110 research outputs found

    Analysis by RNA-seq of transcriptomic changes elicited by heat shock in Leishmania major

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    Besides their medical relevance, Leishmania is an adequate model for studying post-transcriptional mechanisms of gene expression. In this microorganism, mRNA degradation/stabilization mechanisms together with translational control and post-translational modifications of proteins are the major drivers of gene expression. Leishmania parasites develop as promastigotes in sandflies and as amastigotes in mammalians, and during host transmission, the parasite experiences a sudden temperature increase. Here, changes in the transcriptome of Leishmania major promastigotes after a moderate heat shock were analysed by RNA-seq. Several of the up-regulated transcripts code for heat shock proteins, other for proteins previously reported to be amastigote-specific and many for hypothetical proteins. Many of the transcripts experiencing a decrease in their steady-state levels code for transporters, proteins involved in RNA metabolism or translational factors. In addition, putative long noncoding RNAs were identified among the differentially expressed transcripts. Finally, temperature-dependent changes in the selection of the spliced leader addition sites were inferred from the RNA-seq data, and particular cases were further validated by RT-PCR and Northern blotting. This study provides new insights into the post-transcriptional mechanisms by which Leishmania modulate gene expressionThis work was supported by grants (to B.A. and J.M.R.) from Ministerio de Economía, Industria y Competitividad, project number SAF2017-86965-R (co-funded with FEDER funds), and by the Network of Tropical Diseases Research RICET (RD16/0027/0008), co-funded with FEDER funds. The CBMSO receives institutional grants from the Fundación Ramón Areces and from the Fundación Banco de Santande

    Liwe Española SA: Valoración de la empresa con modelo de negociación Fixing

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    El objetivo del presente trabajo es valorar, por medio de diferentes métodos, la empresa Liwe Española, perteneciente al sector textil. Es importante recalcar que hay una gran diferencia entre el valor de una empresa y su precio. Por un lado, el precio es la cantidad monetaria a la que se pacta la venta. Por otro lado, el valor de un mismo bien (en este caso, una empresa) puede discrepar entre diferentes individuos

    Regulation of expression of two LY-6 family genes by intron retention and transcription induced chimerism.

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    RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Regulation of the expression of particular genes can rely on mechanisms that are different from classical transcriptional and translational control. The LY6G5B and LY6G6D genes encode LY-6 domain proteins, whose expression seems to be regulated in an original fashion, consisting of an intron retention event which generates, through an early premature stop codon, a non-coding transcript, preventing expression in most cell lines and tissues. RESULTS: The MHC LY-6 non-coding transcripts have shown to be stable and very abundant in the cell, and not subject to Nonsense Mediated Decay (NMD). This retention event appears not to be solely dependent on intron features, because in the case of LY6G5B, when the intron is inserted in the artificial context of a luciferase expression plasmid, it is fully spliced but strongly stabilises the resulting luciferase transcript. In addition, by quantitative PCR we found that the retained and spliced forms are differentially expressed in tissues indicating an active regulation of the non-coding transcript. EST database analysis revealed that these genes have an alternative expression pathway with the formation of Transcription Induced Chimeras (TIC). This data was confirmed by RT-PCR, revealing the presence of different transcripts that would encode the chimeric proteins CSNKbeta-LY6G5B and G6F-LY6G6D, in which the LY-6 domain would join to a kinase domain and an Ig-like domain, respectively. CONCLUSION: In conclusion, the LY6G5B and LY6G6D intron-retained transcripts are not subjected to NMD and are more abundant than the properly spliced forms. In addition, these genes form chimeric transcripts with their neighbouring same orientation 5' genes. Of interest is the fact that the 5' genes (CSNKbeta or G6F) undergo differential splicing only in the context of the chimera (CSNKbeta-LY6G5B or G6F-LY6G6C) and not on their own

    The Astonishing Large Family of HSP40/DnaJ Proteins Existing in Leishmania

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    Abrupt environmental changes are faced by Leishmania parasites during transmission from a poikilothermic insect vector to a warm-blooded host. Adaptation to harsh environmental conditions, such as nutrient deprivation, hypoxia, oxidative stress and heat shock needs to be accomplished by rapid reconfiguration of gene expression and remodeling of protein interaction networks. Chaperones play a central role in the maintenance of cellular homeostasis, and they are responsible for crucial tasks such as correct folding of nascent proteins, protein translocation across different subcellular compartments, avoiding protein aggregates and elimination of damaged proteins. Nearly one percent of the gene content in the Leishmania genome corresponds to members of the HSP40 family, a group of proteins that assist HSP70s in a variety of cellular functions. Despite their expected relevance in the parasite biology and infectivity, little is known about their functions or partnership with the different Leishmania HSP70s. Here, we summarize the structural features of the 72 HSP40 proteins encoded in the Leishmania infantum genome and their classification into four categories. A review of proteomic data, together with orthology analyses, allow us to postulate cellular locations and possible functional roles for some of them. A detailed study of the members of this family would provide valuable information and opportunities for drug discovery and improvement of current treatments against leishmaniasis.This research was supported by the Spanish Ministerio de Ciencia, Innovación (MICINN), Agencia Estatal de Investigación (AEI), grant number PID2020-117916RB-I00, and Instituto de Salud Carlos III, grant CB21/13/00018 (CIBERINFEC). An institutional grant from Fundacion Ramon Areces is also acknowledged.S

    Leishmania mitochondrial genomes: Maxicircle structure and heterogeneity of minicircles

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    The mitochondrial DNA (mtDNA), which is present in almost all eukaryotic organisms, is a useful marker for phylogenetic studies due to its relative high conservation and its inheritance manner. In Leishmania and other trypanosomatids, the mtDNA (also referred to as kinetoplast DNA or kDNA) is composed of thousands of minicircles and a few maxicircles, catenated together into a complex network. Maxicircles are functionally similar to other eukaryotic mtDNAs, whereas minicircles are involved in RNA editing of some maxicircle-encoded transcripts. Next-generation sequencing (NGS) is increasingly used for assembling nuclear genomes and, currently, a large number of genomic sequences are available. However, most of the time, the mitochondrial genome is ignored in the genome assembly processes. The aim of this study was to develop a pipeline to assemble Leishmania minicircles and maxicircle DNA molecules, exploiting the raw data generated in the NGS projects. As a result, the maxicircle molecules and the plethora of minicircle classes for Leishmania major, Leishmania infantum and Leishmania braziliensis have been characterized. We have observed that whereas the heterogeneity of minicircle sequences existing in a single cell hampers their use for Leishmania typing and classification, maxicircles emerge as an extremely robust genetic marker for taxonomic studies within the clade of kinetoplastidsThis work was supported by grants (to B.A. and J.M.R.) from Proyecto del Ministerio de Economía, Industria y Competitividad SAF2017-86965-R, and by the Network of Tropical Diseases Research RICET (RD16/0027/0008); both grants are co-funded with FEDER funds. The CBMSO receives institutional grants from the Fundación Ramón Areces and from the Fundación Banco de Santande

    Adolescents, Ambivalent Sexism and Social Networks, A Conditioning Factor in the Healthcare of Women

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    Despite gender equality being present in the social and political sphere, we still encounter aspects that are characteristic of sexism. Such aspects impact upon gender inequality and different types of violence towards women. The present article aims to ex amine the behaviour of adolescents from Huelva with regards to ambivalent sexism towards women on social networks and their influence on health. Further, we seek to uncover adolescent’s perceptions with regards to gender differences in the use of social ne tworks , the relationship between sexism and women's emotional well - being was observed. The study sample was formed by young people aged between 14 a nd 16 years who were residing in rural and urban zones in the south of Spain. A mixed methods approach was t aken. At a quantitative level, a sample of 400 young people was recruited. These were admin i stered a questionnaire about sexism which was composed of two scales and has been validated at a national and international level. At a qualitative level, the study counted on 33 young people who participated in in - depth discussions via interviews and discussion groups. The results showed that sexism emerges in adolescence in the analysed sample from the south of Spain. This favoured a digital gender gap and was rei nforced through social networks such as Instagram and Snapchat . Rising a wareness and a critical view of the aforementioned sexism was shown on the behalf of females, particularly those from urban backgrounds

    Interaction of 8 He with 208Pb at near-barrier energies: 4 He and 6 He production

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    Spanish Ministry of Economy and Competitiveness-FPA-2010-22131-CO2-01 (FINURA) y FPA2013-47327-C2-1-RMinistry of Science and Higher Education of Poland-N202 033637National Science Centre of Poland-2013/08/M/ST2/00257 (LEA-COPIGAL) y 2014/14/M/ST2/00738 (COPIN-INFN Collaboration)European Science Foundation-EUI2009-04163432 (EUROGENESIS

    Gene annotation and transcriptome delineation on a de novo genome assembly for the reference Leishmania major friedlin strain

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    Leishmania major is the main causative agent of cutaneous leishmaniasis in humans. The Friedlin strain of this species (LmjF) was chosen when a multi-laboratory consortium undertook the objective of deciphering the first genome sequence for a parasite of the genus Leishmania. The objective was successfully attained in 2005, and this represented a milestone for Leishmania molecular biology studies around the world. Although the LmjF genome sequence was done following a shotgun strategy and using classical Sanger sequencing, the results were excellent, and this genome assembly served as the reference for subsequent genome assemblies in other Leishmania species. Here, we present a new assembly for the genome of this strain (named LMJFC for clarity), generated by the combination of two high throughput sequencing platforms, Illumina short-read sequencing and PacBio Single Molecular Real-Time (SMRT) sequencing, which provides long-read sequences. Apart from resolving uncertain nucleotide positions, several genomic regions were reorganized and a more precise composition of tandemly repeated gene loci was attained. Additionally, the genome annotation was improved by adding 542 genes and more accurate coding-sequences defined for around two hundred genes, based on the transcriptome delimitation also carried out in this work. As a result, we are providing gene models (including untranslated regions and introns) for 11,238 genes. Genomic information ultimately determines the biology of every organism; therefore, our understanding of molecular mechanisms will depend on the availability of precise genome sequences and accurate gene annotations. In this regard, this work is providing an improved genome sequence and updated transcriptome annotations for the reference L. major Friedlin strai

    Variability of the Pr77 sequence of L1Tc retrotransposon among six T. cruzi strains belonging to different discrete typing units (DTUs)

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    All trypanosomatid genomes are colonized by non-LTR retrotransposons which exhibit a highly conserved 77-nt sequence at their 5′ ends, known as the Pr77-hallmark (Pr77). The wide distribution of Pr77 is expected to be related to the gene regulation processes in these organisms as it has promoter and HDV-like ribozyme activities at the DNA and RNA levels, respectively. The identification of Pr77 hallmark-bearing retrotransposons and the study of the associations of mobile elements with relevant genes have been analyzed in the genomes of six strains of Trypanosoma cruzi belonging to different discrete typing units (DTUs) and with different geographical origins and host/vectors. The genomes have been sequenced, assembled and annotated. BUSCO analyses indicated a good quality for the assemblies that were used in comparative analyses. The results show differences among the six genomes in the copy number of genes related to virulence processes, the abundance of retrotransposons bearing the Pr77 sequence and the presence of the Pr77 hallmarks not associated with retroelements. The analyses also show frequent associations of Pr77-bearing retrotransposons and single Pr77 hallmarks with genes coding for trans-sialidases, RHS, MASP or hypothetical proteins, showing variable proportion depending on the type of retroelement, gene class and parasite strain. These differences in the genomic distribution of active retroelements and other Pr77-containing elements have shaped the genome architecture of these six strains and might be contributing to the phenotypic variability existing among the

    Liquid biopsy by NGS: Differential presence of exons (DPE) is related to metastatic potential in a colon-cancer model in the rat

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    Differential presence of exons (DPE) is a method of interpretation of exome sequencing, which has been proposed to design a predictive algorithm with clinical value in patients with colorectal cancer (CRC). The goal of the present study was to examine the reproducibility in a rat model of metastatic colon cancer. DHD/K12-TRb cells were injected in syngenic immunocompetent BD-IX rats. Cells were from two stocks with low and normal metastatic potential, and injected into two separate groups of rats. Five to ten weeks after injection, blood samples were taken prior euthanasia and whole exome sequencing performed. Through DPE analysis, we identified a set of exons whose differential presence in plasma allowed us to compare both groups of tumor-bearing animals. A verification test was performed to confirm that the algorithm was able to classify extracted samples into their corresponding groups of origin. The highest mean probability was 0.8954. In conclusion, the DPE analysis in tumor-bearing animals was able to discriminate between different disease status, which fully supports previous results in CRC patients.This studywas funded by two grants from"Instituto de Salud Carlos III", Spain (FIS; refs. PS09/01815 and PI13/01924
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