Project description:This study focuses metabolic footprinting of Vero cells infected by Mayaro virus. Nuclear magnetic resonance combined with multivariate analytical methods and tools of pattern recognition shows that metabolic changes can be attributed to the effect of Mayaro virus infection. Vero cells infected by Mayaro and incubated for periods of 2h, 6h and 12h show in each period different variations in the levels of several metabolites such as amino acids, organic acids and carbohydrate. These organic compounds are metabolites involved in the pathway of glycolysis, tricarboxylic acid cycle, pentose phosphate pathway, and the oxidation pathway of fatty acids (via the β-oxidation). This study of footprinting analysis demonstrates the effect of the action of virus in the metabolism of the Vero cells, moreover, these analyses indicate intracellular metabolic state, and contributes to the knowledge of the microorganism influence on cellular metabolism.
Project description:Mayaro virus (MAYV) is a mosquito-borne Alphavirus responsible for outbreaks in South America and the Caribbean. In this study we infected Anopheles stephensi with MAYV and sequenced mRNA and small RNA to understand how MAYV infection impacts gene transcription and the expression of small RNAs in the mosquito vector. Genes involved with innate immunity and autophagy are regulated in response to MAYV infection of An. stephensi, we also discover novel miRNAs and describe their expression patterns following bloodmeal ingestion. These results suggest that MAYV does induce a molecular response to infection in its mosquito vector species and that MAYV may have mechanisms to evade the vector immune response.
Project description:Potato genotypes from a diploid potato population were divided in two groups based on their response to Potato virus A (PVA). Plants exhibiting hypersensitive response were compared to plants exhibiting non-necrotic response (i.e. blocking virus movement without cell death).<br>The comparisons were made before inoculation and 12 and 24 hours post-inoculation.<br>
Project description:Brassinosteroids (BRs) are a class of class of phytohormones with important roles in regulating physiological and developmental processes. Small RNAs, including small interfering RNAs and microRNAs (miRNAs), are non-protein coding RNAs that regulate gene expression at the transcriptional and post-transcriptional levels. However, the roles of small RNAs in BR response have not been studied well. In this study, we aimed to identify BR-responsive small RNA clusters and miRNAs in Arabidopsis. In addition, the effect of BR-responsive small RNAs on their transcripts and target genes were examined. Small RNA libraries were constructed from control and epibrassinolide-treated seedlings. After sequencing the small RNA libraries, differentially expressed small RNA clusters were identified by examining the expression levels of small RNAs in 100-nt bins of Arabidopsis genome. To identify the BR-responsive miRNAs, the expression levels of all the annotated mature miRNAs, registered in miRBase, were analyzed. Previously published RNA-seq data were utilized to monitor the BR-responsive expression patterns of differentially expressed small RNA clusters and miRNA target genes. In results, 38 BR-responsive small RNA clusters, including 30 down-regulated and eight up-regulated clusters, were identified. These differentially expressed small RNA clusters were from miRNA loci, transposons, protein-coding genes, pseudo genes and others. Of these, a transgene, BRI1, accumulates small RNAs, which are not found in the wild type. Small RNAs in this transgene are up-regulated by BRs while BRI1 mRNA is down-regulated by BRs. By analyzing the expression patterns of mature miRNAs, we have identified BR-repressed miR398a-5p and BR-induced miR156g. Although miR398a-5p is down-regulated by BRs, its predicted targets were not responsive to BRs. However, SPL3, a target of BR-inducible miR156g, is down-regulated by BRs. BR-responsive small RNAs and miRNAs identified in this study will provide an insight into the role of small RNAs in BR responses in plants. Especially, we suggest that miR156g/SPL3 module might play a role in BR-mediated growth and development in Arabidopsis.
Project description:Influenza virus polymerase transcribes or replicates the segmented RNA genome (vRNA) into respectively viral mRNA or full-length copies and initiates RNA synthesis by binding the conserved 3' and 5' vRNA ends (the promoter). In recent structures of promoter-bound polymerase, the cap-binding and endonuclease domains are configured for cap snatching, which generates capped transcription primers. Here, we present a FluB polymerase structure with a bound complementary cRNA 5' end that exhibits a major rearrangement of the subdomains within the C-terminal two-thirds of PB2 (PB2-C). Notably, the PB2 nuclear localization signal (NLS)- containing domain translocates ~90 A ̊ to bind to the endonuclease domain. FluA PB2-C alone and RNA-free FluC polymerase are similarly arranged. Biophysical and cap-dependent endonuclease assays show that in solution the polymerase explores different conformational distributions depending on which RNA is bound. The inherent flexibility of the polymerase allows it to adopt alternative conformations that are likely important during polymerase maturation into active progeny RNPs.</br></br>Extra contact information:</br><a href="mailto:cusack@embl.fr">Stephen Cusack</a>, EMBL Grenoble Outstation, Unit of Virus Host-Cell Interactions, France ( corresponding author and lab head )
Project description:Theilers murine encephalomyelitis (TME) is an experimentally virus-induced demyelinating leukomyelitis, displaying clinical and pathological similarities to chronic progressive multiple sclerosis. <br>The aim of this study was to identify pathways associated with demyelination using an assumption-free microarray approach. <br>Five-week-old female SJL/JHanHsd-mice were intracerebrally infected with the BeAn-strain of the TME- virus (TMEV) or mock-infected with vehicle only.<br>Groups of 5-6 TMEV- and Mock-infected mice were killed at 14, 42, 98, and 196 days post infection.<br>Total RNA was isolated from the spinal cords and gene expression was measured employing Affymetrix mouse genome 430 2.0 arrays.