Search results for " Gene Expression"
showing 10 items of 695 documents
Specific expression of antimicrobial peptide and HSP70 genes in response to heat-shock and several bacterial challenges in mussels
2007
Abstract Defensin, mytilin and myticin are antimicrobial peptides (AMP) involved in mussel innate immunity. Their in vitro antibacterial activity is different according to the targeted bacterial species. To determine if this specificity is correlated to different regulations of gene expressions, adult mussels were challenged in vivo with either Vibrio splendidus LGP32, Vibrio anguillarum , Micrococcus lysodeikticus or by heat shock. RNAs were isolated from circulating hemocytes and AMP mRNAs were quantified by Q-PCR using 28S rRNA as housekeeping gene. In addition, HSP70 gene expression was also quantified as representing non-specific response to stress. In naive mussels, the three AMP mRNA…
Transcriptional Upregulation of Genes Related to Virulence Activation in Entamoeba histolytica
2007
Background To understand the molecular basis of virulence variability in Entamoeba histolytica , this study presents results about differential gene expression induced by E. histolytica trophozoites in liver of hamsters in order to produce experimental amebic liver abscess (ALA) and consequently reactivate its virulence. Methods Amebic cultures were studied before (BALA) and after (AALA) inoculation in hamster peritoneal cavity. Markers of pathogenicity such as the rate of erythrophagocytosis, hemolytic activity, and cytotoxic effects on MDCK cell monolayers were evaluated in order to correlate these phenotypic characteristics to differential gene expression between virulent and non-virulen…
The Importance of the Variability of Leucocyte Zinc Transporter 8 (ZnT8) Gene Expression
2023
The variability of ZnT8 expression in leukocytes develops in patients witha geneticpredisposition to this condition and it decreases with age. Greater intercellular zinc accumulation may potentially provoke increased levels of its expression, as a support mechanism in zinc homeostasis. The occurrence of ZnT8 antibodies (ZnT8A) may result in leukocyte dysfunction, which is dependent i.a. on the level of ZnT8 expression. The same correlation can be observed in non-pancreatic tissues. ZnT8A occur in approximately 16.5% of research participants without any diabetes symptoms and the frequency of their occurrence decreases with age as well. The occurence of variability of ZnT8 expression in leuko…
Acyl-homoserine lactone production is more common among plant-associated Pseudomonas spp. than among soilborne Pseudomonas spp.
2001
ABSTRACT A total of 137 soilborne and plant-associated bacterial strains belonging to different Pseudomonas species were tested for their ability to synthesize N -acyl-homoserine lactones (NAHL). Fifty-four strains synthesized NAHL. Interestingly, NAHL production appears to be more common among plant-associated than among soilborne Pseudomonas spp. Indeed, 40% of the analyzed Pseudomonas syringae strains produced NAHL which were identified most often as the short-chain NAHL, N -hexanoyl- l -homoserine lactone, N -(3-oxo-hexanoyl)-homoserine lactone, and N -(3-oxo-octanoyl)- l -homoserine lactone (no absolute correlation between genomospecies of P. syringae and their ability to produce NAHL …
Networks of Seed Storage Protein Regulation in Cereals and Legumes at the Dawn of the Omics Era
2012
BAP GEAPSI CT2 (BAP); International audience; Finely regulated and orchestrated events occur during seed development and germination in different cell organelles (mitochondria, peroxisomes, plastids, vacuoles, endoplasmic reticulum, oil bodies and nuclei). Therefore, some of the ongoing investigations pass through sub-cellular organelle purifications for a deeper comprehension of these complex developmental processes. In seed biology, recent ambitious efforts in proteomics have been directed toward organelle isolation from seeds and high-throughput protein separation and identification by mass spectrometry at defined developmental stages. The construction of reference maps allowed identifyi…
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…
Communication and Autoinduction in the species Listeria monocytogenes
2014
International audience; In order to withstand changes in their environment, bacteria have evolved mechanisms to sense the surrounding environment, integrate these signals and adapt their physiology to thrive under fluctuating conditions. Among these mechanisms, the ability of bacteria to exchange information between cells has become a dynamic field of interest for microbiologists over the past four decades. First described by Nelson et al.,1 this phenomenon often referred as either cell-cell communication, Quorum Sensing and/or AutoInduction involves the synthesis of small signal molecules called autoinducers. These signal molecules may be sensed by the bacterial population in the vicinity …
Characterization of Pea (Pisum Sativum L.) genes implicated in arbuscular mycorrhiza formation and function
2010
The arbuscular mycorrhizal (AM) association results from a successful interaction between the genomes of the two symbiotic partners. In this context, the aim of my research was to better characterize the role of the late stage symbiosis-related pea genes PsSym36, PsSym33 and PsSym40 in the functional AM (i) by investigating the effect of mutations in the three genes on fungal and plant gene responses and (ii) by creating conditions for the localization of two of the genes, PsSym36 and PsSym40, on the pea genetic map for future map-based cloning. The expression of a subset of ten fungal and eight plant genes,previously reported to be activated during mycorrhiza development, was compared in G…
Regulation of gene expression during endomycorrhizal infection
1997
International audience
Exploiting Glomus intraradices sequencing data to dissect molecular mechanisms of plant genome control over fungal gene expression in mycorrhiza
2006
International audience