Discerning the relationship between geminiviral infection and vesicle trafficking using virus induced gene silencing

Tomato yellow leaf curl disease is one of the most important threats to tomato crops worldwide. One of its causal agents, Tomato yellow leaf curl Sardinian virus (TYLCSV) is a monopartite member of the genus Begomovirus from the family Geminiviridae. Due to the few proteins encoded by their viral genome, geminiviruses rely heavily on host cellular machineries and interact with a wide range of plant proteins to complete all processes required for infection, such as viral replication, movement and suppression or evasion of plant defence mechanisms. The identification of the host proteins involved in viral infection will be an important step towards the understanding of the mechanisms underlying this process. In our laboratory, transgenic Nicotiana benthamiana plants containing a green fluorescent protein (GFP) expression cassette flanked by two direct repeats of the intergenic region of TYLCSV have been constructed (2IR plants). When these plants are infected with TYLCSV, an overexpression of the reporter gene is observed in those cells where the virus is actively replicating. These plants have been used together with virus induced gene silencing (VIGS) in an effort to identify host genes involved in the infection process using a reverse genetics approach. Using this combined technique our group has identified two genes δ-COP and ARF 1, involved in retrograde vesicle trafficking, which are essential for the infectious process. We are currently assaying genes codifying proteins involved in different pathways of the vesicle trafficking system: Sar1b, γ subunit of AP1, Sec24, SYT1 and two that encode the heavy chain of triskelion proteins. Their effect over viral infection will be presented and discussedUniversidad de Málaga. Campues de Excelencia Internacional Andalucía Tech

Identifying the function of vesicle trafficking in geminiviral infection using virus induced gene silencing

Tomato yellow leaf curl Sardinian virus (TYLCSV) is one of the causal agent of the tomato yel-low leaf curl disease, one of the most important threats to tomato crops worldwide. TYLCSV is a monopartite member of the genus Begomovirus from the family Geminiviridae. To carry out a full infection, geminiviruses need to move inside the infected cell and from one cell to an-other for which they depend on diverse cellular factors. While cell-to-cell movement has been described to occur through plasmodesmata, the way in which geminiviruses move inside the host cells is yet unknown. The identification of the host proteins involved in viral infection will be an important step to-wards the understanding of the mechanisms underlying this process. In our laboratory, trans-genic Nicotianabenthamiana plants containing a green fluorescent protein (GFP) expression cassette flanked by two direct repeats of the intergenic region of TYLCSV have been construct-ed (2IR plants). When these plants are infected with TYLCSV, an overexpression of the reporter gene is observed in those cells where the virus replicates. These plants have been used to-gether with virus induced gene silencing (VIGS) in an effort to identify host genes involved in the infection process using a reverse genetics approach. Using this combined technique our group has identified two genes δ-COP and ARF 1, involved in retrograde vesicle trafficking, which are essential for the infectious process. We are current-ly assaying genes codifying proteins involved in different pathways of the vesicle trafficking system: Sar1b, γ subunit of AP1, Sec24, SYT1 and two that encode the heavy chain of triskelion proteins. Their effect over virus infection will be presented and discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Motor eléctrico: una experiencia en el aula

PDF de 8 páginas con gráficos y figuras a color. Pepe Lozano es maestro del CEIP Talhara en Benacazón. María Acosta Bono es maestra del CEIP Clara Campoamor en Bormujos. Mercedes Díaz Fuentes es maestra del EEI Mª Carmen Gutiérrez en Espartinas. Esteban Moreno Gómez es director de los recursos WEB del programa El CSIC en la Escuela.Presentamos un proyecto, desarrollado en el curso escolar 2013-14, que supuso el trabajo en el aula de conceptos relacionados con el electromagnetismo introducidos de manera experimental. El objetivo de este proyecto era que los alumnos y las alumnas realizasen un recorrido por la historia de esta ciencia para que llegaran a comprender, en último término, el desarrollo y funcionamiento del motor eléctrico. El proyecto tenía como objetivo que el alumnado realizase un recorrido por la historia de esta ciencia con el fin de llegar a comprender, en último término, el desarrollo y funcionamiento del motor eléctrico. En la experiencia participaron niños/as de distintas edades y ciclos educativos y de distintos centros; lo que implicó un trabajo de coordinación entre los distintos docentes. Una representación del alumnado participante presentó los resultados de sus investigaciones en el V Encuentro Científico entre Niños, Maestros e Investigadores celebrado el 27 de mayo de 2014.Peer reviewe

Importance of vesicle trafficking in the establichsment of a geminiviral infection

Importance of vesicle trafficking in the establishment of a geminiviral infection P. CANA-QUIJADA1, T. ROSAS-DÍAZ2, LOZANO-DURÁN R. 2 AND E.R. BEJARANO1 1Dpto. Biología Celular, Genética y Fisiología. Área de Genética Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain E-mail: [email protected] 2. Shanghai Center for Plant Stress Biology (PSC), Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China. INTRODUCTION Geminiviruses produces some of the most devastating diseases for agriculture worldwide. Geminiviral genomes encode only 5 to 7 proteins, forcing them to rely heavily on host cellular machineries and to interact with a high amount of host proteins in order to complete a full infection. The identification of the host proteins involved in viral infection will be an important step towards the understanding of the mechanisms underlying this process and develop new strategies to generate new sources of resistance. Previous efforts from our group have identified several genes involved in vesicle trafficking. OBJECTIVES The main aim of this work is to elucidate the role of the plant cell’s vesicle trafficking in a geminiviral infection. MATHERIALS AND METHODS Transgenic Nicotiana benthamiana plants containing a green fluorescent protein (GFP) expression cassette flanked by two direct repeats of the intergenic region of TYLCSV have been constructed (2IR plants). When these plants are infected with TYLCSV, an overexpression of the reporter gene is observed in those cells where the virus is actively replicating. 2IR plants were used in combination with virus induced gene silencing (VIGS), to identify vesicle trafficking genes involved in the infectious process. Viral replication was monitorized by GFP expression. Viral accumulation was determined using qPCR. RESULTS When silenced, four of the assessed genes reduced dramatically the viral amounts or completely abolished the infection. On the other hand, three of them had no significant effect over the infection and one of them seems to cause a slight increase in viral accumulation. CONCLUSIONS The vesicle trafficking machinery plays an essential role in geminivirus infection. Assays to determine whether the described effect is due to a lack of replication or movement of the virus inside the plant cells are in progress.Universidad de Málaga. Campues de Excelencia Internacional Andalucía Tech

NAHG increases transient transformation of arabidopsis leaves by agrobacterium

Agrobacterium tumefaciens-mediated transient transformation has demonstrated to be an invaluable tool in plant molecular biology studies. However, low efficiency and inconsistency of this method in Arabidopsis has forced the implementation of Nicotiana benthamiana as a surrogate system, limiting applicability. One of the main reasons to underlie the recalcitrance of Arabidopsis to Agrobacterium-mediated transformation is the activation of plant immune responses upon perception of the bacteria. Perception of bacterial pathogen-associated molecular patterns (PAMPs), including EF-Tu, leads to activation of PAMP-triggered immunity (PTI). Activation of PTI ultimately induces salicylic acid (SA) accumulation, which in turn shuts down expression of the vir genes, potentially interfering with the transfer of the T-DNA, and therefore T-DNA gene expression (Yuan et al., 2007; Anand et al., 2008). However, previous results suggested that besides depletion of SA other hormone-mediated defence responses, including jasmonic acid (JA), might be responsible for the low efficiency of transient transformation in Arabidopsis (Tsuda et al., 2012). In this work, we evaluate the efficiency of Agrobacterium-mediated transient transformation in Arabidopsis genotypes affected in JA perception or signalling (coi1, jin1), or with low SA or JA content (sid2, NahG, aos). The results show that impairment of JA signalling reduces or does not affect transient expression in mature leaves, but expression of the NahG transgene dramatically improves this process. We demonstrate that Arabidopsis NahG plants can be efficiently used for transient expression-based functional assays routinely performed in N. benthamiana, such as determination of subcellular localization of GFP-fused proteins or analysis of protein-protein interactions by Bimolecular Fluorescent Complementation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Inverse Probability Weighted Estimating Equations for Randomized Trials in Transfusion Medicine

This is the peer reviewed version of the following article: Cook, R. J., Lee, K.-A., Cuerden, M. and Cotton, C. A. (2013), Inverse probability weighted estimating equations for randomized trials in transfusion medicine. Statist. Med., 32: 4380–4399. doi:10.1002/sim.5827, which has been published in final form at http://dx.doi.org/10.1002/sim.5827. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.Thrombocytopenia is a condition characterized by extremely low platelet counts, which puts patients at elevated risk of morbidity and mortality because of bleeding. Trials in transfusion medicine are routinely designed to assess the effect of experimental platelet products on patients platelet counts. In such trials, patients may receive multiple platelet transfusions over a predefined period of treatment, and a response is available from each such administration. The resulting data comprised multiple responses per patient, and although it is natural to want to use this data in testing for treatment effects, naive analyses of the multiple responses can yield biased estimates of the probability of response and associated treatment effects. These biases arise because only subsets of the patients randomized contribute response data on the second and subsequent administrations of therapy and the balance between treatment groups with respect to potential confounding factors is lost. We discuss the design and analysis issues involved in this setting and make recommendations for the design of future platelet transfusion trials.Natural Sciences and Engineering Research Council of Canada (RJC RGPIN 155849, CAC RGPIN 402474); Canadian Institutes for Health Research (FRN 13887); Canada Research Chair (Tier 1) – CIHR funded (950-226626

Operations of and Future Plans for the Pierre Auger Observatory

Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200

Highlights from the Pierre Auger Observatory

The Pierre Auger Observatory is the world's largest cosmic ray observatory. Our current exposure reaches nearly 40,000 km$^2$ str and provides us with an unprecedented quality data set. The performance and stability of the detectors and their enhancements are described. Data analyses have led to a number of major breakthroughs. Among these we discuss the energy spectrum and the searches for large-scale anisotropies. We present analyses of our X$_{max}$ data and show how it can be interpreted in terms of mass composition. We also describe some new analyses that extract mass sensitive parameters from the 100% duty cycle SD data. A coherent interpretation of all these recent results opens new directions. The consequences regarding the cosmic ray composition and the properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray Conference, Rio de Janeiro 201

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201