Streptococcus mitis is the closest relative of the major human pathogen S. pneumoniae. The 2,15 Mb sequence of the Streptococcus mitis B6 chromosome, an unusually high-level beta-lactam resistant and multiple antibiotic resistant strain, has now been determined to encode 2100 genes. The accessory genome is estimated to represent over 40%, including 75 mostly novel transposases and IS, the prophage phiB6 and another seven phage related regions. Tetracycline resistance mediated by Tn5801, and an u ...[more]
Project description:Antibiotic resistance in Streptococcus pneumoniae is often the result of horizontal gene transfer events involving closely related streptococcal species. Laboratory experiments confirmed that S. mitis DNA functions as donor in transformation experiments, using the laboratory strain S. pneumoniae R6 as recipient and chromosomal DNA of a high level penicillin resistant S. mitis B6 strain. After four transformation steps, alterations in five penicillin-binding proteins (PBP) were observed, and sequence analysis confirmed recombination events in the corresponding PBP genes. In order to detect regions where recombination with S. mitis DNA has occurred we analyzed the S. pneumoniae transformants by microarray analyses, using oligonucleotide microarrays designed for the S. pneumoniae genome and the S. mitis B6 genome as well.
Project description:Exploration of transcriptome expression in 5 control and 4 familial dysautonomia (FD) human olfactory ecto-mesenchymal stem cells (hOE-MSCs) at very early (P1 and P2) and later (P5 and P9) cell passages.
Project description:In order to appreciate the presence of surface protein gene homologues in commensal species S. mitis and S. oralis, comparative genomic hybridization studies using DNA microarrays were performed with 8 S. mitis and 11 S. oralis from different geographic locations. The oligonucleotide microarray was designed based on the genomes of S. pneumoniae R6 and TIGR4 as well as S. mitis B6 to include genes of 63 cell surface proteins. The denatured genomic DNA of the S. mitis and S. oralis strains was labeled with Cy3-dCTP and control S. mitis B6 DNA was labeled with Cy5-dCTP. Hybridization was performed following the manufacturers recommendations using an hybridization temperature of 40C for 16 h. For data processing, microarrays were scanned on the laser scanner Pro Scan Array GX (PerkinElmer) with the low resolution of 50 µm using ScanArrayExpress Software version 4.0. Photomultiplier tube was adjusted to balance the two fluorescence channels and biochips were scanned with a resolution of 10 µm. After elimination of background values fluorescence intensity was determined. Signals that showed an intensity ratio of 0.3 and above were considered to be positive.
Project description:Cy3 and Cy5 direct labelled RNA from Bloodstream MiTat1.1 trypanosomes and Procyclic 427 Lister were hybridized onto JCVI Trypanosoma brucei oligoarrays (version2). Procyclic RNA were used as control for data analysis.
Project description:Four independent pools of zebrafish embryo were injected with prp2 morphants and after 24 hours post fertilization, gene expression profiles were compared to their respective controls, using microarray. A dye swap design experiment using four microarray slides were conducted.
Project description:To study the composition of mRNPs containing TcDhh1, we carried out immunoprecipitation assays with anti-TcDhh1 and epimastigotes lysates. Pre-immune serum was used as control. We also carried out a ribonomic approach to identify the mRNAs present within the TcDhh1 immunoprecipitated complexes. For this purpose, competitive microarray hibridizations were performed against negative controls, the non-precipitated fraction.
Project description:A ﾑCartes dﾒIdentite des Tumeursﾒ (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net ) | Human genome-wide CIT-aCGH-V7-4.7K : 84 HNSCC | Submitter : Aurelien de Reynies <firstname.lastname@example.org> | Project leader : Bohdan Wazylyk <email@example.com>
Project description:<br><br>Annual heart allograft failure in humans rates about 3-5%. The main reason after the first postoperative year is chronic rejection. Myointimal hyperplasia, the hellmark of chronic rejection, results in a specific type of ischemic heart disease. The lack of angina pectoris symptoms allow ventricular arrythmias, sudden cardiac death or heart failure to occur without warning. In addition, diagnostic tools such as endomyocardial biopsy, coronary angiography or intracoronary ultrasound fail to predict the individual risk for myocardial dysfunction.<br><br>The mechanisms responsible for chronic rejection are predominantly alloimmune mediated with activated T cells, macrophages, B cell mediated antibody formation and secreted cytokines responding to HLA and other endothelial cell antigens. In addition, non immunologic risk factors such as recipient age, metabolic factors, hypertension and ischemia contribute to development of this disease. Previous studies have demonstrated that ischemia has a profound influence on short term allograft survival but the underlaying mechanisms remain largely unknown. Apoptosis seems to play a crucial role in ischemia/reperfusion injury and several mechanisms for programmed cell death have been described. However, consequences on long term cell function of viability have not been investigated. <br><br>The aim of this study was to investigate the implication and the mechanism of prolonged cold organ storage as a non immunologic risk factor in the pathogenesis of chronic rejection in a cardiac allograft model. <br><br>We aimed for answering the following specific questions:<br><br>How does cold ischemia affect the alloimmue response short and long term? <br><br>How does prolonged cold ischemia affect gene expression at later time points after transplantation? <br><br>Does it influence gene expression during chronic rejection?<br><br><br><br>