Search results for "Expression des gènes"
showing 7 items of 7 documents
Transcriptome analysis revealed that a quorum sensing system regulates the transfer of the pAt megaplasmid in Agrobacterium tumefaciens.
2016
Background Agrobacterium tumefaciens strain P4 is atypical, as the strain is not pathogenic and produces a for this species unusual quorum sensing signal, identified as N-(3-hydroxy-octanoyl)-homoserine lactone (3OH,C8-HSL). Results By sequence analysis and cloning, a functional luxI-like gene, named cinI, has been identified on the At plasmid of A. tumefaciens strain P4. Insertion mutagenesis in the cinI gene and transcriptome analyses permitted the identification of 32 cinI-regulated genes in this strain, most of them encoding proteins responsible for the conjugative transfer of pAtP4. Among these genes were the avhB genes that encode a type 4 secretion system (T4SS) involved in the forma…
Molecular cloning, gene structure and expression profile of two mouse peroxisomal 3-ketoacyl-CoA thiolase genes
2004
Abstract Background In rats, two peroxisomal 3-ketoacyl-CoA thiolase genes (A and B) have been cloned, whereas only one thiolase gene is found in humans. The aim of this study was thus to clone the different mouse thiolase genes in order to study both their tissue expression and their associated enzymatic activity. Results In this study, we cloned and characterized two mouse peroxisomal 3-ketoacyl-CoA thiolase genes (termed thiolase A and B). Both thiolase A and B genes contain 12 exons and 11 introns. Using RNA extracted from mouse liver, we cloned the two corresponding cDNAs. Thiolase A and B cDNAs possess an open reading frame of 1272 nucleotides encoding a protein of 424 amino acids. In…
Regulation of stress response in Oenococcus oeni as a function of environmental changes and growth phase
2000
International audience; Oenococcus oeni is a lactic acid bacterium which is able to grow in wine and perform malolactic fermentation. To survive and grow in such a harsh environment as wine, O. oeni uses several mechanisms of resistance including stress protein synthesis. The molecular characterisation of three stress genes hsp18, clpX, trxA encoding for a small heat shock protein, an ATPase regulation component of ClpP protease and a thioredoxin, respectively, allow us to suggest the existence in O. oeni of multiple regulation mechanisms as is the case in Bacillus subtilis. One common feature of these genes is that they are expressed under the control of housekeeping promoters. The express…
Inactivation of PadR, the repressor of the phenolic acid stress response, by molecular interaction with Usp1, a universal stress protein from Lactoba…
2009
ABSTRACT The phenolic acid decarboxylase gene padA is involved in the phenolic acid stress response (PASR) in gram-positive bacteria. In Lactobacillus plantarum , the padR gene encodes the negative transcriptional regulator of padA and is cotranscribed with a downstream gene, usp1 , which encodes a putative universal stress protein (USP), Usp1, of unknown function. The usp1 gene is overexpressed during the PASR. However, the role and the mechanism of action of the USPs are unknown in gram-positive bacteria. Therefore, to gain insights into the role of USPs in the PASR; (i) a usp1 deletion mutant was constructed; (ii) the two genes padR and usp1 were coexpressed with padA under its own promo…
Single-cell RNA sequencing unveils the shared and the distinct cytotoxic hallmarks of human TCRVδ1 and TCRVδ2 γδ T lymphocytes
2019
γδ T lymphocytes represent ∼1% of human peripheral blood mononuclear cells and even more cells in most tissues of vertebrates. Although they have important anticancer functions, most current single-cell RNA sequencing (scRNA-seq) studies do not identify γδ T lymphocytes because their transcriptomes at the single-cell level are unknown. Here we show that high-resolution clustering of large scRNA-seq datasets and a combination of gene signatures allow the specific detection of human γδ T lymphocytes and identification of their T cell receptor (TCR)Vδ1 and TCRVδ2 subsets in large datasets from complex cell mixtures. In t -distributed stochastic neighbor embedding plots from blood and tumor sa…
Caractérisation biochimique, physiologique et moléculaire de différents génotypes de Medicago truncatula
2017
Engineering school; Des études de l’interaction entre la légumineuse modèle Medicago truncatula (Mt) avec l’oomycète Aphanomyces euteiches (Ae) ont montré que la glutamine accumulée dans les racines infectées pourrait être un marqueur de sensibilité à ce pathogène végétal. Pour mieux comprendre le rôle de la glutamine dans la résistance de Mt à Ae,nous avons essayé de doser la glutamine racinaire avec un kit de dosage. D’autre part, nous avons analysé l’impact d’une dose sublétale d’un inhibiteur de la glutamine synthétase (enzyme responsable de la synthèse de glutamine chez les plantes) sur le développement de différents génotypes de Mt. Enfin nous nous sommes intéressés à lacapacité de Mt…
Loss of rod sensitivity and gene expression changes in the retina of fructose-fed insulin-resistant mice
2012
Purpose: Metabolic syndrome is of major concern in Western countries since it predisposes individuals to the development of diabetes. Insulin resistance is one of the biochemical features of the metabolic syndrome. Fructose feeding has been used to elicit insulin resistance in rodents. Our purpose was to characterize the functional and gene expression changes in the retina after long term feeding mice with a fructose-enriched diet.Methods: Control and ApoB100,LDLR-/- mice, a murine model of aging of the human retina, were fed with a 60%-rich fructose diet for 8 months. Scotopic single flash and Flicker electroretinograms were recorded to monitor the response of the retina to flash stimuli. …