121 research outputs found

    Simultaneous localization of MLL, AF4 and ENL genes in interphase nuclei by 3D-FISH: MLL translocation revisited

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    BACKGROUND: Haematological cancer is characterised by chromosomal translocation (e.g. MLL translocation in acute leukaemia) and two models have been proposed to explain the origins of recurrent reciprocal translocation. The first, established from pairs of translocated genes (such as BCR and ABL), considers the spatial proximity of loci in interphase nuclei (static "contact first" model). The second model is based on the dynamics of double strand break ends during repair processes (dynamic "breakage first" model). Since the MLL gene involved in 11q23 translocation has more than 40 partners, the study of the relative positions of the MLL gene with both the most frequent partner gene (AF4) and a less frequent partner gene (ENL), should elucidate the MLL translocation mechanism. METHODS: Using triple labeling 3D FISH experiments, we have determined the relative positions of MLL, AF4 and ENL genes, in two lymphoblastic and two myeloid human cell lines. RESULTS: In all cell lines, the ENL gene is significantly closer to the MLL gene than the AF4 gene (with P value < 0.0001). According to the static "contact first" model of the translocation mechanism, a minimal distance between loci would indicate a greater probability of the occurrence of t(11;19)(q23;p13.3) compared to t(4;11)(q21;q23). However this is in contradiction to the epidemiology of 11q23 translocation. CONCLUSION: The simultaneous multi-probe hybridization in 3D-FISH is a new approach in addressing the correlation between spatial proximity and occurrence of translocation. Our observations are not consistent with the static "contact first" model of translocation. The recently proposed dynamic "breakage first" model offers an attractive alternative explanation

    Caracterización morfoagronómica in situ de cacao criollo (Theobroma cacao L.) en lugares de prevalencia natural y su incidencia en la selección de germoplasma promisorio

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    Con el objetivo de identificar árboles de cacao criollo con alto potencial genético, se inició una búsqueda sistemática de germoplasma de cacao in situ entre los meses de abril de 2017 y julio de 2018, para tal fin se efectuaron giras de prospección y colecta en lugares de prevalencia natural de la especie, en diversas localidades de El Salvador, realizando caracterización morfoagronómica de 47 árboles de cacao localizados en los municipios de San Luis Talpa y San Pedro Nonualco, La Paz; Arcatao, Chalatenango; Tenancingo, Cuscatlán y Ciudad Delgado, San Salvador. Se analizaron atributos cualitativos y cuantitativos de cada árbol y de sus segmentos: hojas, flores, frutos, y semillas. Para la caracterización se utilizaron descriptores morfoagronómicos propuestos por la Cocoa Research Centre at the University of West Indies (Trinidad y Tobago), el Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias (INIFAP) y el Instituto Nacional de Investigaciones Agrícolas (INIA). La interpretación de datos se hizo a través de estadística simple y análisis multivariado utilizando el programa IBM SPSS® Statistics Software V.23. El análisis de componentes principales generó 11 conglomerados que reunieron características de 27 árboles. Se encontraron 10 árboles de cacao con características del tipo “criollo de aroma fino”, con frutos con formas angoleta y cundeamor, el 100% de semillas de color blanco y contenidos de grasa menores al 50%. También sobresalieron cuatro árboles con contenidos mayores al 50% de grasa en las semillas, estas características encontradas demuestran que dichos árboles deberían incluirse en programas de producción, alimentación humana y mejoramiento genético. Finalmente se elaboró un catálogo de los árboles caracterizados con semillas de almendra blanca y los clones denominados Santa Clara

    Rescate de patashte (Theobroma bicolor Humb & Bonpl.) y cushta (Theobroma angustifolium) dos especies promisorias en peligro de extinción en El Salvador

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    En El Salvador existen especies vegetales como el patashte (Theobroma bicolor) y la cushta (Theobroma angustifolium) parientes silvestres del cacao, con alto potencial nutritivo para la alimentación y como materia prima para la agroindustria y el desarrollo de productos como chocolate, atoles, snack, entre otros, no obstante, estas especies están en peligro de extinción, por lo que no se cuenta con mucha información técnica. Por tal motivo se realizaron giras de colecta de estas especies, en municipios, con tradición en la producción de cacao a fin de incluir ambas especies en los bancos de germoplasma de cacao que se establecieron como parte del proyecto de rescate de recursos genéticos de cacao. Sin embargo, la situación de ambas especies es crítica por el alto grado de erosión genética, ya que, solamente se lograron obtener muestras de frutos en el cantón Cangrejera, Izalco, Sonsonate. Estas muestras se llevaron al Laboratorio de Química Agrícola de la Facultad de Ciencias Agronómicas de La Universidad de El Salvador (UES), a fin de realizar análisis bromatológicos y conocer de manera preliminar su composición química. Asimismo, desarrollar viveros con ambas especies para siembra en las colecciones de la UES. Como resultado se encontraron concentraciones para patashte y cushta de 16.04 y 4.48% de proteína; de 33.81 y 23.93% de grasa; 35.02 y 44.75% de carbohidratos respectivamente. Por otra parte se establecieron plantas de patashte y cushta en el banco de germoplasma del campus universitario, Estación Experimental y de Prácticas (EEP), San Pedro Nonualco y La cooperativa Hacienda Santa Clara, procurando contribuir al rescate de las mismas. Se concluye que ambas especies tienen potencial para consumo directo con preparaciones artesanales y materia prima para elaboración de muchos productos alimenticios nutritivos, e incluirlos en programas de Seguridad Alimentaria y Nutricional (SAN), por lo que es importante y urgente, proponer y ejecutar estrategias de conservación in situ y ex situ

    Global Metabolomic Profiling of Acute Myocarditis Caused by Trypanosoma cruzi Infection

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    © 2014 Gironès et al. Chagas disease is caused by Trypanosoma cruzi infection, being cardiomyopathy the more frequent manifestation. New chemotherapeutic drugs are needed but there are no good biomarkers for monitoring treatment efficacy. There is growing evidence linking immune response and metabolism in inflammatory processes and specifically in Chagas disease. Thus, some metabolites are able to enhance and/or inhibit the immune response. Metabolite levels found in the host during an ongoing infection could provide valuable information on the pathogenesis and/or identify deregulated metabolic pathway that can be potential candidates for treatment and being potential specific biomarkers of the disease. To gain more insight into those aspects in Chagas disease, we performed an unprecedented metabolomic analysis in heart and plasma of mice infected with T. cruzi. Many metabolic pathways were profoundly affected by T. cruzi infection, such as glucose uptake, sorbitol pathway, fatty acid and phospholipid synthesis that were increased in heart tissue but decreased in plasma. Tricarboxylic acid cycle was decreased in heart tissue and plasma whereas reactive oxygen species production and uric acid formation were also deeply increased in infected hearts suggesting a stressful condition in the heart. While specific metabolites allantoin, kynurenine and p-cresol sulfate, resulting from nucleotide, tryptophan and phenylalanine/tyrosine metabolism, respectively, were increased in heart tissue and also in plasma. These results provide new valuable information on the pathogenesis of acute Chagas disease, unravel several new metabolic pathways susceptible of clinical management and identify metabolites useful as potential specific biomarkers for monitoring treatment and clinical severity in patients.This work was supported by ‘‘Ministerio de Ciencia e Innovación’’ (SAF2010-17833); ‘‘Fondo de Investigaciones Sanitarias’’ (PS09/00538 and PI12/00289); ‘‘Red de Investigación de Centros de Enfermedades Tropicales’’ (RICET RD12/0018/0004); European Union (HEALTH-FE-2008-22303, ChagasEpiNet);‘‘Universidad Autónoma de Madrid’’ and ‘‘Comunidad de Madrid’’ (CC08-UAM/SAL-4440/08); AECID Cooperation with Argentine (A/025417/09 and A/031735/10), Comunidad de Madrid (S-2010/BMD-2332) and ‘‘Fundación Ramón Areces’Peer Reviewe

    Diversidad de artrópodos y sus enemigos naturales asociados al café (Coffea arabica L.) en El Salvador

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    El presente libro pretende dar un aporte en tal sentido, ofreciendo al lector una muestra de la diversidad de fauna invertebrada que se pueden encontrar en los cafetales bajo variados niveles de tecnificación y que en la mayoría de casos se ha logrado comprobar su cría a expensas del cultivo. Sin duda alguna que el esfuerzo no es del todo exhaustivo ya que existe mucha más diversidad por descubrir; pero es una muestra representativa del reto que representa el estudio de la fauna de artrópodos de este cultivo. En consecuencia se espera que motive al lector y a otros interesados en la temática, para profundizar en estos estudios de los cafetales y aumentar así el conocimiento de la entomología nacional. Por tanto, el presente libro ilustra los insectos, arañas y caracoles que están en poblaciones no dañinas que comprende 60 fotografías de arañas depredadoras y 350 fotografías de insectos entre fitófagos y benéficos (depredadores y parasitoides), con más de 200 especies de artrópodos asociados a los cafetales de El Salvador

    Life-Cycle and Genome of OtV5, a Large DNA Virus of the Pelagic Marine Unicellular Green Alga Ostreococcus tauri

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    Large DNA viruses are ubiquitous, infecting diverse organisms ranging from algae to man, and have probably evolved from an ancient common ancestor. In aquatic environments, such algal viruses control blooms and shape the evolution of biodiversity in phytoplankton, but little is known about their biological functions. We show that Ostreococcus tauri, the smallest known marine photosynthetic eukaryote, whose genome is completely characterized, is a host for large DNA viruses, and present an analysis of the life-cycle and 186,234 bp long linear genome of OtV5. OtV5 is a lytic phycodnavirus which unexpectedly does not degrade its host chromosomes before the host cell bursts. Analysis of its complete genome sequence confirmed that it lacks expected site-specific endonucleases, and revealed the presence of 16 genes whose predicted functions are novel to this group of viruses. OtV5 carries at least one predicted gene whose protein closely resembles its host counterpart and several other host-like sequences, suggesting that horizontal gene transfers between host and viral genomes may occur frequently on an evolutionary scale. Fifty seven percent of the 268 predicted proteins present no similarities with any known protein in Genbank, underlining the wealth of undiscovered biological diversity present in oceanic viruses, which are estimated to harbour 200Mt of carbon

    Analyzing factors that influence the folk use and phytonomy of 18 medicinal plants in Navarra

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    BACKGROUND: This article analyzes whether the distribution or area of use of 18 medicinal plants is influenced by ecological and cultural factors which might account for their traditional use and/or phytonymy in Navarra. This discussion may be helpful for comparative studies, touching as it does on other ethnopharmacological issues: a) which cultural and ecological factors affect the selection of medicinal plants; b) substitutions of medicinal plants in popular medicine; c) the relation between local nomenclature and uses. To analyze these questions, this paper presents an example of a species used for digestive disorders (tea and camomile: Jasonia glutinosa, J. tuberosa, Sideritis hyssopifolia, Bidens aurea, Chamaemelum nobile, Santolina chamaecyparissus...), high blood pressure (Rhamnus alaternus, Olea europaea...) or skin diseases (Hylotelephium maximum, H. telephium, Anagallis arvensis, A. foemina). METHODS: Fieldwork began on January 2004 and continued until December 2006. During that time we interviewed 505 informants in 218 locations in Navarra. Information was collected using semi-structured ethnobotanical interviews, and we subsequently made maps using Arc-View 8.0 program to determine the area of use of each taxon. Each map was then compared with the bioclimatic and linguistic map of Navarra, using the soil and ethnographic data for the region, and with other ethnobotanical and ethnopharmacological studies carried out in Europe. RESULTS: The results clearly show that ecological and cultural factors influence the selection of medicinal plants in this region. Climate and substrate are the most important ecological factors that influence the distribution and abundance of plants, which are the biological factors that affect medicinal plant selection. CONCLUSION: The study of edaphological and climatological factors, on the one hand, and culture, on the other, can help us to understand why a plant is replaced by another one for the same purposes, either in the same or in a different area. In many cases, the cultural factor means that the use of a species is more widespread than its ecological distribution. This may also explain the presence of synonyms and polysemies which are useful for discussing ethnopharmacological data

    SnTox3 Acts in Effector Triggered Susceptibility to Induce Disease on Wheat Carrying the Snn3 Gene

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    The necrotrophic fungus Stagonospora nodorum produces multiple proteinaceous host-selective toxins (HSTs) which act in effector triggered susceptibility. Here, we report the molecular cloning and functional characterization of the SnTox3-encoding gene, designated SnTox3, as well as the initial characterization of the SnTox3 protein. SnTox3 is a 693 bp intron-free gene with little obvious homology to other known genes. The predicted immature SnTox3 protein is 25.8 kDa in size. A 20 amino acid signal sequence as well as a possible pro sequence are predicted. Six cysteine residues are predicted to form disulfide bonds and are shown to be important for SnTox3 activity. Using heterologous expression in Pichia pastoris and transformation into an avirulent S. nodorum isolate, we show that SnTox3 encodes the SnTox3 protein and that SnTox3 interacts with the wheat susceptibility gene Snn3. In addition, the avirulent S. nodorum isolate transformed with SnTox3 was virulent on host lines expressing the Snn3 gene. SnTox3-disrupted mutants were deficient in the production of SnTox3 and avirulent on the Snn3 differential wheat line BG220. An analysis of genetic diversity revealed that SnTox3 is present in 60.1% of a worldwide collection of 923 isolates and occurs as eleven nucleotide haplotypes resulting in four amino acid haplotypes. The cloning of SnTox3 provides a fundamental tool for the investigation of the S. nodorum–wheat interaction, as well as vital information for the general characterization of necrotroph–plant interactions

    Finding a Needle in the Virus Metagenome Haystack - Micro-Metagenome Analysis Captures a Snapshot of the Diversity of a Bacteriophage Armoire

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    Viruses are ubiquitous in the oceans and critical components of marine microbial communities, regulating nutrient transfer to higher trophic levels or to the dissolved organic pool through lysis of host cells. Hydrothermal vent systems are oases of biological activity in the deep oceans, for which knowledge of biodiversity and its impact on global ocean biogeochemical cycling is still in its infancy. In order to gain biological insight into viral communities present in hydrothermal vent systems, we developed a method based on deep-sequencing of pulsed field gel electrophoretic bands representing key viral fractions present in seawater within and surrounding a hydrothermal plume derived from Loki's Castle vent field at the Arctic Mid-Ocean Ridge. The reduction in virus community complexity afforded by this novel approach enabled the near-complete reconstruction of a lambda-like phage genome from the virus fraction of the plume. Phylogenetic examination of distinct gene regions in this lambdoid phage genome unveiled diversity at loci encoding superinfection exclusion- and integrase-like proteins. This suggests the importance of fine-tuning lyosgenic conversion as a viral survival strategy, and provides insights into the nature of host-virus and virus-virus interactions, within hydrothermal plumes. By reducing the complexity of the viral community through targeted sequencing of prominent dsDNA viral fractions, this method has selectively mimicked virus dominance approaching that hitherto achieved only through culturing, thus enabling bioinformatic analysis to locate a lambdoid viral “needle" within the greater viral community “haystack". Such targeted analyses have great potential for accelerating the extraction of biological knowledge from diverse and poorly understood environmental viral communities

    Linear and Branched Glyco-Lipopeptide Vaccines Follow Distinct Cross-Presentation Pathways and Generate Different Magnitudes of Antitumor Immunity

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    Glyco-lipopeptides, a form of lipid-tailed glyco-peptide, are currently under intense investigation as B- and T-cell based vaccine immunotherapy for many cancers. However, the cellular and molecular mechanisms of glyco-lipopeptides (GLPs) immunogenicity and the position of the lipid moiety on immunogenicity and protective efficacy of GLPs remain to be determined.We have constructed two structural analogues of HER-2 glyco-lipopeptide (HER-GLP) by synthesizing a chimeric peptide made of one universal CD4(+) epitope (PADRE) and one HER-2 CD8(+) T-cell epitope (HER(420-429)). The C-terminal end of the resulting CD4-CD8 chimeric peptide was coupled to a tumor carbohydrate B-cell epitope, based on a regioselectively addressable functionalized templates (RAFT), made of four alpha-GalNAc molecules. The resulting HER glyco-peptide (HER-GP) was then linked to a palmitic acid moiety, attached either at the N-terminal end (linear HER-GLP-1) or in the middle between the CD4+ and CD8+ T cell epitopes (branched HER-GLP-2). We have investigated the uptake, processing and cross-presentation pathways of the two HER-GLP vaccine constructs, and assessed whether the position of linkage of the lipid moiety would affect the B- and T-cell immunogenicity and protective efficacy. Immunization of mice revealed that the linear HER-GLP-1 induced a stronger and longer lasting HER(420-429)-specific IFN-gamma producing CD8(+) T cell response, while the branched HER-GLP-2 induced a stronger tumor-specific IgG response. The linear HER-GLP-1 was taken up easily by dendritic cells (DCs), induced stronger DCs maturation and produced a potent TLR- 2-dependent T-cell activation. The linear and branched HER-GLP molecules appeared to follow two different cross-presentation pathways. While regression of established tumors was induced by both linear HER-GLP-1 and branched HER-GLP-2, the inhibition of tumor growth was significantly higher in HER-GLP-1 immunized mice (p<0.005).These findings have important implications for the development of effective GLP based immunotherapeutic strategies against cancers
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