; Song, Wanmin; Turcotte, Cynthia; Wang, Shally; Mardis, Elaine R.; Wilson, Richard K.; Dooling, David; Fulton, Lucinda; Fulton, Robert; Weinstock, George; Durbin, Richard M.; Burton, John; Carter, David M.; Churcher, Carol; Coffey, Alison; Cox, Anthony; Palotie, Aarno; Quail, Michael; Skelly, Tom; Stalker, James; Swerdlow, Harold P.; Turner, Daniel; De Witte, Anniek; Giles, Shane; Gibbs, Richard A.; Wheeler, David; Bainbridge, Matthew; Challis, Danny; Sabo, Aniko; Yu, Fuli; Yu, Jin; Wang, Jun; Fang, Xiaodong; Guo, Xiaosen; Li, Ruiqiang; Li, Yingrui; Luo, Ruibang; Tai, Shuaishuai; Wu, Honglong; Zheng, Hancheng; Zheng, Xiaole; Zhou, Yan; Li, Guoqing; Wang, Jian; Yang, Huanming; Marth, Gabor T.; Garrison, Erik P.; Huang, Weichun; Indap, Amit; Kural, Deniz; Lee, Wan-Ping; Leong, Wen Fung; Quinlan, Aaron R.; Stewart, Chip; Stromberg, Michael P.; Ward, Alistair N.; Wu, Jiantao; Lee, Charles; Mills, Ryan E.; Shi, Xinghua; Daly, Mark J.; DePristo, Mark A.; Altshuler, David L.; Ball, Aaron D.; Banks, Eric; Bloom, Toby; Browning, Brian L.; Cibulskis, Kristian; Fennell, Tim J.; Garimella, Kiran V.; Grossman, Sharon R.; Handsaker, Robert E.; Hanna, Matt; Hartl, Chris; Jaffe, David B.; Kernytsky, Andrew M.; Korn, Joshua M.; Li, Heng; Maguire, Jared R.; McCarroll, Steven A.; McKenna, Aaron; Nemesh, James C.; Philippakis, Anthony A.; Poplin, Ryan E.; Price, Alkes; Rivas, Manuel A.; Sabeti, Pardis C.; Schaffner, Stephen F.; Shefler, Erica; Shlyakhter, Ilya A.; Cooper, David N.; Ball, Edward V.; Mort, Matthew; Phillips, Andrew D.; Stenson, Peter D.; Sebat, Jonathan; Makarov, Vladimir; Ye, Kenny; Yoon, Seungtai C.; Bustamante, Carlos D.; Clark, Andrew G.; Boyko, Adam; Degenhardt, Jeremiah; Gravel, Simon; Gutenkunst, Ryan N.; Kaganovich, Mark; Keinan, Alon; Lacroute, Phil; Ma, Xin; Reynolds, Andy; Clarke, Laura; Flicek, Paul; Cunningham, Fiona; Herrero, Javier; Keenen, Stephen; Kulesha, Eugene; Leinonen, Rasko; McLaren, William M.; Radhakrishnan, Rajesh; Smith, Richard E.; Zalunin, Vadim; Zheng-Bradley, Xiangqun; Korbel, Jan O.; Stütz, Adrian M.; Humphray, Sean; Bauer, Markus; Cheetham, R. Keira; Cox, Tony; Eberle, Michael; James, Terena; Kahn, Scott; Murray, Lisa; Chakravarti, Aravinda; Ye, Kai; De La Vega, Francisco M.; Fu, Yutao; Hyland, Fiona C. L.; Manning, Jonathan M.; McLaughlin, Stephen F.; Peckham, Heather E.; Sakarya, Onur; Sun, Yongming A.; Tsung, Eric F.; Batzer, Mark A.; Konkel, Miriam K.; Walker, Jerilyn A.; Sudbrak, Ralf; Albrecht, Marcus W.; Amstislavskiy, Vyacheslav S.; Herwig, Ralf; Parkhomchuk, Dimitri V.; Sherry, Stephen T.; Agarwala, Richa; Khouri, Hoda M.; Morgulis, Aleksandr O.; Paschall, Justin E.; Phan, Lon D.; Rotmistrovsky, Kirill E.; Sanders, Robert D.; Shumway, Martin F.; Xiao, Chunlin; McVean, Gil A.; Auton, Adam; Iqbal, Zamin; Lunter, Gerton; Marchini, Jonathan L.; Moutsianas, Loukas; Myers, Simon; Tumian, Afidalina; Desany, Brian; Knight, James; Winer, Roger; Craig, David W.; Beckstrom-Sternberg, Steve M.; Christoforides, Alexis; Kurdoglu, Ahmet A.; Pearson, John V.; Sinari, Shripad A.; Tembe, Waibhav D.; Haussler, David; Hinrichs, Angie S.; Katzman, Sol J.; Kern, Andrew; Kuhn, Robert M.; Przeworski, Molly; Hernandez, Ryan D.; Howie, Bryan; Kelley, Joanna L.; Melton, S. Cord; Abecasis, Gonçalo R.; Li, Yun; Anderson, Paul; Blackwell, Tom; Chen, Wei; Cookson, William O.; Ding, Jun; Kang, Hyun Min; Lathrop, Mark; Liang, Liming; Moffatt, Miriam F.; Scheet, Paul; Sidore, Carlo; Snyder, Matthew; Zhan, Xiaowei; Zöllner, Sebastian; Awadalla, Philip; Casals, Ferran; Idaghdour, Youssef; Keebler, John; Stone, Eric A.; Zilversmit, Martine; Jorde, Lynn; Xing, Jinchuan; Eichler, Evan E.; Aksay, Gozde; Alkan, Can; Hajirasouliha, Iman; Hormozdiari, Fereydoun; Kidd, Jeffrey M.; Sahinalp, S. Cenk; Sudmant, Peter H.; Mardis, Elaine R.; Chen, Ken; Chinwalla, Asif; Ding, Li; Koboldt, Daniel C.; McLellan, Mike D.; Dooling, David; Weinstock, George; Wallis, John W.; Wendl, Michael C.; Zhang, Qunyuan; Durbin, Richard M.; Albers, Cornelis A.; Ayub, Qasim; Balasubramaniam, Senduran; Barrett, Jeffrey C.; Carter, David M.; Chen, Yuan; Conrad, Donald F.; Danecek, Petr; Dermitzakis, Emmanouil T.; Hu, Min; Huang, Ni; Hurles, Matt E.; Jin, Hanjun; Jostins, Luke; Keane, Thomas M.; Le, Si Quang; Lindsay, Sarah; Long, Quan; MacArthur, Daniel G.; Montgomery, Stephen B.; Parts, Leopold; Stalker, James; Tyler-Smith, Chris; Walter, Klaudia; Zhang, Yujun; Gerstein, Mark B.; Snyder, Michael; Abyzov, Alexej; Balasubramanian, Suganthi; Bjornson, Robert; Du, Jiang; Grubert, Fabian; Habegger, Lukas; Haraksingh, Rajini; Jee, Justin; Khurana, Ekta; Lam, Hugo Y. K.; Leng, Jing; Mu, Xinmeng Jasmine; Urban, Alexander E.; Zhang, Zhengdong; Li, Yingrui; Luo, Ruibang; Marth, Gabor T.; Garrison, Erik P.; Kural, Deniz; Quinlan, Aaron R.; Stewart, Chip; Stromberg, Michael P.; Ward, Alistair N.; Wu, Jiantao; Lee, Charles; Mills, Ryan E.; Shi, Xinghua; McCarroll, Steven A.; Banks, Eric; DePristo, Mark A.; Handsaker, Robert E.; Hartl, Chris; Korn, Joshua M.; Li, Heng; Nemesh, James C.; Sebat, Jonathan; Makarov, Vladimir; Ye, Kenny; Yoon, Seungtai C.; Degenhardt, Jeremiah; Kaganovich, Mark; Clarke, Laura; Smith, Richard E.; Zheng-Bradley, Xiangqun; Korbel, Jan O.; Humphray, Sean; Cheetham, R. Keira; Eberle, Michael; Kahn, Scott; Murray, Lisa; Ye, Kai; De La Vega, Francisco M.; Fu, Yutao; Peckham, Heather E.; Sun, Yongming A.; Batzer, Mark A.; Konkel, Miriam K.; Walker, Jerilyn A.; Xiao, Chunlin; Iqbal, Zamin; Desany, Brian; Blackwell, Tom; Snyder, Matthew; Xing, Jinchuan; Eichler, Evan E.; Aksay, Gozde; Alkan, Can; Hajirasouliha, Iman; Hormozdiari, Fereydoun; Kidd, Jeffrey M.; Chen, Ken; Chinwalla, Asif; Ding, Li; McLellan, Mike D.; Wallis, John W.; Hurles, Matt E.; Conrad, Donald F.; Walter, Klaudia; Zhang, Yujun; Gerstein, Mark B.; Snyder, Michael; Abyzov, Alexej; Du, Jiang; Grubert, Fabian; Haraksingh, Rajini; Jee, Justin; Khurana, Ekta; Lam, Hugo Y. K.; Leng, Jing; Mu, Xinmeng Jasmine; Urban, Alexander E.; Zhang, Zhengdong; Gibbs, Richard A.; Bainbridge, Matthew; Challis, Danny; Coafra, Cristian; Dinh, Huyen; Kovar, Christie; Lee, Sandy; Muzny, Donna; Nazareth, Lynne; Reid, Jeff; Sabo, Aniko; Yu, Fuli; Yu, Jin; Marth, Gabor T.; Garrison, Erik P.; Indap, Amit; Leong, Wen Fung; Quinlan, Aaron R.; Stewart, Chip; Ward, Alistair N.; Wu, Jiantao; Cibulskis, Kristian; Fennell, Tim J.; Gabriel, Stacey B.; Garimella, Kiran V.; Hartl, Chris; Shefler, Erica; Sougnez, Carrie L.; Wilkinson, Jane; Clark, Andrew G.; Gravel, Simon; Grubert, Fabian; Clarke, Laura; Flicek, Paul; Smith, Richard E.; Zheng-Bradley, Xiangqun; Sherry, Stephen T.; Khouri, Hoda M.; Paschall, Justin E.; Shumway, Martin F.; Xiao, Chunlin; McVean, Gil A.; Katzman, Sol J.; Abecasis, Gonçalo R.; Blackwell, Tom; Mardis, Elaine R.; Dooling, David; Fulton, Lucinda; Fulton, Robert; Koboldt, Daniel C.; Durbin, Richard M.; Balasubramaniam, Senduran; Coffey, Allison; Keane, Thomas M.; MacArthur, Daniel G.; Palotie, Aarno; Scott, Carol; Stalker, James; Tyler-Smith, Chris; Gerstein, Mark B.; Balasubramanian, Suganthi; Chakravarti, Aravinda; Knoppers, Bartha M.; Abecasis, Gonçalo R.; Bustamante, Carlos D.; Gharani, Neda; Gibbs, Richard A.; Jorde, Lynn; Kaye, Jane S.; Kent, Alastair; Li, Taosha; McGuire, Amy L.; McVean, Gil A.; Ossorio, Pilar N.; Rotimi, Charles N.; Su, Yeyang; Toji, Lorraine H.; TylerSmith, Chris; Brooks, Lisa D.; Felsenfeld, Adam L.; McEwen, Jean E.; Abdallah, Assya; Juenger, Christopher R.; Clemm, Nicholas C.; Collins, Francis S.; Duncanson, Audrey; Green, Eric D.; Guyer, Mark S.; Peterson, Jane L.; Schafer, Alan J.; Abecasis, Gonçalo R.; Altshuler, David L.; Auton, Adam; Brooks, Lisa D.; Durbin, Richard M.; Gibbs, Richard A.; Hurles, Matt E.; McVean, Gil A.

    2011-01-01

    High-throughput sequencing technology enables population-level surveys of human genomic variation. Here, we examine the joint allele frequency distributions across continental human populations and present an approach for combining complementary aspects of whole-genome, low-coverage data and targeted high-coverage data. We apply this approach to data generated by the pilot phase of the Thousand Genomes Project, including whole-genome 2–4× coverage data for 179 samples from HapMap European, Asian, and African panels as well as high-coverage target sequencing of the exons of 800 genes from 697 individuals in seven populations. We use the site frequency spectra obtained from these data to infer demographic parameters for an Out-of-Africa model for populations of African, European, and Asian descent and to predict, by a jackknife-based approach, the amount of genetic diversity that will be discovered as sample sizes are increased. We predict that the number of discovered nonsynonymous coding variants will reach 100,000 in each population after ∼1,000 sequenced chromosomes per population, whereas ∼2,500 chromosomes will be needed for the same number of synonymous variants. Beyond this point, the number of segregating sites in the European and Asian panel populations is expected to overcome that of the African panel because of faster recent population growth. Overall, we find that the majority of human genomic variable sites are rare and exhibit little sharing among diverged populations. Our results emphasize that replication of disease association for specific rare genetic variants across diverged populations must overcome both reduced statistical power because of rarity and higher population divergence. PMID:21730125

  18. Allelic discrimination in naturalized ovine from Pantanal Sul-Matogrossense by means of microsatellite markers

    Directory of Open Access Journals (Sweden)

    Crispim Bruno do Amaral

    2012-08-01

    Full Text Available The molecular biology techniques that are used in allelic discrimination for individual and sheep breeds characterization are important tools in breeding programs and conservation of genetic resources. The use of microsatellite markers allows allelic differentiation, which in turn allows us to infer the genetic variability of sample populations. The study aimed to test the sensitivity and efficiency of fluorescent capillary electrophoresis, using microsatellite primers, for allelic discrimination of the Crioulo breed from Pantanal sul-matogrossense, as well as verify the possibility of using the products of sequencing in genetic variability analysis. For this test, were used blood samples from Pantaneira breed sheep. The allelic discrimination of eight microsatellites was determined by capillary electrophoresis in automatic sequencer and the results analyses were performed on the programs CERVUS and Dendro-UPGMA. The results indicated the possibility of using this technique for the individual genotyping of all loci tested in electrophoretic analysis and its potential to allelic discrimination even in case of difference between two pairs of bases between the alleles. The resulting dendrogram based on the distance matrix by the UPGMA assembly method, indicated medium similarity coefficient of 0.72 in the group of animals. It was concluded that there is the viability and efficiency of the microsatellite molecular markers technique using capillary electrophoresis for allelic discrimination and the utility of results for studies of genetic variability, paternity diagnosis and characterization of the Crioulo sheep herd from Pantanal sul-matogrossense.

  19. S-allele diversity in Sorbus aucuparia and Crataegus monogyna (Rosaceae: Maloideae).

    Science.gov (United States)

    Raspé, O; Kohn, J R

    2002-06-01

    RT-PCR was used to obtain the first estimates from natural populations of allelic diversity at the RNase-based gametophytic self-incompatibility locus in the Rosaceae. A total of 20 alleles were retrieved from 20 Sorbus aucuparia individuals, whereas 17 alleles were found in 13 Crataegus monogyna samples. Estimates of population-level allele numbers fall within the range observed in the Solanaceae, the only other family with RNase-based incompatibility for which estimates are available. The nucleotide diversity of S-allele sequences was found to be much lower in the two Rosaceae species as compared with the Solanaceae. This was not due to a lower sequence divergence among most closely related alleles. Rather, it is the depth of the entire genealogy that differs markedly in the two families, with Rosaceae S-alleles exhibiting more recent apparent coalescence. We also investigated patterns of selection at the molecular level by comparing nucleotide diversity at synonymous and nonsynonymous sites. Stabilizing selection was inferred for the 5' region of the molecule, while evidence of diversifying selection was present elsewhere. PMID:12180088

  20. Effects of sequence variation on differential allelic transcription factor occupancy and gene expression.

    Science.gov (United States)

    Reddy, Timothy E; Gertz, Jason; Pauli, Florencia; Kucera, Katerina S; Varley, Katherine E; Newberry, Kimberly M; Marinov, Georgi K; Mortazavi, Ali; Williams, Brian A; Song, Lingyun; Crawford, Gregory E; Wold, Barbara; Willard, Huntington F; Myers, Richard M

    2012-05-01

    A complex interplay between transcription factors (TFs) and the genome regulates transcription. However, connecting variation in genome sequence with variation in TF binding and gene expression is challenging due to environmental differences between individuals and cell types. To address this problem, we measured genome-wide differential allelic occupancy of 24 TFs and EP300 in a human lymphoblastoid cell line GM12878. Overall, 5% of human TF binding sites have an allelic imbalance in occupancy. At many sites, TFs clustered in TF-binding hubs on the same homolog in especially open chromatin. While genetic variation in core TF binding motifs generally resulted in large allelic differences in TF occupancy, most allelic differences in occupancy were subtle and associated with disruption of weak or noncanonical motifs. We also measured genome-wide differential allelic expression of genes with and without heterozygous exonic variants in the same cells. We found that genes with differential allelic expression were overall less expressed both in GM12878 cells and in unrelated human cell lines. Comparing TF occupancy with expression, we found strong association between allelic occupancy and expression within 100 bp of transcription start sites (TSSs), and weak association up to 100 kb from TSSs. Sites of differential allelic occupancy were significantly enriched for variants associated with disease, particularly autoimmune disease, suggesting that allelic differences in TF occupancy give functional insights into intergenic variants associated with disease. Our results have the potential to increase the power and interpretability of association studies by targeting functional intergenic variants in addition to protein coding sequences. PMID:22300769

  1. Allelic variation in the squirrel monkey x-linked color vision gene: biogeographical and behavioral correlates.

    Science.gov (United States)

    Cropp, Susan; Boinski, Sue; Li, Wen-Hsiung

    2002-06-01

    Most Neotropical primate species possess a polymorphic X-linked and a monomorphic autosomal color vision gene. Consequently, populations are composed of both dichromatics and trichromatics. Most theories on the maintenance of this genetic system revolve around possible advantages for foraging ecology. To examine the issue from a different angle, we compared the numbers and relative frequencies of alleles at the X-linked locus among three species of Saimiri representing a wide range of geographical and behavioral variation in the genus. Exons 3, 4, and 5 of the X-linked opsin gene were sequenced for a large number of X chromosomes for all three species. Several synonymous mutations were detected in exons 4 and 5 for the originally reported alleles but only a single nonsynonymous change was detected. Two alleles were found that appeared to be the result of recombination events. The low occurrence of recombinant alleles and absence of mutations in the amino acids critical for spectral tuning indicates that stabilizing selection acts to maintain the combinations of critical sites specific to each allele. Allele frequencies were approximately the same for all Saimiri species, with a slight but significant difference between S. boliviensis and S. oerstedii. No apparent correlation exists between allele frequencies and behavioral or biogeographical differences between species, casting doubt on the speculation that the spectral sensitivities of the alleles have been maintained because they are specifically well-tuned to Saimiri visual ecology. Rather, the spectral tuning peaks might have been maintained because they are as widely spaced as possible within the limited range of middlewave to longwave spectra useful to all primates. This arrangement creates a balance between maximizing the distance between spectral tuning peaks (allowing the color opponency of the visual system to distinguish between peaks) and maximizing the number of alleles within a limited range (yielding

  2. Analysis of a Larger SNP Dataset from the HapMap Project Confirmed That the Modern Human A Allele of the ABO Blood Group Genes Is a Descendant of a Recombinant between B and O Alleles

    Directory of Open Access Journals (Sweden)

    Masaya Itou

    2013-01-01

    Full Text Available The human ABO blood group gene consists of three main alleles (A, B, and O that encode a glycosyltransferase. The A and B alleles differ by two critical amino acids in exon 7, and the major O allele has a single nucleotide deletion (Δ261 in exon 6. Previous evolutionary studies have revealed that the A allele is the most ancient, B allele diverged from the A allele with two critical amino acid substitutions in exon 7, and the major O allele diverged from the A allele with Δ261 in exon 6. However, a recent phylogenetic network analysis study showed that the A allele of humans emerged through a recombination between the B and O alleles. In the previous study, a restricted dataset from only two populations was used. In this study, therefore, we used a large single nucleotide polymorphism (SNP dataset from the HapMap Project. The results indicated that the A101-A201-O09 haplogroup was a recombinant lineage between the B and O haplotypes, containing the intact exon 6 from the B allele and the two critical A type sites in exon 7 from the major O allele. Its recombination point was assumed to be located just behind Δ261 in exon 6.

  3. Association between the CCR5 32-bp deletion allele and late onset of schizophrenia

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Timm, Sally; Wang, August G; Søeby, Karen; Lublin, Henrik; Fenger, Mogens; Hemmingsen, Ralf Peter Arnfred; Werge, Thomas

    2006-01-01

    psychiatric hospital department served as a measure of disease onset. RESULTS: Patients and comparison subjects differed marginally in their genotype distribution, with a slightly higher frequency of the deletion allele seen in the patients. The authors found the deletion allele to be associated with higher......OBJECTIVE: The 32-bp deletion allele in chemokine receptor CCR5 has been associated with several immune-mediated diseases and might be implicated in schizophrenia as well. METHOD: The authors genotyped DNA samples from 268 schizophrenia patients and 323 healthy subjects. Age at first admission to a...

  4. Clarifying the Relationship between Average Excesses and Average Effects of Allele Substitutions.

    Science.gov (United States)

    Alvarez-Castro, José M; Yang, Rong-Cai

    2012-01-01

    Fisher's concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance. PMID:22509178

  5. Clarifying the relationship between average excesses and average effects of allele substitutions

    Directory of Open Access Journals (Sweden)

    Jose M eÁlvarez-Castro

    2012-03-01

    Full Text Available Fisher’s concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one-locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance.

  6. Estimation of the frequency of hexosaminidase a variant alleles in the American Jewish population.

    OpenAIRE

    Greenberg, D A; Kaback, M M

    1982-01-01

    There appear to be several alleles of the hexosaminidase A (HEX A) gene that lead to different clinical syndromes. In addition to the infantile-onset Tay-Sachs disease (TSD), there is a juvenile-onset and an adult-onset form, which are also characterized by low HEX A levels. There are also apparently healthy adults with low HEX A activity. Based primarily on data from population screening for TSD carrier status, we estimate the allele frequency of the combined variant alleles for which data a...

  7. Genotype and allele frequency of CYP2C19*17 in a healthy Iranian population

    OpenAIRE

    Payan, Maryam; Tajik, Nader; Rouini, Mohammad Reza; Ghahremani, Mohammad Hossein

    2015-01-01

    Background: Cytochrome P450 2C19 (CYP2C19) is important in metabolism of wide range of drugs. CYP2C19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (URM). Distribution of this variant allele has not been well studied worldwide. The aim of present study was to investigate allele and genotype frequencies of CYP2C19*17 in a healthy Iranian population and compare them with other ethnic groups. Methods: One hundred eighty...

  8. A novel simple method for determining CYP2D6 gene copy number and identifying allele(s with duplication/multiplication.

    Directory of Open Access Journals (Sweden)

    Taimour Langaee

    Full Text Available Cytochrome P450 2D6 (CYP2D6 gene duplication and multiplication can result in ultrarapid drug metabolism and therapeutic failure or excessive response in patients. Long range polymerase chain reaction (PCR, restriction fragment length polymorphism (RFLP and sequencing are usually used for genotyping CYP2D6 duplication/multiplications and identification, but are labor intensive, time consuming, and costly.We developed a simple allele quantification-based Pyrosequencing genotyping method that facilitates CYP2D6 copy number variation (CNV genotyping while also identifying allele-specific CYP2D6 CNV in heterozygous samples. Most routine assays do not identify the allele containing a CNV. A total of 237 clinical and Coriell DNA samples with different known CYP2D6 gene copy numbers were genotyped for CYP2D6 *2, *3, *4, *6, *10, *17, *41 polymorphisms and CNV determination.The CYP2D6 gene allele quantification/identification were determined simultaneously with CYP2D6*2, *3, *4, *6, *10, *17, *41 genotyping. We determined the exact CYP2D6 gene copy number, identified which allele had the duplication or multiplication, and assigned the correct phenotype and activity score for all samples.Our method can efficiently identify the duplicated CYP2D6 allele in heterozygous samples, determine its copy number in a fraction of time compared to conventional methods and prevent incorrect ultrarapid phenotype calls. It also greatly reduces the cost, effort and time associated with CYP2D6 CNV genotyping.

  9. Differences in the ability to suppress interferon β production between allele A and allele B NS1 proteins from H10 influenza A viruses

    Directory of Open Access Journals (Sweden)

    Zohari Siamak

    2010-12-01

    Full Text Available Abstract Background In our previous study concerning the genetic relationship among H10 avian influenza viruses with different pathogenicity in mink (Mustela vison, we found that these differences were related to amino acid variations in the NS1 protein. In this study, we extend our previous work to further investigate the effect of the NS1 from different gene pools on type I IFN promoter activity, the production of IFN-β, as well as the expression of the IFN-β mRNA in response to poly I:C. Results Using a model system, we first demonstrated that NS1 from A/mink/Sweden/84 (H10N4 (allele A could suppress an interferon-stimulated response element (ISRE reporter system to about 85%. The other NS1 (allele B, from A/chicken/Germany/N/49 (H10N7, was also able to suppress the reporter system, but only to about 20%. The differences in the abilities of the two NS1s from different alleles to suppress the ISRE reporter system were clearly reflected by the protein and mRNA expressions of IFN-β as shown by ELISA and RT-PCR assays. Conclusions These studies reveal that different non-structural protein 1 (NS1 of influenza viruses, one from allele A and another from allele B, show different abilities to suppress the type I interferon β expression. It has been hypothesised that some of the differences in the different abilities of the alleles to suppress ISRE were because of the interactions and inhibitions at later stages from the IFN receptor, such as the JAK/STAT pathway. This might reflect the additional effects of the immune evasion potential of different NS1s.

  10. The HLA-DRB1 allele polymorphisms and nasopharyngeal carcinoma.

    Science.gov (United States)

    Yang, Huimin; Yu, Kaihui; Zhang, Ruoheng; Li, Jiatong; Wei, Xiaomou; Zhang, Yuening; Zhang, Chengdong; Xiao, Feifan; Zhao, Dong; Lin, Xuandong; Wu, Huayu; Yang, Xiaoli

    2016-06-01

    Human leukocyte antigen (HLA)-DRB1 has been reported to influence individual's susceptibility to nasopharyngeal carcinoma (NPC) by many studies in recent years; however, these studies provided controversial results. The meta-analysis was thus conducted here to estimate the relationship between HLA-DRB1 polymorphisms and NPC. After an extensive review of journals from various databases (PubMed, the Web of Science, Embase, China National Knowledge Internet (CNKI), and Wanfang Database), 8 out of 69 case-control studies, including 778 cases and 1148 controls, were extracted. The results showed that 4 of 13 polymorphisms allele are statistically significantly associated with NPC, among them, HLA-DRB1*3, HLA-DRB1*9, and HLA-DRB1*10 may increase the risk of NPC while HLA-DRB1*01 has the opposite effect. The pooled odds ratio and 95 % confidence interval (CI) were 1.702 [95 % CI (1.047, 2.765)], 1.363 [95 % CI (1.029, 1.806)], 1.989 [95 % CI (1.042, 3.799)], and 0.461 [95 % CI (0.315, 0.676)], respectively. In a further ethnicity-based subgroup analysis, HLA-DRB1*08, HLA-DRB1*11, and HLA-DRB1*16 were found to be linked with NPC in Asian, Tunisian, and Caucasian, respectively. In Asian, HLA-DRB1*03, 08, and 10 may elevate the risk whereas HLA-DRB1*09 could lower it. In Tunisian, HLA-DRB1*01 and 11 are the protective factors while HLA-DRB1*03 is the only risk factor. In Caucasian, HLA-DRB1*01 and 03 increase the risk and HLA-DRB1*16 lowers it. The most frequent statistically associated gene is found to be HLA-DRB1*03 which has protective influence on Asian and Tunisian. In conclusion, HLA-DRB1*01, DRB1*03, DRB1*09, and DRB1*10 are related with NPC susceptibility, and the association of HLA-DRB1*08, DRB1*11, and DRB1*16 with NPC risk are significantly different in different ethnicities. PMID:27059731

  11. Quantitative threefold allele-specific PCR (QuanTAS-PCR) for highly sensitive JAK2 V617F mutant allele detection

    International Nuclear Information System (INIS)

    The JAK2 V617F mutation is the most frequent somatic change in myeloproliferative neoplasms, making it an important tumour-specific marker for diagnostic purposes and for the detection of minimal residual disease. Sensitive quantitative assays are required for both applications, particularly for the monitoring of minimal residual disease, which requires not only high sensitivity but also very high specificity. We developed a highly sensitive probe-free quantitative mutant-allele detection method, Quantitative Threefold Allele-Specific PCR (QuanTAS-PCR), that is performed in a closed-tube system, thus eliminating the manipulation of PCR products. QuantTAS-PCR uses a threefold approach to ensure allele-specific amplification of the mutant sequence: (i) a mutant allele-specific primer, (ii) a 3′dideoxy blocker to suppress false-positive amplification from the wild-type template and (iii) a PCR specificity enhancer, also to suppress false-positive amplification from the wild-type template. Mutant alleles were quantified relative to exon 9 of JAK2. We showed that the addition of the 3′dideoxy blocker suppressed but did not eliminate false-positive amplification from the wild-type template. However, the addition of the PCR specificity enhancer near eliminated false-positive amplification from the wild-type allele. Further discrimination between true and false positives was enabled by using the quantification cycle (Cq) value of a single mutant template as a cut-off point, thus enabling robust distinction between true and false positives. As 10,000 JAK2 templates were used per replicate, the assay had a sensitivity of 1/10-4 per replicate. Greater sensitivity could be reached by increasing the number of replicates analysed. Variation in replicates when low mutant-allele templates were present necessitated the use of a statistics-based approach to estimate the load of mutant JAK2 copies. QuanTAS-PCR showed comparable quantitative results when validated against a

  12. Seasonal Changes in Brain Serotonin Transporter Binding in Short Serotonin Transporter Linked Polymorphic Region-Allele Carriers but Not in Long-Allele Homozygotes

    DEFF Research Database (Denmark)

    Kalbitzer, Jan; Erritzoe, David; Holst, Klaus K;

    2010-01-01

    ) binding in 57 healthy Scandinavians and related the outcome to season of the year and to the 5-HTTLPR carrier status. Results: We found that the number of daylight minutes at the time of scanning correlated negatively with 5-HTT binding in the putamen and the caudate, with a similar tendency...... of the short 5-HTTLPR allele but not in homozygote carriers of the long allele. Conclusions: Our findings are in line with S-carriers having an increased response in neural circuits involved in emotional processing to stressful environmental stimuli but here demonstrated as a endophenotype with dynamic changes...

  13. MULTIPRED2: A computational system for large-scale identification of peptides predicted to bind to HLA supertypes and alleles

    DEFF Research Database (Denmark)

    Zhang, Guang Lan; DeLuca, David S.; Keskin, Derin B.;

    2011-01-01

    MULTIPRED2 is a computational system for facile prediction of peptide binding to multiple alleles belonging to human leukocyte antigen (HLA) class I and class II DR molecules. It enables prediction of peptide binding to products of individual HLA alleles, combination of alleles, or HLA supertypes...

  14. Allele frequency changes due to hitch-hiking in genomic selection programs

    DEFF Research Database (Denmark)

    Liu, Huiming; Sørensen, Anders Christian; Meuwissen, Theo H E;

    2014-01-01

    Background Genomic selection makes it possible to reduce pedigree-based inbreeding over best linear unbiased prediction (BLUP) by increasing emphasis on own rather than family information. However, pedigree inbreeding might not accurately reflect the loss of genetic variation and the true level of...... inbreeding due to changes in allele frequencies and hitch-hiking. This study aimed at understanding the impact of using long-term genomic selection on changes in allele frequencies, genetic variation and the level of inbreeding. Methods Selection was performed in simulated scenarios with a population of 400......-BLUP, Genomic BLUP and Bayesian Lasso. Changes in allele frequencies at QTL, markers and linked neutral loci were investigated for the different selection criteria and different scenarios, along with the loss of favourable alleles and the rate of inbreeding measured by pedigree and runs of homozygosity. Results...

  15. Polymorphic allele of human IRGM1 is associated with susceptibility to tuberculosis in African Americans.

    Directory of Open Access Journals (Sweden)

    Katherine Y King

    Full Text Available An ancestral polymorphic allele of the human autophagy-related gene IRGM1 is associated with altered gene expression and a genetic risk for Crohn's Disease (CD. We used the single nucleotide polymorphism rs10065172C/T as a marker of this polymorphic allele and genotyped 370 African American and 177 Caucasian tuberculosis (TB cases and 180 African American and 110 Caucasian controls. Among African Americans, the TB cases were more likely to carry the CD-related T allele of rs10065172 (odds ratio of 1.54; 95% confidence interval, 1.17-2.02; P<0.01 compared to controls. Our finding suggests that this CD-related IRGM1 polymorphic allele is also associated with human susceptibility to TB disease among African Americans.

  16. Identification of seven novel HLA class I alleles in New Zealand.

    Science.gov (United States)

    Lamb, G; Choi, K-L; Selwyn, C; Wheeler, A; Hammond, L; Morgan, J; Dunn, P P J

    2015-10-01

    Seven new HLA class I alleles have been identified in the New Zealand population in the process of routine HLA typing and they are described here. Unusual bead positivity in Luminex typing identified potential new alleles in a bone marrow registry donor (B*40:285) and two HIV patients prior to abacavir prescription (B*14:02:09, B*41:29). In addition, four new class I alleles were identified through class I sequencing-based typing (SBT) outside of exons 2 and 3. One mutation was identified in exon 4 (new allele C*12:125) and three have been found in exon 5, an exon rarely sequenced. Two stem cell transplant recipients (B*07:02:45, C*03:279) had novel mutations in exon 5 and one was found in exon 5 of a potentially matched unrelated donor from DKMS, previously thought to be B*40:02:01 (B*40:303). PMID:26212036

  17. Evidence for a genetic association between alleles of monoamine oxidase A gene and bipolar affective disorder

    Energy Technology Data Exchange (ETDEWEB)

    Lim, L.C.C.; Sham, P.; Castle, D. [Institute of Psychiatry, London (United Kingdom)] [and others

    1995-08-14

    We present evidence of a genetic association between bipolar disorder and alleles at 3 monoamine oxidase A (MAOA) markers, but not with alleles of a monoamine oxidase B (MAOB) polymorphism. The 3 MAOA markers, including one associated with low MAOA activity, show strong allelic association with each other but surprisingly not with MAOB. Our results are significantly only for females, though the number of males in our sample is too small to draw any definite conclusions. Our data is consistent with recent reports of reduced MAOA activity in patients with abnormal behavioral phenotypes. The strength of the association is weak, but significant, which suggests that alleles at the MAOA locus contribute to susceptibility to bipolar disorder rather than being a major determinant. 58 refs., 1 fig., 3 tabs.

  18. HLA-B27 allele frequency in Sri Lankan patients with spondyloarthritides.

    Science.gov (United States)

    Kidnapillai, S; Sirisena, N D; Dissanayake, V H

    2016-06-01

    This preliminary study aims to describe the HLA-B27 allele frequency in Sri Lankan patients with spondyloarthritides (SA). An anonymised database of 373 Sri Lankan patients with SA referred for HLA-B27 testing was retrospectively analysed. Eighty five (22.8%) patients were positive for the HLA-B27 allele. A male preponderance was observed among the positives. The HLA-B27 allele frequency in this sample of patients with SA was relatively low compared to published studies in other populations. Further research is needed to identify the predominant subtypes of the allele to determine which subtypes are the most prevalent in a larger sample of Sri Lankan patients with SA, and to define their association with the specific types of SA. PMID:27423748

  19. Using multi-locus allelic sequence data to estimate genetic divergence among four Lilium (Liliaceae cultivars

    Directory of Open Access Journals (Sweden)

    Arwa eShahin

    2014-10-01

    Full Text Available Next Generation Sequencing (NGS may enable estimating relationships among genotypes using allelic variation of multiple nuclear genes simultaneously. We explored the potential and caveats of this strategy in four genetically distant Lilium cultivars to estimate their genetic divergence from transcriptome sequences using three approaches: POFAD (Phylogeny of Organisms from Allelic Data, uses allelic information of sequence data, RAxML (Randomized Accelerated Maximum Likelihood, tree building based on concatenated consensus sequences and Consensus Network (constructing a network summarizing among gene tree conflicts. Twenty six gene contigs were chosen based on the presence of orthologous sequences in all cultivars, seven of which also had an orthologous sequence in Tulipa, used as out-group. The three approaches generated the same topology. Although the resolution offered by these approaches is high, in this case there was no extra benefit in using allelic information. We conclude that these 26 genes can be widely applied to construct a species tree for the genus Lilium.

  20. Phenotypic instability of Arabidopsis alleles affecting a disease Resistance gene cluster

    Directory of Open Access Journals (Sweden)

    Richards Eric J

    2008-04-01

    Full Text Available Abstract Background Three mutations in Arabidopsis thaliana strain Columbia – cpr1, snc1, and bal – map to the RPP5 locus, which contains a cluster of disease Resistance genes. The similar phenotypes, gene expression patterns, and genetic interactions observed in these mutants are related to constitutive activation of pathogen defense signaling. However, these mutant alleles respond differently to various conditions. Exposure to mutagens, such as ethyl methanesulfonate (EMS and γ-irradiation, induce high frequency phenotypic instability of the bal allele. In addition, a fraction of the bal and cpr1 alleles segregated from bal × cpr1 F1 hybrids also show signs of phenotypic instability. To gain more insight into the mechanism of phenotypic instability of the bal and cpr1 mutations, we systematically compared the behavior of these unusual alleles with that of the missense gain-of-function snc1 allele in response to DNA damage or passage through F1 hybrids. Results We found that the cpr1 allele is similar to the bal allele in its unstable behavior after EMS mutagenesis. For both the bal and cpr1 mutants, destabilization of phenotypes was observed in more than 10% of EMS-treated plants in the M1 generation. In addition, exceptions to simple Mendelian inheritance were identified in the M2 generation. Like cpr1 × bal F1 hybrids, cpr1 × snc1 F1 hybrids and bal × snc1 F1 hybrids exhibited dwarf morphology. While only dwarf F2 plants were produced from bal × snc1 F1 hybrids, about 10% wild-type F2 progeny were produced from cpr1 × snc1 F1 hybrids, as well as from cpr1 × bal hybrids. Segregation analysis suggested that the cpr1 allele in cpr1 × snc1 crosses was destabilized during the late F1 generation to early F2 generation. Conclusion With exposure to EMS or different F1 hybrid contexts, phenotypic instability is induced for the bal and cpr1 alleles, but not for the snc1 allele. Our results suggest that the RPP5 locus can adopt different

  1. Genetic tests for alleles of complementary-sex-determiner to support honeybee breeding programmes

    OpenAIRE

    Hyink, Otto; Laas, Frans; Dearden, Peter

    2013-01-01

    International audience The honeybee haplodiploid sex determination system depends on genetic variation at the complementary sex-determiner (csd) locus. In closed populations of honeybees, especially those undergoing selective breeding, the number of csd alleles can drop such that brood viability is affected. Here we present two polymerase chain reaction tests that allow the discrimination of csd alleles. Such tests should find utility in bee breeding programmes allowing the tracking and ma...

  2. SIMPLIFYING CELIAC DISEASE PREDISPOSING HLA-DQ ALLELES DETERMINATION BY THE REAL TIME PCR METHOD

    Directory of Open Access Journals (Sweden)

    Nicole SELLESKI

    2015-06-01

    Full Text Available Background Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Genetic susceptibility is associated with two sets of alleles, DQA1*05 - DQB1*02 and DQA1*03 - DQB1*03:02, which code for class II MHC DQ2 and DQ8 molecules, respectively. Approximately 90%-95% of celiac patients are HLA-DQ2 positive, and half of the remaining patients are HLA-DQ8 positive. In fact, during a celiac disease diagnostic workup, the absence of these specific DQA and DQB alleles has a near perfect negative predictive value. Objective Improve the detection of celiac disease predisposing alleles by combining the simplicity and sensitivity of real-time PCR (qPCR and melting curve analysis with the specificity of sequence-specific primers (SSP. Methods Amplifications of sequence-specific primers for DQA1*05 (DQ2, DQB1*02 (DQ2, and DQA1*03 (DQ8 were performed by the real time PCR method to determine the presence of each allele in independent reactions. Primers for Human Growth Hormone were used as an internal control. A parallel PCR-SSP protocol was used as a reference method to validate our results. Results Both techniques yielded equal results. From a total of 329 samples the presence of HLA predisposing alleles was determined in 187 (56.8%. One hundred fourteen samples (61% were positive for a single allele, 68 (36.3% for two alleles, and only 5 (2.7% for three alleles. Conclusion Results obtained by qPCR technique were highly reliable with no discordant results when compared with those obtained using PCR-SSP.

  3. ACTN3 Allele Frequency in Humans Covaries with Global Latitudinal Gradient

    OpenAIRE

    Friedlander, Scott M.; Herrmann, Amanda L.; Lowry, Daniel P.; Mepham, Emily R.; Lek, Monkol; North, Kathryn N.; Organ, Chris L.

    2013-01-01

    A premature stop codon in ACTN3 resulting in α-actinin-3 deficiency (the ACTN3 577XX genotype) is common in humans and reduces strength, muscle mass, and fast-twitch fiber diameter, but increases the metabolic efficiency of skeletal muscle. Linkage disequilibrium data suggest that the ACTN3 R577X allele has undergone positive selection during human evolution. The allele has been hypothesized to be adaptive in environments with scarce resources where efficient muscle metabolism would be select...

  4. Allele frequencies and segregation of human polymorphic keratins K4 and K5.

    OpenAIRE

    Mischke, D; Wille, G; Wild, A G

    1990-01-01

    Two electrophoretic variants for each of the human keratins K4 and K5 that are expressed in squamous nonkeratinizing epithelia lining the upper digestive tract could be distinguished on SDS-PAGE. Based on a sampling size of 1,299 unrelated individuals, calculation of allele frequencies showed the alleles to be in Hardy-Weinberg equilibrium. The genetic basis of this variation was confirmed by both quantitative gene dosage dependence and the transmission of the variants as Mendelian traits in ...

  5. Detectings low introgression of invasive alleles in an extensively restocked game bird

    OpenAIRE

    Sánchez Donoso, Inés; Huisman, J.; Echegaray, J.; Puigcerver Oliván, Manuel; Rodríguez Teijeiro, José Domingo; Hailer, F.; Vilà i Arbonès, Carles

    2014-01-01

    Interbreeding of two species in the wild implies introgression of alleles from one species into the other only when admixed individuals survive and successfully backcross with the parental species. Consequently, estimating the proportion of first generation hybrids in a population may not inform about the evolutionary impact of hybridization. Samples obtained over a long time span may offer a more accurate view of the spreading of introgressed alleles in a species" gene pool. Common quail (Co...

  6. Analysis of FBN1 allele expression by dermal fibroblasts from Marfan syndrome patients

    Energy Technology Data Exchange (ETDEWEB)

    Putman, E.A.; Cao, S.N.; Milewicz, D.M. [Univ. of Texas Medical School, Houston, TX (United States)

    1994-09-01

    Screening for mutations in the FBN1 cDNA from Marfan patient cell strains has detected mutations in only 10-15% of patients. In an attempt to explain this poor detection rate, we examined FBN1 allele expression and fibrillin synthesis by 26 cell strains from Marfan patients. DNA from the patients and 10 controls was assessed for the presence of a polymorphic Rsa I restriction site in the 3{prime} untranslated region of the FBN1 gene. Twelve of 26 patient and 5 of 10 control DNAs were heterozygous. Fibroblast RNA from the heterozygous cell strains was reverse-transcribed and subsequently PCR amplified using a [{sup 32}P]-labelled primer, digested with Rsa I and analyzed. Although 3 samples showed no transcript from one allele by ethidium bromide staining, a Betagen scanner detected low levels (10-15%) of that allele. In addition, there was unequal expression of the two alleles in three other patients; for example, only 30% expression from one allele. The remaining patients and the controls had equal expression of each allele. Fibrillin protein synthesis by fibroblasts from these heterozygous patients was also examined. After a 30 minute pulse with [{sup 35}S]-cysteine, cell lysates were collected and proteins analyzed by SDS-PAGE. The amount of fibrillin produced relative to a reference protein was determined using a Betagen scanner. Fibrillin protein synthesis was reduced in 2 of the 3 patients with very low RNA production from one of the FBN1 alleles. All other Marfan and control cell strains showed normal amounts of fibrillin synthesized. The low expression levels from one allele may contribute to, but not fully account for, the low detection rate of FBN1 mutations. Interestingly, protein synthesis levels were not affected in 4 of 6 cell strains demonstrating low levels of RNA expression.

  7. HLA Class II Allele and Haplotype Frequencies in Iranian Patients with Leukemia

    Directory of Open Access Journals (Sweden)

    Farideh Khosravi

    2007-09-01

    Full Text Available Previous studies demonstrated significant differences in a number of HLA allele frequencies in leukemia patients and normal subjects. In this study, we have analyzed HLA class II alleles and haplotypes in 110 leukemia patients (60 acute myelogenous leukemia "AML", 50 chronic myelogenous leukemia"CML" and 180 unrelated normal subjects. Blood samples were collected from all of the patients and control subjects. DNA was extracted by salting out method and HLA typing was performed using PCR-SSP method. Significant positive association with AML was obtained for HLA-DRB1*11allele (35% vs. 24.7%, P=0.033. Two alleles including HLA-DRB4 and -DQB1*0303 were significantly less frequent in AML patients than in controls. HLA-DQB1*0303 allele was never observed in CML patients compared with allele frequency in controls (4.2%. According to haplotype analysis, HLA-DRB1*0101/DQA1*0104/-DQB1*0501 frequencies were significantly higher and -DRB1*16/-DQA1*01021/-DQB1*0501 frequencies were significantly lower in CML patients than in controls .In conclusion it is suggested that HLA-DRB1*16 allele and HLA-DRB1*15/-DQA1*0103/-DQB1*06011 and -DRB1*16/-DQA1*01021/-DQB1*0501 haplotypes predispose individuals to AML and HLA-DRB4 allele predispose to CML. Future studies are needed to confirm these results and establish the role of these associations in AML and CML.

  8. Heterozygosity for the alpha1-antitrypsin Z allele may confer genetic risk of cholangiocarcinoma

    OpenAIRE

    Mihalache, Florentina; HÖBLINGER, AKSANA; Grünhage, Frank; Krawczyk, Marcin; Gärtner, Barbara C.; Acalovschi, Monica; Sauerbruch, Tilman; Lammert, Frank; Zimmer, Vincent

    2010-01-01

    Abstract Background & Aim: Alpha1-antitrypsin (?1AT) deficiency caused by Z allele homozygosity represents a risk factor for hepatocellular carcinoma. Previous studies have implicated ?1AT Z heterozygosity in cholangiocarcinogenesis. We assessed the ?common? Z and S alleles as well as the promoter variant rs8004738 for association with cholangiocarcinoma (CCA). Patients & Methods: We genotyped 182 Caucasian patients and 350 controls for rs28929474 (Z), rs17580 (S) and the varia...

  9. The lipoprotein lipase gene in combined hyperlipidemia: evidence of a protective allele depletion

    OpenAIRE

    Malloy Mary J; Pullinger Clive R; Kulkarni Medha V; Wung Shu-Fen; Kane John P; Aouizerat Bradley E

    2006-01-01

    Abstract Background Lipoprotein Lipase (LPL), a key enzyme in lipid metabolism, catalyzes the hydrolysis of triglycerides (TG) from TG-rich lipoproteins, and serves a bridging function that enhances the cellular uptake of lipoproteins. Abnormalities in LPL function are associated with pathophysiological conditions, including familial combined hyperlipidemia (FCH). Whereas two LPL susceptibility alleles were found to co-segregate in a few FCH kindred, a role for common, protective alleles rema...

  10. No evidence for allelic association between bipolar disorder and monoamine oxidase A gene polymorphisms

    Energy Technology Data Exchange (ETDEWEB)

    Craddock, N.; Daniels, J.; Roberts, E. [Univ. of Wales, College of Medicine, Cardiff (United Kingdom)] [and others

    1995-08-14

    We have tested the hypothesis that DNA markers in the MAOA gene show allelic association with bipolar affective disorder. Eighty-four unrelated Caucasian patients with DSM III-R bipolar disorder and 84 Caucasian controls were typed for three markers in MAOA: a dinucleotide repeat in intron 2, a VNTR in intron 1, and an Fnu4HI RFLP in exon 8. No evidence for allelic association was observed between any of the markers and bipolar disorder. 9 refs., 1 tab.

  11. Semi-parametric Allelic Tests For Mapping Multiple Phenotypes: Binomial Regression And Mahalanobis Distance

    Science.gov (United States)

    Majumdar, Arunabha; Witte, John S.; Ghosh, Saurabh

    2016-01-01

    Binary phenotypes commonly arise due to multiple underlying quantitative precursors. Genetic variants may impact multiple traits in a pleiotropic manner. Hence, simultaneously analyzing such correlated traits may be more powerful than analyzing individual traits. Various genotype-level methods, e.g. MultiPhen [O'Reilly et al., 2012], have been developed to identify genetic factors underlying a multivariate phenotype. For univariate phenotypes, the usefulness and applicability of allele-level tests have been investigated. The test of allele frequency difference among cases and controls is commonly used for mapping case-control association. However, allelic methods for multivariate association mapping have not been studied much. We explore two allelic tests of multivariate association: one using a Binomial regression model based on inverted regression of genotype on phenotype (BAMP), and the other employing the Mahalanobis distance between two sample means of the multivariate phenotype vector for two alleles at a SNP (DAMP). These methods can incorporate both discrete and continuous phenotypes. Some theoretical properties for BAMP are studied. Using simulations, the power of the methods for detecting multivariate association are compared with the genotype-level test MultiPhen. The allelic tests yield marginally higher power than MultiPhen for multivariate phenotypes. For one/two binary traits under recessive mode of inheritance, allelic tests are found substantially more powerful. All three tests are applied to two real data and the results offer some support for the simulation study. Since the allelic approaches assume Hardy-Weinberg Equilibrium (HWE), we propose a hybrid approach for testing multivariate association that implements MultiPhen when HWE is violated and BAMP otherwise. PMID:26493781

  12. Semiparametric Allelic Tests for Mapping Multiple Phenotypes: Binomial Regression and Mahalanobis Distance.

    Science.gov (United States)

    Majumdar, Arunabha; Witte, John S; Ghosh, Saurabh

    2015-12-01

    Binary phenotypes commonly arise due to multiple underlying quantitative precursors and genetic variants may impact multiple traits in a pleiotropic manner. Hence, simultaneously analyzing such correlated traits may be more powerful than analyzing individual traits. Various genotype-level methods, e.g., MultiPhen (O'Reilly et al. []), have been developed to identify genetic factors underlying a multivariate phenotype. For univariate phenotypes, the usefulness and applicability of allele-level tests have been investigated. The test of allele frequency difference among cases and controls is commonly used for mapping case-control association. However, allelic methods for multivariate association mapping have not been studied much. In this article, we explore two allelic tests of multivariate association: one using a Binomial regression model based on inverted regression of genotype on phenotype (Binomial regression-based Association of Multivariate Phenotypes [BAMP]), and the other employing the Mahalanobis distance between two sample means of the multivariate phenotype vector for two alleles at a single-nucleotide polymorphism (Distance-based Association of Multivariate Phenotypes [DAMP]). These methods can incorporate both discrete and continuous phenotypes. Some theoretical properties for BAMP are studied. Using simulations, the power of the methods for detecting multivariate association is compared with the genotype-level test MultiPhen's. The allelic tests yield marginally higher power than MultiPhen for multivariate phenotypes. For one/two binary traits under recessive mode of inheritance, allelic tests are found to be substantially more powerful. All three tests are applied to two different real data and the results offer some support for the simulation study. We propose a hybrid approach for testing multivariate association that implements MultiPhen when Hardy-Weinberg Equilibrium (HWE) is violated and BAMP otherwise, because the allelic approaches assume HWE

  13. Receptor-Mediated Uptake and Intracellular Sorting of Multivalent Lipid Nanoparticles Against the Epidermal Growth Factor Receptor (EGFR) and the Human EGFR 2 (HER2)

    Science.gov (United States)

    Tran, David Tu

    the experimental data, models were developed to help interpret and predict the binding and trafficking of lipid nanoparticles. The crosslink multivalent binding model of lipid nanoparticles to monovalent receptors was able to predict ligand valence for optimum binding, cell association concentrations, offer explanations to the antagonistic effects observed from high ligand valence, and predict the binding limitations of both ligand valence and ligand affinity. Hopefully, the models will serve as valuable tools for future optimizations in targeted liposomal drug delivery.

  14. The lipoprotein lipase gene in combined hyperlipidemia: evidence of a protective allele depletion

    Directory of Open Access Journals (Sweden)

    Malloy Mary J

    2006-07-01

    Full Text Available Abstract Background Lipoprotein Lipase (LPL, a key enzyme in lipid metabolism, catalyzes the hydrolysis of triglycerides (TG from TG-rich lipoproteins, and serves a bridging function that enhances the cellular uptake of lipoproteins. Abnormalities in LPL function are associated with pathophysiological conditions, including familial combined hyperlipidemia (FCH. Whereas two LPL susceptibility alleles were found to co-segregate in a few FCH kindred, a role for common, protective alleles remains unexplored. The LPL Ser447Stop (S447X allele is associated with anti-atherogenic lipid profiles and a modest reduction in risk for coronary disease. We hypothesize that significant depletion of the 447X allele exists in combined hyperlipidemia cases versus controls. A case-control design was employed. The polymorphism was assessed by restriction assay in 212 cases and 161 controls. Genotypic, allelic, and phenotypic associations were examined. Results We found evidence of significant allelic (447Xcontrol: 0.130 vs. 447Xcase: 0.031, χ2 = 29.085; 1df; p 2 = 26.09; 1df; p Conclusion These findings suggest a role for the S447X polymorphism in combined hyperlipidemia and demonstrate the importance of evaluating both susceptibility and protective genetic risk factors.

  15. Allelic variation of bile salt hydrolase genes in Lactobacillus salivarius does not determine bile resistance levels.

    LENUS (Irish Health Repository)

    Fang, Fang

    2009-09-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

  16. Human leukocyte antigen class II susceptibility conferring alleles among non-insulin dependent diabetes mellitus patients

    International Nuclear Information System (INIS)

    To determine the frequency of Human Leukocyte Antigen (HLA) class II susceptibility conferring alleles among type 2 Diabetes mellitus patients, in comparison with healthy controls. Cross-sectional comparative study. Patients with non-insulin dependent Diabetes mellitus meeting World Health Organization criteria were studied. These were compared with age and gender matched healthy control subjects. For each subject (patients as well as controls), DNA was extracted from ethylene diamine tetra-acetate sample and HLA class II DRB1 typing was carried out at allele group level (DRB1*01-DRB1*16) by sequence specific primers. Human leukocyte antigen DRB1 type was determined by agarose gel electrophoresis and results were recorded. Frequencies were determined as number of an allele divided by total number of alleles per group; p-value was computed using Pearson's chi-square test. Among the 100 patients, there were 63 males and 37 females with 68 controls. A total of 13 different HLA DRB1 alleles were detected, with DRB1*15 being the commonest in both the groups. The allele DRB1*13 had statistically significant higher frequency in patient group as compared to controls (p 0.005). HLA DRB1*13 was found with a significantly increased frequency in non-insulin dependent Diabetes mellitus. (author)

  17. Allelic association of the D2 dopamine receptor gene with cocaine dependence.

    Science.gov (United States)

    Noble, E P; Blum, K; Khalsa, M E; Ritchie, T; Montgomery, A; Wood, R C; Fitch, R J; Ozkaragoz, T; Sheridan, P J; Anglin, M D

    1993-10-01

    The objective of the present study was to examine allelic prevalence of the D2 dopamine receptor (DRD2) gene in male cocaine-dependent (CD) Caucasian (non-Hispanic) subjects and to determine the relationship of DRD2 alleles to family history and selected behavioral measures. The prevalence of the A1 allele in CD subjects (n = 53) was 50.9%. It was significantly higher than either the 16.0% prevalence (P abusing controls (n = 100) or the 30.9% prevalence (P abusers were not excluded. Similarly, a significantly higher prevalence (P abusing controls (n = 53); 38.5% vs. 13.2%. Logistic regression analysis of CD subjects identified potent routes of cocaine use and the interaction of early deviant behaviors and parental alcoholism as significant risk factors associated with the A1 allele. The cumulative number of these three risk factors in CD subjects was positively and significantly (P < 10(-3)) related to A1 allelic prevalence. The data showing a strong association of the minor alleles (A1 and B1) of the DRD2 with cocaine dependence suggest that a gene, located on the q22-q23 region of chromosome 11, confers susceptibility to this drug disorder. PMID:8261891

  18. The Burden of JAK2V617F Mutated Allele in Turkish Patients With Myeloproliferative Neoplasms

    Science.gov (United States)

    Yonal-Hindilerden, Ipek; Daglar-Aday, Aynur; Akadam-Teker, Basak; Yilmaz, Ceylan; Nalcaci, Meliha; Yavuz, Akif Selim; Sargin, Deniz

    2015-01-01

    Background Studies regarding the impact of JAK2V617F allele burden on phenotypic properties and clinical course in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) have reported variable results. We aimed to analyze the association of mutated JAK2V617F allele burden with laboratory characteristics and clinical phenotype in Turkish patients (107 essential thrombocythemia (ET) and 77 primary myelofibrosis (PMF)). Methods Peripheral blood samples of 184 patients with Ph-negative MPNs were analyzed for JAK2V617F allele status and burden. JAK2 MutaScreen assay (Ipsogen, Luminy Biotech, Marseille, France) was used to detect the JAK2V617F status and quantitative JAK2V617F allele burdens in genomic DNA using TaqMan allelic discrimination. Results Frequency of JAK2V617F-positive patients with high mutation load (allele burden > 50%) was higher in PMF compared to ET (23.4% and 4.7%, respectively; P = 0.001). We found significant association between ET patients with high JAK2V617F allele burden and lower hemoglobin (Hgb) and hematocrit (Hct), higher LDH levels and more prevalent massive splenomegaly (P = 0.001, P = 0.001, P = 0.012 and P = 0.015, respectively). ET patients with high mutation load displayed higher prevalence of bleeding compared to low mutation load and wild-type mutational status (P = 0.003). Rate of DVT was significantly higher in ET patients with mutant allele burden in upper half compared to lower half and wild-type (P = 0.029). We observed significant association between PMF patients with high JAK2V617F allele burden and higher Hgb, Hct levels and leukocyte counts (P = 0.003, P = 0.021 and P = 0.001, respectively). Conclusions Our study demonstrated JAK2V617F allele burden correlates with clinical features in ET and PMF. We conclude quantification of JAK2V617F mutation contributes to the workup of Ph-negative MPNs. PMID:25584101

  19. Simple allele-discriminating PCR for cost-effective and rapid genotyping and mapping

    Directory of Open Access Journals (Sweden)

    Bui Minh

    2009-01-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are widely observed between individuals, ecotypes, and species, serving as an invaluable molecular marker for genetic, genomic, ecological and evolutionary studies. Although, a large number of SNP-discriminating methods are currently available, few are suited for low-throughput and low-cost applications. Here, we describe a genotyping method named Simple Allele-discriminating PCR (SAP, which is ideally suited for the small-scale genotyping and gene mapping routinely performed in small to medium research or teaching laboratories. Results We demonstrate the feasibility and application of SAP to discriminate wild type alleles from their respective mutant alleles in Arabidopsis thaliana. Although the design principle was previously described, it is unclear if the method is technically robust, reliable, and applicable. Three primers were designed for each individual SNP or allele with two allele-discriminating forward primers (one for wild type and one for the mutant allele and a common reverse primer. The two allele-discriminating forward primers are designed so that each incorporates one additional mismatch at the adjacent (penultimate site from the SNP, resulting in two mismatches between the primer and its non-target template and one mismatch between the primer and its target template. The presence or absence of the wild type or the mutant allele correlates with the presence or absence of respective PCR product. The presence of both wild type-specific and mutant-specific PCR products would indicate heterozygosity. SAP is shown here to discriminate three mutant alleles (lug-3, lug-16, and luh-1 from their respective wild type alleles. In addition, the SAP principle is shown to work in conjunction with fluorophore-labeled primers, demonstrating the feasibility of applying SAP to high throughput SNP analyses. Conclusion SAP offers an excellent alternative to existing SNP

  20. Allelic associations of two polymorphic microsatellites in intron 40 of the human von Willebrand factor gene

    Energy Technology Data Exchange (ETDEWEB)

    Pena, S.D.J.; De Souza, K.T. (Nucleo de Genetica Medica de Minas Gerais, Belo Horizonte (Brazil)); De Andrade, M.; Chakraborty, R. (Univ. of Texas Graduate School of Biomedical Sciences, Houston, TX (United States))

    1994-01-18

    At intron 40 of the von Willebrand factor (vWF) gene, two GATA-repeat polymorphic sites exist that are physically separated by 212 bp. At the first site (vWF1 locus), seven segregating repeat alleles were observed in a Brazilian Caucasian population, and at the second (vWF2 locus) there were eight alleles, detected through PCR amplifications of this DNA region. Haplotype analysis of individuals revealed 36 different haplotypes in a sample of 338 chromosomes examined. Allele frequencies between generations and gender at each locus were not significantly different, and the genotype frequencies were consistent with their Hardy-Weinberg expectations. Linkage disequilibrium between loci is highly significant with positive allele size association; that is, large alleles at the loci tend to occur together, and so do the same alleles. Variability at each locus appeared to have arisen in a stepwise fashion, suggesting replication slippage as a possible mechanism of production of new alleles. However, the authors observed an increased number of haplotypes, in contrast with the predictions of a stepwise production of variation in the entire region, suggesting some form of cooperative changes between loci that could be due to either gene conversion, or a common control mechanism of production of new variation at these repeat polymorphism sites. The high degree of polymorphism (gene diversity values of 72% and 78% at vWF1 and vWF2, respectively, and of 93% at the haplotype level) makes these markers informative for paternity testing, genetic counseling, and individual-identification purposes.

  1. Allelic analysis of sheath blight resistance with association mapping in rice.

    Directory of Open Access Journals (Sweden)

    Limeng Jia

    Full Text Available Sheath blight (ShB caused by the soil-borne pathogen Rhizoctonia solani is one of the most devastating diseases in rice world-wide. Global attention has focused on examining individual mapping populations for quantitative trait loci (QTLs for ShB resistance, but to date no study has taken advantage of association mapping to examine hundreds of lines for potentially novel QTLs. Our objective was to identify ShB QTLs via association mapping in rice using 217 sub-core entries from the USDA rice core collection, which were phenotyped with a micro-chamber screening method and genotyped with 155 genome-wide markers. Structure analysis divided the mapping panel into five groups, and model comparison revealed that PCA5 with genomic control was the best model for association mapping of ShB. Ten marker loci on seven chromosomes were significantly associated with response to the ShB pathogen. Among multiple alleles in each identified loci, the allele contributing the greatest effect to ShB resistance was named the putative resistant allele. Among 217 entries, entry GSOR 310389 contained the most putative resistant alleles, eight out of ten. The number of putative resistant alleles presented in an entry was highly and significantly correlated with the decrease of ShB rating (r = -0.535 or the increase of ShB resistance. Majority of the resistant entries that contained a large number of the putative resistant alleles belonged to indica, which is consistent with a general observation that most ShB resistant accessions are of indica origin. These findings demonstrate the potential to improve breeding efficiency by using marker-assisted selection to pyramid putative resistant alleles from various loci in a cultivar for enhanced ShB resistance in rice.

  2. Enzymatic glycosylation of multivalent scaffolds

    Czech Academy of Sciences Publication Activity Database

    Bojarová, Pavla; Rosencrantz, R. R.; Elling, L.; Křen, Vladimír

    2013-01-01

    Roč. 42, č. 11 (2013), s. 4774-4797. ISSN 0306-0012 R&D Projects: GA MŠk(CZ) LD13042; GA ČR GAP207/10/0321 Institutional support: RVO:61388971 Keywords : N-ACETYLGLUCOSAMINYLTRANSFERASE-III * MUCIN TANDEM REPEAT * NEIGHBORING RESIDUE GLYCOSYLATION Subject RIV: CC - Organic Chemistry Impact factor: 30.425, year: 2013

  3. Frequency and characterization of known and novel RHD variant alleles in 37 782 Dutch D-negative pregnant women.

    Science.gov (United States)

    Stegmann, Tamara C; Veldhuisen, Barbera; Bijman, Renate; Thurik, Florentine F; Bossers, Bernadette; Cheroutre, Goedele; Jonkers, Remco; Ligthart, Peter; de Haas, Masja; Haer-Wigman, Lonneke; van der Schoot, C Ellen

    2016-05-01

    To guide anti-D prophylaxis, Dutch D- pregnant women are offered a quantitative fetal-RHD-genotyping assay to determine the RHD status of their fetus. This allowed us to determine the frequency of different maternal RHD variants in 37 782 serologically D- pregnant women. A variant allele is present in at least 0·96% of Dutch D- pregnant women The D- serology could be confirmed after further serological testing in only 54% of these women, which emphasizes the potential relevance of genotyping of blood donors. 43 different RHD variant alleles were detected, including 15 novel alleles (11 null-, 2 partial D- and 2 DEL-alleles). Of those novel null alleles, one allele contained a single missense mutation (RHD*443C>G) and one allele had a single amino acid deletion (RHD*424_426del). The D- phenotype was confirmed by transduction of human D- erythroblasts, consolidating that, for the first time, a single amino acid change or deletion causes the D- phenotype. Transduction also confirmed the phenotypes for the two new variant DEL-alleles (RHD*721A>C and RHD*884T>C) and the novel partial RHD*492C>A allele. Notably, in three additional cases the DEL phenotype was observed but sequencing of the coding sequence, flanking introns and promoter region revealed an apparently wild-type RHD allele without mutations. PMID:27018217

  4. Cytochrome P450 2D6 variants in a Caucasian population: Allele frequencies and phenotypic consequences

    Energy Technology Data Exchange (ETDEWEB)

    Sachse, C.; Brockmoeller, J.; Bauer, S.; Roots, I. [Humboldt Univ., Berlin (Germany)

    1997-02-01

    Cytochrome P450 2D6 (CYP2D6) metabolizes many important drugs. CYP2D6 activity ranges from complete deficiency to ultrafast metabolism, depending on at least 16 different known alleles. Their frequencies were determined in 589 unrelated German volunteers and correlated with enzyme activity measured by phenotyping with dextromethorphan or debrisoquine. For genotyping, nested PCR-RFLP tests from a PCR amplificate of the entire CYP2D6 gene were developed. The frequency of the CYP2D6*1 allele coding for extensive metabolizer (EM) phenotype was .364. The alleles coding for slightly (CYP2D6*2) or moderately (*9 and *10) reduced activity (intermediate metabolizer phenotype [IM]) showed frequencies of .324, .018, and .015, respectively. By use of novel PCR tests for discrimination, CYP2D6 gene duplication alleles were found with frequencies of.005 (*1 x 2), .013 (* 2 x 2), and .001 (*4 x 2). Frequencies of alleles with complete deficiency (poor metabolizer phenotype [PM]) were .207 (*4), .020 (*3 and *5), .009 (*6), and .001 (*7, *15, and *16). The defective CYP2D6 alleles *8, *11, *12, *13, and *14 were not found. All 41 PMs (7.0%) in this sample were explained by five mutations detected by four PCR-RFLP tests, which may suffice, together with the gene duplication test, for clinical prediction of CYP2D6 capacity. Three novel variants of known CYP2D6 alleles were discovered: *1C (T{sub 1957}C), *2B (additional C{sub 2558}T), and *4E (additional C{sub 2938}T). Analysis of variance showed significant differences in enzymatic activity measured by the dextromethorphan metabolic ratio (MR) between carriers of EN/PM (mean MR = .006) and IM/PM (mean MR = .014) alleles and between carriers of one (mean MR = .009) and two (mean MR = .003) functional alleles. The results of this study provide a solid basis for prediction of CYP2D6 capacity, as required in drug research and routine drug treatment. 35 refs., 4 figs., 5 tabs.

  5. Predicting Carriers of Ongoing Selective Sweeps without Knowledge of the Favored Allele

    Science.gov (United States)

    Zakov, Shay; Rosenberg, Noah A.; Bafna, Vineet

    2015-01-01

    Methods for detecting the genomic signatures of natural selection have been heavily studied, and they have been successful in identifying many selective sweeps. For most of these sweeps, the favored allele remains unknown, making it difficult to distinguish carriers of the sweep from non-carriers. In an ongoing selective sweep, carriers of the favored allele are likely to contain a future most recent common ancestor. Therefore, identifying them may prove useful in predicting the evolutionary trajectory—for example, in contexts involving drug-resistant pathogen strains or cancer subclones. The main contribution of this paper is the development and analysis of a new statistic, the Haplotype Allele Frequency (HAF) score. The HAF score, assigned to individual haplotypes in a sample, naturally captures many of the properties shared by haplotypes carrying a favored allele. We provide a theoretical framework for computing expected HAF scores under different evolutionary scenarios, and we validate the theoretical predictions with simulations. As an application of HAF score computations, we develop an algorithm (PreCIOSS: Predicting Carriers of Ongoing Selective Sweeps) to identify carriers of the favored allele in selective sweeps, and we demonstrate its power on simulations of both hard and soft sweeps, as well as on data from well-known sweeps in human populations. PMID:26402243

  6. GENETIC STRUCTURE AND ALLEL DIVERSITY OF THREE BALINESE GENERATIONS BASED ON FIVE AUTOSOMAL MICROSATELLITE DNA LOCI

    Directory of Open Access Journals (Sweden)

    Ayu Saka Laksmita

    2015-09-01

    Full Text Available This research was aimed to find out the genetic structures of three generations of Balinese population, in order to determine the best loci used for paternity testing among this population, and observed the mutation rate of these loci. The DNA samples were taken from the epithelium cell of 25 families which were collected from the children, father, mother, grandfather and grandmother of the children, from both mother and father sides (family with three generations. The DNA was extracted in Phenol-Chloroform method with modifications. DNA amplification was conducted in PCR method using pairs of primer 5, namely: FGA, D18S51, D2S1338, TPOX, and D16S539, and its products were electrophoresed and visualized in 10% of PAGE, stained in silver nitrate. The genetic structures of the three family generations showed 30 variants with different frequencies in each locus. The highest heterozygosity value was detected in FGA (8 alleles, then followed by D18S51 (7 alleles, TPOX (6 alleles, D16S539 (5 alleles, and the lowest was in D2S1338 (4 alleles. The highest value of heterozigosity and Power of Discrimination were found in FGA, followed by TPOX, D18S51, D2S1338, and the lowest was in D16S539. Therefore, it can be concluded that out of five loci tested, 4 of them can be recommended to be used for paternity testing of Balinese population, except D16S539

  7. SNPsplit: Allele-specific splitting of alignments between genomes with known SNP genotypes.

    Science.gov (United States)

    Krueger, Felix; Andrews, Simon R

    2016-01-01

    Sequencing reads overlapping polymorphic sites in diploid mammalian genomes may be assigned to one allele or the other. This holds the potential to detect gene expression, chromatin modifications, DNA methylation or nuclear interactions in an allele-specific fashion. SNPsplit is an allele-specific alignment sorter designed to read files in SAM/BAM format and determine the allelic origin of reads or read-pairs that cover known single nucleotide polymorphic (SNP) positions. For this to work libraries must have been aligned to a genome in which all known SNP positions were masked with the ambiguity base 'N' and aligned using a suitable mapping program such as Bowtie2, TopHat, STAR, HISAT2, HiCUP or Bismark. SNPsplit also provides an automated solution to generate N-masked reference genomes for hybrid mouse strains based on the variant call information provided by the Mouse Genomes Project. The unique ability of SNPsplit to work with various different kinds of sequencing data including RNA-Seq, ChIP-Seq, Bisulfite-Seq or Hi-C opens new avenues for the integrative exploration of allele-specific data. PMID:27429743

  8. Allelic losses in mouse skin tumors induced by {gamma}-irradiation of p53 heterozygotes

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, Tomonori; Sato, Hiroki; Hatakeyama, Katsuyoshi; Kominami, Ryo [Niigata Univ. (Japan). Graduate School of Medical and Dental Sciences; Kitagawa, Tomoyuki [Cancer Inst., Tokyo (Japan)

    2002-09-01

    Skin tumors were induced by {gamma}-irradiation in F{sub 1} mice between C3H/He or BALB/c and MSM carrying a p53-deficient allele. The incidence was 39.1% (34/87) in p53(KO/+) mice of the C3H/MSM genetic background and 14.3% (19/133) in those of the BALB/MSM background. Interestingly, most of the tumors (82%) lost the wild-type p53 allele and no skin tumor was found in p53(+/+) F{sub 1} mice. This suggests a requirement of p53 loss for the skin cancer development. Genome scan localized a chromosomal locus showing frequent allelic losses near D12Mit2, which may harbor a tumor suppressor gene. In addition, 23 loci distributed on 13 chromosomes exhibited allelic losses at frequencies of more than 20%. The genome-wide occurrence of allelic losses suggests that genomic instability of the skin tumors may be implicated in radiation-induced carcinogenesis. The present study is the first to report a mouse model system useful for the analysis of radiation induction of skin cancer in man. (author)

  9. Genome Destabilizing Mutator Alleles Drive Specific Mutational Trajectories in Saccharomyces cerevisiae

    Science.gov (United States)

    Stirling, Peter C.; Shen, Yaoqing; Corbett, Richard; Jones, Steven J. M.; Hieter, Philip

    2014-01-01

    In addition to environmental factors and intrinsic variations in base substitution rates, specific genome-destabilizing mutations can shape the mutational trajectory of genomes. How specific alleles influence the nature and position of accumulated mutations in a genomic context is largely unknown. Understanding the impact of genome-destabilizing alleles is particularly relevant to cancer genomes where biased mutational signatures are identifiable. We first created a more complete picture of cellular pathways that impact mutation rate using a primary screen to identify essential Saccharomyces cerevisiae gene mutations that cause mutator phenotypes. Drawing primarily on new alleles identified in this resource, we measure the impact of diverse mutator alleles on mutation patterns directly by whole-genome sequencing of 68 mutation-accumulation strains derived from wild-type and 11 parental mutator genotypes. The accumulated mutations differ across mutator strains, displaying base-substitution biases, allele-specific mutation hotspots, and break-associated mutation clustering. For example, in mutants of POLα and the Cdc13–Stn1–Ten1 complex, we find a distinct subtelomeric bias for mutations that we show is independent of the target sequence. Together our data suggest that specific genome-instability mutations are sufficient to drive discrete mutational signatures, some of which share properties with mutation patterns seen in tumors. Thus, in a population of cells, genome-instability mutations could influence clonal evolution by establishing discrete mutational trajectories for genomes. PMID:24336748

  10. Allele-Independent Turnover of Human Leukocyte Antigen (HLA) Class Ia Molecules.

    Science.gov (United States)

    Prevosto, Claudia; Usmani, M Farooq; McDonald, Sarah; Gumienny, Aleksandra M; Key, Tim; Goodman, Reyna S; Gaston, J S Hill; Deery, Michael J; Busch, Robert

    2016-01-01

    Major histocompatibility complex class I (MHCI) glycoproteins present cytosolic peptides to CD8+ T cells and regulate NK cell activity. Their heavy chains (HC) are expressed from up to three MHC gene loci (human leukocyte antigen [HLA]-A, -B, and -C in humans), whose extensive polymorphism maps predominantly to the antigen-binding groove, diversifying the bound peptide repertoire. Codominant expression of MHCI alleles is thus functionally critical, but how it is regulated is not fully understood. Here, we have examined the effect of polymorphism on the turnover rates of MHCI molecules in cell lines with functional MHCI peptide loading pathways and in monocyte-derived dendritic cells (MoDCs). Proteins were labeled biosynthetically with heavy water (2H2O), folded MHCI molecules immunoprecipitated, and tryptic digests analysed by mass spectrometry. MHCI-derived peptides were assigned to specific alleles and isotypes, and turnover rates quantified by 2H incorporation, after correcting for cell growth. MHCI turnover half-lives ranged from undetectable to a few hours, depending on cell type, activation state, donor, and MHCI isotype. However, in all settings, the turnover half-lives of alleles of the same isotype were similar. Thus, MHCI protein turnover rates appear to be allele-independent in normal human cells. We propose that this is an important feature enabling the normal function and codominant expression of MHCI alleles. PMID:27529174

  11. Allele-specific copy number profiling by next-generation DNA sequencing.

    Science.gov (United States)

    Chen, Hao; Bell, John M; Zavala, Nicolas A; Ji, Hanlee P; Zhang, Nancy R

    2015-02-27

    The progression and clonal development of tumors often involve amplifications and deletions of genomic DNA. Estimation of allele-specific copy number, which quantifies the number of copies of each allele at each variant loci rather than the total number of chromosome copies, is an important step in the characterization of tumor genomes and the inference of their clonal history. We describe a new method, falcon, for finding somatic allele-specific copy number changes by next generation sequencing of tumors with matched normals. falcon is based on a change-point model on a bivariate mixed Binomial process, which explicitly models the copy numbers of the two chromosome haplotypes and corrects for local allele-specific coverage biases. By using the Binomial distribution rather than a normal approximation, falcon more effectively pools evidence from sites with low coverage. A modified Bayesian information criterion is used to guide model selection for determining the number of copy number events. Falcon is evaluated on in silico spike-in data and applied to the analysis of a pre-malignant colon tumor sample and late-stage colorectal adenocarcinoma from the same individual. The allele-specific copy number estimates obtained by falcon allows us to draw detailed conclusions regarding the clonal history of the individual's colon cancer. PMID:25477383

  12. HLA-DQA1/B1 alleles as putative susceptibility markers in congenital toxoplasmosis.

    Science.gov (United States)

    Shimokawa, Paulo Tadashi; Targa, Lília Spaleta; Yamamoto, Lidia; Rodrigues, Jonatas Cristian; Kanunfre, Kelly Aparecida; Okay, Thelma Suely

    2016-05-18

    Host and parasite genotypes are among the factors associated with congenital toxoplasmosis pathogenesis. As HLA class II molecules play a key role in the immune system regulation, the aim of this study was to investigate whether HLA-DQA1/B1 alleles are associated with susceptibility or protection to congenital toxoplasmosis. One hundred and twenty-two fetuses with and 103 without toxoplasmosis were studied. The two study groups were comparable according to a number of socio-demographic and genetic variables. HLA alleles were typed by PCR-SSP. In the HLA-DQA1 region, the allele frequencies showed that *01:03 and *03:02 alleles could confer susceptibility (OR= 3.06, p = 0.0002 and OR= 9.60, p= 0.0001, respectively) as they were more frequent among infected fetuses. Regarding the HLA-DQB1 region, the *05:04 allele could confer susceptibility (OR = 6.95, p toxoplasmosis and the most severe cases has been shown. PMID:26856406

  13. A pseudodeficiency allele common in non-Jewish Tay-Sachs carriers: Implications for carrier screening

    Energy Technology Data Exchange (ETDEWEB)

    Triggs-Raine, B.L.; Akerman, B.R.; Gravel, R.A. (McGill Univ.-Montreal Children' s Hospital Research Institute, Montreal, Quebec (Canada)); Mules, E.H.; Thomas, G.H.; Dowling, C.E. (Johns Hopkins School of Medicine, Baltimore, MD (United States)); Kaback, M.M.; Lim-Steele, J.S.T. (Univ. of California, San Diego, CA (United States)); Natowicz, M.R. (Eunice Kennedy Shriver Center for Mental Retardation, Waltham, MA (United States)); Grebner, E.E. (Thomas Jefferson Univ., Philadelphia, PA (United States)); Navon, R.R. (Tel-Aviv Univ., Kfar-Sava (Israel)); Welch, J.P. (Dalhousie Univ., Halifax, Nova, Scotia (Canada)); Greenberg, C.R. (Univ. of Manitoba, Winnipeg (Canada))

    1992-10-01

    Deficiency of [beta]-hexosaminidase A (Hex A) activity typically results in Tay-Sachs disease. However, healthy subjects found to be deficient in Hex A activity (i.e., pseudodeficient) by means of in vitro biochemical tests have been described. The authors analyzed the HEXA gene of one pseudodeficient subject and identified both a C[sub 739]-to-T substitution that changes Arg[sub 247][yields]Trp on one allele and a previously identified Tay-Sachs disease mutation of the second allele. Six additional pseudodeficient subjects were found to have the C[sub 739]-to-T but for none of 36 Jewish enzyme-defined carries who did not have one of three known mutations common to this group. The C[sub 739]-to-T allele, together with a [open quotes]true[close quotes] Tay-Sachs disease allele, causes Hex A pseudodeficiency. Given both the large proportion of non-Jewish carriers with this allele and that standard biochemical screening cannot differentiate between heterozygotes for the C[sub 739]-to-T mutations and Tay-Sachs disease carriers, DNA testing for this mutation in at-risk couples is essential. This could prevent unnecessary or incorrect prenatal diagnoses. 40 refs., 3 figs., 4 tabs.

  14. Allele-specific copy-number discovery from whole-genome and whole-exome sequencing.

    Science.gov (United States)

    Wang, WeiBo; Wang, Wei; Sun, Wei; Crowley, James J; Szatkiewicz, Jin P

    2015-08-18

    Copy-number variants (CNVs) are a major form of genetic variation and a risk factor for various human diseases, so it is crucial to accurately detect and characterize them. It is conceivable that allele-specific reads from high-throughput sequencing data could be leveraged to both enhance CNV detection and produce allele-specific copy number (ASCN) calls. Although statistical methods have been developed to detect CNVs using whole-genome sequence (WGS) and/or whole-exome sequence (WES) data, information from allele-specific read counts has not yet been adequately exploited. In this paper, we develop an integrated method, called AS-GENSENG, which incorporates allele-specific read counts in CNV detection and estimates ASCN using either WGS or WES data. To evaluate the performance of AS-GENSENG, we conducted extensive simulations, generated empirical data using existing WGS and WES data sets and validated predicted CNVs using an independent methodology. We conclude that AS-GENSENG not only predicts accurate ASCN calls but also improves the accuracy of total copy number calls, owing to its unique ability to exploit information from both total and allele-specific read counts while accounting for various experimental biases in sequence data. Our novel, user-friendly and computationally efficient method and a complete analytic protocol is freely available at https://sourceforge.net/projects/asgenseng/. PMID:25883151

  15. Rapid, efficient and precise allele replacement in the fission yeast Schizosaccharomyces pombe

    Science.gov (United States)

    Gao, Jun; Kan, Fengling; Wagnon, Jacy L.; Storey, Aaron J.; Protacio, Reine M.; Davidson, Mari K.; Wahls, Wayne P.

    2013-01-01

    Gene targeting provides a powerful tool to modify endogenous loci to contain specific mutations, insertions and deletions. Precise allele replacement, with no other chromosomal changes (e.g., insertion of selectable markers or heterologous promoters), maintains physiologically relevant context. Established methods for precise allele replacement in fission yeast employ two successive rounds of transformation and homologous recombination and require genotyping at each step. The relative efficiency of homologous recombination is low and a high rate of false positives during the second round of gene targeting further complicates matters. We report that pop-in, pop-out allele replacement circumvents these problems. We present data for 39 different allele replacements, involving simple and complex modifications at seven different target loci, that illustrate the power and utility of the approach. We also developed and validated a rapid, efficient process for precise allele replacement that requires only one round each of transformation and genotyping. We show that this process can be applied in population scale to an individual target locus, without genotyping, to identify clones with an altered phenotype (targeted forward genetics). It is therefore suitable for saturating, in situ, locus-specific mutation screens (e.g., of essential or non-essential genes and regulatory DNA elements) within normal chromosomal context. PMID:24026504

  16. Unusually high frequency MHC class I alleles in Mauritian origin cynomolgus macaques.

    Science.gov (United States)

    Krebs, Kendall C; Jin, ZheYuan; Rudersdorf, Richard; Hughes, Austin L; O'Connor, David H

    2005-10-15

    Acute shortages of Indian origin Rhesus macaques significantly hinder HIV/AIDS research. Cellular immune responses are particularly difficult to study because only a subset of animals possess MHC class I (MHC I) alleles with defined peptide-binding specificities. To expand the pool of nonhuman primates suitable for studies of cellular immunity, we defined 66 MHC I alleles in Cynomolgus macaques (Macaca fascicularis) of Chinese, Vietnamese, and Mauritian origin. Most MHC I alleles were found only in animals from a single geographic origin, suggesting that Cynomolgus macaques from different origins are not interchangeable in studies of cellular immunity. Animals from Mauritius may be particularly valuable because >50% of these Cynomolgus macaques share the MHC class I allele combination Mafa-B*430101, Mafa-B*440101, and Mafa-B*460101. The increased MHC I allele sharing of Mauritian origin Cynomolgus macaques may dramatically reduce the overall number of animals needed to study cellular immune responses in nonhuman primates while simultaneously reducing the confounding effects of genetic heterogeneity in HIV/AIDS research. PMID:16210628

  17. Safety and immunogenicity of multi-antigen AMA1-based vaccines formulated with CoVaccine HT™ and Montanide ISA 51 in rhesus macaques

    Directory of Open Access Journals (Sweden)

    Walraven Vanessa

    2011-07-01

    Full Text Available Abstract Background Increasing the breadth of the functional antibody response through immunization with Plasmodium falciparum apical membrane antigen 1 (PfAMA1 multi-allele vaccine formulations has been demonstrated in several rodent and rabbit studies. This study assesses the safety and immunogenicity of three PfAMA1 Diversity-Covering (DiCo vaccine candidates formulated as an equimolar mixture (DiCo mix in CoVaccine HT™ or Montanide ISA 51, as well as that of a PfAMA1-MSP119 fusion protein formulated in Montanide ISA 51. Methods Vaccine safety in rhesus macaques was monitored by animal behaviour observation and assessment of organ and systemic functions through clinical chemistry and haematology measurements. The immunogenicity of vaccine formulations was assessed by enzyme-linked immunosorbent assays and in vitro parasite growth inhibition assays with three culture-adapted P. falciparum strains. Results These data show that both adjuvants were well tolerated with only transient changes in a few of the chemical and haematological parameters measured. DiCo mix formulated in CoVaccine HT™ proved immunologically and functionally superior to the same candidate formulated in Montanide ISA 51. Immunological data from the fusion protein candidate was however difficult to interpret as four out of six immunized animals were non-responsive for unknown reasons. Conclusions The study highlights the safety and immunological benefits of DiCo mix as a potential human vaccine against blood stage malaria, especially when formulated in CoVaccine HT™, and adds to the accumulating data on the specificity broadening effects of DiCo mix.

  18. Microsatellite D21D210 (GT-12) allele frequencies in sporadic Alzheimer's disease

    International Nuclear Information System (INIS)

    Four disease-causing mutations have so far been described in the amyloid precursor protein gene on chromosome 21 in familial early-onset Alzheimer's disease. Linkage analysis with a fourteen-allele microsatellite at D21S210 named GT-12 has proven useful in the elucidation of amyloid presursor protein gene involvement in Alzheimer's disease families, as it is closely linked to the gene. Most cases of Alzheimer's disease are thought to be sporadic and not familial. However, evidence from earlier studies suggests an important genetic contribution also in sporadic cases, where gene-environment interaction may contribute to the disease. We have determined frequencies of the GT-12 alleles in 78 Swedish and 49 British sporadic Alzheimer's disease cases and 104 healthy elderly control subjects, to investigate if the disease associates with a particular genotype in GT-12. However, no differences in allele frequencies were observed between any of the groups. (au) (26 refs.)

  19. Differential allelic expression of a fibrillin gene (FBNI) in patients with Marfan syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hewett, D.; Lynch, J.; Sykes, B. [Univ. of Oxford (United Kingdom); Firth, H. [Churchill Hospital, Oxford (United Kingdom); Child, A. [St. George`s Hospital Medical School, London (United Kingdom)

    1994-09-01

    Marfan syndrome is a connective-tissue disorder affecting cardiovascular, skeletal, and ocular systems. The major Marfan locus has been identified as the FBN1 gene on chromosome 15; this codes for the extracellular-matrix protein fibrillin, a 350-kD constituent of the 8-10-nm elastin-associated microfibrils. The authors identified five MFS patients who were heterozygous for an RsaI restriction-site dimorphism in the 3{prime} UTR of the FBN1 gene. This expressed variation was used to distinguish the mRNA output from each of the two FBN1 alleles in fibroblast cultures from these five patients. Three of the patients were shown to produce <5% of the normal level of FBN1 transcripts from one of their alleles. This null-allele phenotype was not observed in 10 nonmarfanoid fibroblast cell lines. 26 refs., 4 figs.

  20. HLA Alleles Associated with Slow Progression to AIDS Truly Prefer to Present HIV-1 p24

    DEFF Research Database (Denmark)

    Borghans, J. A.; Molgaard, A.; Boer, R. J. de;

    2007-01-01

    BACKGROUND: The mechanism behind the association between human leukocyte antigen (HLA) molecules and the rate of HIV-1 disease progression is still poorly understood. Recent data suggest that "protective" HLA molecules, i.e. those associated with a low HIV-1 viral load and relatively slow disease...... effect, we predicted HIV-1 epitopes from the whole genome of HIV-1, and found that protective HLA alleles have a true preference for the p24 Gag protein, while non-protective HLA alleles preferentially target HIV-1 Nef. In line with this, we found a significant negative correlation between the predicted...... affinity of the best-binding p24 epitopes and the relative hazard of HIV-1 disease progression for a large number of HLA molecules. When the epitopes targeted by protective HLA alleles were mapped to the known p24 structure, we found that mutations in these epitopes are likely to disturb the p24 dimer...

  1. HLA alleles associated with slow progression to AIDS truly prefer to present HIV-1 p24

    DEFF Research Database (Denmark)

    Borghans, José A M; Mølgaard, Anne; de Boer, Rob J;

    2007-01-01

    BACKGROUND: The mechanism behind the association between human leukocyte antigen (HLA) molecules and the rate of HIV-1 disease progression is still poorly understood. Recent data suggest that "protective" HLA molecules, i.e. those associated with a low HIV-1 viral load and relatively slow disease...... effect, we predicted HIV-1 epitopes from the whole genome of HIV-1, and found that protective HLA alleles have a true preference for the p24 Gag protein, while non-protective HLA alleles preferentially target HIV-1 Nef. In line with this, we found a significant negative correlation between the predicted...... affinity of the best-binding p24 epitopes and the relative hazard of HIV-1 disease progression for a large number of HLA molecules. When the epitopes targeted by protective HLA alleles were mapped to the known p24 structure, we found that mutations in these epitopes are likely to disturb the p24 dimer...

  2. Allelic association at the D14S43 locus in early onset Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Brice, A.; Tardieu, S.; Campion, D.; Martinez, M. [and others

    1995-04-24

    The D14S43 marker is closely linked to the major gene for early onset autosomal dominant Alzheimer`s disease on chromosome 14. Allelic frequencies at the D14S43 locus were compared in 113 familial and isolated cases of early onset Alzheimer`s disease (<60 years of age at onset) (EOAD) and 109 unaffected individuals of the same geographic origin. Allele 7 was significantly (P = 0.033) more frequent in type 1 EOAD patients (13.2%), defined by the presence of at least another first degree relative with EOAD, than in controls (4.1%). Since an autosomal dominant gene is probably responsible for type 1 patients, allelic association may reflect linkage disequilibrium at the D14S43 locus. This would mean that some patients share a common ancestral mutation. However, since multiple tests were carried out, this result must be interpreted with caution, and needs confirmation in an independent sample. 16 refs., 2 tabs.

  3. Independent Emergence of the Plasmodium falciparum Kelch Propeller Domain Mutant Allele C580Y in Guyana.

    Science.gov (United States)

    Chenet, Stella M; Akinyi Okoth, Sheila; Huber, Curtis S; Chandrabose, Javin; Lucchi, Naomi W; Talundzic, Eldin; Krishnalall, Karanchand; Ceron, Nicolas; Musset, Lise; Macedo de Oliveira, Alexandre; Venkatesan, Meera; Rahman, Reyaud; Barnwell, John W; Udhayakumar, Venkatachalam

    2016-05-01

    Suspected artemisinin resistance in Plasmodium falciparum can be explored by examining polymorphisms in the Kelch (PfK13) propeller domain. Sequencing of PfK13 and other gene resistance markers was performed on 98 samples from Guyana. Five of these samples carried the C580Y allele in the PfK13 propeller domain, with flanking microsatellite profiles different from those observed in Southeast Asia. These molecular data demonstrate independent emergence of the C580Y K13 mutant allele in Guyana, where resistance alleles to previously used drugs are fixed. Therefore, in Guyana and neighboring countries, continued molecular surveillance and periodic assessment of the therapeutic efficacy of artemisinin-based combination therapy are warranted. PMID:26690347

  4. Characterization of new allele influencing flowering time in bread wheat introgressed from Triticum militinae.

    Science.gov (United States)

    Ivaničová, Zuzana; Jakobson, Irena; Reis, Diana; Šafář, Jan; Milec, Zbyněk; Abrouk, Michael; Doležel, Jaroslav; Järve, Kadri; Valárik, Miroslav

    2016-09-25

    Flowering time variation was identified within a mapping population of doubled haploid lines developed from a cross between the introgressive line 8.1 and spring bread wheat cv. Tähti. The line 8.1 carried introgressions from tetraploid Triticum militinae in the cv. Tähti genetic background on chromosomes 1A, 2A, 4A, 5A, 7A, 1B and 5B. The most significant QTL for the flowering time variation was identified within the introgressed region on chromosome 5A and its largest effect was associated with the VRN-A1 locus, accounting for up to 70% of phenotypic variance. The allele of T. militinae origin was designated as VRN-A1f-like. The effect of the VRN-A1f-like allele was verified in two other mapping populations. QTL analysis identified that in cv. Tähti and cv. Mooni genetic background, VRN-A1f-like allele incurred a delay of 1.9-18.6 days in flowering time, depending on growing conditions. Sequence comparison of the VRN-A1f-like and VRN-A1a alleles from the parental lines of the mapping populations revealed major mutations in the promoter region as well as in the first intron, including insertion of a MITE element and a large deletion. The sequence variation allowed construction of specific diagnostic PCR markers for VRN-A1f-like allele determination. Identification and quantification of the effect of the VRN-A1f-like allele offers a useful tool for wheat breeding and for studying fine-scale regulation of flowering pathways in wheat. PMID:26899284

  5. Estimation of allele frequency and association mapping using next-generation sequencing data

    Directory of Open Access Journals (Sweden)

    Andersen Gitte

    2011-06-01

    Full Text Available Abstract Background Estimation of allele frequency is of fundamental importance in population genetic analyses and in association mapping. In most studies using next-generation sequencing, a cost effective approach is to use medium or low-coverage data (e.g., X. However, SNP calling and allele frequency estimation in such studies is associated with substantial statistical uncertainty because of varying coverage and high error rates. Results We evaluate a new maximum likelihood method for estimating allele frequencies in low and medium coverage next-generation sequencing data. The method is based on integrating over uncertainty in the data for each individual rather than first calling genotypes. This method can be applied to directly test for associations in case/control studies. We use simulations to compare the likelihood method to methods based on genotype calling, and show that the likelihood method outperforms the genotype calling methods in terms of: (1 accuracy of allele frequency estimation, (2 accuracy of the estimation of the distribution of allele frequencies across neutrally evolving sites, and (3 statistical power in association mapping studies. Using real re-sequencing data from 200 individuals obtained from an exon-capture experiment, we show that the patterns observed in the simulations are also found in real data. Conclusions Overall, our results suggest that association mapping and estimation of allele frequencies should not be based on genotype calling in low to medium coverage data. Furthermore, if genotype calling methods are used, it is usually better not to filter genotypes based on the call confidence score.

  6. Mining the human phenome using allelic scores that index biological intermediates.

    Directory of Open Access Journals (Sweden)

    David M Evans

    2013-10-01

    Full Text Available It is common practice in genome-wide association studies (GWAS to focus on the relationship between disease risk and genetic variants one marker at a time. When relevant genes are identified it is often possible to implicate biological intermediates and pathways likely to be involved in disease aetiology. However, single genetic variants typically explain small amounts of disease risk. Our idea is to construct allelic scores that explain greater proportions of the variance in biological intermediates, and subsequently use these scores to data mine GWAS. To investigate the approach's properties, we indexed three biological intermediates where the results of large GWAS meta-analyses were available: body mass index, C-reactive protein and low density lipoprotein levels. We generated allelic scores in the Avon Longitudinal Study of Parents and Children, and in publicly available data from the first Wellcome Trust Case Control Consortium. We compared the explanatory ability of allelic scores in terms of their capacity to proxy for the intermediate of interest, and the extent to which they associated with disease. We found that allelic scores derived from known variants and allelic scores derived from hundreds of thousands of genetic markers explained significant portions of the variance in biological intermediates of interest, and many of these scores showed expected correlations with disease. Genome-wide allelic scores however tended to lack specificity suggesting that they should be used with caution and perhaps only to proxy biological intermediates for which there are no known individual variants. Power calculations confirm the feasibility of extending our strategy to the analysis of tens of thousands of molecular phenotypes in large genome-wide meta-analyses. We conclude that our method represents a simple way in which potentially tens of thousands of molecular phenotypes could be screened for causal relationships with disease without having to

  7. HLA B27 allele types in homogeneous groups of juvenile idiopathic arthritis patients in Latvia

    Directory of Open Access Journals (Sweden)

    Guseinova Dinara

    2010-10-01

    Full Text Available Abstract Juvenile idiopathic arthritis (JIA is a heterogeneous condition and therapeutic strategies vary in different JIA types. The routinely accepted practice to start with Sulphasalazine (SS as the first line treatment in patients with HLA B27 positive JIA proves to be ineffective in a large proportion of children. Objective to investigate HLA B27 positive JIA patients clinical characteristics, determined HLA B27 allele types and their connection with antirheumatic treatment in homogenous patient groups. Materials and methods 56 patients diagnosed with JIA and observed over the period 2006 to 2009 included in the study. HLAB27 allele types were determined using PCR method. Results In HLA B27 positive JIA patients mean disease onset was 12.34 ± 3.3 years. Most common (44% JIA type was enthesitis related arthritis. Positive response to the treatment with SS was found in 32% of patients, Methotrexate (MTX - in 43%, combined treatment - SS with MTX was effective in 12.5%. 12.5% of patients required combination MTX with Enbrel. Eight HLA B27 allele types were found in JIA patients in Latvia: *2702, *2703, *2704, *2705, *2710, *2715, *2717, *2728. The most common was *2705 - in 55% of cases. Among all the patients enthesitis related arthritis most commonly occurred in patients with HLAB*2705 allele (OR = 2.01, p Conclusions There are 8 different HLA B27 alleles in JIA patients in Latvia and the most common is *2705, but in order to assert them to be disease associated alleles, more extensive studies are needed, including control group of HLA B27 positive healthy individuals. Standard treatment approach with SS proves to be unsatisfactory in the majority of JIA patients. To improve children's quality of life achieving rapid disease control, the first line treatment in HLA B27 positive patients should be MTX. In order to start with the most appropriate drug it is necessary to determine HLAB 27 type at the onset of disease.

  8. Allelic Imbalance in Regulation of ANRIL through Chromatin Interaction at 9p21 Endometriosis Risk Locus.

    Science.gov (United States)

    Nakaoka, Hirofumi; Gurumurthy, Aishwarya; Hayano, Takahide; Ahmadloo, Somayeh; Omer, Waleed H; Yoshihara, Kosuke; Yamamoto, Akihito; Kurose, Keisuke; Enomoto, Takayuki; Akira, Shigeo; Hosomichi, Kazuyoshi; Inoue, Ituro

    2016-04-01

    Genome-wide association studies (GWASs) have discovered numerous single nucleotide polymorphisms (SNPs) associated with human complex disorders. However, functional characterization of the disease-associated SNPs remains a formidable challenge. Here we explored regulatory mechanism of a SNP on chromosome 9p21 associated with endometriosis by leveraging "allele-specific" functional genomic approaches. By re-sequencing 1.29 Mb of 9p21 region and scrutinizing DNase-seq data from the ENCODE project, we prioritized rs17761446 as a candidate functional variant that was in perfect linkage disequilibrium with the original GWAS SNP (rs10965235) and located on DNase I hypersensitive site. Chromosome conformation capture followed by high-throughput sequencing revealed that the protective G allele of rs17761446 exerted stronger chromatin interaction with ANRIL promoter. We demonstrated that the protective allele exhibited preferential binding affinities to TCF7L2 and EP300 by bioinformatics and chromatin immunoprecipitation (ChIP) analyses. ChIP assays for histone H3 lysine 27 acetylation and RNA polymerase II reinforced the enhancer activity of the SNP site. The allele specific expression analysis for eutopic endometrial tissues and endometrial carcinoma cell lines showed that rs17761446 was a cis-regulatory variant where G allele was associated with increased ANRIL expression. Our work illuminates the allelic imbalances in a series of transcriptional regulation from factor binding to gene expression mediated by chromatin interaction underlie the molecular mechanism of 9p21 endometriosis risk locus. Functional genomics on common disease will unlock functional aspect of genotype-phenotype correlations in the post-GWAS stage. PMID:27055116

  9. Allelic Imbalance in Regulation of ANRIL through Chromatin Interaction at 9p21 Endometriosis Risk Locus

    Science.gov (United States)

    Nakaoka, Hirofumi; Gurumurthy, Aishwarya; Hayano, Takahide; Ahmadloo, Somayeh; Omer, Waleed H; Yoshihara, Kosuke; Yamamoto, Akihito; Kurose, Keisuke; Enomoto, Takayuki; Akira, Shigeo; Hosomichi, Kazuyoshi; Inoue, Ituro

    2016-01-01

    Genome-wide association studies (GWASs) have discovered numerous single nucleotide polymorphisms (SNPs) associated with human complex disorders. However, functional characterization of the disease-associated SNPs remains a formidable challenge. Here we explored regulatory mechanism of a SNP on chromosome 9p21 associated with endometriosis by leveraging “allele-specific” functional genomic approaches. By re-sequencing 1.29 Mb of 9p21 region and scrutinizing DNase-seq data from the ENCODE project, we prioritized rs17761446 as a candidate functional variant that was in perfect linkage disequilibrium with the original GWAS SNP (rs10965235) and located on DNase I hypersensitive site. Chromosome conformation capture followed by high-throughput sequencing revealed that the protective G allele of rs17761446 exerted stronger chromatin interaction with ANRIL promoter. We demonstrated that the protective allele exhibited preferential binding affinities to TCF7L2 and EP300 by bioinformatics and chromatin immunoprecipitation (ChIP) analyses. ChIP assays for histone H3 lysine 27 acetylation and RNA polymerase II reinforced the enhancer activity of the SNP site. The allele specific expression analysis for eutopic endometrial tissues and endometrial carcinoma cell lines showed that rs17761446 was a cis-regulatory variant where G allele was associated with increased ANRIL expression. Our work illuminates the allelic imbalances in a series of transcriptional regulation from factor binding to gene expression mediated by chromatin interaction underlie the molecular mechanism of 9p21 endometriosis risk locus. Functional genomics on common disease will unlock functional aspect of genotype-phenotype correlations in the post-GWAS stage. PMID:27055116

  10. Genetic exchange of fimbrial alleles exemplifies the adaptive virulence strategy of Porphyromonas gingivalis.

    Directory of Open Access Journals (Sweden)

    Jennifer E Kerr

    Full Text Available Porphyromonas gingivalis is a gram-negative anaerobic bacterium, a member of the human oral microbiome, and a proposed "keystone" pathogen in the development of chronic periodontitis, an inflammatory disease of the gingiva. P. gingivalis is a genetically diverse species, and is able to exchange chromosomal DNA between strains by natural competence and conjugation. In this study, we investigate the role of horizontal DNA transfer as an adaptive process to modify behavior, using the major fimbriae as our model system, due to their critical role in mediating interactions with the host environment. We show that P. gingivalis is able to exchange fimbrial allele types I and IV into four distinct strain backgrounds via natural competence. In all recombinants, we detected a complete exchange of the entire fimA allele, and the rate of exchange varies between the different strain backgrounds. In addition, gene exchange within other regions of the fimbrial genetic locus was identified. To measure the biological implications of these allele swaps we compared three genotypes of fimA in an isogenic background, strain ATCC 33277. We demonstrate that exchange of fimbrial allele type results in profound phenotypic changes, including the quantity of fimbriae elaborated, membrane blebbing, auto-aggregation and other virulence-associated phenotypes. Replacement of the type I allele with either the type III or IV allele resulted in increased invasion of gingival fibroblast cells relative to the isogenic parent strain. While genetic variability is known to impact host-microbiome interactions, this is the first study to quantitatively assess the adaptive effect of exchanging genes within the pan genome cloud. This is significant as it presents a potential mechanism by which opportunistic pathogens may acquire the traits necessary to modify host-microbial interactions.

  11. Existence of the rdl mutant alleles among the anopheles malaria vector in Indonesia

    Directory of Open Access Journals (Sweden)

    Asih Puji BS

    2012-02-01

    Full Text Available Abstract Background The gamma-aminobutyric acid (GABA receptor-chloride channel complex is known to be the target site of dieldrin, a cyclodiene insecticide. GABA-receptors, with a naturally occurring amino acid substitution, A302S/G in the putative ion-channel lining region, confer resistance to cyclodiene insecticides that includes aldrin, chlordane, dieldrin, heptachlor, endrin and endosulphan. Methods A total of 154 mosquito samples from 10 provinces of malaria-endemic areas across Indonesia (Aceh, North Sumatra, Bangka Belitung, Lampung, Central Java, East Nusa Tenggara, West Nusa Tenggara, West Sulawesi, Molucca and North Molucca were obtained and identified by species, using morphological characteristic. The DNA was individually extracted using chelex-ion exchanger and the DNA obtained was used for analyses using sequencing method. Results Molecular analysis indicated 11% of the total 154 Anopheles samples examined, carried Rdl mutant alleles. All of the alleles were found in homozygous form. Rdl 302S allele was observed in Anopheles vagus (from Central Java, Lampung, and West Nusa Tenggara, Anopheles aconitus (from Central Java, Anopheles barbirostris (from Central Java and Lampung, Anopheles sundaicus (from North Sumatra and Lampung, Anopheles nigerrimus (from North Sumatra, whereas the 302 G allele was only found in Anopheles farauti from Molucca. Conclusion The existence of the Rdl mutant allele indicates that, either insecticide pressure on the Anopheles population in these areas might still be ongoing (though not directly associated with the malaria control programme or that the mutant form of the Rdl allele is relatively stable in the absence of insecticide. Nonetheless, the finding suggests that integrated pest management is warranted in malaria-endemic areas where insecticides are widely used for other purposes.

  12. Correlation between carboxylesterase alleles and insecticide resistance in Culex pipiens complex from China

    Directory of Open Access Journals (Sweden)

    Liu Yangyang

    2011-12-01

    Full Text Available Abstract Background In China, large amounts of chemical insecticides are applied in fields or indoors every year, directly or indirectly bringing selection pressure on vector mosquitoes. Culex pipiens complex has evolved to be resistant to all types of chemical insecticides, especially organophosphates, through carboxylesterases. Six resistant carboxylesterase alleles (Ester were recorded previously and sometimes co-existed in one field population, representing a complex situation for the evolution of Ester genes. Results In order to explore the evolutionary scenario, we analyzed the data from an historical record in 2003 and a recent investigation on five Culex pipiens pallens populations sampled from north China in 2010. Insecticide bioassays showed that these five populations had high resistance to pyrethroids, medium resistance to organophosphates, and low resistance to carbamates. Six types of Ester alleles, EsterB1, Ester2, Ester8, Ester9, EsterB10, and Ester11 were identified, and the overall pattern of their frequencies in geographic distribution was consistent with the report seven years prior to this study. Statistical correlation analysis indicated that Ester8 and Ester9 positively correlated with resistance to four insecticides, and EsterB10 to one insecticide. The occurrences of these three alleles were positively correlated, while the occurrence of EsterB1 was negatively correlated with Ester8, indicating an allelic competition. Conclusion Our analysis suggests that one insecticide can select multiple Ester alleles and one Ester allele can work on multiple insecticides. The evolutionary scenario of carboxylesterases under insecticide selection is possibly "one to many".

  13. Data analysis issues for allele-specific expression using Illumina's GoldenGate assay

    Directory of Open Access Journals (Sweden)

    Dermitzakis Emmanouil T

    2010-05-01

    Full Text Available Abstract Background High-throughput measurement of allele-specific expression (ASE is a relatively new and exciting application area for array-based technologies. In this paper, we explore several data sets which make use of Illumina's GoldenGate BeadArray technology to measure ASE. This platform exploits coding SNPs to obtain relative expression measurements for alleles at approximately 1500 positions in the genome. Results We analyze data from a mixture experiment where genomic DNA samples from pairs of individuals of known genotypes are pooled to create allelic imbalances at varying levels for the majority of SNPs on the array. We observe that GoldenGate has less sensitivity at detecting subtle allelic imbalances (around 1.3 fold compared to extreme imbalances, and note the benefit of applying local background correction to the data. Analysis of data from a dye-swap control experiment allowed us to quantify dye-bias, which can be reduced considerably by careful normalization. The need to filter the data before carrying out further downstream analysis to remove non-responding probes, which show either weak, or non-specific signal for each allele, was also demonstrated. Throughout this paper, we find that a linear model analysis of the data from each SNP is a flexible modelling strategy that allows for testing of allelic imbalances in each sample when replicate hybridizations are available. Conclusions Our analysis shows that local background correction carried out by Illumina's software, together with quantile normalization of the red and green channels within each array, provides optimal performance in terms of false positive rates. In addition, we strongly encourage intensity-based filtering to remove SNPs which only measure non-specific signal. We anticipate that a similar analysis strategy will prove useful when quantifying ASE on Illumina's higher density Infinium BeadChips.

  14. Etude des phénomènes de reconnaissance moléculaire spécifique aux interfaces biologiques par AFM : investigation de l'influence de la multivalence sur les interactions sucre-lectine

    OpenAIRE

    Mastouri, Amira

    2013-01-01

    Le présent projet vise à analyser l'influence de la multivalence dans les interactions sucres-lectines. En collaboration avec des équipes externes, une étude par microscopie à force atomique (AFM) de l'interaction entre des ligands synthétiques de différentes valences et leurs lectines spécifiques a été entreprise. Dans le cadre de cette étude, une première caractérisation fondamentale de l'interaction sucre-lectine a été menée. Cette caractérisation concerne plus particulièrement l'influence...

  15. Fine Mapping Seronegative and Seropositive Rheumatoid Arthritis to Shared and Distinct HLA Alleles by Adjusting for the Effects of Heterogeneity

    OpenAIRE

    Han, Buhm; Diogo, Dorothée; Eyre, Steve; Kallberg, Henrik; Zhernakova, Alexandra; Bowes, John; Padyukov, Leonid; Okada, Yukinori; González-Gay, Miguel A.; Rantapää-Dahlqvist, Solbritt; Martin, Javier; Huizinga, Tom W.J.; Plenge, Robert M.; Worthington, Jane; Gregersen, Peter K.

    2014-01-01

    Despite progress in defining human leukocyte antigen (HLA) alleles for anti-citrullinated-protein-autoantibody-positive (ACPA+) rheumatoid arthritis (RA), identifying HLA alleles for ACPA-negative (ACPA−) RA has been challenging because of clinical heterogeneity within clinical cohorts. We imputed 8,961 classical HLA alleles, amino acids, and SNPs from Immunochip data in a discovery set of 2,406 ACPA− RA case and 13,930 control individuals. We developed a statistical approach to identify and ...

  16. Natural Host Genetic Resistance to Lentiviral CNS Disease: A Neuroprotective MHC Class I Allele in SIV-Infected Macaques

    OpenAIRE

    Mankowski, Joseph L.; Queen, Suzanne E.; Fernandez, Caroline S.; Tarwater, Patrick M.; Karper, Jami M.; Adams, Robert J.; Kent, Stephen J.

    2008-01-01

    Human immunodeficiency virus (HIV) infection frequently causes neurologic disease even with anti-retroviral treatment. Although associations between MHC class I alleles and acquired immunodeficiency syndrome (AIDS) have been reported, the role MHC class I alleles play in restricting development of HIV-induced organ-specific diseases, including neurologic disease, has not been characterized. This study examined the relationship between expression of the MHC class I allele Mane-A*10 and develop...

  17. Pedigree genotyping: a new pedigree-based approach of QTL identification and allele mining by exploiting breeding material

    OpenAIRE

    Weg, van de, H; Voorrips, R. E.; Finkers, H. J.; Kodde, L.P.; Meulenbroek, E.J.; Jansen, J; Bink, M.C.A.M.

    2005-01-01

    To date, molecular markers have been made available for many economically important traits. Unfortunately, lack of knowledge of their allelic variation hampers their full exploitation in commercial breeding programs. These markers have usually been identified in one single cross. Consequently, only one or two favourable alleles of the related QTL are identified and may be exploited for marker-assisted breeding (MAB), while a breeding program may include several alleles. Selection for only the...

  18. Allelic variations in Glu-1 and Glu-3 loci of historical and modern Iranian bread wheat (Triticum aestivum L.) cultivars

    Indian Academy of Sciences (India)

    Ali Izadi-Darbandi; Bahman Yazdi-Samadi; Ali-Akbar Su-Boushehri; Mohsen Mohammadi

    2010-08-01

    Proline and glutamine-rich wheat seed endosperm proteins are collectively referred to as prolamins. They are comprised of HMW-GSs, LMW-GSs and gliadins. HMW-GSs are major determinants of gluten elasticity and LMW-GSs considerably affect dough extensibility and maximum dough resistance. The inheritance of glutenin subunits follows Mendelian genetics with multiple alleles in each locus. Identification of the banding patterns of glutenin subunits could be used as an estimate for screening high quality wheat germplasm. Here, by means of a two-step 1D-SDS-PAGE procedure, we identified the allelic variations in high and low-molecular-weight glutenin subunits in 65 hexaploid wheat (Triticum aestivum L.) cultivars representing a historical trend in the cultivars introduced or released in Iran from the years 1940 to 1990. Distinct alleles 17 and 19 were detected for Glu-1 and Glu-3 loci, respectively. The allelic frequencies at the Glu-1 loci demonstrated unimodal distributions. At Glu-A1, Glu-B1 and Glu-D1, we found that the most frequent alleles were the null, 7 + 8, 2 + 12 alleles, respectively, in Iranian wheat cultivars. In contrast, Glu-3 loci showed bimodal or trimodal distributions. At Glu-A3, the most frequent alleles were c and e. At Glu-B3 the most frequent alleles were a, b and c. At Glu-D3 locus, the alleles b and a, were the most and the second most frequent alleles in Iranian wheat cultivars. This led to a significantly higher Nei coefficient of genetic variations in Glu-3 loci (0.756) as compared to Glu-1 loci (0.547). At Glu-3 loci, we observed relatively high quality alleles in Glu-A3 and Glu-D3 loci and low quality alleles at Glu-B3 locus.

  19. Statistical model for degraded DNA samples and adjusted probabilities for allelic drop-out

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Mogensen, Helle Smidt;

    2012-01-01

    DNA samples found at a scene of crime or obtained from the debris of a mass disaster accident are often subject to degradation. When using the STR DNA technology, the DNA profile is observed via a so-called electropherogram (EPG), where the alleles are identified as signal peaks above a certain...... level or above a signal to noise threshold. Degradation implies that these peak intensities decrease in strength for longer short tandem repeat (STR) sequences. Consequently, long STR loci may fail to produce peak heights above the limit of detection resulting in allelic or locus drop-outs. In this...

  20. Statistical model for degraded DNA samples and adjusted probabilities for allelic drop-out

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Mogensen, Helle Smidt;

    2012-01-01

    Abstract DNA samples found at a scene of crime or obtained from the debris of a mass disaster accident are often subject to degradation. When using the STR DNA technology, the DNA profile is observed via a so-called electropherogram (EPG), where the alleles are identified as signal peaks above a...... certain level or above a signal to noise threshold. Degradation implies that these peak intensities decrease in strength for longer short tandem repeat (STR) sequences. Consequently, long STR loci may fail to produce peak heights above the limit of detection resulting in allelic or locus drop-outs. In...

  1. Allelic heterogeneity of G6PD deficiency in West Africa and severe malaria susceptibility

    OpenAIRE

    Clark, Taane G.; Fry, Andrew E.; Auburn, Sarah; Campino, Susana; Diakite, Mahamadou; Green, Angela; Richardson, Anna; Teo, Yik Y; Small, Kerrin; Wilson, Jonathan; Jallow, Muminatou; Sisay-Joof, Fatou; Pinder, Margaret; Sabeti, Pardis; Kwiatkowski, Dominic P.

    2009-01-01

    Several lines of evidence link glucose-6-phosphate dehydrogenase (G6PD) deficiency to protection from severe malaria. Early reports suggested most G6PD deficiency in sub-Saharan Africa was because of the 202A/376G G6PD A− allele, and recent association studies of G6PD deficiency have employed genotyping as a convenient way to determine enzyme status. However, further work has suggested that other G6PD deficiency alleles are relatively common in some regions of West Africa. To investigate the ...

  2. The effect of wild card designations and rare alleles in forensic DNA database searches

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Bright, Jo Anne; Buckleton, John S.;

    2015-01-01

    may be compromised in quantity or quality. When an individual's profile cannot be resolved from a DNA mixture, ambiguity is introduced. A wild card, F, may be used in place of an allele that has dropped out or when an ambiguous profile is resolved from a DNA mixture. Variant alleles that do...... not been determined. The F and R designation are treated as wild cards for searching, which results in increased chance of adventitious matches. We investigated the probability of adventitious matches given these two types of wild cards....

  3. Detection of cis-acting regulatory SNPs using allelic expression data

    OpenAIRE

    Xiao, Rui; Scott, Laura J.

    2011-01-01

    Allelic expression (AE) imbalance between the two alleles of a gene can be used to detect cis-acting regulatory SNPs (rSNPs) in individuals heterozygous for a transcribed SNP (tSNP). In this paper, we propose three tests for AE analysis focusing on phase-unknown data and any degree of linkage disequilibrium (LD) between the rSNP and tSNP: a test based on the minimum p-value of a one-sided F and two-sided t tests proposed previously for phase-unknown data, a test that combines these two p-valu...

  4. Geographical distribution of GmTfl1 alleles in Chinese soybean varieties

    Institute of Scientific and Technical Information of China (English)

    Guifeng; Liu; Lin; Zhao; Benjamin; J.Averitt; Ying; Liu; Bo; Zhang; Ruzhen; Chang; Yansong; Ma; Xiaoyan; Luan; Rongxia; Guan; Lijuan; Qiu

    2015-01-01

    Stem growth habit is an important agronomic trait in soybean and is subject to artificial selection. This study aimed to provide a theory for genotypic selection of stem growth habit for breeding purposes by analyzing the alleles of Gm Tfl1 gene in Chinese soybean varieties and establishing a database of Gm Tfl1 variation. Using knowledge of insertion and deletion(Indel) in the non-coding region and four single-nucleotide polymorphisms(SNPs) in the coding sequences of the Gm Tfl1 gene, four CAPS and one Indel markers were developed and used to test 1120 Chinese soybean varieties. We found that the dominant Gm Tfl1 allele was prevalent in accessions from the Northern ecoregion, whereas the recessive allele, Gmtfl1, was more common in the Southern ecoregion, and the proportions of Gm Tfl1 and recessive alleles were respectively 40.1% and 59.9% in the Huang-Huai ecoregion. The proportion of Gm Tfl1 decreased and that of Gmtfl1 increased, gradually from north to south. Allele Gm Tfl1-a was present in higher proportions in the Huang-Huai spring, Huang-Huai summer, and Northern spring sub-ecoregions than that in the other sub-ecoregions. Gm Tfl1-b was common in the Northeast spring, Northern spring and Southern summer sub-ecoregions. Gmtfl1-ta was found mainly in the Huang-Huai spring,Huang-Huai summer and Southern spring sub-ecoregions. The Gmtfl1-ab allele was distributed in all six soybean sub-ecoregions. The Gmtfl1-bb allele was distributed mainly in the Huang-Huai spring and summer and Southern spring and summer sub-ecoregions,but the Gmtfl1-tb allele was detected only in the Huang-Huai summer sub-ecoregion. The distributions of Gm Tfl1 and Gmtfl1 have shown no large changes in nearly 60 years of breeding, but the frequency of the recessive genotype Gmtfl1 has shown a rising trend in the last 20 years. This study provides a theoretical foundation for breeding new soybean varieties for different ecoregions.

  5. Efficient allele-specific targeting of LRRK2 R1441 mutations mediated by RNAi.

    Directory of Open Access Journals (Sweden)

    Laura de Yñigo-Mojado

    Full Text Available Since RNA interference (RNAi has the potential to discriminate between single nucleotide changes, there is growing interest in the use of RNAi as a promising therapeutical approach to target dominant disease-associated alleles. Mutations in the leucine-rich repeat kinase 2 (LRRK2 gene have been linked to dominantly inherited Parkinson's disease (PD. We focused on three LRRK2 mutations (R1441G/C and the more prevalent G2109S hoping to identify shRNAs that would both recognize and efficiently silence the mutated alleles preferentially over the wild-type alleles. Using a luciferase-based reporter system, we identified shRNAs that were able to specifically target the R1441G and R1441C alleles with 80% silencing efficiency. The same shRNAs were able to silence specifically mRNAs encoding either partial or full-length mutant LRRK2 fusion proteins, while having a minimal effect on endogenous wild-type LRRK2 expression when transfected in 293FT cells. Shifting of the mutant recognition site (MRS from position 11 to other sites (4 and 16, within the 19-mer window of our shRNA design reduced specificity and overall silencing efficiency. Developing an allele-specific RNAi of G2019S was problematic. Placement of the MRS at position 10 resulted in efficient silencing of reporters (75-80%, but failed to discriminate between mutant and wild-type alleles. Shifting of the MRS to positions 4, 5, 15, 16 increased the specificity of the shRNAs, but reduced the overall silencing efficiency. Consistent with previous reports, these data confirm that MRS placement influences both allele-specificity and silencing strength of shRNAs, while further modification to hairpin design or MRS position may lead to the development of effective G2019S shRNAs. In summary, the effective shRNA against LRRK2 R1441 alleles described herein suggests that RNAi-based therapy of inherited Parkinson's disease is a viable approach towards developing effective therapeutic interventions for

  6. The zeste-white interaction: induction and genetic analysis of a novel class of zeste alleles

    OpenAIRE

    Lifschytz, Eliezer; Green, Melvin M.

    1984-01-01

    The recovery and analysis of a novel class of zeste mutations is described. zop6 and zop11 do not require two w+ genes for their expression unless the z+ gene is present. Analysis of genetic interactions among zeste alleles proved that zop mutations are strong antagonists of the z+ gene product. zop6 is readily reverted by X-rays or by ethylmethane sulphonate to a range of intermediate zeste alleles and thus it is considered to be an insertional mutation. We suggest that z1 and op mutations a...

  7. Nucleotide sequences of chimpanzee MHC class I alleles: evidence for trans-species mode of evolution.

    OpenAIRE

    Mayer, W.E.; Jonker, M; Klein, D; Ivanyi, P; van Seventer, G; Klein, J.

    1988-01-01

    To obtain an insight into the evolutionary origin of the major histocompatibility complex (MHC) class I polymorphism, a cDNA library was prepared from a heterozygous chimpanzee cell line expressing MHC class I molecules crossreacting with allele-specific HLA-A11 antibodies. The library was screened with human class I locus-specific DNA probes, and clones encoding both alleles at the A and B loci have been identified and sequenced. In addition, the sequences of two HLA-A11 subtypes differing b...

  8. Association of HLA class II alleles and CTLA-4 polymorphism with type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Rana J EI Wafai

    2011-01-01

    Full Text Available Type-1 diabetes mellitus (T1DM is a progressive complex autoimmune disease in which combinations of environmental as well as genetic factors contribute to T-cell mediated destruction of insulin-secreting β-cells of the pancreas. HLA class II alleles on chromosome 6p21 [insulin dependent diabetes mellitus 1 (IDDM1], especially DR and DQ, show strong association with T1DM. In addition, several studies have suggested that polymorphisms in the CTLA-4 gene (IDDM12 on chromosome 2q33 form part of the genetic susceptibility for type 1 diabetes. The aim of this study was to analyze HLA alleles of the DQB1 and DRB1 genes using polymerase chain reaction using sequence specific primers (PCR-SSP technique and to investigate the asso-ciation of the A49G CTLA-4 polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis in Lebanese T1DM patients. The study was conduc-ted on 39 Lebanese T1DM patients. Results of HLA typing showed an increased frequency of the HLA-DQB1FNx010201, HLA-DQB1FNx010302, HLA-DRB1FNx010301 and HLA-DRB1FNx010401 alleles, sugges-ting risk association and thus can be considered as susceptibility alleles. On the other hand, strong protection against the disease was conferred by the HLA-DRB1FNx01110101, HLA-DQB1FNx010301 and HLADQB1FNx010601 alleles. RFLP analysis of the A49G polymorphism showed a significant increase in the G allele and GG genotype frequencies in patients, suggesting that CTLA-4 may be considered as a susceptibility gene for the development of T1DM in the Lebanese population. Analysis of the two polymorphisms showed no detectable association between the two genes. However, a significant negative association of the G allele with the DQB1FNx010201 allele was ob-served. This might indicate that the two genetic risk factors, namely HLA and CTLA-4, act independently of each other with no additive effect.

  9. A pseudodeficiency allele common in non-Jewish Tay-Sachs carriers: Implications for carrier screening

    OpenAIRE

    Triggs-Raine, B L; Mules, E H; Kaback, M M; Lim-Steele, J. S. T.; Dowling, C E; Akerman, B R; Natowicz, M R; Grebner, E E; Navon, R; Welch, J. P.; Greenberg, C.R.; Thomas, G H; Gravel, R A

    1992-01-01

    Deficiency of β-hexosaminidase A (Hex A) activity typically results in Tay-Sachs disease. However, healthy subjects found to be deficient in Hex A activity (i.e., pseudodeficient) by means of in vitro biochemical tests have been described. We analyzed the HEXA gene of one pseudodeficient subject and identified both a C739-to-T substitution that changes Arg247→Trp on one allele and a previously identified Tay-Sachs disease mutation on the second allele. Six additional pseudodeficient subjects ...

  10. The allelic modulation of apolipoprotein E expression by oestrogen: potential relevance for Alzheimer's disease

    OpenAIRE

    Lambert, J; Coyle, N; Lendon, C

    2004-01-01

    Background: The ε4 allele of the apolipoprotein E (APOE) gene is a major genetic risk factor for Alzheimer's disease but appears to be associated with greater risk in women than in men. Some studies suggest that the level of APOE may of its own modulate the risk for Alzheimer's disease. Sex differences and an apparent benefit of oestrogen therapy suggest a role for oestrogen. APOE expression is influenced by oestrogen and oestrogen therapy may not benefit women bearing an APOE ε4 allele. Thes...

  11. DNA Repair Dependence of Somatic Mutagenesis of Transposon-Caused WHITE Alleles in DROSOPHILA MELANOGASTER after Treatment with Alkylating Agents

    OpenAIRE

    Fujikawa, Kazuo; Kondo, Sohei

    1986-01-01

    DNA repair-defective alleles of the mei-9, mei-41, mus-104 and mus-101 loci of Drosophila melanogaster were introduced into stocks bearing the UZ and SZ marker sets. Males with the UZ marker set, z1 (zeste allele) and w+(TE) (genetically unstable white allele presumably caused by a transposable element), or the SZ marker set, z1 and w+R (semistable white allele caused by partial duplication of the w+ locus plus transposon insert), were exposed to EMS at the first instar. After emergence, a...

  12. Approximate sampling formulas for general finite-alleles models of mutation

    CERN Document Server

    Bhaskar, Anand; Song, Yun S

    2011-01-01

    Many applications in genetic analyses utilize sampling distributions, which describe the probability of observing a sample of DNA sequences randomly drawn from a population. In the one-locus case with special models of mutation such as the infinite-alleles model or the finite-alleles parent-independent mutation model, closed-form sampling distributions under the coalescent have been known for many decades. However, no exact formula is currently known for more general models of mutation that are of biological interest. Models with finitely-many alleles are considered in this paper, and approximate closed-form sampling formulas are derived for an arbitrary recurrent mutation model or for a reversible recurrent mutation model, depending on whether the number of distinct observed allele types is at most three or four, respectively. Two different approaches---one based on perturbation expansion and the other on an urn construction related to the coalescent---are developed here. Computation in the former approach i...

  13. Allelic losses at genomic instability-associated loci in villous adenomas and adjacent colorectal cancers.

    Science.gov (United States)

    Brenner, Bruce M; Stoler, Daniel L; Rodriguez, Luz; Karpenko, Matthew J; Swede, Helen; Petrelli, Nicholas J; Anderson, Garth R

    2007-04-01

    Allelic imbalances in premalignant villous adenomas were compared with those in adjacent microdissected colorectal carcinoma that had arisen directly from the adenomas. Carcinoma-adenoma pairs were examined from 17 patients who underwent resections for colorectal cancer. In all, 28 microsatellite markers were examined, from regions of the genome where individual allelic losses have been associated with overall genomic instability in colorectal carcinomas. Microsatellite instability (MSI) was also evaluated for each marker in each tissue type. Loss of heterozygosity for multiple markers was found in 35% of adenomas and 65% of carcinomas; the average fractional allelic loss rate was 2.5 times higher in carcinomas than in adenomas. Of the 17 patients, 4 had MSI for >30% of markers in both adenoma and carcinoma, with no significant differences between the two tissues. Markers with particularly high imbalance rates in adenomas were seen on chromosomes 11, 14, and 15. These findings provide further evidence that genomic instability is an ongoing process during carcinogenesis, with a markedly increased frequency of allelic losses seen in carcinomas, compared with adjacent adenomas. Markers on chromosomes 11, 14, and 15 may become valuable tools in the identification of patients destined to progress to colorectal carcinomas. PMID:17350461

  14. Allele frequencies of the third component of complement (C3) in MS patients.

    OpenAIRE

    Bulman, D E; Armstrong, H; Ebers, G C

    1991-01-01

    No difference was found in the allele frequency of C3 (third component of complement) in 129 multiple sclerosis (MS) patients compared with both 69 controls or with similar reported controls from the published literature. An association cannot be confirmed between C3 and MS.

  15. Limited efficacy of hydroxyurea in lowering of the JAK2 V617F allele burden

    DEFF Research Database (Denmark)

    Larsen, Thomas Stauffer; Pallisgaard, Niels; de Stricker, Karin;

    2009-01-01

    Besides being an invaluable marker of clonal disease in chronic myeloproliferative disorders (CMPDs), the JAK2 V617F mutation and the mutated allele burden have an impact on disease phenotype and may provide information on prognosis. Recently, hydroxyurea (HU) has been shown to induce a rapid dec...

  16. Positive selection on multiple antique allelic lineages of transferrin in the polyploid Carassius auratus.

    Science.gov (United States)

    Yang, Lin; Gui, Jian-Fang

    2004-07-01

    Transferrin polymorphism has been studied in the polyploid Carassius auratus by cloning and sequence analysis of cDNAs from its three subspecies C. auratus gibelio, C. auratus auratus, and C. auratus cuvieri. DNA polymorphism of extremely high extent was shown for the transferrin gene by the 248 segregation sites among coding region sequences of its alleles. The deduced amino acid sequences of the transferrin alleles showed variable theoretical physicochemical parameters, which might constitute molecular basis for their electrophoretic heterogeneity. Positive selection was inferred by the replacement/synonymous ratios larger than 1 in partial allelic lineages which was subsequently confirmed by likelihood simulation under neutral or selection models. Furthermore, the correspondent sites to these selected codons were collectively located at two planes in the crystallographic structure of rabbit transferrin, which suggested that the rapid evolution of C. auratus transferrin might correlate to its adaptation to variable environmental elements such as oxygen pressure. The minimal 26 recombination events were detected among coding sequences of C. auratus transferrin, with partial mosaic sequences and breakpoints identified by identity scanning and information site analyses. Phylogenetic analyses revealed multiple antique allelic lineages of transferrin, which was estimated to diverge fifteen to twenty MYA. All these features strongly suggested the role of balancing selection in long persistence of high transferrin polymorphism in C. auratus. Furthermore, owing to its particular evolutionary backgrounds, the silver crucian carp might possess a distinctive balancing selection mechanism. PMID:15014154

  17. Naturally occurring ERAP1 haplotypes encode functionally distinct alleles with fine substrate specificity.

    Science.gov (United States)

    Reeves, Emma; Edwards, Christopher J; Elliott, Tim; James, Edward

    2013-07-01

    Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims peptides for MHC class I presentation, influencing the degree and specificity of CD8(+) T cell responses. Single-nucleotide polymorphisms within the exons encoding ERAP1 are associated with autoimmune diseases and cervical carcinoma, but it is not known whether they act independently or as disease-associated haplotypes. We sequenced ERAP1 from 20 individuals and show that single-nucleotide polymorphisms occur as distinct haplotypes in the human population and that these haplotypes encode functionally distinct ERAP1 alleles. Using a wide range of substrates, we are able to demonstrate that for any given substrate distinct ERAP1 alleles can be "normal," "hypofunctional," or "hyperfunctional" and that each allele has a trend bias toward one of these three activities. Thus, the repertoire of peptides presented at the cell surface for recognition by CTL is likely to depend on the precise combination of both MHC class I and ERAP1 alleles expressed within an individual, and has important implications for predisposition to disease. PMID:23733883

  18. HLA-DRB1 alleles genotyping in patients with rheumatoid arthritis in Chinese.

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Objective: To explore the role of HLA-DRB1 genes in the development of rheumatoid arthritis (RA) and the correlations between HLA-DR alleles and clinical manifestations of patients with RA. Methods: 86 patients and 106 race matched controls in whom HLADR typing was performed by the method of DNA amplification with sequence-specific primers (PCR-SSP)

  19. Two Distinct Waxy Alleles Impact the Granule-Bound Starch Synthase in Sorghum

    Science.gov (United States)

    The granule-bound starch synthase (GBSS) is the enzyme responsible for amylose synthesis in starch granules. Loss of GBSS activity results in starch granules containing mostly amylopectin and little or no amylose, a phenotype described as waxy. Previously, two phenotypic classes of waxy alleles we...

  20. Human-specific derived alleles of CD33 and other genes protect against postreproductive cognitive decline.

    Science.gov (United States)

    Schwarz, Flavio; Springer, Stevan A; Altheide, Tasha K; Varki, Nissi M; Gagneux, Pascal; Varki, Ajit

    2016-01-01

    The individuals of most vertebrate species die when they can no longer reproduce. Humans are a rare exception, having evolved a prolonged postreproductive lifespan. Elders contribute to cooperative offspring care, assist in foraging, and communicate important ecological and cultural knowledge, increasing the survival of younger individuals. Age-related deterioration of cognitive capacity in humans compromises these benefits and also burdens the group with socially costly members. We investigated the contribution of the immunoregulatory receptor CD33 to a uniquely human postreproductive disease, Alzheimer's dementia. Surprisingly, even though selection at advanced age is expected to be weak, a CD33 allele protective against Alzheimer's disease is derived and unique to humans and favors a functional molecular state of CD33 resembling that of the chimpanzee. Thus, derived alleles may be compensatory and restore interactions altered as a consequence of human-specific brain evolution. We found several other examples of derived alleles at other human loci that protect against age-related cognitive deterioration arising from neurodegenerative disease or cerebrovascular insufficiency. Selection by inclusive fitness may be strong enough to favor alleles protecting specifically against cognitive decline in postreproductive humans. Such selection would operate by maximizing the contributions of postreproductive individuals to the fitness of younger kin. PMID:26621708

  1. Short aggrecan gene repetitive alleles associated with lumbar degenerative disc disease in Turkish patients.

    Science.gov (United States)

    Eser, O; Eser, B; Cosar, M; Erdogan, M O; Aslan, A; Yıldız, H; Solak, M; Haktanır, A

    2011-01-01

    We investigated a possible association between aggrecan gene polymorphism and lumbar degenerative disc disease in Turkish patients. One hundred 20-30-year-old patients with or without low back pain were selected for the study. Lumbar magnetic resonance imaging was performed on all patients. The patient group had low back pain clinically and degenerative disc disease radiographically. The control group included patients with and without low back pain: all were negative radiographically for degenerative disc disease. Genomic DNA was extracted from all participants. A PCR assay were used to evaluate variable number of tandem repeat polymorphism of aggrecan gene alleles to determine if there was any correlation with degenerative disc disease. Significant associations were found between short repeated alleles of the aggrecan gene and severe disc degeneration. A significant association was also found between short repeated alleles of the aggrecan gene and multilevel disc herniation as well as extrusion and sequestration types of disc herniation. In Turkish population, short repeated alleles of the aggrecan gene are associated with increased disc degeneration and disc herniation. PMID:21948754

  2. Precision-engineering the Pseudomonas aeruginosa genome with two-step allelic exchange

    Science.gov (United States)

    Hmelo, Laura R.; Borlee, Bradley R.; Almblad, Henrik; Love, Michelle E.; Randall, Trevor E.; Tseng, Boo Shan; Lin, Chuyang; Irie, Yasuhiko; Storek, Kelly M.; Yang, Jaeun Jane; Siehnel, Richard J.; Howell, P. Lynne; Singh, Pradeep K.; Tolker-Nielsen, Tim; Parsek, Matthew R.; Schweizer, Herbert P.; Harrison, Joe J.

    2016-01-01

    Allelic exchange is an efficient method of bacterial genome engineering. This protocol describes the use of this technique to make gene knockouts and knockins, as well as single nucleotide insertions, deletions and substitutions in Pseudomonas aeruginosa. Unlike other approaches to allelic exchange, this protocol does not require heterologous recombinases to insert or excise selective markers from the target chromosome. Rather, positive and negative selection are enabled solely by suicide vector-encoded functions and host cell proteins. Here, mutant alleles, which are flanked by regions of homology to the recipient chromosome, are synthesized in vitro and then cloned into allelic exchange vectors using standard procedures. These suicide vectors are then introduced into recipient cells by conjugation. Homologous recombination then results in antibiotic resistant single-crossover mutants in which the plasmid has integrated site-specifically into the chromosome. Subsequently, unmarked double-crossover mutants are isolated directly using sucrose-mediated counter-selection. This two-step process yields seamless mutations that are precise to a single base pair of DNA. The entire procedure requires ~2 weeks. PMID:26492139

  3. The 3020insC Allele of NOD2 Predisposes to Cancers of Multiple Organs

    Directory of Open Access Journals (Sweden)

    Lubiński Jan

    2005-03-01

    Full Text Available Abstract The NOD2 gene has been associated with susceptibility to Crohn's disease and individuals with Crohn's disease are at increased risk for cancer at a number of organ sites. We studied the association between the 3020insC allele of the NOD2 gene and cancer among 2604 cancer patients and 1910 controls from Poland. Patients were diagnosed with one of twelve types of cancer in the Szczecin region between 1994 and 2004. Significant associations were found for colon cancer (OR = 1.8; 95% CI 1.2 to 2.6, for lung cancer (OR = 1.7; 95% CI = 1.1 to 2.5 and for ovarian cancer (OR = 1.6; 95% CI 1.1 to 2.3. In addition, a significant association was found for early-onset laryngeal cancer (OR = 2.9; 95% CI 1.4 to 6.2 and for breast cancer in the presence of DCIS (OR = 2.1 95% CI = 1.2 to 3.6. The NOD2 3020insC allele is relatively common (in Poland 7.3% of individuals and may be responsible for an important fraction of cancer cases. We estimate that the lifetime cancer risk among carriers of this allele is 30% higher than that of individuals with two wild-type alleles.

  4. [Genetic study of the Penta E locus and identification of rare alleles].

    Science.gov (United States)

    Lai, Li; Shen, Xiaoli; Han, Lili; Chen, Dian; Hu, Jie

    2015-10-01

    OBJECTIVE To study the genetic polymorphisms of Penta E locus in Fujian Han population. METHODS Polymorphisms of the Penta E locus in 851 unrelated individuals were analyzed using polymerase chain reaction-short tandem repeat (PCR-STR). The mutation rate of rare alleles was analyzed in 494 paternity identification cases (in a total of 674 meiosis). RESULTS Twenty-six alleles were identified for the Penta E locus, with their frequencies ranging from 0.0006 to 0.1528. There were 7 rare alleles, among which Penta E-28.4 ([AAAGA]29) was identified for the first time. Genetic parameters of the Penta E locus in Fujian Han population were obtained, including PIC= 0.91, PE= 0.817, PD= 0.986, and mutation rate= 0.0015. CONCLUSION The Penta E locus is highly polymorphic and has a low mutation rate in Fujian Han population. It also has a good prospect in genetics applications. DNA sequencing is a good method for identifying rare alleles. PMID:26418985

  5. Registration of hard kernel puroindoline allele nearisogenic line hexaploid wheat genetic stocks.

    Science.gov (United States)

    Seven puroindoline allele near-isogenic line (NIL) hexaploid wheat (Triticum aestivum L.) genetic stocks (GS-xxxx – GS-xxxx; PI 644080 – PI 644086) were developed by Dr. Craig F. Morris at the USDA-ARS Western Wheat Quality Laboratory, Pullman, Washington. As they incorporate the first seven known ...

  6. Allelic Dropout in the ENG Gene, Affecting the Results of Genetic Testing in Hereditary Hemorrhagic Telangiectasia

    DEFF Research Database (Denmark)

    Tørring, Pernille M; Kjeldsen, A.D.; Ousager, L.B.;

    2012-01-01

    Background: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal-dominant vascular disorder with three disease-causing genes identified to date: ENG, ACVRL1, and SMAD4. We report an HHT patient with allelic dropout that on routine sequence analysis for a known mutation in the family (c.817...

  7. Exome sequencing identifies rare LDLR and APOA5 alleles conferring risk for myocardial infarction

    DEFF Research Database (Denmark)

    Do, Ron; Stitziel, Nathan O; Won, Hong-Hee;

    2015-01-01

    -synonymous mutations were at 4.2-fold increased risk for MI; carriers of null alleles at LDLR were at even higher risk (13-fold difference). Approximately 2% of early MI cases harbour a rare, damaging mutation in LDLR; this estimate is similar to one made more than 40 years ago using an analysis of total cholesterol...

  8. Overdispersion in allelic counts and θ-correction in forensic genetics

    DEFF Research Database (Denmark)

    Tvedebrink, Torben

    2009-01-01

    A statistical model for incorporating the extra variability in allelic counts due to subpopulation structures is presented. In forensic genetics, this effect is modelled by the identical-by-decent-parameter, θ . It is shown, that θ may be defined as an overdispersion parameter capturing the extra...

  9. SNP calling, genotype calling, and sample allele frequency estimation from new-generation sequencing data

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Korneliussen, Thorfinn Sand; Albrechtsen, Anders;

    2012-01-01

    calculated using a dynamic programming algorithm and numerically optimized using analytical derivatives. We then use a bayesian method for estimating the sample allele frequency in a single site, and show how the method can be used for genotype calling and SNP calling. We also show how the method can be...

  10. The effect of subdivision on variation at multi-allelic loci under balancing selection

    DEFF Research Database (Denmark)

    Schierup, M H; Vekemans, X; Charlesworth, D

    2000-01-01

    Simulations are used to investigate the expected pattern of variation at loci under different forms of multi-allelic balancing selection in a finite island model of a subdivided population. The objective is to evaluate the effect of restricted migration among demes on the distribution of polymorp...

  11. Heterologous expression of the Arabidopsis etr1-1 allele inhibits the senescence of carnation flowers

    NARCIS (Netherlands)

    Bovy, A.G.; Angenent, G.C.; Dons, H.J.M.; Altvorst, van A.

    1999-01-01

    The Arabidopsis thaliana etr1-1 allele, capable of conferring ethylene insensitivity in a heterologous host, was introduced into transgenic carnation plants. This gene was expressed under control of either its own promoter, the constitutive CaMV 35S promoter or the flower-specific petunia FBP1 promo

  12. Allelic differences within and among sister spores of the arbuscular mycorrhizal fungus Glomus etunicatum suggest segregation at sporulation.

    Directory of Open Access Journals (Sweden)

    Eva Boon

    Full Text Available Arbuscular mycorrhizal fungi (AMF are root-inhabiting fungi that form mutualistic symbioses with their host plants. AMF are made up of coenocytic networks of hyphae through which nuclei and organelles can freely migrate. In this study, we investigated the possibility of a genetic bottleneck and segregation of allelic variation at sporulation for a low-copy Polymerase1-like gene, PLS. Specifically, our objectives were (1 to estimate what allelic diversity is passed on to a single spore (2 to determine whether this diversity is less than the total amount of variation found in all spores (3 to investigate whether there is any differential segregation of allelic variation. We inoculated three tomato plants with a single spore of Glomus etunicatum each and after six months sampled between two and three daughter spores per tomato plant. Pyrosequencing PLS amplicons in eight spores revealed high levels of allelic diversity; between 43 and 152 alleles per spore. We corroborated the spore pyrosequencing results with Sanger- and pyrosequenced allele distributions from the original parent isolate. Both sequencing methods retrieved the most abundant alleles from the offspring spore allele distributions. Our results indicate that individual spores contain only a subset of the total allelic variation from the pooled spores and parent isolate. Patterns of allele diversity between spores suggest the possibility for segregation of PLS alleles among spores. We conclude that a genetic bottleneck could potentially occur during sporulation in AMF, with resulting differences in genetic variation among sister spores. We suggest that the effects of this bottleneck may be countered by anastomosis (hyphal fusion between related hyphae.

  13. Combination of null alleles with 7+9 allelic pair at Glu-B1 locus on the long arm of group 1 chromosome improves wheat dough functionality for tortillas

    Science.gov (United States)

    Deletion of one or more high molecular weight glutenin subunit (HMW-GS) alleles reduces gluten strength in a way that may be beneficial for tortilla quality. Wheat lines in which one or more of the HMW-GS alleles were absent from Glu-A1, Glu-B1 or Glu-D1 locus (deletion lines) were compared with non...

  14. Allelic expression analysis of the osteoarthritis susceptibility locus that maps to MICAL3

    Directory of Open Access Journals (Sweden)

    Ratnayake Madhushika

    2012-03-01

    Full Text Available Abstract Background A genome-wide association scan with subsequent replication study that involved over 67,000 individuals of European ancestry has produced evidence of association of single nucleotide polymorphism rs2277831 to primary osteoarthritis (OA with a P-value of 2.9 × 10-5. rs2277831, an A/G transition, is located in an intron of MICAL3. This gene is located on chromosome 22q11.21 and the association signal encompasses two additional genes, BCL2L13 and BID. It is becoming increasingly apparent that many common complex traits are mediated by cis-acting regulatory polymorphisms that influence, in a tissue-specific manner, gene expression or transcript stability. Methods We used total and allelic expression analysis to assess whether the OA association to rs2277831 is mediated by an influence on MICAL3, BCL2L13 or BID expression. Using RNA extracted from joint tissues of 60 patients who had undergone elective joint replacement surgery, we assessed whether rs2277831 correlated with allelic expression of either of the three genes by: 1 measuring the expression of each gene by quantitative PCR and then stratifying the data by genotype at rs2277831 and 2 accurately discriminating and quantifying the mRNA synthesised from the alleles of OA patients using allelic-quantitative PCR. Results We found no evidence for a correlation between gene expression and genotype at rs2277831, with P-values of 0.09 for BCL2L13, 0.07 for BID and 0.33 for MICAL3. In the allelic expression analysis we observed several examples of significant (p BCL2L13 (P = 0.004, 2.09 at BID (P = 0.001 and the most extreme case being at MICAL3, with an allelic expression ratio of 5.47 (P = 0.001. However, there was no correlation observed between the pattern of allelic expression and the genotype at rs2277831. Conclusions In the tissues that we have studied, our data do not support our hypothesis that the association between rs2277831 and OA is due to the effect this SNP has on

  15. Always look on both sides: phylogenetic information conveyed by simple sequence repeat allele sequences.

    Directory of Open Access Journals (Sweden)

    Stéphanie Barthe

    Full Text Available Simple sequence repeat (SSR markers are widely used tools for inferences about genetic diversity, phylogeography and spatial genetic structure. Their applications assume that variation among alleles is essentially caused by an expansion or contraction of the number of repeats and that, accessorily, mutations in the target sequences follow the stepwise mutation model (SMM. Generally speaking, PCR amplicon sizes are used as direct indicators of the number of SSR repeats composing an allele with the data analysis either ignoring the extent of allele size differences or assuming that there is a direct correlation between differences in amplicon size and evolutionary distance. However, without precisely knowing the kind and distribution of polymorphism within an allele (SSR and the associated flanking region (FR sequences, it is hard to say what kind of evolutionary message is conveyed by such a synthetic descriptor of polymorphism as DNA amplicon size. In this study, we sequenced several SSR alleles in multiple populations of three divergent tree genera and disentangled the types of polymorphisms contained in each portion of the DNA amplicon containing an SSR. The patterns of diversity provided by amplicon size variation, SSR variation itself, insertions/deletions (indels, and single nucleotide polymorphisms (SNPs observed in the FRs were compared. Amplicon size variation largely reflected SSR repeat number. The amount of variation was as large in FRs as in the SSR itself. The former contributed significantly to the phylogenetic information and sometimes was the main source of differentiation among individuals and populations contained by FR and SSR regions of SSR markers. The presence of mutations occurring at different rates within a marker's sequence offers the opportunity to analyse evolutionary events occurring on various timescales, but at the same time calls for caution in the interpretation of SSR marker data when the distribution of within

  16. Detection of ancestry informative HLA alleles confirms the admixed origins of Japanese population.

    Science.gov (United States)

    Nakaoka, Hirofumi; Mitsunaga, Shigeki; Hosomichi, Kazuyoshi; Shyh-Yuh, Liou; Sawamoto, Taiji; Fujiwara, Tsutomu; Tsutsui, Naohisa; Suematsu, Koji; Shinagawa, Akira; Inoko, Hidetoshi; Inoue, Ituro

    2013-01-01

    The polymorphisms in the human leukocyte antigen (HLA) region are powerful tool for studying human evolutionary processes. We investigated genetic structure of Japanese by using five-locus HLA genotypes (HLA-A, -B, -C, -DRB1, and -DPB1) of 2,005 individuals from 10 regions of Japan. We found a significant level of population substructure in Japanese; particularly the differentiation between Okinawa Island and mainland Japanese. By using a plot of the principal component scores, we identified ancestry informative alleles associated with the underlying population substructure. We examined extent of linkage disequilibrium (LD) between pairs of HLA alleles on the haplotypes that were differentiated among regions. The LDs were strong and weak for pairs of HLA alleles characterized by low and high frequencies in Okinawa Island, respectively. The five-locus haplotypes whose alleles exhibit strong LD were unique to Japanese and South Korean, suggesting that these haplotypes had been recently derived from the Korean Peninsula. The alleles characterized by high frequency in Japanese compared to South Korean formed segmented three-locus haplotype that was commonly found in Aleuts, Eskimos, and North- and Meso-Americans but not observed in Korean and Chinese. The serologically equivalent haplotype was found in Orchid Island in Taiwan, Mongol, Siberia, and Arctic regions. It suggests that early Japanese who existed prior to the migration wave from the Korean Peninsula shared ancestry with northern Asian who moved to the New World via the Bering Strait land bridge. These results may support the admixture model for peopling of Japanese Archipelago. PMID:23577161

  17. Detection of ancestry informative HLA alleles confirms the admixed origins of Japanese population.

    Directory of Open Access Journals (Sweden)

    Hirofumi Nakaoka

    Full Text Available The polymorphisms in the human leukocyte antigen (HLA region are powerful tool for studying human evolutionary processes. We investigated genetic structure of Japanese by using five-locus HLA genotypes (HLA-A, -B, -C, -DRB1, and -DPB1 of 2,005 individuals from 10 regions of Japan. We found a significant level of population substructure in Japanese; particularly the differentiation between Okinawa Island and mainland Japanese. By using a plot of the principal component scores, we identified ancestry informative alleles associated with the underlying population substructure. We examined extent of linkage disequilibrium (LD between pairs of HLA alleles on the haplotypes that were differentiated among regions. The LDs were strong and weak for pairs of HLA alleles characterized by low and high frequencies in Okinawa Island, respectively. The five-locus haplotypes whose alleles exhibit strong LD were unique to Japanese and South Korean, suggesting that these haplotypes had been recently derived from the Korean Peninsula. The alleles characterized by high frequency in Japanese compared to South Korean formed segmented three-locus haplotype that was commonly found in Aleuts, Eskimos, and North- and Meso-Americans but not observed in Korean and Chinese. The serologically equivalent haplotype was found in Orchid Island in Taiwan, Mongol, Siberia, and Arctic regions. It suggests that early Japanese who existed prior to the migration wave from the Korean Peninsula shared ancestry with northern Asian who moved to the New World via the Bering Strait land bridge. These results may support the admixture model for peopling of Japanese Archipelago.

  18. Novel Natural Allelic Variations at the Rht-1 Loci in Wheat

    Institute of Scientific and Technical Information of China (English)

    Aixia Li; HongQing Ling; Aimin Zhang; Wenlong Yang; Xueyuan Lou; Dongcheng Liu; Jiazhu Sun; Xiaoli Guo; Jing Wang; Yiwen Li; Kehui Zhan

    2013-01-01

    Plant height is an important agronomic trait. Dramatic increase in wheat yield during the“green revolution”is mainly due to the widespread utilization of the Reduced height (Rht)-1 gene. We analyzed the natural allelic variations of three homoeologous loci Rht-A1, Rht-B1, and Rht-D1 in Chinese wheat (Triticum aestivum L.) micro-core collections and the Rht-B1/D1 genotypes in over 1,500 bred cultivars and germplasms using a modified EcoTILLING. We identified six new Rht-A1 allelic variations (Rht-A1b-g), eight new Rht-B1 allelic variations (Rht-B1h-o), and six new Rht-D1 allelic variations (Rht-D1e-j). These allelic variations contain single nucleotide polymorphisms (SNPs) or small insertions and deletions in the coding or uncoding regions, involving two frame-shift mutations and 15 missenses. Of which, Rht-D1e and Rht-D1h resulted in the loss of interactions of GID1-DELLA-GID2, Rht-B1i could increase plant height. We found that the Rht-B1h contains the same SNPs and 197 bp fragment insertion as reported in Rht-B1c. Further detection of Rht-B1h in Tibet wheat germplasms and wheat relatives indicated that Rht-B1c may originate from Rht-B1h. These results suggest rich genetic diversity at the Rht-1 loci and provide new resources for wheat breeding.

  19. Distribution of CYP2D6 alleles and phenotypes in the Brazilian population.

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    Deise C Friedrich

    Full Text Available The CYP2D6 enzyme is one of the most important members of the cytochrome P450 superfamily. This enzyme metabolizes approximately 25% of currently prescribed medications. The CYP2D6 gene presents a high allele heterogeneity that determines great inter-individual variation. The aim of this study was to evaluate the variability of CYP2D6 alleles, genotypes and predicted phenotypes in Brazilians. Eleven single nucleotide polymorphisms and CYP2D6 duplications/multiplications were genotyped by TaqMan assays in 1020 individuals from North, Northeast, South, and Southeast Brazil. Eighteen CYP2D6 alleles were identified in the Brazilian population. The CYP2D6*1 and CYP2D6*2 alleles were the most frequent and widely distributed in different geographical regions of Brazil. The highest number of CYPD6 alleles observed was six and the frequency of individuals with more than two copies ranged from 6.3% (in Southern Brazil to 10.2% (Northern Brazil. The analysis of molecular variance showed that CYP2D6 is homogeneously distributed across different Brazilian regions and most of the differences can be attributed to inter-individual differences. The most frequent predicted metabolic status was EM (83.5%. Overall 2.5% and 3.7% of Brazilians were PMs and UMs respectively. Genomic ancestry proportions differ only in the prevalence of intermediate metabolizers. The IM predicted phenotype is associated with a higher proportion of African ancestry and a lower proportion of European ancestry in Brazilians. PM and UM classes did not vary among regions and/or ancestry proportions therefore unique CYP2D6 testing guidelines for Brazilians are possible and could potentially avoid ineffective or adverse events outcomes due to drug prescriptions.

  20. Allelic Variation at the Rht8 Locus in a 19th Century Wheat Collection

    Directory of Open Access Journals (Sweden)

    Linnéa Asplund

    2012-01-01

    Full Text Available Wheat breeding during the 20th century has put large efforts into reducing straw length and increasing harvest index. In the 1920s an allele of Rht8 with dwarfing effects, found in the Japanese cultivar “Akakomugi,” was bred into European cultivars and subsequently spread over the world. Rht8 has not been cloned, but the microsatellite marker WMS261 has been shown to be closely linked to it and is commonly used for genotyping Rht8. The “Akakomugi” allele is strongly associated with WMS261-192bp. Numerous screens of wheat cultivars with different geographical origin have been performed to study the spread and influence of the WMS261-192bp during 20th century plant breeding. However, the allelic diversity of WMS261 in wheat cultivars before modern plant breeding and introduction of the Japanese dwarfing genes is largely unknown. Here, we report a study of WMS261 allelic diversity in a historical wheat collection from 1865 representing worldwide major wheats at the time. The majority carried the previously reported 164 bp or 174 bp allele, but with little geographical correlation. In a few lines, a rare 182 bp fragment was found. Although straw length was recognized as an important character already in the 19th century, Rht8 probably played a minor role for height variation. The use of WMS261 and other functional markers for analyses of historical specimens and characterization of historic crop traits is discussed.

  1. Simultaneous SNP identification and assessment of allele-specific bias from ChIP-seq data

    Directory of Open Access Journals (Sweden)

    Ni Yunyun

    2012-09-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs have been associated with many aspects of human development and disease, and many non-coding SNPs associated with disease risk are presumed to affect gene regulation. We have previously shown that SNPs within transcription factor binding sites can affect transcription factor binding in an allele-specific and heritable manner. However, such analysis has relied on prior whole-genome genotypes provided by large external projects such as HapMap and the 1000 Genomes Project. This requirement limits the study of allele-specific effects of SNPs in primary patient samples from diseases of interest, where complete genotypes are not readily available. Results In this study, we show that we are able to identify SNPs de novo and accurately from ChIP-seq data generated in the ENCODE Project. Our de novo identified SNPs from ChIP-seq data are highly concordant with published genotypes. Independent experimental verification of more than 100 sites estimates our false discovery rate at less than 5%. Analysis of transcription factor binding at de novo identified SNPs revealed widespread heritable allele-specific binding, confirming previous observations. SNPs identified from ChIP-seq datasets were significantly enriched for disease-associated variants, and we identified dozens of allele-specific binding events in non-coding regions that could distinguish between disease and normal haplotypes. Conclusions Our approach combines SNP discovery, genotyping and allele-specific analysis, but is selectively focused on functional regulatory elements occupied by transcription factors or epigenetic marks, and will therefore be valuable for identifying the functional regulatory consequences of non-coding SNPs in primary disease samples.

  2. Investigation of MGMT and DAPK1 methylation patterns in diffuse large B-cell lymphoma using allelic MSP-pyrosequencing

    DEFF Research Database (Denmark)

    Kristensen, Lasse Sommer; Treppendahl, Marianne Bach; Asmar, Fazila;

    2013-01-01

    The tumor suppressor genes MGMT and DAPK1 become methylated in several cancers including diffuse large B-cell lymphoma (DLBCL). However, allelic methylation patterns have not been investigated in DLBCL. We developed a fast and cost-efficient method for the analysis of allelic methylation based on...

  3. Transmission of an FMR1 premutation allele in a large family identified through newborn screening: the role of AGG interruptions

    Science.gov (United States)

    Yrigollen, Carolyn M.; Mendoza-Morales, Guadalupe; Hagerman, Randi; Tassone, Flora

    2014-01-01

    The CGG repeat within the premutation range in the FMR1 gene can lead to neurodegenerative disorders and intellectual disabilities. An increase in size upon transmission from parent to child is more likely to occur for larger alleles and without AGG interruptions. We describe the molecular structure and the transmission of an FMR1 premutation allele in a multigenerational family, identified through newborn screening for fragile X syndrome. Transmission of the premutation allele was traced through 5 generations in 14 of the 23 individuals who were genotyped through cascade testing. Allele size instability during transmission was observed but no expansions to a full mutation were detected. Clinical and molecular characterizations of the participants lead to the diagnosis of FXTAS in one subject identified as a premutation carrier. A gradual small increase in the size of the premutation allele was observed during transmission through five generations. The relative stability is likely due to the presence of two AGGs within the allele. The detection of AGG interruptions within the premutation alleles is important in genetic counseling to better predict the risk of expansion during transmission from a premutation to a full mutation allele. PMID:23739124

  4. Effective marker alleles associated with type II resistance of wheat to Fusarium head blight infection in fields

    Science.gov (United States)

    Molecular markers associated with known quantitative trait loci (QTLs) for type 2 resistance to Fusarium head blight (FHB) in bi-parental mapping populations usually have more than two alleles in breeding populations. Therefore, understanding the association of each allele with FHB response is parti...

  5. Identification and distribution of three serologically undetected alleles of HLA-DR by oligonucleotide x DNA typing analysis

    International Nuclear Information System (INIS)

    Recent progress in the molecular biology of human major histocompatibility complex class II genes (HLA-DP, -DQ, -DR) have shown that the genetic complexity and allelic polymorphism are greater than expected. In the case of HLA-DR, three DR β-chain loci have been identified and linked, two of which (DR βI and DR βIII, now assigned names HLA-DR1B and HLA-DR3B) are functional. The authors have shown that the HLA micropolymorphism detected at the DNA sequence level can easily be analyzed by hybridization with allele-specific oligonucleotides (HLA oligotyping). In the case of the HLA DRw52 supertypic specificity, which includes the DR3, DR5, DRw6, and DRw8 haplotypes, three alleles, referred to as DRw52a, DRw52b, and DRw52c, have recently been identified at the HLA-DR3B locus by DNA sequencing. Hybridization with locus- and allele-specific oligonucleotide probes (designated 52a, 52b, and 52c) has been performed on DNA from normal individuals forming a panel of 82 haplotypes to establish the distribution of these three alleles. Individuals of the DR3 haplotype had either the DRw52a or DRw52b allele, and individuals of extended haplotype HLA-A1,B8,DR3 had only the DRw52a allele. DR5 individuals all had the DRw52b allele, while individuals of DRw6 haplotype had the DRw52a, -52b, or -52c allele. None of these three alleles are found in DRw8 individuals. Analysis of this micropolymorphism, undetectable by common typing procedures, is therefore now operational for more accurate HLA matching for transplantation and for improving correlations between HLA and disease susceptibility

  6. Allelic Variation of Cytochrome P450s Drives Resistance to Bednet Insecticides in a Major Malaria Vector.

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    Sulaiman S Ibrahim

    2015-10-01

    Full Text Available Scale up of Long Lasting Insecticide Nets (LLINs has massively contributed to reduce malaria mortality across Africa. However, resistance to pyrethroid insecticides in malaria vectors threatens its continued effectiveness. Deciphering the detailed molecular basis of such resistance and designing diagnostic tools is critical to implement suitable resistance management strategies. Here, we demonstrated that allelic variation in two cytochrome P450 genes is the most important driver of pyrethroid resistance in the major African malaria vector Anopheles funestus and detected key mutations controlling this resistance. An Africa-wide polymorphism analysis of the duplicated genes CYP6P9a and CYP6P9b revealed that both genes are directionally selected with alleles segregating according to resistance phenotypes. Modelling and docking simulations predicted that resistant alleles were better metabolizers of pyrethroids than susceptible alleles. Metabolism assays performed with recombinant enzymes of various alleles confirmed that alleles from resistant mosquitoes had significantly higher activities toward pyrethroids. Additionally, transgenic expression in Drosophila showed that flies expressing resistant alleles of both genes were significantly more resistant to pyrethroids compared with those expressing the susceptible alleles, indicating that allelic variation is the key resistance mechanism. Furthermore, site-directed mutagenesis and functional analyses demonstrated that three amino acid changes (Val109Ile, Asp335Glu and Asn384Ser from the resistant allele of CYP6P9b were key pyrethroid resistance mutations inducing high metabolic efficiency. The detection of these first DNA markers of metabolic resistance to pyrethroids allows the design of DNA-based diagnostic tools to detect and track resistance associated with bednets scale up, which will improve the design of evidence-based resistance management strategies.

  7. Allelic Variation of Cytochrome P450s Drives Resistance to Bednet Insecticides in a Major Malaria Vector.

    Science.gov (United States)

    Ibrahim, Sulaiman S; Riveron, Jacob M; Bibby, Jaclyn; Irving, Helen; Yunta, Cristina; Paine, Mark J I; Wondji, Charles S

    2015-10-01

    Scale up of Long Lasting Insecticide Nets (LLINs) has massively contributed to reduce malaria mortality across Africa. However, resistance to pyrethroid insecticides in malaria vectors threatens its continued effectiveness. Deciphering the detailed molecular basis of such resistance and designing diagnostic tools is critical to implement suitable resistance management strategies. Here, we demonstrated that allelic variation in two cytochrome P450 genes is the most important driver of pyrethroid resistance in the major African malaria vector Anopheles funestus and detected key mutations controlling this resistance. An Africa-wide polymorphism analysis of the duplicated genes CYP6P9a and CYP6P9b revealed that both genes are directionally selected with alleles segregating according to resistance phenotypes. Modelling and docking simulations predicted that resistant alleles were better metabolizers of pyrethroids than susceptible alleles. Metabolism assays performed with recombinant enzymes of various alleles confirmed that alleles from resistant mosquitoes had significantly higher activities toward pyrethroids. Additionally, transgenic expression in Drosophila showed that flies expressing resistant alleles of both genes were significantly more resistant to pyrethroids compared with those expressing the susceptible alleles, indicating that allelic variation is the key resistance mechanism. Furthermore, site-directed mutagenesis and functional analyses demonstrated that three amino acid changes (Val109Ile, Asp335Glu and Asn384Ser) from the resistant allele of CYP6P9b were key pyrethroid resistance mutations inducing high metabolic efficiency. The detection of these first DNA markers of metabolic resistance to pyrethroids allows the design of DNA-based diagnostic tools to detect and track resistance associated with bednets scale up, which will improve the design of evidence-based resistance management strategies. PMID:26517127

  8. Rapid detection of the CYP2A6*12 hybrid allele by Pyrosequencing® technology

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    Gallagher Margaret L

    2009-08-01

    Full Text Available Abstract Background Identification of CYP2A6 alleles associated with reduced enzyme activity is important in the study of inter-individual differences in drug metabolism. CYP2A6*12 is a hybrid allele that results from unequal crossover between CYP2A6 and CYP2A7 genes. The 5' regulatory region and exons 1–2 are derived from CYP2A7, and exons 3–9 are derived from CYP2A6. Conventional methods for detection of CYP2A6*12 consist of two-step PCR protocols that are laborious and unsuitable for high-throughput genotyping. We developed a rapid and accurate method to detect the CYP2A6*12 allele by Pyrosequencing technology. Methods A single set of PCR primers was designed to specifically amplify both the CYP2A6*1 wild-type allele and the CYP2A6*12 hybrid allele. An internal Pyrosequencing primer was used to generate allele-specific sequence information, which detected homozygous wild-type, heterozygous hybrid, and homozygous hybrid alleles. We first validated the assay on 104 DNA samples that were also genotyped by conventional two-step PCR and by cycle sequencing. CYP2A6*12 allele frequencies were then determined using the Pyrosequencing assay on 181 multi-ethnic DNA samples from subjects of African American, European Caucasian, Pacific Rim, and Hispanic descent. Finally, we streamlined the Pyrosequencing assay by integrating liquid handling robotics into the workflow. Results Pyrosequencing results demonstrated 100% concordance with conventional two-step PCR and cycle sequencing methods. Allele frequency data showed slightly higher prevalence of the CYP2A6*12 allele in European Caucasians and Hispanics. Conclusion This Pyrosequencing assay proved to be a simple, rapid, and accurate alternative to conventional methods, which can be easily adapted to the needs of higher-throughput studies.

  9. Novel alleles of 31-bp VNTR polymorphism in the human cystathionine -synthase (CBS) gene were detected in healthy Asians

    Indian Academy of Sciences (India)

    Yik-Yuen Gan; Chuan-Fei Chen

    2010-12-01

    A 31-bp variable number of tandem repeats (VNTR) polymorphism of the cystathionine -synthase (CBS) gene was earlier reported in Caucasians of predominantly European descent and Indo–Caucasoid populations.We report here for the first time, the detection of allele 20, which was absent in Caucasian and Indo–Caucasoid populations, as a common allele present in Singaporean Chinese (6.25%), Indians (11.7%), and Malays (11.5%). Hence, allele 20 might be a specific allele for Asian populations. A relatively common allele 19 found in the Caucasian and Indo–Caucasoid populations (10.4%–10.6%) was absent in the Asian samples of this study. Therefore, allele 19 might be a specific allele for the Caucasian populations. A novel and rare allele 13, which was not reported before in the Caucasian and Indo–Caucasoid populations, was found in 0.5% of Singaporean Chinese as genotype 13/17 heterozygotes. The presence of alleles 13 and 20 were verified by DNA sequencing. There were five new genotypes (13/17, 16/20, 17/20, 18/20 and 20/20) not reported before in the Caucasian and Indo–Caucasoid populations, detected in this study. Nine genotypes (15/18, 16/18, 16/21, 17/19, 18/19, 18/21, 19/19, 19/21 and 21/21) which were present in the Caucasian and/or Indo–Caucasoid populations were absent in this study. Our results showed that CBS 31-bp VNTR polymorphism has a distinct genetic difference in allele and genotype frequencies between the European Caucasians, Indo–Caucasoid and Asian populations.

  10. Restrictive flamenco alleles are maintained in Drosophila melanogaster population cages, despite the absence of their endogenous gypsy retroviral targets.

    Science.gov (United States)

    Pélisson, Alain; Payen-Groschêne, Geneviève; Terzian, Christophe; Bucheton, Alain

    2007-02-01

    The flamenco (flam) locus, located at 20A1-3 in the centromeric heterochromatin of the Drosophila melanogaster X chromosome, is a major regulator of the gypsy/mdg4 endogenous retrovirus. In restrictive strains, functional flam alleles maintain gypsy proviruses in a repressed state. By contrast, in permissive strains, proviral amplification results from infection of the female germ line and subsequent insertions into the chromosomes of the progeny. A restrictive/permissive polymorphism prevails in natural and laboratory populations. This polymorphism was assumed to be maintained by the interplay of opposite selective forces; on one hand, the increase of genetic load caused by proviral insertions would favor restrictive flam alleles because they make flies resistant to these gypsy replicative transpositions and, on the other, a hypothetical resistance cost would select against such alleles in the absence of the retrovirus. However, the population cage data presented in this paper do not fit with this simple resistance cost hypothesis because restrictive alleles were not eliminated in the absence of functional gypsy proviruses; on the contrary, using 2 independent flam allelic pairs, the restrictive frequency rose to about 90% in every experimental population, whatever the pair of alleles and the allelic proportions in the initial inoculum. These data suggest that the flam polymorphism is maintained by some strong balancing selection, which would act either on flam itself, independently of the deleterious effect of gypsy, or on a hypothetical flanking gene, in linkage disequilibrium with flam. Alternatively, restrictive flam alleles might also be resistant to some other retroelements that would be still present in the cage populations, causing a positive selection for these alleles. Whatever selective forces that maintain high levels of restrictive alleles independently of gypsy, this unknown mechanism can set up an interesting kind of antiviral innate immunity, at

  11. The importance of HLA DRB1 gene allele to clinical features and disability in patients with multiple sclerosis in Lithuania

    Science.gov (United States)

    2013-01-01

    Background The association of HLA DRB1 alleles with susceptibility to multiple sclerosis (MS) has been consistently reported although its effect on the clinical features and disability is still unclear probably due to diversity in ethnicity and geographic location of the studied populations. The aim of the present study was to investigate the influence of HLA DRB1 alleles on the clinical features and disability of the patients with MS in Lithuania. Methods This was a prospective study of 120 patients with MS. HLA DRB1 alleles were genotyped using the polymerase chain reaction. Results The first symptoms of MS in patients with HLA DRB1*15 allele manifested at younger age than in those without this allele (28.32 +/− 5.49 yrs vs. 30.94 +/− 8.43 yrs, respectively, p = 0.043). HLA DRB1*08 allele was more prevalent among relapsing-remitting (RR) MS patients than among patients with progressive course of MS (25.0% vs. 8.3%, respectively, chi^2 = 6.000, p = 0.05). MS patients with this allele had lower relapse rate than those without this allele (1.00 +/− 0.97 and 1.44 +/− 0.85, respectively, p = 0.043). Degree of disability during the last visit was lower among the patients with HLA DRB1*08 allele (EDSS score 3.15 +/− 1.95 vs. 4.49 +/− 1.96, p = 0.006), and higher among those with HLA DRB1*15 allele (EDSS score 4.60 +/− 2.10 vs.4.05 +/− 1.94, p = 0.047) compared to patients without these alleles but there were no significant associations between these alleles and the duration of the disease to disability. HLA DRB1*08 allele (OR = 0.18, 95% CI 0,039-0,8, p = 0.029) was demonstradet to be independent factor to take a longer time to reach an EDSS of 6, while HLA DRB1*01 allele (OR = 5.92, 95% CI 1,30-26,8, p = 0.021) was related in a shorter time to reach and EDSS of 6. Patients with HLA DRB1*08 allele had lower IgG index compared to patients without this allele (0.58 +/− 0.17 and 0.73 +/− 0.31, respectively, p

  12. Composition and functional analysis of low-molecular-weight glutenin alleles with Aroona near-isogenic lines of bread wheat

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    Zhang Xiaofei

    2012-12-01

    Full Text Available Abstract Background Low-molecular-weight glutenin subunits (LMW-GS strongly influence the bread-making quality of bread wheat. These proteins are encoded by a multi-gene family located at the Glu-A3, Glu-B3 and Glu-D3 loci on the short arms of homoeologous group 1 chromosomes, and show high allelic variation. To characterize the genetic and protein compositions of LMW-GS alleles, we investigated 16 Aroona near-isogenic lines (NILs using SDS-PAGE, 2D-PAGE and the LMW-GS gene marker system. Moreover, the composition of glutenin macro-polymers, dough properties and pan bread quality parameters were determined for functional analysis of LMW-GS alleles in the NILs. Results Using the LMW-GS gene marker system, 14–20 LMW-GS genes were identified in individual NILs. At the Glu-A3 locus, two m-type and 2–4 i-type genes were identified and their allelic variants showed high polymorphisms in length and nucleotide sequences. The Glu-A3d allele possessed three active genes, the highest number among Glu-A3 alleles. At the Glu-B3 locus, 2–3 m-type and 1–3 s-type genes were identified from individual NILs. Based on the different compositions of s-type genes, Glu-B3 alleles were divided into two groups, one containing Glu-B3a, B3b, B3f and B3g, and the other comprising Glu-B3c, B3d, B3h and B3i. Eight conserved genes were identified among Glu-D3 alleles, except for Glu-D3f. The protein products of the unique active genes in each NIL were detected using protein electrophoresis. Among Glu-3 alleles, the Glu-A3e genotype without i-type LMW-GS performed worst in almost all quality properties. Glu-B3b, B3g and B3i showed better quality parameters than the other Glu-B3 alleles, whereas the Glu-B3c allele containing s-type genes with low expression levels had an inferior effect on bread-making quality. Due to the conserved genes at Glu-D3 locus, Glu-D3 alleles showed no significant differences in effects on all quality parameters. Conclusions This work

  13. Spinocerebellar ataxia type 17: Report of a family with reduced penetrance of an unstable Gln49 TBP allele, haplotype analysis supporting a founder effect for unstable alleles and comparative analysis of SCA17 genotypes

    Directory of Open Access Journals (Sweden)

    Schwinger Eberhard

    2005-07-01

    Full Text Available Abstract Background Spinocerebellar ataxia type 17 (SCA17, a neurodegenerative disorder in man, is caused by an expanded polymorphic polyglutamine-encoding trinucleotide repeat in the gene for TATA-box binding protein (TBP, a main transcription factor. Observed pathogenic expansions ranged from 43 – 63 glutamine (Gln codons (Gln43–63. Reduced penetrance is known for Gln43–48 alleles. In the vast majority of families with SCA17 an expanded CAG repeat interrupted by a CAA CAG CAA element is inherited stably. Results Here, we report the first pedigree with a Gln49 allele that is a not interrupted, b unstable upon transmission, and c associated with reduced penetrance or very late age of onset. The 76-year-old father of two SCA17 patients carries the Gln49 TBP allele but presents without obvious neurological symptoms. His children with Gln53 and Gln52 developed ataxia at the age of 41 and 50. Haplotype analysis of this and a second family both with uninterrupted expanded and unstable pathological SCA17 alleles revealed a common core genotype not present in the interrupted expansion of an unrelated SCA17 patient. Review of the literature did not present instability in SCA17 families with expanded alleles interrupted by the CAA CAG CAA element. Conclusion The presence of a Gln49 SCA17 allele in an asymptomatic 76-year-old male reams the discussion of reduced penetrance and genotypes producing very late disease onset. In SCA17, uninterrupted expanded alleles of TBP are associated with repeat instability and a common founder haplotype. This suggests for uninterrupted expanded alleles a mutation mechanism and some clinical genetic features distinct from those alleles interrupted by a CAA CAG CAA element.

  14. An allelic series of Trp63 mutations defines TAp63 as a modifier of EEC syndrome.

    Science.gov (United States)

    Vernersson Lindahl, Emma; Garcia, Elvin L; Mills, Alea A

    2013-08-01

    Human Ectrodactyly, Ectodermal dysplasia, Clefting (EEC) syndrome is an autosomal dominant developmental disorder defined by limb deformities, skin defects, and craniofacial clefting. Although associated with heterozygous missense mutations in TP63, the genetic basis underlying the variable expressivity and incomplete penetrance of EEC is unknown. Here, we show that mice heterozygous for an allele encoding the Trp63 p.Arg318His mutation, which corresponds to the human TP63 p.Arg279His mutation found in patients with EEC, have features of human EEC. Using an allelic series, we discovered that whereas clefting and skin defects are caused by loss of Trp63 function, limb anomalies are due to gain- and/or dominant-negative effects of Trp63. Furthermore, we identify TAp63 as a strong modifier of EEC-associated phenotypes with regard to both penetrance and expressivity. PMID:23775923

  15. Telomeric Allelic Imbalance Indicates Defective DNA Repair and Sensitivity to DNA-Damaging Agents

    DEFF Research Database (Denmark)

    Birkbak, Nicolai J.; Wang, Zhigang C.; Kim, Ji-Young;

    2012-01-01

    DNA repair competency is one determinant of sensitivity to certain chemotherapy drugs, such as cisplatin. Cancer cells with intact DNA repair can avoid the accumulation of genome damage during growth and also can repair platinum-induced DNA damage. We sought genomic signatures indicative of...... defective DNA repair in cell lines and tumors and correlated these signatures to platinum sensitivity. The number of subchromosomal regions with allelic imbalance extending to the telomere (NtAI) predicted cisplatin sensitivity in vitro and pathologic response to preoperative cisplatin treatment in patients...... mutation. Thus, accumulation of telomeric allelic imbalance is a marker of platinum sensitivity and suggests impaired DNA repair. SIGNIFICANCE: Mutations in BRCA genes cause defects in DNA repair that predict sensitivity to DNA damaging agents, including platinum; however, some patients without BRCA...

  16. Mining the Human Phenome Using Allelic Scores That Index Biological Intermediates

    DEFF Research Database (Denmark)

    Evans, David M; Brion, Marie Jo A; Paternoster, Lavinia;

    2013-01-01

    aetiology. However, single genetic variants typically explain small amounts of disease risk. Our idea is to construct allelic scores that explain greater proportions of the variance in biological intermediates, and subsequently use these scores to data mine GWAS. To investigate the approach's properties, we...... indexed three biological intermediates where the results of large GWAS meta-analyses were available: body mass index, C-reactive protein and low density lipoprotein levels. We generated allelic scores in the Avon Longitudinal Study of Parents and Children, and in publicly available data from the first......It is common practice in genome-wide association studies (GWAS) to focus on the relationship between disease risk and genetic variants one marker at a time. When relevant genes are identified it is often possible to implicate biological intermediates and pathways likely to be involved in disease...

  17. Mediterranean river buffalo oxytocin-neurophysin I (OXT gene: structure, promoter analysis and allele detection

    Directory of Open Access Journals (Sweden)

    L. Ramunno

    2010-02-01

    Full Text Available Oxytocin (OXT is a very abundant nonapeptide neurohypophysial hormone implicated in several aspects of reproduction, including social, sexual and maternal behaviour, induction of labour and milk ejection. The nucleotide sequence of the whole OXTneurophysin I encoding gene (OXT in Mediterranean river buffalo was determined, plus 993 nucleotides at the 5’ flanking region. Buffalo oxytocin gene sequence analysis showed two transitions in the promoter region (C→T in position – 966 and G→A in position – 790 and one transversion G→T at the 170th nucleotide of the second exon, responsible for the Arg97→Leu aa substitution which identifies an allele named OXT B. A PCR-RFLP based method for a rapid identification of carriers of these alleles has been developed.

  18. Genotype and allele frequencies of heme oxygenase-1 promoter region in a Greek cohort

    Institute of Scientific and Technical Information of China (English)

    Eleni P. Katana; Lemonia G. Skoura; Zacharias G Scouras; Michail A. Daniilidis

    2011-01-01

    Background Heme oxygenase-1 (HO-1) is an enzyme,which catabolizes heme into carbon monoxide,biliverdin and free iron.The induction of this enzyme is an important cytoprotective mechanism,which occurs as an adaptive and beneficial response to a wide variety of oxidant stimuli.HO-1 inducibility is mainly modulated by a (GT)n polymorphism in the promoter region,and has been shown that short (S) repeats are associated with greater up-regulation of HO-1,compared with long (L) repeats.Methods In the present study,250 healthy Greek individuals have been screened in order to estimate the frequencies of (GT)n alleles in the HO-1 gene.Results Nineteen different alleles,ranging from 17 to 39 repeats,with (GT)23 and (GT)30 being the most common ones,were identified.Conclusion The possible role of this polymorphism in disease states is discussed.

  19. Allele-specific amplification and electrochemiluminescence method for single nucleotide polymorphism analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new approach combined the specificity of allele-specific amplification (ASA) with the sensitivity of electrochemiluminescence (ECL) assay for single nucleotide polymorphism (SNP) analysis was proposed. Briefly, target gene was amplified by a biotin-labeled allele-specific forward primer and a Ru(bpy)32+ (TBR)-labeled universal reverse primer. Then, the amplicon was captured onto streptavidin-coated paramagnetic beads through biotin label, and detected by measuring the ECL signal of TBR label. Different genotypes were distinguished according to the ECL values of the amplicons by different genotypic primers. K-ras oncogene was used as a target to validate the feasibility of the method. The experiment results show that the different genotypes can be clearly distinguished by ASA-ECL assay. The method is useful in SNP analysis due to its sensitivity,safety, and simplicity.(C) 2007 Da Xing. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  20. Allelic variants of DYX1C1 are not associated with dyslexia in India

    Directory of Open Access Journals (Sweden)

    Saviour Pushpa

    2008-01-01

    Full Text Available Dyslexia is a hereditary neurological disorder that manifests as an unexpected difficulty in learning to read despite adequate intelligence, education, and normal senses. The prevalence of dyslexia ranges from 3 to 15% of the school aged children. Many genetic studies indicated that loci on 6p21.3, 15q15-21, and 18p11.2 have been identified as promising candidate gene regions for dyslexia. Recently, it has been suggested that allelic variants of gene, DYX1C1 influence dyslexia. In the present study, exon 2 and 10 of DYX1C1 has been analyzed to verify whether these single nucleotide polymorphisms (SNPs influence dyslexia, in our population. Our study identified 4 SNPs however, none of these SNPS were found to be significantly associated with dyslexia suggesting DYX1C1 allelic variants are not associated with dyslexia.

  1. Detection of mutation by allele-specific loop-mediated isothermal amplification (AS-LAMP).

    Science.gov (United States)

    Aonuma, Hiroka; Badolo, Athanase; Okado, Kiyoshi; Kanuka, Hirotaka

    2013-01-01

    For effective control of pathogen-transmitting mosquitoes, precise surveillance data of mosquito distribution are essential. Recently, an increase of insecticide resistance due to the kdr mutation in Anopheles gambiae, a mosquito that transmits the malaria parasite, has been reported. With the aim of developing a simple and effective method for surveying resistant mosquitoes, LAMP was applied to the allele-specific detection of the kdr gene in An. gambiae. Allele-specific LAMP (AS-LAMP) method successfully distinguished the kdr homozygote from the heterozygote and the wild type. The robustness of AS-LAMP suggests its usefulness for routine identification of insects, not only mosquitoes but also other vectors and agricultural pests. Here we describe the method of AS-LAMP to detect mutation in Anopheles mosquitoes. PMID:24026691

  2. Attenuated Expression of DFFB is a Hallmark of Oligodendrogliomas with 1p-Allelic Loss

    Directory of Open Access Journals (Sweden)

    Fuller Gregory N

    2005-09-01

    Full Text Available Abstract Allelic loss of chromosome 1p is frequently observed in oligodendroglioma. We screened 177 oligodendroglial tumors for 1p deletions and found 6 tumors with localized 1p36 deletions. Several apoptosis regulation genes have been mapped to this region, including Tumor Protein 73 (p73, DNA Fragmentation Factor subunits alpha (DFFA and beta (DFFB, and Tumor Necrosis Factor Receptor Superfamily Members 9 and 25 (TNFRSF9, TNFRSF25. We compared expression levels of these 5 genes in pairs of 1p-loss and 1p-intact tumors using quantitative reverse-transcriptase PCR (QRTPCR to test if 1p deletions had an effect on expression. Only the DFFB gene demonstrated decreased expression in all tumor pairs tested. Mutational analysis did not reveal DFFB mutations in 12 tested samples. However, it is possible that DFFB haploinsufficiency from 1p allelic loss is a contributing factor in oligodendroglioma development.

  3. Stable association of a pigmentation allele with an oncogene: nonhybrid melanomas in Xiphophorus variatus.

    Science.gov (United States)

    Kazianis, S; Borowsky, R

    1995-01-01

    Sex-linked genes in several species of the fish genus Xiphophorus cause macromelanophore pigmentation patterns on the flanks of the fish. Some, but not all, of these patterns can develop into melanomas. The tumorigenic alleles are tightly linked to a supernumerary oncogene sequence, Xmrk. The data show that the association of Xmrk with two of the tumorigenic alleles of X. variatus, P2 and Li, holds over a broad geographic area. From the distribution of the fish and the geology of the area, it is probable that this association is older than the late Tertiary. The persistence of this association suggests that Xmrk confers some benefit on P2-and Li-bearing individuals to offset the deleterious effect. The nature of this benefit remains unknown. PMID:7608512

  4. Allelic variation at a single gene increases food value in a drought-tolerant staple cereal.

    Science.gov (United States)

    Gilding, Edward K; Frère, Celine H; Cruickshank, Alan; Rada, Anna K; Prentis, Peter J; Mudge, Agnieszka M; Mace, Emma S; Jordan, David R; Godwin, Ian D

    2013-01-01

    The production of adequate agricultural outputs to support the growing human population places great demands on agriculture, especially in light of ever-greater restrictions on input resources. Sorghum is a drought-adapted cereal capable of reliable production where other cereals fail, and thus represents a good candidate to address food security as agricultural inputs of water and arable land grow scarce. A long-standing issue with sorghum grain is that it has an inherently lower digestibility. Here we show that a low-frequency allele type in the starch metabolic gene, pullulanase, is associated with increased digestibility, regardless of genotypic background. We also provide evidence that the beneficial allele type is not associated with deleterious pleiotropic effects in the modern field environment. We argue that increasing the digestibility of an adapted crop is a viable way forward towards addressing food security while maximizing water and land-use efficiency. PMID:23403584

  5. ACTN3 allele frequency in humans covaries with global latitudinal gradient.

    Directory of Open Access Journals (Sweden)

    Scott M Friedlander

    Full Text Available A premature stop codon in ACTN3 resulting in α-actinin-3 deficiency (the ACTN3 577XX genotype is common in humans and reduces strength, muscle mass, and fast-twitch fiber diameter, but increases the metabolic efficiency of skeletal muscle. Linkage disequilibrium data suggest that the ACTN3 R577X allele has undergone positive selection during human evolution. The allele has been hypothesized to be adaptive in environments with scarce resources where efficient muscle metabolism would be selected. Here we test this hypothesis by using recently developed comparative methods that account for evolutionary relatedness and gene flow among populations. We find evidence that the ACTN3 577XX genotype evolved in association with the global latitudinal gradient. Our results suggest that environmental variables related to latitudinal variation, such as species richness and mean annual temperature, may have influenced the adaptive evolution of ACTN3 577XX during recent human history.

  6. Contribution of non-reference alleles in mtDNA of Alzheimer's disease patients.

    Science.gov (United States)

    Casoli, Tiziana; Di Stefano, Giuseppina; Spazzafumo, Liana; Balietti, Marta; Giorgetti, Belinda; Giuli, Cinzia; Postacchini, Demetrio; Fattoretti, Patrizia; Conti, Fiorenzo

    2014-04-01

    Many observations suggest that mutations of mitochondrial DNA (mtDNA) could be responsible for the neurodegenerative changes of Alzheimer's disease (AD). Here we examined the signal intensity of the four alleles of each mtDNA nucleotide position (np) in whole blood of AD patients and age-matched controls using MitoChip v2.0 array. Our analysis identified 270 significantly different nps which, with one exception, showed an increased contribution of non-reference alleles in AD patients. Principal component analysis (PCA) and cluster analysis showed that five of these nps could discriminate AD from control subjects with 80% of cases correctly classified. Our data support the hypothesis of mtDNA alterations as an important factor in the etiology of AD. PMID:25590040

  7. HIV-1 disease-influencing effects associated with ZNRD1, HCP5 and HLA-C alleles are attributable mainly to either HLA-A10 or HLA-B*57 alleles.

    Directory of Open Access Journals (Sweden)

    Gabriel Catano

    Full Text Available A recent genome-wide association study (GWAS suggested that polymorphisms in or around the genes HCP5, HLA-C and ZNRD1 confer restriction against HIV-1 viral replication or disease progression. Here, we also find that these alleles are associated with different aspects of HIV disease, albeit mainly in European Americans. Additionally, we offer that because the GWAS cohort was a subset of HIV-positive individuals, selected based in part on having a low viral load, the observed associations for viral load are magnified compared with those we detect in a large well-characterized prospective natural history cohort of HIV-1-infected persons. We also find that because of linkage disequilibrium (LD patterns, the dominant viral load- and disease-influencing associations for the ZNRD1 or HLA-C and HCP5 alleles are apparent mainly when these alleles are present in HLA-A10- or HLA-B*57-containing haplotypes, respectively. ZNRD1 alleles lacking HLA-A10 did not confer disease protection whereas ZNRD1-A10 haplotypes did. When examined in isolation, the HCP5-G allele associates with a slow disease course and lower viral loads. However, in multivariate models, after partitioning out the protective effects of B*57, the HCP5-G allele associates with disease-acceleration and enhanced viral replication; these associations for HCP5-G are otherwise obscured because of the very strong LD between this allele and a subset of protective B*57 alleles. Furthermore, HCP5 and HLA-C alleles stratify B*57-containing genotypes into those that associate with either striking disease retardation or progressive disease, providing one explanation for the long-standing conundrum of why some HLA-B*57-carrying individuals are long-term non-progressors, whereas others exhibit progressive disease. Collectively, these data generally underscore the strong dependence of genotype-phenotype relationships upon cohort design, phenotype selection, LD patterns and populations studied. They

  8. Identification of novel alleles of the rice blast resistance gene Pi54

    OpenAIRE

    Kumar Vasudevan; Wilhelm Gruissem; Bhullar, Navreet K

    2015-01-01

    Rice blast is one of the most devastating rice diseases and continuous resistance breeding is required to control the disease. The rice blast resistance gene Pi54 initially identified in an Indian cultivar confers broad-spectrum resistance in India. We explored the allelic diversity of the Pi54 gene among 885 Indian rice genotypes that were found resistant in our screening against field mixture of naturally existing M. oryzae strains as well as against five unique strains. These genotypes are...

  9. An Allelic Series of Trp63 Mutations Defines TAp63 as a Modifier of EEC Syndrome

    OpenAIRE

    Lindahl, Emma Vernersson; Garcia, Elvin L.; Mills, Alea A.

    2013-01-01

    Human Ectrodactyly, Ectodermal dysplasia, Clefting (EEC) syndrome is an autosomal dominant developmental disorder defined by limb deformities, skin defects, and craniofacial clefting. Although associated with heterozygous missense mutations in TP63, the genetic basis underlying the variable expressivity and incomplete penetrance of EEC is unknown. Here we show that mice heterozygous for an allele encoding the Trp63 p.Arg318His mutation, which corresponds to the human TP63 p.Arg279His mutation...

  10. DRD2 A1 allele and P300 abnormalities in obesity

    Energy Technology Data Exchange (ETDEWEB)

    Blum, K. [Univ. of Texas Health Science Center, San Antonio, TX (United States)]|[PATH Foundation, Princeton, NJ (United States); Wood, R.; Sheridan, L.P.J. [Univ. of Texas Health Science Center, San Antonio, TX (United States)] [and others

    1994-09-01

    Obesity is a heterogeneous and prevalent disorder having both inheritable and environmental components. The role of the dopamine system in P300 has been implicated. We genotyped 193 neuropsychiatrically ill patients with and without comorbid drug and alcohol/abuse/dependence and obesity for the prevalence of the A1 allele of the DRD2 gene. We found a significant linear trend ({chi}{sup 2} = 40.4, df=1, p<0.00001) where the percent prevalence of the A1 increased with increasing polysubstance abuse. Where the A1 allele was found in 44% of 40 obese subjects, the A1 allele prevalence was found in as much as 91% of 11 obese subjects with comorbid polysubstance abuse. 53 obese subjects having a mean body weight (BMI) of 34.6{+-}8.2 were mapped for brain electrical activity and compared with 15 controls with a BMI of 22.3{+-}3.0 (P<.001). The P3 amplitude was significantly different (two tailed; t=3.24, df=16.2, P = 0.005), whereas P3 latency was not significant. Preliminarily, we found a significant decreased P3 amplitude correlated with parental polysubstance abuse (p=0.4) with prolongation of P3 latency correlated with the three risk factors of parental substance abuse, chemical dependency and carbohydrate bingeing (P<0.02). Finally, in a small sample, the A1 allele was present in 25% of probands having 0 risk compared to 66% in those obese subjects with any risk. This work represents the first electrophysiological data to implicate P3 abnormalities in a subset of obesity and further confirms an association of the DRD2 gene and a electrophysiological marker previously indicated to have predictive value in vulnerability to addictive behaviors.

  11. Genotyping of infectious laryngotracheitis virus using allelic variations from multiple genomic regions.

    Science.gov (United States)

    Choi, Eun-Jung; La, Tae-Min; Choi, In-Soo; Song, Chang-Seon; Park, Seung-Yong; Lee, Joong-Bok; Lee, Sang-Won

    2016-08-01

    Live attenuated vaccines are extensively used worldwide to control the outbreak of infectious laryngotracheitis. Virulent field strains showing close genetic relationship with the infectious laryngotracheitis virus (ILTV) vaccines of chicken embryo origin have been detected in the poultry industry. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, a reliable molecular epidemiological method, of multiple genomic regions was performed. The PCR-RFLP is a time-consuming method that requires considerable amount of intact viral genomic DNA to amplify genomic regions greater than 4 kb. In this study, six variable genomic regions were selected and amplified for sequencing. The multi-allelic PCR-sequence genotyping showed better discrimination power than that of previous PCR-sequencing schemes using single or two target regions. The allelic variation patterns yielded 16 strains of ILTV classified into 14 different genotypes. Three Korean field strains, 550/05/Ko, 0010/05/Ko and 40032/08/Ko, were found to have the same genotype as the commercial vaccine strain, Laryngo Vac (Zoetis, Florham Park, NJ, USA). Three other Korean field strains, 40798/10/Ko, 12/07/Ko, and 30678/14/Ko, showed recombined allelic patterns. The multi-allelic PCR-sequencing method was proved to be an efficient and practical procedure to classify the different strains of ILTV. The method could serve as an alternate diagnostic and differentiating tool for the classification of ILTV, and contribute to understanding of the epidemiology of the disease at a global level. PMID:26956802

  12. Specific Silencing of L392V PSEN1 Mutant Allele by RNA Interference

    OpenAIRE

    Malgorzata Sierant; Alina Paduszynska; Julia Kazmierczak-Baranska; Benedetta Nacmias; Sandro Sorbi; Silvia Bagnoli; Elzbieta Sochacka; Barbara Nawrot

    2011-01-01

    RNA interference (RNAi) technology provides a powerful molecular tool to reduce an expression of selected genes in eukaryotic cells. Short interfering RNAs (siRNAs) are the effector molecules that trigger RNAi. Here, we describe siRNAs that discriminate between the wild type and mutant (1174 C→G) alleles of human Presenilin1 gene (PSEN1). This mutation, resulting in L392V PSEN1 variant, contributes to early onset familial Alzheimer's disease. Using the dual fluorescence assay, flow cytometry ...

  13. HLA B27 allele types in homogeneous groups of juvenile idiopathic arthritis patients in Latvia

    OpenAIRE

    Guseinova Dinara; Lazareva Arina; Sochnevs Arturs; Zavadska Dace; Eglite Jelena; Stanevicha Valda; Shantere Ruta; Gardovska Dace

    2010-01-01

    Abstract Juvenile idiopathic arthritis (JIA) is a heterogeneous condition and therapeutic strategies vary in different JIA types. The routinely accepted practice to start with Sulphasalazine (SS) as the first line treatment in patients with HLA B27 positive JIA proves to be ineffective in a large proportion of children. Objective to investigate HLA B27 positive JIA patients clinical characteristics, determined HLA B27 allele types and their connection with antirheumatic treatment in homogenou...

  14. Allele-specific silencing of mutant Huntington’s disease gene

    OpenAIRE

    Zhang, Yu; Engelman, Joshua; Friedlander, Robert M.

    2009-01-01

    Huntington’s disease (HD) is an autosomal-dominant neurodegenerative disorder caused by a poly-glutamine expansion in huntingtin, the protein encoded by the HD gene. PolyQ-expanded huntingtin is toxic to neurons, especially the medium spiny neurons (MSNs) of the striatum. At the same time, wild-type huntingtin has important -- indeed essential -- protective functions. Any effective molecular therapy must preserve the expression of wild-type huntingtin, while silencing the mutant allele. We hy...

  15. An improved allele-specific PCR primer design method for SNP marker analysis and its application

    OpenAIRE

    Liu Jing; Huang Shunmou; Sun Meiyu; Liu Shengyi; Liu Yumei; Wang Wanxing; Zhang Xiurong; Wang Hanzhong; Hua Wei

    2012-01-01

    Abstract Background Although Single Nucleotide Polymorphism (SNP) marker is an invaluable tool for positional cloning, association study and evolutionary analysis, low SNP detection efficiency by Allele-Specific PCR (AS-PCR) still restricts its application as molecular marker like other markers such as Simple Sequence Repeat (SSR). To overcome this problem, primers with a single nucleotide artificial mismatch introduced within the three bases closest to the 3’end (SNP site) have been used in ...

  16. HaploSNPer: a web-based allele and SNP detection tool

    OpenAIRE

    Voorrips Roeland E; Leunissen Jack AM; Tang Jifeng; van der Linden C Gerard; Vosman Ben

    2008-01-01

    Abstract Background Single nucleotide polymorphisms (SNPs) and small insertions or deletions (indels) are the most common type of polymorphisms and are frequently used for molecular marker development. Such markers have become very popular for all kinds of genetic analysis, including haplotype reconstruction. Haplotypes can be reconstructed for whole chromosomes but also for specific genes, based on the SNPs present. Haplotypes in the latter context represent the different alleles of a gene. ...

  17. Association of ERAP1 Allelic Variants with Risk of Ankylosing Spondylitis

    OpenAIRE

    Zvyagin, I.; Dorodnykh, V.; Mamedov, I.; Staroverov, D.; Bochkova, A.; Rebrikov, D.; Lebedev, Y.

    2010-01-01

    Ankylosing spondylitis (AS) belongs to a group of autoimmune diseases affecting the axial skeleton. Beside the hla-b*27 allele, several other human genes that control the variety processes of immune homeostasis are considered to be associated with AS manifestation in different human populations. Among strong associated non-MHC genes erap 1 encoding the endoplasmic reticulum aminopeptidase 1 isoform was recently identified by single nucleotide polymorphisms (SNPs) meta analysis. In our study w...

  18. Variation within the vat(E) Allele of Enterococcus faecium Isolates from Retail Poultry Samples

    OpenAIRE

    Simjee, S.; McDermott, P. F.; Wagner, D D; White, D. G.

    2001-01-01

    In a survey of retail meat samples, twelve quinupristin-dalfopristin-resistant (MICs, ≥4 mg/liter) Enterococcus faecium isolates that carried a vat(E) gene were recovered. DNA sequence comparison revealed five new variations in the vat(E) allele among 12 isolates, which were designated vat(E-4) through vat(E-8); two isolates had vat(E-1). There was no correlation between the number of base changes and the quinupristin-dalfopristin MIC.

  19. Natalizumab-related anaphylactoid reactions in MS patients are associated with HLA class II alleles

    OpenAIRE

    De la Hera, Belén; Urcelay, Elena; Brassat, David; Chan, Andrew; Vidal-Jordana, Angela; Salmen, Anke; Villar, Luisa Maria; Álvarez-Cermeño, José Carlos; Izquierdo, Guillermo; Fernández, Oscar; Oliver, Begoña; Saiz, Albert; Ara, Jose Ramón; Vigo, Ana G.; Arroyo, Rafael

    2014-01-01

    Objectives: We aimed to investigate potential associations between human leukocyte antigen (HLA) class I and class II alleles and the development of anaphylactic/anaphylactoid reactions in patients with multiple sclerosis (MS) treated with natalizumab. Methods: HLA class I and II genotyping was performed in patients with MS who experienced anaphylactic/anaphylactoid reactions and in patients who did not develop infusion-related allergic reactions following natalizumab administration. Results:...

  20. Sexual selection by female immunity against paternal antigens can fix loss of function alleles.

    Science.gov (United States)

    Ghaderi, Darius; Springer, Stevan A; Ma, Fang; Cohen, Miriam; Secrest, Patrick; Taylor, Rachel E; Varki, Ajit; Gagneux, Pascal

    2011-10-25

    Humans lack the common mammalian cell surface molecule N-glycolylneuraminic acid (Neu5Gc) due to a CMAH gene inactivation, which occurred approximately three million years ago. Modern humans produce antibodies specific for Neu5Gc. We hypothesized that anti-Neu5Gc antibodies could enter the female reproductive tract and target Neu5Gc-positive sperm or fetal tissues, reducing reproductive compatibility. Indeed, female mice with a human-like Cmah(-/-) mutation and immunized to express anti-Neu5Gc antibodies show lower fertility with Neu5Gc-positive males, due to prezygotic incompatibilities. Human anti-Neu5Gc antibodies are also capable of targeting paternally derived antigens and mediate cytotoxicity against Neu5Gc-bearing chimpanzee sperm in vitro. Models of populations polymorphic for such antigens show that reproductive incompatibility by female immunity can drive loss-of-function alleles to fixation from moderate initial frequencies. Initially, the loss of a cell-surface antigen can occur due to drift in isolated populations or when natural selection favors the loss of a receptor exploited by pathogens, subsequently the same loss-of-function allele can come under sexual selection because it avoids being targeted by the female immune system. Thus, we provide evidence of a link between sexual selection and immune function: Antigenicity in females can select against foreign paternal antigens on sperm and rapidly fix loss-of-function alleles. Similar circumstances existed when the CMAH null allele was polymorphic in ancestral hominins, just before the divergence of Homo from australopithecines. PMID:21987817

  1. An improved assay for the determination of Huntington`s disease allele size

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, C.; Klinger, K.; Miller, G. [Intergrated Genetics, Framingham, MA (United States)

    1994-09-01

    The hallmark of Huntington`s disease (HD) is the expansion of a polymorphic (CAG)n repeat. Several methods have been published describing PCR amplification of this region. Most of these assays require a complex PCR reaction mixture to amplify this GC-rich region. A consistent problem with trinucleotide repeat PCR amplification is the presence of a number of {open_quotes}stutter bands{close_quotes} which may be caused by primer or amplicon slippage during amplification or insufficient polymerase processivity. Most assays for HD arbitrarily select a particular band for diagnostic purposes. Without a clear choice for band selection such an arbitrary selection may result in inconsistent intra- or inter-laboratory findings. We present an improved protocol for the amplification of the HD trinucleotide repeat region. This method simplifies the PCR reaction buffer and results in a set of easily identifiable bands from which to determine allele size. HD alleles were identified by selecting bands of clearly greater signal intensity. Stutter banding was much reduced thus permitting easy identification of the most relevant PCR product. A second set of primers internal to the CCG polymorphism was used in selected samples to confirm allele size. The mechanism of action of N,N,N trimethylglycine in the PCR reaction is not clear. It may be possible that the minimal isostabilizing effect of N,N,N trimethylglycine at 2.5 M is significant enough to affect primer specificity. The use of N,N,N trimethylglycine in the PCR reaction facilitated identification of HD alleles and may be appropriate for use in other assays of this type.

  2. Verification of predictions from estimators of favorable alleles to improve yield of sweet corn hybrids

    OpenAIRE

    Malvar Pintos, Rosa Ana; Revilla Temiño, Pedro; Ordás Pérez, Amando; Cartea González, María Elena; Soengas Fernández, María del Pilar

    2004-01-01

    Sweet corn (Zea mays L.) breeding has focused on quality, with yield and agronomic performance as secondary traits. Elite American and European field corn inbreds were selected to improve the agronomic value of sweet corn for European conditions. Our objective was to compare realized results and predictions of methods to identify potential donors for improving agronomic performance of sweet corn hybrids. Yield and three agronomic traits were recorded. Estimates of favorable dominant alleles p...

  3. Allelic Discrimination by TaqMan-PCR for Genotyping of Human Neutrophil Antigens.

    Science.gov (United States)

    Steffensen, Rudi; Baech, John; Nielsen, Kaspar R

    2015-01-01

    Neutrophil antigens are implicated in a variety of clinical conditions, including neonatal immune neutropenia, transfusion-related acute lung injury, refractoriness to granulocyte transfusions, febrile transfusion reactions, and autoimmune neutropenia. In this report, we describe simultaneous genotyping of human neutrophil antigens (HNA)-1, -3, -4, and -5 using PCR with allele-specific TaqMan probes and end-point fluorescence detection, which is a robust, rapid, and reproducible method, allowing for high-throughput genotyping. PMID:26024637

  4. Allelic variation in human mitochondrial genes based on patterns of restriction site polymorphism.

    OpenAIRE

    Whittam, T S; Clark, A. G.; Stoneking, M; Cann, R. L.; Wilson, A. C.

    1986-01-01

    Restriction maps of 145 human mtDNAs representing samples from five geographic regions were used to construct multilocus genotypes for 28 genetic loci of the mitochondrial genome. Alleles were defined as distinct combinations of the presence or absence of polymorphic restriction sites within each locus. The 28 loci included 13 genes encoding proteins, 10 genes specifying tRNAs, 2 genes specifying rRNAs, and 3 noncoding regions consisting of the D loop, the light strand origin of replication, ...

  5. Fast individual ancestry inference from DNA sequence data leveraging allele frequencies for multiple populations

    OpenAIRE

    Bansal, Vikas; Libiger, Ondrej

    2015-01-01

    Background Estimation of individual ancestry from genetic data is useful for the analysis of disease association studies, understanding human population history and interpreting personal genomic variation. New, computationally efficient methods are needed for ancestry inference that can effectively utilize existing information about allele frequencies associated with different human populations and can work directly with DNA sequence reads. Results We describe a fast method for estimating the...

  6. Sexual selection by female immunity against paternal antigens can fix loss of function alleles

    Science.gov (United States)

    Ghaderi, Darius; Springer, Stevan A.; Ma, Fang; Cohen, Miriam; Secrest, Patrick; Taylor, Rachel E.; Varki, Ajit; Gagneux, Pascal

    2011-01-01

    Humans lack the common mammalian cell surface molecule N-glycolylneuraminic acid (Neu5Gc) due to a CMAH gene inactivation, which occurred approximately three million years ago. Modern humans produce antibodies specific for Neu5Gc. We hypothesized that anti-Neu5Gc antibodies could enter the female reproductive tract and target Neu5Gc-positive sperm or fetal tissues, reducing reproductive compatibility. Indeed, female mice with a human-like Cmah(−/−) mutation and immunized to express anti-Neu5Gc antibodies show lower fertility with Neu5Gc-positive males, due to prezygotic incompatibilities. Human anti-Neu5Gc antibodies are also capable of targeting paternally derived antigens and mediate cytotoxicity against Neu5Gc-bearing chimpanzee sperm in vitro. Models of populations polymorphic for such antigens show that reproductive incompatibility by female immunity can drive loss-of-function alleles to fixation from moderate initial frequencies. Initially, the loss of a cell-surface antigen can occur due to drift in isolated populations or when natural selection favors the loss of a receptor exploited by pathogens, subsequently the same loss-of-function allele can come under sexual selection because it avoids being targeted by the female immune system. Thus, we provide evidence of a link between sexual selection and immune function: Antigenicity in females can select against foreign paternal antigens on sperm and rapidly fix loss-of-function alleles. Similar circumstances existed when the CMAH null allele was polymorphic in ancestral hominins, just before the divergence of Homo from australopithecines. PMID:21987817

  7. Rapid Detection of Rifampicin- and Isoniazid-Resistant Mycobacterium tuberculosis using TaqMan Allelic Discrimination

    OpenAIRE

    Darban-Sarokhalil, Davood; Nasiri, Mohammad J.; Fooladi, Abbas A.I.; Heidarieh, Parvin; Feizabadi, Mohammad M

    2016-01-01

    Objectives Multidrug-resistant tuberculosis (MDR-TB) is a global problem that many countries are challenged with. Rapid and accurate detection of MDR-TB is critical for appropriate treatment and controlling of TB. The aim of the present study was to evaluate the TaqMan allelic discrimination without minor groove binder (MGB) as a rapid, efficient, and low-cost method for detection of drug resistant strains of Mycobacterium tuberculosis. Methods A total of 112 M. tuberculosis isolates from cas...

  8. Predictable allele frequency changes due to habitat fragmentation in the Glanville fritillary butterfly.

    Science.gov (United States)

    Fountain, Toby; Nieminen, Marko; Sirén, Jukka; Wong, Swee Chong; Hanski, Ilkka

    2016-03-01

    Describing the evolutionary dynamics of now extinct populations is challenging, as their genetic composition before extinction is generally unknown. The Glanville fritillary butterfly has a large extant metapopulation in the Åland Islands in Finland, but declined to extinction in the nearby fragmented southwestern (SW) Finnish archipelago in the 20th century. We genotyped museum samples for 222 SNPs across the genome, including SNPs from candidate genes and neutral regions. SW Finnish populations had significantly reduced genetic diversity before extinction, and their allele frequencies gradually diverged from those in contemporary Åland populations over 80 y. We identified 15 outlier loci among candidate SNPs, mostly related to flight, in which allele frequencies have changed more than the neutral expectation. At outlier loci, allele frequencies in SW Finland shifted in the same direction as newly established populations deviated from old local populations in contemporary Åland. Moreover, outlier allele frequencies in SW Finland resemble those in fragmented landscapes as opposed to continuous landscapes in the Baltic region. These results indicate selection for genotypes associated with good colonization capacity in the highly fragmented landscape before the extinction of the populations. Evolutionary response to habitat fragmentation may have enhanced the viability of the populations, but it did not save the species from regional extinction in the face of severe habitat loss and fragmentation. These results highlight a potentially common situation in changing environments: evolutionary changes are not strong enough to fully compensate for the direct adverse effects of environmental change and thereby rescue populations from extinction. PMID:26903642

  9. Molecular characterization of both alleles in an unusual Tay-Sachs disease BI variant

    Energy Technology Data Exchange (ETDEWEB)

    Coulter-Mackie, M.B. (Univ. of Western Ontario, London (Canada) Child Health Research Institute, Children' s Hospital of Western Ontario, London (Canada) Child Parent Resource Institute, London, Ontario (Canada))

    1994-06-01

    In a recent report, the authors described an exon 6 mutation in a Tay-Sachs B1 variant patient, first reported by Gordon et al. (1988), who displayed a typical B1 variant biochemical phenotype - i.e., (a) significant levels of hexosaminidase A (Hex A) activity in an assay with a neutral synthetic substrate, 4-methylumbelliferyl-[beta]-N-acetylglucosamide, and (b) <2% of control Hex A in a test on the sulfated substrate, 4-methylumbelliferyl-[beta]-N-acetylglucosamide-6-sulfate. The patient was found to carry a double mutation (G[sub 574][yields]C [val[sub 192][yields]leu] and G[sub 598][yields]A [val[sub 200][yields]met]) inherited from her mother. Only the 574 mutation produced a deleterious effect on Hex A activity in transfected COS0-1 cells, producing a B1 variant biochemical phenotype. The paternal allele apparently caused decreased abundance of mRNA, since no candidate paternal mutations were found in cloned reverse transcription-PCR (RT-PCR) products in the reported study. The biochemical phenotype of the original patient and the properties of the cDNA carrying the G[sub 574] [yields] C mutation in transient expression studies were compatible with a B1 variant mutation. The possibility remained that there might be some contribution from the paternal allele to the patient's phenotype. However, the paternal allele produces relatively low yields of a largely mis-spliced mRNA whose product would not be functional. Therefore, the G[sub 574] [yields] C (val[yields]leu) mutation in the maternal allele is clearly confirmed as a B1 variant mutation with all the ramifications for the substrate binding site and/or catalytic center that this implies.

  10. Segregation of Tay-Sachs and Sandhoff alleles in a non-Jewish family.

    OpenAIRE

    Lane, A B; Young, E.; Jenkins, T

    1980-01-01

    A non-Jewish family is presented in which the genes for Tay-Sachs disease and Sandhoff disease are segregating. Individuals heterozygous for both alleles have low serum and white cell total hexosaminidase levels together with a proportion of heat-labile hexosaminidase A (HEX A) which falls in the normal range. The individuals would not be detected as carriers of Tay-Sachs disease or Sandhoff disease in a population screening program.

  11. Generation of New Hairless Alleles by Genomic Engineering at the Hairless Locus in Drosophila melanogaster

    Science.gov (United States)

    Praxenthaler, Heiko; Smylla, Thomas K.; Nagel, Anja C.; Preiss, Anette; Maier, Dieter

    2015-01-01

    Hairless (H) is the major antagonist within the Notch signalling pathway of Drosophila melanogaster. By binding to Suppressor of Hairless [Su(H)] and two co-repressors, H induces silencing of Notch target genes in the absence of Notch signals. We have applied genomic engineering to create several new H alleles. To this end the endogenous H locus was replaced with an attP site by homologous recombination, serving as a landing platform for subsequent site directed integration of different H constructs. This way we generated a complete H knock out allele HattP, reintroduced a wild type H genomic and a cDNA-construct (Hgwt, Hcwt) as well as two constructs encoding H proteins defective of Su(H) binding (HLD, HiD). Phenotypes regarding viability, bristle and wing development were recorded, and the expression of Notch target genes wingless and cut was analysed in mutant wing discs or in mutant cell clones. Moreover, genetic interactions with Notch (N5419) and Delta (DlB2) mutants were addressed. Overall, phenotypes were largely as expected: both HLD and HiD were similar to the HattP null allele, indicating that most of H activity requires the binding of Su(H). Both rescue constructs Hgwt and Hcwt were homozygous viable without phenotype. Unexpectedly, the hemizygous condition uncovered that they were not identical to the wild type allele: notably Hcwt showed a markedly reduced activity, suggesting the presence of as yet unidentified regulatory or stabilizing elements in untranslated regions of the H gene. Interestingly, Hgwt homozygous cells expressed higher levels of H protein, perhaps unravelling gene-by-environment interactions. PMID:26448463

  12. Prediction of peptides binding to MHC class I alleles by partial periodic pattern mining

    OpenAIRE

    Meydan, Cem; Sezerman, Uğur; Sezerman, Ugur; Otu, Hasan

    2009-01-01

    MHC (Major Histocompatibility Complex) is a key player in the immune response of an organism. It is important to be able to predict which antigenic peptides will bind to a spe-cific MHC allele and which will not, creating possibilities for controlling immune response and for the applications of immunotherapy. However a problem encountered in the computational binding prediction methods for MHC class I is the presence of bulges and loops in the peptides, changing the total length. Most machine...

  13. Genome-wide survey of allele-specific splicing in humans

    OpenAIRE

    Nembaware, Victoria; Lupindo, Bukiwe; Schouest, Katherine; Spillane, Charles; Scheffler, Konrad; Seoighe, Cathal

    2008-01-01

    Background Accurate mRNA splicing depends on multiple regulatory signals encoded in the transcribed RNA sequence. Many examples of mutations within human splice regulatory regions that alter splicing qualitatively or quantitatively have been reported and allelic differences in mRNA splicing are likely to be a common and important source of phenotypic diversity at the molecular level, in addition to their contribution to genetic disease susceptibility. However, because the effect of a mutation...

  14. Genome-wide survey of allele-specific splicing in humans

    OpenAIRE

    Scheffler Konrad; Spillane Charles; Schouest Katherine; Lupindo Bukiwe; Nembaware Victoria; Seoighe Cathal

    2008-01-01

    Abstract Background Accurate mRNA splicing depends on multiple regulatory signals encoded in the transcribed RNA sequence. Many examples of mutations within human splice regulatory regions that alter splicing qualitatively or quantitatively have been reported and allelic differences in mRNA splicing are likely to be a common and important source of phenotypic diversity at the molecular level, in addition to their contribution to genetic disease susceptibility. However, because the effect of a...

  15. Allele Frequency Data for 17 Short Tandem Repeats in a Czech Population Sample

    Czech Academy of Sciences Publication Activity Database

    Šimková, H.; Faltus, Václav; Marván, Richard; Pexa, T.; Stenzl, V.; Brouček, J.; Hořínek, A.; Mazura, Ivan; Zvárová, Jana

    2009-01-01

    Roč. 4, č. 1 (2009), e15-e17. ISSN 1872-4973 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : short tandem repeat (STR) * allelic frequency * PowerPlex 16 System * AmpflSTR Identifiler * population genetics * Czech Republic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.421, year: 2009

  16. Allele-specific gene silencing in two mouse models of autosomal dominant skeletal myopathy.

    Directory of Open Access Journals (Sweden)

    Ryan E Loy

    Full Text Available We explored the potential of mutant allele-specific gene silencing (ASGS in providing therapeutic benefit in two established mouse models of the autosomal dominantly-inherited muscle disorders, Malignant Hyperthermia (MH and Central Core Disease (CCD. Candidate ASGS siRNAs were designed and validated for efficacy and specificity on ryanodine receptor (RyR1 cDNA mini-constructs expressed in HEK293 cells using RT-PCR- and confocal microscopy-based assays. In vivo delivery of the most efficacious identified siRNAs into flexor digitorum brevis (FDB muscles was achieved by injection/electroporation of footpads of 4-6 month old heterozygous Ryr1(Y524S/+ (YS/+ and Ryr1(I4895T/+ (IT/+ knock-in mice, established mouse models of MH with cores and CCD, respectively. Treatment of IT/+ mice resulted in a modest rescue of deficits in the maximum rate (∼38% rescue and magnitude (∼78% of ligand-induced Ca(2+ release that occurred in the absence of a change in the magnitude of electrically-evoked Ca(2+ release. Compared to the difference between the caffeine sensitivity of Ca(2+ release in FDB fibers from YS/+ and WT mice treated with SCR siRNA (EC(50: 1.1 mM versus 4.4 mM, respectively, caffeine sensitivity was normalized in FDB fibers from YS/+ mice following 2 (EC(50: 2.8 mM and 4 week (EC(50: 6.6 mM treatment with YS allele-specific siRNA. Moreover, the temperature-dependent increase in resting Ca(2+ observed in FDB fibers from YS/+ mice was normalized to WT levels after 2 weeks of treatment with YS allele-specific siRNA. As determined by quantitative real time PCR, the degree of functional rescue in YS/+ and IT/+ mice correlated well with the relative increase in fractional WT allele expression.

  17. A four-element based transposon system for allele specific tagging in plants – Theoretical considerations

    Indian Academy of Sciences (India)

    Sanjay Phogat; Pradeep Kumar Burma; Deepak Pental

    2000-03-01

    The two-element transposon constructs, utilizing either Ac/Ds or Spm/dSpm, allow random tagging of genes in heterologous model species, but are inadequate for directed tagging of specific alleles of agronomic importance. We propose the use of Ac/Ds in conjunction with Spm/dSpm to develop a four-element system for directed tagging of crop-specific alleles. The four-element based construct would include both Ds and dSpm along with relevant marker genes and would function in two steps. In the first step dSpm(Ds) stocks (a minimum of two) would be crossed to a line containing transposases of Spm and unlinked integrations would be selected from segregating population by the use of a negative selection marker to develop stocks representing integration of dSpm(Ds) at a large number of locations in the genome. Selections would be made for a line in which dSpm(Ds) shows partial or complete linkage to the allele of interest. In the second step selected line would be crossed to a line containing Ac transposase to induce transpositions of Ds element to linked sites thereby exploiting the natural tendency of Ds element to jump to linked sites. Unlinked jumps of dSpm(Ds) and linked jumps of Ds could be monitored by appropriate marker genes. The proposed model would allow tagging of allele of interest in chromosome addition lines and also help in the efficient use of genic male sterility systems for hybrid seed production by tightly marking the fertility restorer gene with a negative selection marker.

  18. Multiple Alleles of Treponema pallidum Repeat Gene D in Treponema pallidum Isolates

    OpenAIRE

    Centurion-Lara, Arturo; Sun, Eileen S.; Barrett, Lynn K.; Castro, Christa; Lukehart, Sheila A.; Van Voorhis, Wesley C.

    2000-01-01

    Two new tprD alleles have been identified in Treponema pallidum: tprD2 is found in 7 of 12 T. pallidum subsp. pallidum isolates and 7 of 8 non-pallidum isolates, and tprD3 is found in one T. pallidum subsp. pertenue isolate. Antibodies against TprD2 are found in persons with syphilis, demonstrating that tprD2 is expressed during infection.

  19. Allele-specific locus binding and genome editing by CRISPR at the p16INK4a locus

    Science.gov (United States)

    Fujita, Toshitsugu; Yuno, Miyuki; Fujii, Hodaka

    2016-01-01

    The clustered regularly interspaced short palindromic repeats (CRISPR) system has been adopted for a wide range of biological applications including genome editing. In some cases, dissection of genome functions requires allele-specific genome editing, but the use of CRISPR for this purpose has not been studied in detail. In this study, using the p16INK4a gene in HCT116 as a model locus, we investigated whether chromatin states, such as CpG methylation, or a single-nucleotide gap form in a target site can be exploited for allele-specific locus binding and genome editing by CRISPR in vivo. First, we showed that allele-specific locus binding and genome editing could be achieved by targeting allele-specific CpG-methylated regions, which was successful for one, but not all guide RNAs. In this regard, molecular basis underlying the success remains elusive at this stage. Next, we demonstrated that an allele-specific single-nucleotide gap form could be employed for allele-specific locus binding and genome editing by CRISPR, although it was important to avoid CRISPR tolerance of a single nucleotide mismatch brought about by mismatched base skipping. Our results provide information that might be useful for applications of CRISPR in studies of allele-specific functions in the genomes. PMID:27465215

  20. Investigation of MGMT and DAPK1 methylation patterns in diffuse large B-cell lymphoma using allelic MSP-pyrosequencing

    Science.gov (United States)

    Kristensen, Lasse Sommer; Treppendahl, Marianne Bach; Asmar, Fazila; Girkov, Mia Seremet; Nielsen, Helene Myrtue; Kjeldsen, Tina Ellegaard; Ralfkiaer, Elisabeth; Hansen, Lise Lotte; Grønbæk, Kirsten

    2013-01-01

    The tumor suppressor genes MGMT and DAPK1 become methylated in several cancers including diffuse large B-cell lymphoma (DLBCL). However, allelic methylation patterns have not been investigated in DLBCL. We developed a fast and cost-efficient method for the analysis of allelic methylation based on pyrosequencing of methylation specific PCR (MSP) products including a SNP. Allelic methylation patterns were reliably analyzed in standards of known allelic methylation status even when diluted in unmethylated DNA to below 1% methylation. When studying 148 DLBCL patients MGMT and DAPK1 methylation was observed in 19% and 89%, respectively, and among methylated and heterozygous patients 29% and 55%, respectively, were biallelically methylated. An association between the T-allele of the rs16906252 SNP and MGMT methylation was observed (p-value = 0.04), and DAPK1 methylation of the A-allele was associated with shorter overall survival (p-value = 0.006). In future cancer research allelic MSP-pyrosequencing may be used to study a wide range of other loci. PMID:24071855

  1. Gamma ray-induced loss of expression of HLA and glyoxalase I alleles in lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Kavathas, P.; Bach, F.H.; DeMars, R.

    1980-07-01

    Gamma rays from a cesium source were used to generate human lymphoblastoid cell line variants that had lost expression of all major histocompatibility complex antigens coded for by a single haplotype. The cell line was heterozygous at the glyoxalase I locus and had the HLA haplotypes HLA-A1, B8, DRw3, and HLA-A2, B5, DRw1. We selected with anti-HLA-B8 antiserum in a population of cells that had been irradiated with 300R. The incidence of B8-loss variants was 4.1 X 10/sup -5/ on day 5 after irradiation. Analysis of variants showed that expressions of HLA and GLO alleles trans to B8 were retained. However, expression of additional cis-linked HLA and GLO gene products was lost in 12 of 17 variants. Variants that had lost expression of (i) HLA-B8, (ii) HLA-B8, A1, (iii) HLA-B8, A1, DRw3, or (iv) HLA-B8, A1, DRw3 and the cis-linked glyoxalase I allele were obtained. Karyotype analysis was performed on eight variants that had lost expression of two or more cis-linked alleles. Three variants had two normal appearing no. 6 chromosomes, four variants had a deletion that included the region coding for HLA genes on the short arm of one no. 6 chromosome, and one variant had an inversion or translocation involving the short arm of one no. 6.

  2. Gamma ray-induced loss of expression of HLA and glyoxalase I alleles in lymphoblastoid cells

    International Nuclear Information System (INIS)

    Gamma rays from a cesium source were used to generate human lymphoblastoid cell line variants that had lost expression of all major histocompatibility complex antigens coded for by a single haplotype. The cell line was heterozygous at the glyoxalase I locus and had the HLA haplotypes HLA-A1, B8, DRw3, and HLA-A2, B5, DRw1. We selected with anti-HLA-B8 antiserum in a population of cells that had been irradiated with 300R. The incidence of B8-loss variants was 4.1 X 10-5 on day 5 after irradiation. Analysis of variants showed that expressions of HLA and GLO alleles trans to B8 were retained. However, expression of additional cis-linked HLA and GLO gene products was lost in 12 of 17 variants. Variants that had lost expression of (i) HLA-B8, (ii) HLA-B8, A1, (iii) HLA-B8, A1, DRw3, or (iv) HLA-B8, A1, DRw3 and the cis-linked glyoxalase I allele were obtained. Karyotype analysis was performed on eight variants that had lost expression of two or more cis-linked alleles. Three variants had two normal appearing no. 6 chromosomes, four variants had a deletion that included the region coding for HLA genes on the short arm of one no. 6 chromosome, and one variant had an inversion or translocation involving the short arm of one no. 6

  3. Detection of Allelic Frequency Differences between the Sexes in Humans: A Signature of Sexually Antagonistic Selection.

    Science.gov (United States)

    Lucotte, Elise A; Laurent, Romain; Heyer, Evelyne; Ségurel, Laure; Toupance, Bruno

    2016-01-01

    Sexually antagonistic (SA) selection, a form of selection that can occur when both sexes have different fitness optima for a trait, is a major force shaping the evolution of organisms. A seminal model developed by Rice (Rice WR. 1984. Sex chromosomes and the evolution of sexual dimorphism. Evolution 38:735-742.) predicts that the X chromosome should be a hotspot for the accumulation of loci under SA selection as compared with the autosomes. Here, we propose a methodological framework designed to detect a specific signature of SA selection on viability, differences in allelic frequencies between the sexes. Applying this method on genome-wide single nucleotide polymorphism (SNP) data in human populations where no sex-specific population stratification could be detected, we show that there are overall significantly more SNPs exhibiting differences in allelic frequencies between the sexes on the X chromosome as compared with autosomes, supporting the predictions of Rice's model. This pattern is consistent across populations and is robust to correction for potential biases such as differences in linkage disequilibrium, sample size, and genotyping errors between chromosomes. Although SA selection is not the only factor resulting in allelic frequency differences between the sexes, we further show that at least part of the identified X-linked loci is caused by such a sex-specific processes. PMID:27189992

  4. Allele Frequencies of 10 Autosomal STR Loci from Chakma and Tripura Tribal Populations in Bangladesh

    Directory of Open Access Journals (Sweden)

    Ahmad Ferdous

    2010-01-01

    Full Text Available Allele frequencies of ten autosomal STR loci, D3S1358, vWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01, and FGA were investigated in Chakma and Tripura tribal populations of Bangladesh. In both the populations, all loci were in Hardy-Weinberg equilibrium except for FGA locus in Chakma and D21S11 in Tripura. All the loci were highly polymorphic in Chakma population with an observed heterozygosity (Ho of >0.7 and moderately polymorphic in Tripura population (Ho>0.6. However, both the population showed least polymorphism at TH01 locus (Ho<0.6. A comparison between Chakma and Tripura population data revealed statistically significant differences in allele frequency distribution for most of the loci. A similar comparison with the mainstream Bengali population using previously published data from this lab also showed significant difference in allele frequency with these two tribal populations.

  5. Association of ABO Blood Group Phenotype and Allele Frequency with Chikungunya Fever

    Science.gov (United States)

    Rujirojindakul, Pairaya; Chongsuvivatwong, Virasakdi; Limprasert, Pornprot

    2015-01-01

    Background. The objective of this study was to investigate the association of the ABO blood group phenotype and allele frequency with CHIK fever. Methods. A rural community survey in Southern Thailand was conducted in August and September 2010. A total of 506 villagers were enrolled. Cases were defined as individuals having anti-CHIK IgG by hemagglutination ≥1 : 10. Results. There were 314 cases (62.1%) with CHIK seropositivity. Females were less likely to have positive anti-CHIK IgG with odds ratio (OR) (95% CI) of 0.63 (0.43, 0.93). All samples tested were Rh positive. Distribution of CHIK seropositivity versus seronegativity (P value) in A, B, AB, and O blood groups was 80 versus 46 (0.003), 80 versus 48 (0.005), 24 versus 20 (0.55), and 130 versus 78 (<0.001), respectively. However, chi-square test between ABO and CHIK infection showed no statistical significance (P = 0.76). Comparison of the ABO blood group allele frequency between CHIK seropositivity and seronegativity was not statistically significant. Conclusion. This finding demonstrated no association of the ABO blood group phenotypes and allele frequencies with CHIK infection. PMID:25977691

  6. Effect of the hope FT-B1 allele on wheat heading time and yield components.

    Science.gov (United States)

    Nitcher, Rebecca; Pearce, Stephen; Tranquilli, Gabriela; Zhang, Xiaoqin; Dubcovsky, Jorge

    2014-01-01

    Precise regulation of flowering time is critical for plant reproductive success and, in cereals, to maximize grain yields. Seasonal cues including temperature and day length are integrated to regulate the timing of flowering. In temperate cereals, extended periods of cold (vernalization) release the repression of FLOWERING LOCUS T1 (FT1), which is upregulated in the leaves in response to inductive long-day photoperiods. FT1 is a homolog of rice HD3a, which encodes a protein transported from leaves to the shoot apical meristem to induce flowering. A rare FT-B1 allele from the wheat variety "Hope" has been previously shown to be associated with an early flowering phenotype under long-day photoperiods. Here, we demonstrate that the Hope FT-B1 allele accelerates flowering even under short days, and that it is epistatic to the VERNALIZATION 1 (VRN1) gene. On average, the introgression of Hope FT-B1 into 6 genetic backgrounds resulted in 2.6 days acceleration of flowering (PHope FT-B1 allele could be useful in wheat breeding programs to subtly accelerate floral development and increase adaptation to changing environments. PMID:25063863

  7. Combining allele frequency uncertainty and population substructure corrections in forensic DNA calculations.

    Science.gov (United States)

    Cowell, Robert

    2016-07-01

    In forensic DNA calculations of relatedness of individuals and in DNA mixture analyses, at least two sources of uncertainty are present concerning the allele frequencies used for evaluating genotype probabilities when evaluating likelihoods. They are: (i) imprecision in the estimates of the allele frequencies in the population by using an inevitably finite database of DNA profiles to estimate them; and (ii) the existence of population substructure. Green and Mortera [6] showed that these effects may be taken into account individually using a common Dirichlet model within a Bayesian network formulation, but that when taken in combination this is not the case; however they suggested an approximation that could be used. Here we develop a slightly different approximation that is shown to be exact in the case of a single individual. We demonstrate the numerical closeness of the approximation using a published database of allele counts, and illustrate the effect of incorporating the approximation into calculations of a recently published statistical model of DNA mixtures. PMID:27231804

  8. Microsatellite D21D210 (GT-12) allele frequencies in sporadic Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Lannfelt, L.; Lilius, L.; Viitanen, M.; Winblad, B.; Basun, H. [Huddinge Hospital, Karolinska Institute, Dept. of Geriatric Medicine, (Sweden); Houlden, H.; Rossor, M. [St. Mary`s Hospital, Dept. of Neurology, Medical School, London (United Kingdom); Hardy, J. [University of South Florida, Suncoast Alzheimer`s Disease Research Labs, Department of Psychiatry, Tampa (United States)

    1995-02-01

    Four disease-causing mutations have so far been described in the amyloid precursor protein gene on chromosome 21 in familial early-onset Alzheimer`s disease. Linkage analysis with a fourteen-allele microsatellite at D21S210 named GT-12 has proven useful in the elucidation of amyloid presursor protein gene involvement in Alzheimer`s disease families, as it is closely linked to the gene. Most cases of Alzheimer`s disease are thought to be sporadic and not familial. However, evidence from earlier studies suggests an important genetic contribution also in sporadic cases, where gene-environment interaction may contribute to the disease. We have determined frequencies of the GT-12 alleles in 78 Swedish and 49 British sporadic Alzheimer`s disease cases and 104 healthy elderly control subjects, to investigate if the disease associates with a particular genotype in GT-12. However, no differences in allele frequencies were observed between any of the groups. (au) (26 refs.).

  9. Allele-specific deposition of macroH2A1 in Imprinting Control Regions

    Energy Technology Data Exchange (ETDEWEB)

    Choo, J H; Kim, J D; Chung, J H; Stubbs, L; Kim, J

    2006-01-13

    In the current study, we analyzed the deposition patterns of macroH2A1 at a number of different genomic loci located in X chromosome and autosomes. MacroH2A1 is preferentially deposited at methylated CpG CpG-rich regions located close to promoters. The macroH2A1 deposition patterns at the methylated CpG islands of several imprinted domains, including the Imprinting Control Regions (ICRs) of Xist, Peg3, H19/Igf2 Igf2, Gtl2/Dlk1, and Gnas domains, show consistent allele-specificity towards inactive, methylated alleles. The macroH2A1 deposition levels at the ICRs and other Differentially Methylated Regions (DMRs) of these domains are also either higher or comparable to those observed at the inactive X chromosome of female mammals. Overall, our results indicate that besides DNA methylation macroH2A1 is another epigenetic component in the chromatin of ICRs displaying differential association with two parental alleles.

  10. Generation of mice harbouring a conditional loss-of-function allele of Gata6

    Directory of Open Access Journals (Sweden)

    Duncan Stephen A

    2006-04-01

    Full Text Available Abstract The zinc finger transcription factor GATA6 is believed to have important roles in the development of several organs including the liver, gastrointestinal tract and heart. However, analyses of the contribution of GATA6 toward organogenesis have been hampered because Gata6-/- mice fail to develop beyond gastrulation due to defects in extraembryonic endoderm function. We have therefore generated a mouse line harbouring a conditional loss-of-function allele of Gata6 using Cre/loxP technology. LoxP elements were introduced into introns flanking exon 2 of the Gata6 gene by homologous recombination in ES cells. Mice containing this altered allele were bred to homozygosity and were found to be viable and fertile. To assess the functional integrity of the loxP sites and to confirm that we had generated a Gata6 loss-of-function allele, we bred Gata6 'floxed' mice to EIIa-Cre mice in which Cre is ubiquitously expressed, and to Villin-Cre mice that express Cre in the epithelial cells of the intestine. We conclude that we have generated a line of mice in which GATA6 activity can be ablated in a cell type specific manner by expression of Cre recombinase. This line of mice can be used to establish the role of GATA6 in regulating embryonic development and various aspects of mammalian physiology.

  11. The HLA-DRA*0102 allele: correct nucleotide sequence and associated HLA haplotypes.

    Science.gov (United States)

    Kralovicova, J; Marsh, S G E; Waller, M J; Hammarstrom, L; Vorechovsky, I

    2002-09-01

    Here we correct the nucleotide sequence of a single known variant of the HLA-DRA gene. We show that the coding regions of the HLA-DRA*0101 and HLA-DRA*0102 alleles do not differ at two codons as reported previously, but only in codon 217. Using nucleotide sequencing and DNA samples from individuals homozygous in the major histocompatibility complex, we found that the variant, leucine 217-encoding HLA-DRA*0102 allele was present on the haplotypes HLA-B*0801, DRB1*03011, DQB1*0201 (ancestral haplotype AH8.1), HLA-B*07021, DRB1*15011, DQB1*0602 (AH7.1), HLA-B*1501, DRB1*15011, DQB1*0602, HLA-B*1501, DRB1*1402, DQB1*03011 and HLA-A3, B*07021, DRB1*1301, DQB1*0603. The HLA-DRA*0101 allele coding for valine 217 was observed on the haplotypes HLA-B*5701, DRB1*0701, DQB1*03032 (AH57.1), HLA-DRB1*04011, DQB1*0302, HLA-DRB1*0701, DQB1*0202, and HLA-DRB1*0101, DQB1*05011. PMID:12445311

  12. Interactions Between SNP Alleles at Multiple Loci and Variation in Skin Pigmentation in 122 Caucasians

    Directory of Open Access Journals (Sweden)

    Sumiko Anno

    2007-01-01

    Full Text Available This study was undertaken to clarify the molecular basis for human skin color variation and the environmental adaptability to ultraviolet irradiation, with the ultimate goal of predicting the impact of changes in future environments on human health risk. One hundred twenty-two Caucasians living in Toledo, Ohio participated. Back and cheek skin were assayed for melanin as a quantitative trait marker. Buccal cell samples were collected and used for DNA extraction. DNA was used for SNP genotyping using the Masscode™ system, which entails two-step PCR amplification and a platform chemistry which allows cleavable mass spectrometry tags. The results show gene-gene interaction between SNP alleles at multiple loci (not necessarily on the same chromosome contributes to inter-individual skin color variation while suggesting a high probability of linkage disequilibrium. Confirmation of these findings requires further study with other ethic groups to analyze the associations between SNP alleles at multiple loci and human skin color variation. Our overarching goal is to use remote sensing data to clarify the interaction between atmospheric environments and SNP allelic frequency and investigate human adaptability to ultraviolet irradiation. Such information should greatly assist in the prediction of the health effects of future environmental changes such as ozone depletion and increased ultraviolet exposure. If such health effects are to some extent predictable, it might be possible to prepare for such changes in advance and thus reduce the extent of their impact.

  13. Length of normal alleles of C9ORF72 GGGGCC repeat do not influence disease phenotype

    Science.gov (United States)

    Rutherford, Nicola J.; Heckman, Michael G.; DeJesus-Hernandez, Mariely; Baker, Matt C.; Soto-Ortolaza, Alexandra I.; Rayaprolu, Sruti; Stewart, Heather; Finger, Elizabeth; Volkening, Kathryn; Seeley, William W.; Hatanpaa, Kimmo J.; Lomen-Hoerth, Catherine; Kertesz, Andrew; Bigio, Eileen H.; Lippa, Carol; Knopman, David S.; Kretzschmar, Hans A.; Neumann, Manuela; Caselli, Richard J.; White, Charles L.; Mackenzie, Ian R.; Petersen, Ronald C.; Strong, Michael J.; Miller, Bruce L.; Boeve, Bradley F.; Uitti, Ryan J.; Boylan, Kevin; Wszolek, Zbigniew K.; Graff-Radford, Neill R.; Dickson, Dennis W.; Ross, Owen A.; Rademakers, Rosa

    2012-01-01

    Expansions of the non-coding GGGGCC hexanucleotide repeat in the chromosome 9 open reading frame 72 (C9ORF72) gene were recently identified as the long sought-after cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) on chromosome 9p. In this study we aimed to determine whether the length of the normal - unexpanded - allele of the GGGGCC repeat in C9ORF72 plays a role in the presentation of disease or affects age at onset in C9ORF72 mutation carriers. We also studied whether the GGGGCC repeat length confers risk or affects age at onset in FTD and ALS patients without C9ORF72 repeat expansions. C9ORF72 genotyping was performed in 580 FTD, 995 ALS and 160 FTD-ALS patients and 1444 controls, leading to the identification of 211 patients with pathogenic C9ORF72 repeat expansions and an accurate quantification of the length of the normal alleles in all patients and controls. No meaningful association between the repeat length of the normal alleles of the GGGGCC repeat in C9ORF72 and disease phenotype or age at onset was observed in C9ORF72 mutation carriers or non-mutation carriers. PMID:22840558

  14. HLA-DRB1 allele in 35 patients with alveolar echinococcosis in Gansu Province of China

    Institute of Scientific and Technical Information of China (English)

    LI Furong李富荣; SHI Youen石佑恩; SHI Dazhong史大中; Dominique Angele Vuitton; Philip Simon Craig

    2003-01-01

    Objective To investigate the association between histocompatibility leukocyte antigen (HLA)-DRB1 alleles and alveolar echinococcosis (AE).Methods Thirty-five patients with AE in high prevalence areas in Gansu Province of China were tested for the HLA-DRB1 gene using the polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The results were compared with those of 104 healthy individuals.Results The frequency of the HLA-DRB1·040x gene was 26% in the patient group, which was significantly higher than that in the control group (9.62%) with a relative risk (RR) of 4.45 (χ2 =13.67, P<0.01), and an etiological fraction (EF) of 0.20. The frequency of the HLA-DRB1·0701 allele was significantly lower in the patient group (2.86%) as compared to the control group (13.94%; χ2=6.67, P<0.05) with a preventable fraction (PF) of 0.30. The frequencies of other DRB1 alleles were not significantly different.Conclusion Susceptibility to AE is significantly associated with the HLA-DRB1·040x. HLA-DRB1·0701 gene might confer protection against AE in humans.

  15. HLA-DRB1 alleles in four Amerindian populations from Argentina and Paraguay.

    Science.gov (United States)

    Parolín, Maria L; Carnese, Francisco R

    2009-04-01

    The major histocompatibility complex (MHC) is one of the biological systems of major polymorphisms. The study of HLA class II variability has allowed the identification of several alleles that are characteristic to Amerindian populations, and it is an excellent tool to define the relations and biological affinities among them. In this work, we analyzed the allelic distribution of the HLA-DRB1 class II locus in four Amerindian populations: Mapuche (n = 34) and Tehuelche (n = 23) from the Patagonian region of Argentina, and Wichi SV (n = 24) and Lengua (n = 17) from the Argentinean and Paraguayan Chaco regions, respectively. In all of these groups, relatively high frequencies of Amerindian HLA-DRB1 alleles were observed (DRB1*0403, DRB1*0407, DRB1*0411, DRB1*0417, DRB1*0802, DRB1*0901, DRB1*1402, DRB1*1406 and DRB1*1602). However, we also detected the presence of non-Amerindian variants in Mapuche (35%) and Tehuelche (22%). We compared our data with those obtained in six indigenous groups of the Argentinean Chaco region and in a sample from Buenos Aires City. The genetic distance dendrogram showed a clear-cut division between the Patagonian and Chaco populations, which formed two different clusters. In spite of their linguistic differences, it can be inferred that the biological affinities observed are in concordance with the geographic distributions and interethnic relations established among the groups studied. PMID:21637670

  16. Forensic Spanish allele and haplotype database for a 17 X-STR panel.

    Science.gov (United States)

    Prieto-Fernández, Endika; Núñez, Carolina; Baeta, Miriam; Jiménez-Moreno, Susana; Martínez-Jarreta, Begoña; de Pancorbo, Marian M

    2016-09-01

    The currently developed 17 X-STR panel (DXS8378, DXS9898, DXS7133, GATA31E08, GATA172D05, DXS6801, DXS7423, DXS6809, DXS6799, DXS7132, DXS9902, DXS6800, DXS6789, DXS10075, DXS10079, DXS6807, and DXS6803) offers a highly discriminative tool for forensic identification and kinship testing. With the aim of providing a global Spanish population X-STR database, we present haplotype and allele frequencies and parameters of forensic interest for the 17 X-STR panel obtained from 593 unrelated individuals from Alicante, Aragon, the Basque Country, Andalusia, Galicia, Madrid, and Barcelona that represent the most populated regions of the Spanish Peninsular territory. The seven populations were compared to test possible population genetic substructures. The lack of significant differences among the studied Spanish populations supports the use of the allele and haplotype frequency database presented herein as a global Spanish population sample useful for statistical evaluation in forensic casework. After conducting the LD plots derived from HapMap and pairwise linkage disequilibrium tests, DXS7132, DXS10075, and DXS10079 markers were included in a cluster and haplotype frequencies were calculated. The improvement in the forensic parameters for the Spanish population using 17 X-STRs in comparison to the previous 10 X-STR allele frequencies database is also shown. PMID:27388427

  17. Seed fates in crop-wild hybrid sunflower: crop allele and maternal effects.

    Science.gov (United States)

    Pace, Brian A; Alexander, Helen M; Emry, Jason D; Mercer, Kristin L

    2015-02-01

    Domestication has resulted in selection upon seed traits found in wild populations, yet crop-wild hybrids retain some aspects of both parental phenotypes. Seed fates of germination, dormancy, and mortality can influence the success of crop allele introgression in crop-wild hybrid zones, especially if crop alleles or crop-imparted seed coverings result in out-of-season germination. We performed a seed burial experiment using crop, wild, and diverse hybrid sunflower (Helianthus annuus) cross types to test how a cross type's maternal parent and nuclear genetic composition might affect its fate under field conditions. We observed higher maladaptive fall germination in the crop- and F1- produced seeds than wild-produced seeds and, due to an interaction with percent crop alleles, fall germination was higher for cross types with more crop-like nuclear genetics. By spring, crop-produced cross types had the highest overwintering mortality, primarily due to higher fall germination. Early spring germination was identical across maternal types, but germination continued for F1-produced seeds. In conclusion, the more wild-like the maternal parent or the less proportion of the cross type's genome contributed by the crop, the greater likelihood a seed will remain ungerminated than die. Wild-like dormancy may facilitate introgression through future recruitment from the soil seed bank. PMID:25685189

  18. Lichen planopilaris is associated with HLA DRB1*11 and DQB1*03 alleles.

    Science.gov (United States)

    Pavlovsky, Lev; Israeli, Moshe; Sagy, Eti; Berg, Amy L; David, Michael; Shemer, Avner; Klein, Tirza; Hodak, Emmilia

    2015-02-01

    There are no studies of the possible association of the human leukocyte antigen (HLA) system with lichen planopilaris (LPP). To determine whether the HLA system is associated with LPP, 40 consecutive Jewish Israeli patients with LPP (study group) and 252 volunteers (controls) were typed for DRB1*and DQB1* loci by molecular methods. Compared with controls, the study group had a significantly higher frequency of the DRB1*11 allele (62% vs. 21%, corrected p-value (pc) = 0.001) owing to increased frequencies of DRB1*11: 01 and DRB1*11: 04. The DQB1*03 allele was also expressed at a significantly higher frequency in the study group (70% vs. 33%, pc = 0.0005); specifically, the frequency of DQB1*03: 01 was increased. The majority (82.5%) of the patients were of non-Ashkenazi origin. We conclude that LPP appears to be over-represented in non-Ashkenazi Jewish patients and is associated with an increased frequency of HLA DRB1*11 and DQB1*03 alleles. These findings suggest that immunogenetic factors play a role in LPP. PMID:24806356

  19. Disparities in allele frequencies and population differentiation for 101 disease-associated single nucleotide polymorphisms between Puerto Ricans and non-Hispanic whites

    Science.gov (United States)

    Background: Variations in gene allele frequencies can contribute to differences in the prevalence of some common complex diseases among populations. Natural selection modulates the balance in allele frequencies across populations. Population differentiation (FST) can evidence environmental selection...

  20. Tri-allelic pattern of short tandem repeats identifies the murderer among identical twins and suggests an embryonic mutational origin.

    Science.gov (United States)

    Wang, Li-Feng; Yang, Ying; Zhang, Xiao-Nan; Quan, Xiao-Liang; Wu, Yuan-Ming

    2015-05-01

    Monozygotic twins can be co-identified by genotyping of short tandem repeats (STRs); however, for distinguishing them, STR genotyping is ineffective, especially in the case of murder. Here, a rarely occurring tri-allelic pattern in the vWA locus (16, 18, 19) was identified only in the DNA of one identical twin, which could help to exonerate the innocent twin in a murder charge. This mutation was defined as primary through genotyping of the family and could be detected in blood, buccal and semen samples from the individual; however, two alternative allele-balanced di-allelic patterns (16, 18 or 16, 19) were detected in hair root sheath cells. Such a kind of segregation indicates a one-step mutation occurs in cell mitosis, which is after embryonic zygote formation and during the early development of the individual after the division of the blastocyte. Sequencing revealed the insertion between the allele 18 and 19 is a repeat unit of TAGA/TCTA (plus/minus strand), which belongs to "AGAT/ATCT"-based core repeats identified from all tri-allelic pattern reports recorded in the STR base and a detailed model was proposed for STR repeat length variation caused by false priming during DNA synthesis. Our model illustrates the possible origination of allele-balanced and unbalanced tri-allelic pattern, clarifies that the genotypes of parent-child mismatches, aberrant di-allelic patterns, and type 1 or 2 tri-allelic patterns should be considered as independent, but interconnected forms of STR mutation. PMID:25732248

  1. Allelic polymorphism of Ovar-DRB1 exon2 gene and parasite resistance in two dairy sheep breeds

    Directory of Open Access Journals (Sweden)

    Stavros Spetsarias

    2016-02-01

    Full Text Available The Ovar-DRB1 gene locus is one of the most polymorphic genes of the Major Histocompatibility Complex (Ovar-MHC and holds a functional role to antigen presentation. The aim of this study was: a to describe the Ovar-DRB1 locus variability in two dairy Greek sheep breeds and b to investigate associations between this variability with resistance to gastrointestinal parasitosis. Blood and faecal samples were collected from 231 and 201 animals of Arta and Kalarrytiko breeds, respectively. The identification of alleles was performed using the sequence–base method. Faecal egg counting (FEC of the gastrointestinal parasites and measures of blood plasma pepsinogen levels were performed in order to evaluate parasitological parameters. From this study in the overall examined animals, thirty-nine Ovar-DRB1 alleles were identified, among them, ten new alleles, reported for the first time in the literature. In Arta breed a total of twenty-four alleles were found. Among the detected alleles, ten were breed specific and five were new. Regarding the Kalarrytiko breed, twenty-nine alleles were found, fifteen of them were unique and nine were new. The studied breeds differed in their allelic profile, with only 12 common from the total of 134 different recorded genotypes. A higher number of animals with high parasitic load and high plasma pepsinogen values were found in Kalarrytiko. Associations between Ovar-DRB1 alleles with FEC values were found with certain heterozygous genotypes to present significantly reduced FEC values. The large number of detected alleles with low frequencies and the fact that the majority of animals were heterozygous, make hard to find strong associations

  2. Cost-effective genome-wide estimation of allele frequencies from pooled DNA in Atlantic salmon (Salmo salar L.

    Directory of Open Access Journals (Sweden)

    Ozerov Mikhail

    2013-01-01

    Full Text Available Abstract Background New sequencing technologies have tremendously increased the number of known molecular markers (single nucleotide polymorphisms; SNPs in a variety of species. Concurrently, improvements to genotyping technology have now made it possible to efficiently genotype large numbers of genome-wide distributed SNPs enabling genome wide association studies (GWAS. However, genotyping significant numbers of individuals with large number of SNPs remains prohibitively expensive for many research groups. A possible solution to this problem is to determine allele frequencies from pooled DNA samples, such ‘allelotyping’ has been presented as a cost-effective alternative to individual genotyping and has become popular in human GWAS. In this article we have tested the effectiveness of DNA pooling to obtain accurate allele frequency estimates for Atlantic salmon (Salmo salar L. populations using an Illumina SNP-chip. Results In total, 56 Atlantic salmon DNA pools from 14 populations were analyzed on an Atlantic salmon SNP-chip containing probes for 5568 SNP markers, 3928 of which were bi-allelic. We developed an efficient quality control filter which enables exclusion of loci showing high error rate and minor allele frequency (MAF close to zero. After applying multiple quality control filters we obtained allele frequency estimates for 3631 bi-allelic loci. We observed high concordance (r > 0.99 between allele frequency estimates derived from individual genotyping and DNA pools. Our results also indicate that even relatively small DNA pools (35 individuals can provide accurate allele frequency estimates for a given sample. Conclusions Despite of higher level of variation associated with array replicates compared to pool construction, we suggest that both sources of variation should be taken into account. This study demonstrates that DNA pooling allows fast and high-throughput determination of allele frequencies in Atlantic salmon enabling cost

  3. Differential effects of the APOE e4 allele on different domains of cognitive ability across the life-course.

    Science.gov (United States)

    Marioni, Riccardo E; Campbell, Archie; Scotland, Generation; Hayward, Caroline; Porteous, David J; Deary, Ian J

    2016-06-01

    The association between APOE genotype and cognitive function suggests a positive role for the e2 allele and a negative role for the e4 allele. Both alleles have relatively low frequencies in the general population; hence, meta-analyses have been based on many small, heterogeneous studies. Here, we report the APOE-cognition associations in the largest single analysis to date. APOE status and cognitive ability were measured in 18 337 participants from the Generation Scotland study between 2006 and 2011. The age range was 18-94 years with a mean of 47 (SD 15). Four cognitive domains were assessed: verbal declarative memory (paragraph recall), processing speed (digit symbol substitution), verbal fluency (phonemic verbal fluency), and vocabulary (Mill Hill synonyms). Linear regression was used to assess the associations between APOE genetic status and cognition. Possession of the e4 allele was associated with lower scores on the measures of memory and processing speed in subjects aged >60. Across all age ranges, the e4 allele was linked to better verbal fluency scores. In younger subjects (≤60 years) the e4 allele was linked to higher vocabulary scores. There were no associations between the e2 allele and cognitive ability. As seen in previous meta-analyses, the APOE e4 allele is linked to poorer cognitive performance in the domains of memory and processing speed. By contrast, positive associations were seen between the e4 allele and measures of verbal fluency and vocabulary. All associations were relatively small and, in many cases, nominally significant despite the very large sample size. PMID:26395552

  4. Marker-Assisted Selection for Recognizing Wheat Mutant Genotypes Carrying HMW Glutenin Alleles Related to Baking Quality

    OpenAIRE

    Mohammad Javad Zamani; Mohammad Reza Bihamta; Behnam Naserian Khiabani; Zahra Tahernezhad; Mohammad Taher Hallajian; Marzieh Varasteh Shamsi

    2014-01-01

    Allelic diversity of HMW glutenin loci in several studies revealed that allelic combinations affect dough quality. Dx5 + Dy10 subunits are related to good baking quality and Dx2 + Dy12 are related to undesirable baking quality. One of the most regular methods to evaluate the baking quality is SDS-PAGE which is used to improve baking quality labs. Marker-assisted selection is the method which can recognize the alleles related to baking quality and this method is based on polymerase chain reac...

  5. Molecular characterization of five new S alleles associated with self-incompatibility in local Spanish almond cultivars

    OpenAIRE

    Kodad, Ossama; Sánchez, A.; Saibo, N.; M. M. Oliveira; Socias i Company, Rafel

    2011-01-01

    Almond is a highly heterozygous species with a high number of S-alleles controlling its gametophytic self-incompatibility system (GSI). In this work we have analysed Spanish local almond cultivars for S-RNase allele diversity. By cloning and sequencing five new S-RNase alleles were identified: S31 (804 bp) in 'Pou de Felanitx' and 'Totsol', S32 (855 bp) in 'Taiatona', S33 (1165 bp) in 'Pou d'Establiments' and 'Muel', S34 (1663 bp) in 'Pané-Barquets', and S35 (1658 bp) in 'Planeta de les Garri...

  6. Novel Molecular Variants of Allele I of the Escherichia coli P Fimbrial Adhesin Gene papG

    OpenAIRE

    Johnson, James R.; Stell, Adam L.; Kaster, Nicholas; Fasching, Claudine; O'Bryan, Timothy T.

    2002-01-01

    P fimbriae of extraintestinal pathogenic Escherichia coli mediate digalactoside-specific adherence via the tip adhesin molecule PapG, which occurs in three known variants (I to III), which are encoded by the corresponding three alleles of papG. In the present study, newly discovered variants of papG allele I and the respective wild-type source strains were characterized. One of the new papG allele I variants conferred a unique agglutination phenotype that combined the phenotypes associated wi...

  7. Identification of a novel HLA-A allele, HLA-A*01:195, in a UAE national.

    Science.gov (United States)

    Abdrabou, Wael; Witzel, Ini-Isabée; Paduch, Agnieszka; Tay, Guan; Alsafar, Habiba

    2016-07-01

    A novel human leucocyte antigen (HLA)-A allele, HLA-A*01:195, was identified by sequence-based typing (SBT) in a UAE national subject. The novel allele is identical to its closest known allele, HLA-A*01:01:01:01, in exon 2, 3 and 4, except for a single nucleotide mutation of A to G at position 442 in exon 3 (codon 124 in the α2 domain of the α chain of the mature protein). This A to G mutation results in an amino acid change of isoleucine #124 to valine. PMID:27184862

  8. Inheritance of 15 microsatellites in the Pacific oyster Crassostrea gigas: segregation and null allele identification for linkage analysis

    Institute of Scientific and Technical Information of China (English)

    LI Li; GUO Ximing; ZHANG Guofan

    2009-01-01

    Microsatellites were screened in a backcross family of the Pacific oyster, Crassostrea gigas. Fifteen microsatellite loci were distinguishable and polymorphic with 6 types of allele-combinations. Null alleles were detected in 46.7% of loci, accounting for 11.7% of the total alleles. Four loci did not segregate in Mendelian Ratios. Three linkage groups were identified among 7 of the 15 segregating loci. Fluorescence-based automated capillary electrophoresis (ABI 310 Genetic Analyzer) that used to detect the microsatellite loci, has been proved a fast, precise, and reliable method in microsatellite genotyping.

  9. Aberrant allele-specific replication, independent of parental origin, in blood cells of cancer patients

    International Nuclear Information System (INIS)

    Allelic counterparts of biallelically expressed genes display an epigenetic symmetry normally manifested by synchronous replication, different from genes subjected to monoallelic expression, which normally are characterized by an asynchronous mode of replication (well exemplified by the SNRPN imprinted locus). Malignancy was documented to be associated with gross modifications in the inherent replication-timing coordination between allelic counterparts of imprinted genes as well as of biallelically expressed loci. The cancer-related allelic replication timing aberrations are non-disease specific and appear in peripheral blood cells of cancer patients, including those with solid tumors. As such they offer potential blood markers for non-invasive cancer test. The present study was aimed to gain some insight into the mechanism leading to the replication timing alterations of genes in blood lymphocytes of cancer patients. Peripheral blood samples derived from patients with prostate cancer were chosen to represent the cancerous status, and samples taken from patients with no cancer but with benign prostate hyperplasia were used to portray the normal status. Fluorescence In Situ Hybridization (FISH) replication assay, applied to phytohemagglutinin (PHA)-stimulated blood lymphocytes, was used to evaluate the temporal order (either synchronous or asynchronous) of genes in the patients' cells. We demonstrated that: (i) the aberrant epigenetic profile, as delineated by the cancer status, is a reversible modification, evidenced by our ability to restore the normal patterns of replication in three unrelated loci (CEN15, SNRPN and RB1) by introducing an archetypical demethylating agent, 5-azacytidine; (ii) following the rehabilitating effect of demethylation, an imprinted gene (SNRPN) retains its original parental imprint; and (iii) the choice of an allele between early or late replication in the aberrant asynchronous replication, delineated by the cancer status, is not

  10. Comprehensive genotyping in two homogeneous Graves' disease samples reveals major and novel HLA association alleles.

    Directory of Open Access Journals (Sweden)

    Pei-Lung Chen

    Full Text Available BACKGROUND: Graves' disease (GD is the leading cause of hyperthyroidism and thyroid eye disease inherited as a complex trait. Although geoepidemiology studies showed relatively higher prevalence of GD in Asians than in Caucasians, previous genetic studies were contradictory concerning whether and/or which human leukocyte antigen (HLA alleles are associated with GD in Asians. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a case-control association study (499 unrelated GD cases and 504 controls and a replication in an independent family sample (419 GD individuals and their 282 relatives in 165 families. To minimize genetic and phenotypic heterogeneity, we included only ethnic Chinese Han population in Taiwan and excluded subjects with hypothyroidism. We performed direct and comprehensive genotyping of six classical HLA loci (HLA-A, -B, -C, -DPB1, -DQB1 and -DRB1 to 4-digit resolution. Combining the data of two sample populations, we found that B*46:01 (odds ratio under dominant model [OR]  = 1.33, Bonferroni corrected combined P [P(Bc]  = 1.17 x 10⁻², DPB1*05:01 (OR  = 2.34, P(Bc = 2.58 x 10⁻¹⁰, DQB1*03:02 (OR  = 0.62, P(Bc  = 1.97 x 10⁻², DRB1*15:01 (OR  = 1.68, P(Bc = 1.22 x 10⁻² and DRB1*16:02 (OR  = 2.63, P(Bc  = 1.46 x 10⁻⁵ were associated with GD. HLA-DPB1*05:01 is the major gene of GD in our population and singly accounts for 48.4% of population-attributable risk. CONCLUSIONS/SIGNIFICANCE: These GD-associated alleles we identified in ethnic Chinese Hans, and those identified in other Asian studies, are totally distinct from the known associated alleles in Caucasians. Identification of population-specific association alleles is the critical first step for individualized medicine. Furthermore, comparison between different susceptibility/protective alleles across populations could facilitate generation of novel hypothesis about GD pathophysiology and indicate a new direction for future

  11. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

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    Anupam Paliwal

    2013-08-01

    Full Text Available Allele-specific DNA methylation (ASM is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons, one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs, each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS peaks near CTCF binding sites with ASM.

  12. Comparative anatomy of chromosomal domains with imprinted and non-imprinted allele-specific DNA methylation.

    Science.gov (United States)

    Paliwal, Anupam; Temkin, Alexis M; Kerkel, Kristi; Yale, Alexander; Yotova, Iveta; Drost, Natalia; Lax, Simon; Nhan-Chang, Chia-Ling; Powell, Charles; Borczuk, Alain; Aviv, Abraham; Wapner, Ronald; Chen, Xiaowei; Nagy, Peter L; Schork, Nicholas; Do, Catherine; Torkamani, Ali; Tycko, Benjamin

    2013-08-01

    Allele-specific DNA methylation (ASM) is well studied in imprinted domains, but this type of epigenetic asymmetry is actually found more commonly at non-imprinted loci, where the ASM is dictated not by parent-of-origin but instead by the local haplotype. We identified loci with strong ASM in human tissues from methylation-sensitive SNP array data. Two index regions (bisulfite PCR amplicons), one between the C3orf27 and RPN1 genes in chromosome band 3q21 and the other near the VTRNA2-1 vault RNA in band 5q31, proved to be new examples of imprinted DMRs (maternal alleles methylated) while a third, between STEAP3 and C2orf76 in chromosome band 2q14, showed non-imprinted haplotype-dependent ASM. Using long-read bisulfite sequencing (bis-seq) in 8 human tissues we found that in all 3 domains the ASM is restricted to single differentially methylated regions (DMRs), each less than 2kb. The ASM in the C3orf27-RPN1 intergenic region was placenta-specific and associated with allele-specific expression of a long non-coding RNA. Strikingly, the discrete DMRs in all 3 regions overlap with binding sites for the insulator protein CTCF, which we found selectively bound to the unmethylated allele of the STEAP3-C2orf76 DMR. Methylation mapping in two additional genes with non-imprinted haplotype-dependent ASM, ELK3 and CYP2A7, showed that the CYP2A7 DMR also overlaps a CTCF site. Thus, two features of imprinted domains, highly localized DMRs and allele-specific insulator occupancy by CTCF, can also be found in chromosomal domains with non-imprinted ASM. Arguing for biological importance, our analysis of published whole genome bis-seq data from hES cells revealed multiple genome-wide association study (GWAS) peaks near CTCF binding sites with ASM. PMID:24009515

  13. HLA-G allele and haplotype frequencies in a healthy population of Iran.

    Science.gov (United States)

    Kuroshli, Zahra; Gourabi, Hamid; Bazrgar, Masoud; Sanati, Mohammad Hossein; Bahraminejad, Elmira; Anisi, Khadije

    2014-06-01

    The human leukocyte antigen (HLA)-G molecule is expressed in cytotrophoblast cells, adult thymic epithelial cells, erythroblasts, pancreatic islets and mesenchymal stem cells. Although, HLA-G expression in allotransplanted patients is correlated with a better allograft acceptance, it is associated with an advanced grade of the tumor in cancer. In addition to the role on the immune system, HLA-G is also involved in successful pregnancy through the embryo implantation, fetal survival and the initial steps of hematopoiesis and angiogenesis. The aim of this study was determination of HLA-G allele frequencies in a healthy population of Iran. In this research, we selected 100 samples from healthy Iranian individuals and henceforth, we used polymerase chain reaction (PCR) followed by sequencing technique for exon 2, 3, 4 and intron 2 of the gene for evaluating the HLA-G alleles frequencies. Investigation of intronic (intron 2) variation is the novelty of our study. The obtained results indicated thirteen alleles of HLA-G in Iranian individuals including G*01:01:01:01, G*01:06, G*01:01:01:06, G*01:01:02, G*01:01:03, G*01:01:05, G*01:01:06, G*01:01:07, G*01:01:08, G*01:03, G*01:04:01, G*01:04:03, and G*01:04:04. According to this study, the most prevalent alleles in the Iranian population were G*01:01:01:01 (52.5%), G*01:01:02 (16%) and G*01:04:03 (14.5%) and also the lowest alleles regarding the frequency were G*01:01:01:06 (0.5%) and G*01:03 (0.5%). The results of G*01:01:01:01 and G*01:04:01 frequencies showed some similarities with the polish population. Our results were similar to the north Indian population for the frequencies of G*01:06 and G*01:01:02. PMID:24659125

  14. Ploidy mosaicism and allele-specific gene expression differences in the allopolyploid Squalius alburnoides

    Directory of Open Access Journals (Sweden)

    Matos Isa

    2011-12-01

    Full Text Available Abstract Background Squalius alburnoides is an Iberian cyprinid fish resulting from an interspecific hybridisation between Squalius pyrenaicus females (P genome and males of an unknown Anaecypris hispanica-like species (A genome. S. alburnoides is an allopolyploid hybridogenetic complex, which makes it a likely candidate for ploidy mosaicism occurrence, and is also an interesting model to address questions about gene expression regulation and genomic interactions. Indeed, it was previously suggested that in S. alburnoides triploids (PAA composition silencing of one of the three alleles (mainly of the P allele occurs. However, not a whole haplome is inactivated but a more or less random inactivation of alleles varying between individuals and even between organs of the same fish was seen. In this work we intended to correlate expression differences between individuals and/or between organs to the occurrence of mosaicism, evaluating if mosaics could explain previous observations and its impact on the assessment of gene expression patterns. Results To achieve our goal, we developed flow cytometry and cell sorting protocols for this system generating more homogenous cellular and transcriptional samples. With this set-up we detected 10% ploidy mosaicism within the S. alburnoides complex, and determined the allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin in cells from liver and kidney of mosaic and non-mosaic individuals coming from different rivers over a wide geographic range. Conclusions Ploidy mosaicism occurs sporadically within the S. alburnoides complex, but in a frequency significantly higher than reported for other organisms. Moreover, we could exclude the influence of this phenomenon on the detection of variable allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin in cells from liver and kidney of triploid individuals. Finally, we determined that the expression patterns

  15. Effects of feeding a spray-dried multivalent polyclonal antibody preparation on feedlot performance, feeding behavior, carcass characteristics, rumenitis, and blood gas profile of Brangus and Nellore yearling bulls.

    Science.gov (United States)

    Millen, D D; Pacheco, R D L; DiLorenzo, N; Martins, C L; Marino, C T; Bastos, J P S T; Mariani, T M; Barducci, R S; Sarti, L M N; DiCostanzo, A; Rodrigues, P H M; Arrigoni, M D B

    2015-09-01

    The objective of this study was to evaluate the effects of replacing monensin (MON) with a spray-dried multivalent polyclonal antibody preparation (PAP) against several ruminal microorganisms on feedlot performance, carcass characteristics, feeding behavior, blood gas profile, and the rumenitis incidence of Brangus and Nellore yearling bulls. The study was designed as a completely randomized design with a 2 × 2 factorial arrangement, replicated 6 times (4 bulls per pen and a total of 24 pens), in which bulls ( = 48) of each biotype were fed diets containing either MON fed at 300 mg/d or PAP fed at 3 g/d. No significant feed additive main effects were observed for ADG ( = 0.27), G:F ( = 0.28), HCW ( = 0.99), or dressing percentage ( = 0.80). However, bulls receiving PAP had greater DMI ( = 0.02) and larger ( = 0.02) final LM area as well as greater ( Brangus bulls had greater ( Brangus bulls. In addition, Brangus bulls had greater ( Brangus bulls, MON led to greater ( Brangus bulls fed PAP. Feeding a spray-dried PAP led to similar feedlot performance compared with that when feeding MON. Spray-dried PAP might provide a new technology alternative to ionophores. PMID:26440339

  16. Precision-engineering the Pseudomonas aeruginosa genome with two-step allelic exchange

    DEFF Research Database (Denmark)

    Hmelo, Laura R; Borlee, Bradley R; Almblad, Henrik;

    2015-01-01

    homology to the recipient chromosome, are synthesized in vitro and then cloned into allelic exchange vectors using standard procedures. These suicide vectors are then introduced into recipient cells by conjugation. Homologous recombination then results in antibiotic-resistant single-crossover mutants in......Allelic exchange is an efficient method of bacterial genome engineering. This protocol describes the use of this technique to make gene knockouts and knock-ins, as well as single-nucleotide insertions, deletions and substitutions, in Pseudomonas aeruginosa. Unlike other approaches to allelic...... exchange, this protocol does not require heterologous recombinases to insert or excise selective markers from the target chromosome. Rather, positive and negative selections are enabled solely by suicide vector-encoded functions and host cell proteins. Here, mutant alleles, which are flanked by regions of...

  17. Association of the apolipoprotein E {epsilon}4 allele with clinical subtypes of autopsy-confirmed Alzheimer`s Disease

    Energy Technology Data Exchange (ETDEWEB)

    Zubenko, G.S.; Stiffler, S.; Kopp, U. [Univ. of Pittsburgh School of Medicine, PA (United States)] [and others

    1994-09-15

    Consistent with previous reports, we observed a significant association of the APOE {epsilon}4 allele with Alzheimer`s Disease (AD) in a series of 91 autopsy-confirmed cases. The {epsilon}4 allele frequency was higher in cases with a family history of AD-like dementia (0.54 {+-} 0.07), although the {epsilon}4 allele frequency in the AD cases with a negative family history (0.38 {+-} 0.05) remained significantly greater than that for the non-AD control group (0.13 {+-} 0.03). A similar increase in {epsilon}4 allele frequency (0.54 {+-} 0.07) was observed in the AD cases with amyloid angiopathy, compared to those who did not have amyloid angiopathy (0.35 {+-} 0.04). Contrary to previous reports, no effect of the dosage of the {epsilon}4 allele was found on the age of onset of dementia among the AD cases and, contrary to reports suggesting an association of {epsilon}4 and atherosclerosis, the {epsilon}4 allele frequency was similar in cases with or without concurrent brain infarcts. Modest but consistent correlations were observed between the dosage of {epsilon}4 alleles and the cortical density of senile plaques, but not neurofibrillary tangles. The last finding suggests that the pathogenic events mediated by the {epsilon}4 allele may be more directly involved in the formation of senile plaques, the identifying lesions in AD, than neurofibrillary tangles. A robust association of both the presence of an {epsilon}4 allele and a family history of AD-like dementia with concurrent amyloid angiopathy occurred within our sample of AD cases. This association arose from an interaction of the {epsilon}4 allele with a separate familial factor for which a family history of dementia served as a surrogate. These results suggest that amyloid angiopathy may be a common or central feature of a form of familial AD that is associated with the transmission of the APOE {epsilon}4 allele. 22 refs., 2 figs., 5 tabs.

  18. Normal synaptonemal complex and abnormal recombination nodules in two alleles of the Drosophila meiotic mutant mei-W68.

    OpenAIRE

    Carpenter, Adelaide T. C.

    2003-01-01

    The meiotic phenotypes of two mutant alleles of the mei-W68 gene, 1 and L1, were studied by genetics and by serial-section electron microscopy. Despite no or reduced exchange, both mutant alleles have normal synaptonemal complex. However, neither has any early recombination nodules; instead, both exhibit high numbers of very long (up to 2 microm) structures here named "noodles." These are hypothesized to be formed by the unchecked extension of identical but much shorter structures ephemerally...

  19. An explicit transition density expansion for a multi-allelic Wright-Fisher diffusion with general diploid selection

    OpenAIRE

    Steinrücken, Matthias; Wang, Y. X. Rachel; Song, Yun S.

    2012-01-01

    Characterizing time-evolution of allele frequencies in a population is a fundamental problem in population genetics. In the Wright-Fisher diffusion, such dynamics is captured by the transition density function, which satisfies well-known partial differential equations. For a multi-allelic model with general diploid selection, various theoretical results exist on representations of the transition density, but finding an explicit formula has remained a difficult problem. In this paper, a techni...

  20. Allelic gene expression imbalance of bovine IGF2, LEP and CCL2 genes in liver, kidney and pituitary

    OpenAIRE

    Olbromski, R.; Siadkowska, E.; Żelazowska, B.; Zwierzchowski, L.

    2012-01-01

    Allelic expression imbalance (AEI) is an important genetic factor being the cause of differences in phenotypic traits that can be heritable. Studying AEI can be useful in searching for factors that modulate gene expression and help to understand molecular mechanisms underlying phenotypic changes. Although it was commonly recognized in many species and we know many genes show allelic expression imbalance, this phenomena was not studied on a larger scale in cattle. Using the pyrosequencing meth...

  1. Molecular screening of domestic germplasm for allelic variants at the dwarfing gene Rht8 locus in wheat

    Directory of Open Access Journals (Sweden)

    Kobiljski Borislav

    2006-01-01

    Full Text Available In last 7 years, researches revealed the presence of 16 allelic variants at the Xgwm 261 locus with 165, 174, 180, 192, 194, 196, 197, 198, 200, 201 202, 204, 205, 207, 210 and 215 base pairs, while nearly 90% of the worldwide wheat germplasm carry one of the alleles with 165bp, 174bp or 192bp. The results of microsatellite screening of 269 wheat varieties and advanced lines from Serbia and Montenegro showed clear selection pressure for the three main fragments at Rht8 locus, but also trend to expand allelic variability in the locus (in the most recent varieties and advanced lines avoiding "adaptive uniformity" of the elite germplasm. The presence of 192bp allele as diagnostic of Rht8 has been confirmed as quite common in wheat genotypes from Serbia and Montenegro, but not at the rate it has been determined in earlier researches. Out of 269 registered wheat varieties and advanced lines 73.6% carry 192bp allele, 14.9% are with 174bp allele, 7% carry 165 fragment and 4.56% novel fragments around 200bp in length. This research revealed that from the beginning of the 1990s wheat breeding objectives in Serbia and Montenegro were partially focused towards novel alleles (different from 192bp at Xgwm261 locus. Recently registered varieties from Novi Sad have either the 192bp fragment (Cipovka, Simfonija, Balada, Arija, Rapsodija Helena, Diva, Vila, Astra, 174bp fragment (Sofija, Dragana, Italija Francuska, Oda or fragments around 200bp (Sonata, Kantata, Jefimija. In addition, two very promising advanced lines (NS 260/02 and NS 2-4629/1 and some excellent advanced lines frequently used as parents in hybridization (NS 20/96, NS 23/94, NS 85/97 and L152/89 also carry allele around 200bp in size.

  2. Evidence of still-ongoing convergence evolution of the lactase persistence T-13910 alleles in humans

    DEFF Research Database (Denmark)

    Enattah, Nabil Sabri; Trudeau, Aimee; Pimenoff, Ville;

    2007-01-01

    A single-nucleotide variant, C/T(-13910), located 14 kb upstream of the lactase gene (LCT), has been shown to be completely correlated with lactase persistence (LP) in northern Europeans. Here, we analyzed the background of the alleles carrying the critical variant in 1,611 DNA samples from 37 po...... more than once and that there is a still-ongoing process of convergent evolution of the LP alleles in humans....

  3. DPA1*02012: A DPA1*0201-related Mhc class II allele in West Africa

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.G.; May, J.; Spauke, D.; Schnittger, L. [Bernhard Nocht Institute for Tropical Medicine, Hamburg (Germany)

    1994-12-31

    DNA techniques such as sequence-specific oligonucleotide probe (SSOP) hybridizations, restriction-fragment length polymorphism (RFLP) analyses, and DNA sequencing have greatly supported the characterization of Mhc class II allelic polymorphism. Here the authors describe a DPA 1 allele which has been identified in two male individuals from Liberia and Benin, West Africa, during a survey study on Mhc class II associations with the different manifestations after infection with Onchocerca volvulus. 4 refs., 1 fig.

  4. FEATURE OF HETEROSIS IN Capsicum annuum L. IN CONNECTION WITH DEGREE OF IDENTITY OF KEY ALLELES OF ECONOMIC VALUABLE DETERMINANTS

    OpenAIRE

    O.O. Timina; A.S. Ryabova

    2011-01-01

    With the use of parental forms of Capsicum annuum L. (Dobrynya Nikitich, Kolobok, Prometei varieties and also L 48 and L 49 lines) by the regressioncluster analysis the authors revealed the correlation between degree of identity of key alleles of economic valuable determinants and effect of heterosis. It was shown, that for the prognosis of heterosis in the conditions of the film nonheated greenhouse on module of marketable crop the degree of identity alleles in three clusters: fruit’s length...

  5. Apolipoprotein E ε4 allele and malondialdehyde level are independent risk factors for Alzheimer’s disease

    OpenAIRE

    López-Riquelme, Natividad; Alom-Poveda, Jordi; Viciano-Morote, Nuria; Llinares-Ibor, Isabel; Tormo-Díaz, Consuelo

    2016-01-01

    Background: The ε4 allele of Apolipoprotein E is involved in lipid metabolism. Oxidative stress produces an increase in lipid peroxidation that has been implicated in the pathogenic cascade in Alzheimer’s disease. This study estimated the effect of the ε4 allele, malondialdehyde and lipid levels on the risk for Alzheimer’s disease. Methods: A total of 41 control subjects and 73 patients with Alzheimer’s disease were recruited. The Apolipoprotein E genotype was determined by amplification of e...

  6. No association between germline allele-specific expression of TGFBR1 and colorectal cancer risk in Caucasian and Ashkenazi populations

    OpenAIRE

    Seguí, N; Stevens, K. N.; Guinó, E.; Rozek, L S; Moreno, V R; Capellá, G; Gruber, S B; Valle, L.

    2011-01-01

    Background: Germline allele-specific expression (ASE) of the TGFBR1 gene has been reported as a strong risk factor for colorectal cancer (CRC) with an odds ratio close to 9. Considering the potential implications of the finding, we undertook the task of validating the initial results in this study. Methods: Allele-specific expression was measured using the highly quantitative and robust technique of pyrosequencing. Individuals from two different populations were studied, one Caucasian-dominat...

  7. Use of allele-specific FAIRE to determine functional regulatory polymorphism using large-scale genotyping arrays.

    OpenAIRE

    Smith, Andrew J. P.; Howard, Philip; Shah, Sonia; Eriksson, Per; Stender, Stefan; Giambartolomei, Claudia; Folkersen, Lasse; Tybjærg-Hansen, Anne; Kumari, Meena; Palmen, Jutta; Hingorani, Aroon D.; Talmud, Philippa J; Humphries, Steve E.

    2012-01-01

    Following the widespread use of genome-wide association studies (GWAS), focus is turning towards identification of causal variants rather than simply genetic markers of diseases and traits. As a step towards a high-throughput method to identify genome-wide, non-coding, functional regulatory variants, we describe the technique of allele-specific FAIRE, utilising large-scale genotyping technology (FAIRE-gen) to determine allelic effects on chromatin accessibility and regulatory potential. FAIRE...

  8. Independent introduction of two lactase-persistence alleles into human populations reflects different history of adaptation to milk culture

    DEFF Research Database (Denmark)

    Enattah, Nabil Sabri; Jensen, Tine G K; Boyd, Mette;

    2008-01-01

    same history, probably related to the same cattle domestication event. In contrast, the compound Arab allele shows a different, highly divergent ancestral haplotype, suggesting that these two major global LP alleles have arisen independently, the latter perhaps in response to camel milk consumption....... These results support the convergent evolution of the LP in diverse populations, most probably reflecting different histories of adaptation to milk culture....

  9. Inducible and Constitutive Activation of Two Polymorphic Promoter Alleles of the Candida albicans Multidrug Efflux Pump MDR1

    OpenAIRE

    Sasse, Christoph; Schillig, Rebecca; Reimund, Alexandra; Merk, Julia; Morschhäuser, Joachim

    2012-01-01

    Overexpression of the multidrug efflux pump MDR1 confers resistance to the antifungal drug fluconazole on Candida albicans. It has been reported that two types of MDR1 promoters exist in C. albicans and that homozygosity for the allele with higher activity may promote fluconazole resistance. We found that the two MDR1 promoter alleles in strain SC5314 were equally well activated by inducing chemicals or hyperactive forms of the transcription factors Mrr1 and Cap1, which control MDR1 expressio...

  10. Development of allele-specific multiplex PCR to determine the length of poly-T in intron 8 of CFTR

    OpenAIRE

    Neng Chen; Prada, Anne E.

    2014-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis has been implemented for Cystic Fibrosis (CF) carrier screening, and molecular diagnosis of CF and congenital bilateral absence of the vas deferens (CBAVD). Although poly-T allele analysis in intron 8 of CFTR is required when a patient is positive for R117H, it is not recommended for routine carrier screening. Therefore, commercial kits for CFTR mutation analysis were designed either to mask the poly-T allele re...

  11. HLA-DRB1*14 is a protective allele for multiple sclerosis in an admixed Colombian population

    OpenAIRE

    Toro, Jaime; Cuellar-Giraldo, David; Díaz-Cruz, Camilo; Burbano, Lisseth-Estefania; Guío, Claudia-Marcela; Reyes, Saúl; Cortes, Fabián; Cárdenas-Robledo, Simón; Diana M. Narváez; Cárdenas, Wilmer; Porras, Alexandra; Lattig, María-Claudia; Groot de Restrepo, Helena

    2015-01-01

    Objective: The aim of this study was to determine ancestry informative markers, mitochondrial DNA haplogroups, and the association between HLA-DRB1 alleles and multiple sclerosis (MS) in a group of patients from Bogotá, Colombia. Methods: In this case-control study, genomic DNA was isolated and purified from blood samples. HLA-DRB1 allele genotyping was done using PCR. Mitochondrial hypervariable region 1 was amplified and haplogroups were determined using HaploGrep software. Genomic ancestry...

  12. Corrective recombination of mouse immunoglobulin kappa alleles in Abelson murine leukemia virus-transformed pre-B cells.

    OpenAIRE

    Feddersen, R M; Van Ness, B G

    1990-01-01

    Previous characterization of mouse immunoglobulin kappa gene rearrangement products cloned from murine plasmacytomas has indicated that two recombination events can take place on a single kappa allele (R. M. Feddersen and B. G. Van Ness, Proc. Natl. Acad. Sci. USA 82:4792-4797, 1985; M. A. Shapiro and M. Weigert, J. Immunol. 139:3834-3839, 1987). To determine whether multiple recombinations on a single kappa allele can contribute to the formation of productive V-J genes through corrective rec...

  13. Upstream Transcription Factor 1 (USF1) allelic variants regulate lipoprotein metabolism in women and USF1 expression in atherosclerotic plaque

    OpenAIRE

    Fan, Yue-Mei; Hernesniemi, Jussi; Oksala, Niku; Levula, Mari; Raitoharju, Emma; Collings, Auni; Hutri-Kähönen, Nina; Juonala, Markus; Marniemi, Jukka; Lyytikäinen, Leo-Pekka; Seppälä, Ilkka; Mennander, Ari; Tarkka, Matti; Kangas, Antti J.; Soininen, Pasi

    2014-01-01

    Upstream transcription factor 1 (USF1) allelic variants significantly influence future risk of cardiovascular disease and overall mortality in females. We investigated sex-specific effects of USF1 gene allelic variants on serum indices of lipoprotein metabolism, early markers of asymptomatic atherosclerosis and their changes during six years of follow-up. In addition, we investigated the cis-regulatory role of these USF1 variants in artery wall tissues in Caucasians. In the Cardiovascular Ris...

  14. A novel allele of Saccharomyces cerevisiae RFA1 that is deficient in recombination and repair and suppressible by RAD52.

    OpenAIRE

    Firmenich, A A; Elias-Arnanz, M; Berg, P

    1995-01-01

    To understand the mechanisms involved in homologous recombination, we have performed a search for Saccharomyces cerevisiae mutants unable to carry out plasmid-to-chromosome gene conversion. For this purpose, we have developed a colony color assay in which recombination is induced by the controlled delivery of double-strand breaks (DSBs). Recombination occurs between a chromosomal mutant ade2 allele and a second plasmid-borne ade2 allele where DSBs are introduced via the site-specific HO endon...

  15. MASTR: A Technique for Mosaic Mutant Analysis with Spatial and Temporal Control of Recombination Using Conditional Floxed Alleles in Mice

    Directory of Open Access Journals (Sweden)

    Zhimin Lao

    2012-08-01

    Full Text Available Mosaic mutant analysis, the study of cellular defects in scattered mutant cells in a wild-type environment, is a powerful approach for identifying critical functions of genes and has been applied extensively to invertebrate model organisms. A highly versatile technique has been developed in mouse: MASTR (mosaic mutant analysis with spatial and temporal control of recombination, which utilizes the increasing number of floxed alleles and simultaneously combines conditional gene mutagenesis and cell marking for fate analysis. A targeted allele (R26MASTR was engineered; the allele expresses a GFPcre fusion protein following FLP-mediated recombination, which serves the dual function of deleting floxed alleles and marking mutant cells with GFP. Within 24 hr of tamoxifen administration to R26MASTR mice carrying an inducible FlpoER transgene and a floxed allele, nearly all GFP-expressing cells have a mutant allele. The fate of single cells lacking FGF8 or SHH signaling in the developing hindbrain was analyzed using MASTR, and it was revealed that there is only a short time window when neural progenitors require FGFR1 for viability and that granule cell precursors differentiate rapidly when SMO is lost. MASTR is a powerful tool that provides cell-type-specific (spatial and temporal marking of mosaic mutant cells and is broadly applicable to developmental, cancer, and adult stem cell studies.

  16. Natural host genetic resistance to lentiviral CNS disease: a neuroprotective MHC class I allele in SIV-infected macaques.

    Directory of Open Access Journals (Sweden)

    Joseph L Mankowski

    Full Text Available Human immunodeficiency virus (HIV infection frequently causes neurologic disease even with anti-retroviral treatment. Although associations between MHC class I alleles and acquired immunodeficiency syndrome (AIDS have been reported, the role MHC class I alleles play in restricting development of HIV-induced organ-specific diseases, including neurologic disease, has not been characterized. This study examined the relationship between expression of the MHC class I allele Mane-A*10 and development of lentiviral-induced central nervous system (CNS disease using a well-characterized simian immunodeficiency (SIV/pigtailed macaque model. The risk of developing CNS disease (SIV encephalitis was 2.5 times higher for animals that did not express the MHC class I allele Mane-A*10 (P = 0.002; RR = 2.5. Animals expressing the Mane-A*10 allele had significantly lower amounts of activated macrophages, SIV RNA, and neuronal dysfunction in the CNS than Mane-A*10 negative animals (P<0.001. Mane-A*10 positive animals with the highest CNS viral burdens contained SIV gag escape mutants at the Mane-A*10-restricted KP9 epitope in the CNS whereas wild type KP9 sequences dominated in the brain of Mane-A*10 negative animals with comparable CNS viral burdens. These concordant findings demonstrate that particular MHC class I alleles play major neuroprotective roles in lentiviral-induced CNS disease.

  17. "HLA Class II Allele and Haplotype Frequencies in Iranian Patients with Acute Myelogenous Leukemia and Control Group "

    Directory of Open Access Journals (Sweden)

    Abdolfattah Sarafnejad

    2006-09-01

    Full Text Available Previous studies have demonstrated some significant differences in HLA allele frequencies in leukemic patients and normal subjects. We have analyzed HLA class II alleles and haplotypes in 60 Iranian patients with acute myelogenous leukemia (AML and 180 unrelated normal subjects. Blood samples were collected after obtaining informed consents. From the patients and control DNA extraction and HLA typing were performed using PCR-SSP method. Significant positive association with the disease was found for HLA-DRB1*11 allele (35% vs. 24.7%, p=0.033. Two alleles including HLA-DRB4 and –DQB1*0303 were found to be significantly decreased in patients compared to controls. Regarding haplotype analysis, no significant association was found between case and control groups. It is suggested that HLA-DRB1*11 allele plays as a presumptive predisposing factor while the HLA-DRB4 and –DQB1*0303 alleles are suggested as protective genetic factors against acute myelogenous leukemia. Larger studies are needed to confirm and establish the role of these associations with acute myelogenous leukemia.

  18. HLA-E(⁎)01:03 Allele in Lung Transplant Recipients Correlates with Higher Chronic Lung Allograft Dysfunction Occurrence.

    Science.gov (United States)

    Di Cristofaro, Julie; Pelardy, Mathieu; Loundou, Anderson; Basire, Agnès; Gomez, Carine; Chiaroni, Jacques; Thomas, Pascal; Reynaud-Gaubert, Martine; Picard, Christophe

    2016-01-01

    Lung transplantation (LTx) is a valid therapeutic option for selected patients with end-stage lung disease. HLA-E seems to play a major role in the immune response to different viral infections and to affect transplantation outcome, in Hematopoietic Stem Cell Transplantation, for example. Two nonsynonymous alleles, HLA-E(⁎)01:01 and HLA-E(⁎)01:03, have functional differences, involving relative peptide affinity, cell surface expression, and potential lytic activity of NK cells. The aim of this retrospective study was to determine the impact of these two alleles for LTx recipients on anti-HLA alloimmunization risk, overall survival, and chronic rejection (CLAD). HLA-E was genotyped in 119 recipients who underwent LTx from 1998 to 2010 in a single transplantation center. In univariate analysis, both HLA-E homozygous states were associated with impaired overall survival compared to heterozygous HLA-E alleles (p = 0.01). In multivariate analysis, HLA-E(⁎)01:03 allele showed increased CLAD occurrence when compared to homozygous HLA-E(⁎)01:01 status (HR: 3.563 (CI 95%, 1.016-12), p = 0.047). HLA-E allele did not affect pathogen infection or the production of de novo DSA. This retrospective study shows an uninvestigated, deleterious association of HLA-E alleles with LTx and requires verification using a larger cohort. PMID:27493971

  19. HLA-E⁎01:03 Allele in Lung Transplant Recipients Correlates with Higher Chronic Lung Allograft Dysfunction Occurrence

    Directory of Open Access Journals (Sweden)

    Julie Di Cristofaro

    2016-01-01

    Full Text Available Lung transplantation (LTx is a valid therapeutic option for selected patients with end-stage lung disease. HLA-E seems to play a major role in the immune response to different viral infections and to affect transplantation outcome, in Hematopoietic Stem Cell Transplantation, for example. Two nonsynonymous alleles, HLA-E⁎01:01 and HLA-E⁎01:03, have functional differences, involving relative peptide affinity, cell surface expression, and potential lytic activity of NK cells. The aim of this retrospective study was to determine the impact of these two alleles for LTx recipients on anti-HLA alloimmunization risk, overall survival, and chronic rejection (CLAD. HLA-E was genotyped in 119 recipients who underwent LTx from 1998 to 2010 in a single transplantation center. In univariate analysis, both HLA-E homozygous states were associated with impaired overall survival compared to heterozygous HLA-E alleles (p=0.01. In multivariate analysis, HLA-E⁎01:03 allele showed increased CLAD occurrence when compared to homozygous HLA-E⁎01:01 status (HR: 3.563 (CI 95%, 1.016–12, p=0.047. HLA-E allele did not affect pathogen infection or the production of de novo DSA. This retrospective study shows an uninvestigated, deleterious association of HLA-E alleles with LTx and requires verification using a larger cohort.

  20. Two domain-disrupted hda6 alleles have opposite epigenetic effects on transgenes and some endogenous targets

    KAUST Repository

    Zhang, ShouDong

    2015-12-15

    HDA6 is a RPD3-like histone deacetylase. In Arabidopsis, it mediates transgene and some endogenous target transcriptional gene silencing (TGS) via histone deacetylation and DNA methylation. Here, we characterized two hda6 mutant alleles that were recovered as second-site suppressors of the DNA demethylation mutant ros1–1. Although both alleles derepressed 35S::NPTII and RD29A::LUC in the ros1–1 background, they had distinct effects on the expression of these two transgenes. In accordance to expression profiles of two transgenes, the alleles have distinct opposite methylation profiles on two reporter gene promoters. Furthermore, both alleles could interact in vitro and in vivo with the DNA methyltransferase1 with differential interactive strength and patterns. Although these alleles accumulated different levels of repressive/active histone marks, DNA methylation but not histone modifications in the two transgene promoters was found to correlate with the level of derepression of the reporter genes between the two had6 alleles. Our study reveals that mutations in different domains of HDA6 convey different epigenetic status that in turn controls the expression of the transgenes as well as some endogenous loci.