Bibliographies thématiques / Search and recombination

Littérature scientifique sur le sujet « Search and recombination »

Auteur : Grafiati
Publié le 14 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Sommaire

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Search and recombination ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Search and recombination"

1

Inbar, Ori, et Martin Kupiec. « Homology Search and Choice of Homologous Partner during Mitotic Recombination ». Molecular and Cellular Biology 19, no 6 (1 juin 1999) : 4134–42. http://dx.doi.org/10.1128/mcb.19.6.4134.

Texte intégral
Résumé :
ABSTRACT Homologous recombination is an important DNA repair mechanism in vegetative cells. During the repair of double-strand breaks, genetic information is transferred between the interacting DNA sequences (gene conversion). This event is often accompanied by a reciprocal exchange between the homologous molecules, resulting in crossing over. The repair of DNA damage by homologous recombination with repeated sequences dispersed throughout the genome might result in chromosomal aberrations or in the inactivation of genes. It is therefore important to understand how the suitable homologous partner for recombination is chosen. We have developed a system in the yeast Saccharomyces cerevisiae that can monitor the fate of a chromosomal double-strand break without the need to select for recombinants. The broken chromosome is efficiently repaired by recombination with one of two potential partners located elsewhere in the genome. One of the partners has homology to the broken ends of the chromosome, whereas the other is homologous to sequences distant from the break. Surprisingly, a large proportion of the repair is carried out by recombination involving the sequences distant from the broken ends. This repair is very efficient, despite the fact that it requires the processing of a large chromosomal region flanking the break. Our results imply that the homology search involves extensive regions of the broken chromosome and is not carried out exclusively by sequences adjacent to the double-strand break. We show that the mechanism that governs the choice of homologous partners is affected by the length and sequence divergence of the interacting partners, as well as by mutations in the mismatch repair genes. We present a model to explain how the suitable homologous partner is chosen during recombinational repair. The model provides a mechanism that may guard the integrity of the genome by preventing recombination between dispersed repeated sequences.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Elf, Johan. « Hypothesis : Homologous Recombination Depends on Parallel Search ». Cell Systems 3, no 4 (octobre 2016) : 325–27. http://dx.doi.org/10.1016/j.cels.2016.10.005.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

You, Xuemei, Yinghong Ma, Zhiyuan Liu et Mingzhao Xie. « An ABC Algorithm with Recombination ». International Journal of Computers Communications & ; Control 13, no 4 (25 juillet 2018) : 590–601. http://dx.doi.org/10.15837/ijccc.2018.4.3275.

Texte intégral
Résumé :
Artificial bee colony (ABC) is an efficient swarm intelligence algorithm, which has shown good exploration ability. However, its exploitation capacity needs to be improved. In this paper, a novel ABC variant with recombination (called RABC) is proposed to enhance the exploitation. RABC firstly employs a new search model inspired by the updating equation of particle swarm optimization (PSO). Then, both the new search model and the original ABC model are recombined to build a hybrid search model. The effectiveness of the proposed RABC is validated on ten famous benchmark optimization problems. Experimental results show RABC can significantly improve the quality of solutions and accelerate the convergence speed.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Renkawitz, Jörg, Claudio A. Lademann et Stefan Jentsch. « Mechanisms and principles of homology search during recombination ». Nature Reviews Molecular Cell Biology 15, no 6 (14 mai 2014) : 369–83. http://dx.doi.org/10.1038/nrm3805.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Messeni Petruzzelli, Antonio, et Tommaso Savino. « Search, Recombination, and Innovation : Lessons from Haute Cuisine ». Long Range Planning 47, no 4 (août 2014) : 224–38. http://dx.doi.org/10.1016/j.lrp.2012.09.001.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Miné-Hattab, Judith, et Rodney Rothstein. « Increased chromosome mobility facilitates homology search during recombination ». Nature Cell Biology 14, no 5 (8 avril 2012) : 510–17. http://dx.doi.org/10.1038/ncb2472.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Drugan, Mădălina M., et Dirk Thierens. « Geometrical Recombination Operators for Real-Coded Evolutionary MCMCs ». Evolutionary Computation 18, no 2 (juin 2010) : 157–98. http://dx.doi.org/10.1162/evco.2010.18.2.18201.

Texte intégral
Résumé :
Markov chain Monte Carlo (MCMC) algorithms are sampling methods for intractable distributions. In this paper, we propose and investigate algorithms that improve the sampling process from multi-dimensional real-coded spaces. We present MCMC algorithms that run a population of samples and apply recombination operators in order to exchange useful information and preserve commonalities in highly probable individual states. We call this class of algorithms Evolutionary MCMCs (EMCMCs). We introduce and analyze various recombination operators which generate new samples by use of linear transformations, for instance, by translation or rotation. These recombination methods discover specific structures in the search space and adapt the population samples to the proposal distribution. We investigate how to integrate recombination in the MCMC framework to sample from a desired distribution. The recombination operators generate individuals with a computational effort that scales linearly in the number of dimensions and the number of parents. We present results from experiments conducted on a mixture of multivariate normal distributions. These results show that the recombinative EMCMCs outperform the standard MCMCs for target distributions that have a nontrivial structural relationship between the dimensions.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Ellis, S. C., et J. Bland-Hawthorn. « THE SEARCH FOR CELESTIAL POSITRONIUM VIA THE RECOMBINATION SPECTRUM ». Astrophysical Journal 707, no 1 (23 novembre 2009) : 457–71. http://dx.doi.org/10.1088/0004-637x/707/1/457.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

DEL RÍO, MANUEL BELTRÁN, CHRISTOPHER R. STEPHENS et DAVID A. ROSENBLUETH. « FITNESS LANDSCAPE EPISTASIS AND RECOMBINATION ». Advances in Complex Systems 18, no 07n08 (novembre 2015) : 1550026. http://dx.doi.org/10.1142/s0219525915500265.

Texte intégral
Résumé :
Homologous recombination is an important operator in the evolution of biological organisms. However, there is still no clear, generally accepted understanding of why it exists and under what circumstances it is useful. In this paper, we consider its utility in the context of an infinite population haploid model with selection and homologous recombination. We define utility in terms of two metrics — the increase in frequency of fit genotypes, and the increase in average population fitness, relative to those associated with selection only. Explicitly, we explore the full parameter space of a two-locus two-allele system, showing, as a function of the landscape and the initial population, that recombination is beneficial in terms of these metrics in two distinct regimes: a relatively landscape independent regime — the search regime — where recombination aids in the search for a fit genotype that is absent or at low frequency in the population; and the modular regime, where recombination allows for the juxtaposition of fit “modules” or Building Blocks (BBs). Thus, we conclude that the ubiquity and utility of recombination is intimately associated with the existence of modularity and redundancy in biological fitness landscapes.
Styles APA, Harvard, Vancouver, ISO, etc.
10

Alejska, M. « A universal BMV-based RNA recombination system--how to search for general rules in RNA recombination ». Nucleic Acids Research 33, no 12 (1 juillet 2005) : e105-e105. http://dx.doi.org/10.1093/nar/gni106.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Plus de sources

Thèses sur le sujet "Search and recombination"

1

Browne, Cameron Bolitho. « Automatic generation and evaluation of recombination games ». Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/17025/1/Cameron_Browne_Thesis.pdf.

Texte intégral
Résumé :
Many new board games are designed each year, ranging from the unplayable to the truly exceptional. For each successful design there are untold numbers of failures; game design is something of an art. Players generally agree on some basic properties that indicate the quality and viability of a game, however these properties have remained subjective and open to interpretation. The aims of this thesis are to determine whether such quality criteria may be precisely defined and automatically measured through self-play in order to estimate the likelihood that a given game will be of interest to human players, and whether this information may be used to direct an automated search for new games of high quality. Combinatorial games provide an excellent test bed for this purpose as they are typically deep yet described by simple welldefined rule sets. To test these ideas, a game description language was devised to express such games and a general game system implemented to play, measure and explore them. Key features of the system include modules for measuring statistical aspects of self-play and synthesising new games through the evolution of existing rule sets. Experiments were conducted to determine whether automated game measurements correlate with rankings of games by human players, and whether such correlations could be used to inform the automated search for new high quality games. The results support both hypotheses and demonstrate the emergence of interesting new rule combinations.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Browne, Cameron Bolitho. « Automatic generation and evaluation of recombination games ». Queensland University of Technology, 2008. http://eprints.qut.edu.au/17025/.

Texte intégral
Résumé :
Many new board games are designed each year, ranging from the unplayable to the truly exceptional. For each successful design there are untold numbers of failures; game design is something of an art. Players generally agree on some basic properties that indicate the quality and viability of a game, however these properties have remained subjective and open to interpretation. The aims of this thesis are to determine whether such quality criteria may be precisely defined and automatically measured through self-play in order to estimate the likelihood that a given game will be of interest to human players, and whether this information may be used to direct an automated search for new games of high quality. Combinatorial games provide an excellent test bed for this purpose as they are typically deep yet described by simple welldefined rule sets. To test these ideas, a game description language was devised to express such games and a general game system implemented to play, measure and explore them. Key features of the system include modules for measuring statistical aspects of self-play and synthesising new games through the evolution of existing rule sets. Experiments were conducted to determine whether automated game measurements correlate with rankings of games by human players, and whether such correlations could be used to inform the automated search for new high quality games. The results support both hypotheses and demonstrate the emergence of interesting new rule combinations.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Anstett, Benjamin [Verfasser], et Peter [Akademischer Betreuer] Becker. « Homology search guidance by the yeast recombination enhancer / Benjamin Anstett ; Betreuer : Peter Becker ». München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1132995329/34.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Lönneborg, Rosa. « In search of a biosensor for DNT detection : Studies of inducer response and specificity of DntR ». Doctoral thesis, Stockholms universitet, Institutionen för biokemi och biofysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-64129.

Texte intégral
Résumé :
The primary aim of the work presented in this thesis was to change the inducer specificity of the DntR protein in order to improve the response to DNT. The long-term goal is to use this protein in a biosensor for DNT, a signature compound for detection of the explosive TNT. Another aspect of this work was to understand the mechanisms of inducer binding and how the binding of an inducer molecule changes the DntR structure into a state that triggers transcriptional activation. In the papers included in this thesis the inducer specificity of wt DntR has been investigated under different conditions. The functional effects of specific mutations have also been investigated, in some cases in combination with structure determination using X-ray crystallography. In addition, structural data offering insights into the details of inducer binding and conformational changes upon inducer binding are presented and discussed in terms of mechanisms for transcriptional activation by DntR. Furthermore, a directed evolution strategy was employed in order to find variants of DntR with improved response to DNT. A variant with a large improvement in the DNT response was isolated and characterized. In optimized growth conditions, this DntR variant had a nearly 10-fold increase in fluorescence in response to DNT compared to wt DntR. Specific substitutions found in this DntR variant are suggested to be important for changing the inducer response.
Syftet med denna avhandling har varit att förbättra förmågan hos proteinet DntR att upptäcka DNT. Det långsiktiga målet har varit att använda DntR i en biosensor för att upptäcka sprängämnet TNT, som avger DNT som en ”signaturmolekyl”. En annan aspekt har varit att bättre förstå den detaljerade mekanismen för hur DntR fungerar. DntR är ett protein som binder till en viss DNA sekvens (promotor) och reglerar hur gener intill denna promotorsekvens läses av. När en inducerande molekyl som t.ex. DNT binder till DntR förändras proteinets struktur på ett sådant sätt att DntR kan aktivera transkription av de gener som finns intill promotor-sekvensen. För att mäta hur DntR reagerar på olika inducerande molekyler har DntR uttryckts i bakterien Escherichia coli, som också innehållit promotorn som DntR binder till. Intill promotorn sitter en gen som kodar för proteinet GFP. När en inducerande molekyl binder till DntR, slås avläses gfp-genen, och det fluorescerande proteinet GFP produceras. Ju mer GFP som produceras i cellerna, desto högre fluorescens kan uppmätas när cellerna analyseras.   I de artiklar som presenteras i avhandlingen har vi undersökt hur olika substitutioner i DntR proteinet påverkar specificiten och sensitiviteten och hur dessa egenskaper kan påverkas av olika experimentella faktorer. Effekten av substitutioner har relaterats till strukturdata, där bilder av hur proteinet ser ut på molekylär nivå har tagits fram. Dessutom presenteras även en bild av hur DntR förändras beroende på om inducerande molekyler är bundna eller inte. En sådan strukturbild ökar förståelsen för de mekanismer som gör att bindning av en inducerande molekyl orsakar en förändring av formen hos DntR på så sätt att avläsning av gener kan aktiveras. Vi har också använt en metod där evolutionära processer härmats för att få fram varianter av DntR med förbättrad respons till DNT. En variant med en drastisk ökning av DNT-responsen har isolerats, och dess egenskaper har karaktäriserats.
At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript
Styles APA, Harvard, Vancouver, ISO, etc.
5

Flamm, Christoph, Ivo L. Hofacker, Bärbel M. R. Stadler et Peter F. Stadler. « Saddles and Barrier in Landscapes of Generalized Search Operators ». 2007. https://ul.qucosa.de/id/qucosa%3A32606.

Texte intégral
Résumé :
Barrier trees are a convenient way of representing the structure of complex combinatorial landscapes over graphs. Here we generalize the concept of barrier trees to landscapes defined over general multi-parent search operators based on a suitable notion of topological connectedness that depends explicitly on the search operator. We show that in the case of recombination spaces, path-connectedness coincides with connectedness as defined by the mutation operator alone. In contrast, topological connectedness is more general and depends on the details of the recombination operators as well. Barrier trees can be meaningfully defined for both concepts of connectedness.
Styles APA, Harvard, Vancouver, ISO, etc.

Chapitres de livres sur le sujet "Search and recombination"

1

Zäpfel, Günther, Roland Braune et Michael Bögl. « Metaheuristics Based on Solution Recombination ». Dans Metaheuristic Search Concepts, 121–43. Berlin, Heidelberg : Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-11343-7_7.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Crampton, David. « The Search for High Redshift Quasars ». Dans The Post-Recombination Universe, 19–31. Dordrecht : Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-3035-3_2.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Whitley, Darrell. « Exploiting Decomposability Using Recombination in Genetic Algorithms : An Exploratory Discussion ». Dans Search Based Software Engineering, 5–15. Berlin, Heidelberg : Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-23716-4_2.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Mühlenbein, H., et T. Mahnig. « Evolutionary Algorithms : From Recombination to Search Distributions ». Dans Natural Computing Series, 135–73. Berlin, Heidelberg : Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-662-04448-3_7.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Yu, Yang, Chao Qian et Zhi-Hua Zhou. « Towards Analyzing Recombination Operators in Evolutionary Search ». Dans Parallel Problem Solving from Nature, PPSN XI, 144–53. Berlin, Heidelberg : Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15844-5_15.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Friedrich, Tobias, Timo Kötzing, Martin S. Krejca et Andrew M. Sutton. « The Benefit of Recombination in Noisy Evolutionary Search ». Dans Algorithms and Computation, 140–50. Berlin, Heidelberg : Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-48971-0_13.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Dozier, Gerry, Hurley Cunningham, Winard Britt et Funing Zhang. « Distributed Constraint Satisfaction, Restricted Recombination, and Hybrid Genetic Search ». Dans Genetic and Evolutionary Computation – GECCO 2004, 1078–87. Berlin, Heidelberg : Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-24854-5_106.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Cotta, Carlos, et José M. Troya. « Using Dynastic Exploring Recombination to Promote Diversity in Genetic Search ». Dans Parallel Problem Solving from Nature PPSN VI, 325–34. Berlin, Heidelberg : Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/3-540-45356-3_32.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Candresse, Thierry, Frédéric Revers, Olivier Le Gall, Sandra A. Kofalvi, José Marcos et Vicente Pallás. « Systematic Search for Recombination Events in plant Viruses and Viroids ». Dans Virus-Resistant Transgenic Plants : Potential Ecological Impact, 20–25. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-662-03506-1_2.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

García, Marcos Diez, et Alberto Moraglio. « A Unifying View on Recombination Spaces and Abstract Convex Evolutionary Search ». Dans Evolutionary Computation in Combinatorial Optimization, 179–95. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-16711-0_12.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Search and recombination"

1

Friedrich, Tobias, Timo Kötzing, Martin S. Krejca et Andrew M. Sutton. « The Benefit of Recombination in Noisy Evolutionary Search ». Dans GECCO '16 : Genetic and Evolutionary Computation Conference. New York, NY, USA : ACM, 2016. http://dx.doi.org/10.1145/2908961.2930953.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Gissler, Armand, Anne Auger et Nikolaus Hansen. « Learning rate adaptation by line search in evolution strategies with recombination ». Dans GECCO '22 : Genetic and Evolutionary Computation Conference. New York, NY, USA : ACM, 2022. http://dx.doi.org/10.1145/3512290.3528760.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Xie, Yu, Qinglong Wang, Jian Ding, Fangfang Meng, Shanhong Li et Chunxia Zhao. « Enhancing the search ability of differential evolutionary through partial intermediate recombination ». Dans 2017 32nd Youth Academic Annual Conference of Chinese Association of Automation (YAC). IEEE, 2017. http://dx.doi.org/10.1109/yac.2017.7967598.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Chicano, Francisco, Darrell Whitley, Gabriela Ochoa et Renato Tinós. « Optimizing one million variable NK landscapes by hybridizing deterministic recombination and local search ». Dans GECCO '17 : Genetic and Evolutionary Computation Conference. New York, NY, USA : ACM, 2017. http://dx.doi.org/10.1145/3071178.3071285.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Abdelbar, Ashraf M., et Khalid M. Salama. « Solution recombination in an indicator-based many-objective ant colony optimizer for continuous search spaces ». Dans 2017 IEEE Symposium Series on Computational Intelligence (SSCI). IEEE, 2017. http://dx.doi.org/10.1109/ssci.2017.8280806.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Watchareeruetai, Ukrit, Yoshinori Takeuchi, Tetsuya Matsumoto, Hiroaki Kudo et Noboru Ohnishi. « Improving search performance of linear genetic programming based image recognition program synthesis by redundancy-removed recombination ». Dans 2008 IEEE Conference on Soft Computing in Industrial Applications (SMCia). IEEE, 2008. http://dx.doi.org/10.1109/smcia.2008.5045996.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Aydın, Kemal Bartu, Levent Aydin et Fethullah Güneş. « Stochastic Optimization of TiO2-Graphene Nanocomposite by Using Neuro-Regression Approach for Maximum Photocatalytic Degradation Rate ». Dans International Students Science Congress. Izmir International Guest Student Association, 2021. http://dx.doi.org/10.52460/issc.2021.044.

Texte intégral
Résumé :
TiO2 is one of the most common materials for photocatalytic applications due to its stability, affordability, and photoactive efficiency. However, it has some drawbacks, such as limited solar radiation response and quick recombination of excitons. Using graphene could be one of the methods to enhance the photocatalytic properties of TiO2. This study intends to optimize the photocatalytic performance of TiO2/Graphene (TiO2/G) nanocomposite by using neuro-regression analysis. In the analysis, the effect of some hydrothermal synthesis parameters, namely, amount of graphene oxide, ethanol/water ratio, and hydrothermal reaction time on the photocatalytic activity of TiO2/G nanocomposite, have been investigated. The parameters were determined from a literature study focused on overcoming the drawbacks of TiO2 by combining it with graphene oxide. Nelder-Mead, Simulated Annealing, Differential Evolution, and Random Search algorithms are used to obtain the optimum synthesis parameters for maximum photocatalytic activity in the optimization process. The results are indicated that all algorithms give the realizable value for design variables and photodegradation rate.
Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Search and recombination"

1

Pawlowski, Wojtek P., et Avraham A. Levy. What shapes the crossover landscape in maize and wheat and how can we modify it. United States Department of Agriculture, janvier 2015. http://dx.doi.org/10.32747/2015.7600025.bard.

Texte intégral
Résumé :
Meiotic recombination is a process in which homologous chromosomes engage in the exchange of DNA segments, creating gametes with new genetic makeup and progeny with new traits. The genetic diversity generated in this way is the main engine of crop improvement in sexually reproducing plants. Understanding regulation of this process, particularly the regulation of the rate and location of recombination events, and devising ways of modifying them, was the major motivation of this project. The project was carried out in maize and wheat, two leading crops, in which any advance in the breeder’s toolbox can have a huge impact on food production. Preliminary work done in the USA and Israeli labs had established a strong basis to address these questions. The USA lab pioneered the ability to map sites where recombination is initiated via the induction of double-strand breaks in chromosomal DNA. It has a long experience in cytological analysis of meiosis. The Israeli lab has expertise in high resolution mapping of crossover sites and has done pioneering work on the importance of epigenetic modifications for crossover distribution. It has identified genes that limit the rates of recombination. Our working hypothesis was that an integrative analysis of double-strand breaks, crossovers, and epigenetic data will increase our understanding of how meiotic recombination is regulated and will enhance our ability to manipulate it. The specific objectives of the project were: To analyze the connection between double-strand breaks, crossover, and epigenetic marks in maize and wheat. Protocols developed for double-strand breaks mapping in maize were applied to wheat. A detailed analysis of existing and new data in maize was conducted to map crossovers at high resolution and search for DNA sequence motifs underlying crossover hotspots. Epigenetic modifications along maize chromosomes were analyzed as well. Finally, a computational analysis tested various hypotheses on the importance of chromatin structure and specific epigenetic modifications in determining the locations of double-strand breaks and crossovers along chromosomes. Transient knockdowns of meiotic genes that suppress homologous recombination were carried out in wheat using Virus-Induced Gene Silencing. The target genes were orthologs of FANCM, DDM1, MET1, RECQ4, and XRCC2.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Wilson, Thomas E., Avraham A. Levy et Tzvi Tzfira. Controlling Early Stages of DNA Repair for Gene-targeting Enhancement in Plants. United States Department of Agriculture, mars 2012. http://dx.doi.org/10.32747/2012.7697124.bard.

Texte intégral
Résumé :
Gene targeting (GT) is a much needed technology as a tool for plant research and for the precise engineering of crop species. Recent advances in this field have shown that the presence of a DNA double-strand break (DSB) in a genomic locus is critical for the integration of an exogenous DNA molecule introduced into this locus. This integration can occur via either non-homologous end joining (NHEJ) into the break or homologous recombination (HR) between the broken genomic DNA and the introduced vector. A bottleneck for DNA integration via HR is the machinery responsible for homology search and strand invasion. Important proteins in this pathway are Rad51, Rad52 and Rad54. We proposed to combine our respective expertise: on the US side, in the design of zincfinger nucleases (ZFNs) for the induction of DNA DSBs at any desired genomic locus and in the integration of DNA molecules via NHEJ; and on the Israeli side in the HR events, downstream of the DSB, that lead to homology search and strand invasion. We sought to test three major pathways of targeted DNA integration: (i) integration by NHEJ into DSBs induced at desired sites by specially designed ZFNs; (ii) integration into DSBs induced at desired sites combined with the use of Rad51, Rad52 and Rad54 proteins to maximize the chances for efficient and precise HR-mediated vector insertion; (iii) stimulation of HR by Rad51, Rad52 and Rad54 in the absence of DSB induction. We also proposed to study the formation of dsT-DNA molecules during the transformation of plant cells. dsT-DNA molecules are an important substrate for HR and NHEJ-mediatedGT, yet the mode of their formation from single stranded T-DNA molecules is still obscure. In addition we sought to develop a system for assembly of multi-transgene binary vectors by using ZFNs. The latter may facilitate the production of binary vectors that may be ready for genome editing in transgenic plants. ZFNs were proposed for the induction of DSBs in genomic targets, namely, the FtsH2 gene whose loss of function can easily be identified in somatic tissues as white sectors, and the Cruciferin locus whose targeting by a GFP or RFP reporter vectors can give rise to fluorescent seeds. ZFNs were also proposed for the induction of DSBs in artificial targets and for assembly of multi-gene vectors. We finally sought to address two important cell types in terms of relevance to plant transformation, namely GT of germinal (egg) cells by floral dipping, and GT in somatic cells by root and leave transformation. To be successful, we made use of novel optimized expression cassettes that enable coexpression of all of the genes of interest (ZFNs and Rad genes) in the right tissues (egg or root cells) at the right time, namely when the GT vector is delivered into the cells. Methods were proposed for investigating the complementation of T-strands to dsDNA molecules in living plant cells. During the course of this research, we (i) designed, assembled and tested, in vitro, a pair of new ZFNs capable of targeting the Cruciferin gene, (ii) produced transgenic plants which expresses for ZFN monomers for targeting of the FtsH2 gene. Expression of these enzymes is controlled by constitutive or heat shock induced promoters, (iii) produced a large population of transgenic Arabidopsis lines in which mutated mGUS gene was incorporated into different genomic locations, (iv) designed a system for egg-cell-specific expression of ZFNs and RAD genes and initiate GT experiments, (v) demonstrated that we can achieve NHEJ-mediated gene replacement in plant cells (vi) developed a system for ZFN and homing endonuclease-mediated assembly of multigene plant transformation vectors and (vii) explored the mechanism of dsTDNA formation in plant cells. This work has substantially advanced our understanding of the mechanisms of DNA integration into plants and furthered the development of important new tools for GT in plants.
Styles APA, Harvard, Vancouver, ISO, etc.
Vous pouvez également être intéressé par les bibliographies sur le sujet « Search and recombination » pour d’autres types de sources :
Articles de revues
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie