Search results for "MESH : Genes"
showing 10 items of 13 documents
Diversifying selection on MHC class I in the house sparrow (Passer domesticus).
2009
10 pages; International audience; Genes of the major histocompatibility complex (MHC) are the most polymorphic loci known in vertebrates. Two main hypotheses have been put forward to explain the maintenance of MHC diversity: pathogen-mediated selection and MHC-based mate choice. Host-parasite interactions can maintain MHC diversity via frequency-dependent selection, heterozygote advantage, and diversifying selection (spatially and/or temporally heterogeneous selection). In this study, we wished to investigate the nature of selection acting on the MHC class I across spatially structured populations of house sparrows (Passer domesticus) in France. To infer the nature of the selection, we comp…
Antagonistic effects of a Mhc class I allele on malaria-infected house sparrows.
2008
8 pages; International audience; Genes of the Major Histocompatibility Complex (Mhc) play a fundamental role during the immune response because MHC molecules expressed on cell surface allow the recognition and presentation of antigenic peptides to T-lymphocytes. Although Mhc alleles have been found to correlate with pathogen resistance in several host-parasite systems, several studies have also reported associations between Mhc alleles and an accrued infection risk or an accelerated disease progression. The existence of these susceptibility alleles is puzzling, as the cost generated by the infection should rapidly eliminate them from the population. Here, we show that susceptibility alleles…
Arabidopsis thaliana nicotianamine synthase 4 is required for proper response to iron deficiency and to cadmium exposure.
2013
International audience; The nicotianamine synthase (NAS) enzymes catalyze the formation of nicotianamine (NA), a non-proteinogenic amino acid involved in iron homeostasis. We undertook the functional characterization of AtNAS4, the fourth member of the Arabidopsis thaliana NAS gene family. A mutant carrying a T-DNA insertion in AtNAS4 (atnas4), as well as lines overexpressing AtNAS4 both in the atnas4 and the wild-type genetic backgrounds, were used to decipher the role of AtNAS4 in NA synthesis, iron homeostasis and the plant response to iron deficiency or cadmium supply. We showed that AtNAS4 is an important source for NA. Whereas atnas4 had normal growth in iron-sufficient medium, it dis…
TP53 codon 72 polymorphism and cervical cancer
2009
Background Cervical cancer is caused primarily by human papillomaviruses (HPV). The polymorphism rs1042522 at codon 72 of the TP53 tumour-suppressor gene has been investigated as a genetic cofactor. More than 80 studies were done between 1998 and 2006, after it was initially reported that women who are homozygous for the arginine allele had a risk for cervical cancer seven times higher than women who were heterozygous for the allele. However, results have been inconsistent. Here we analyse pooled data from 49 studies to determine whether there is an association between TP53 codon 72 polymorphism and cervical cancer.Methods Individual data on 7946 cases and 7888 controls from 49 different st…
Expression profiling of prospero in the Drosophila larval chemosensory organ: Between growth and outgrowth
2010
AbstractBackgroundThe antenno-maxilary complex (AMC) forms the chemosensory system of theDrosophilalarva and is involved in gustatory and olfactory perception. We have previously shown that a mutant allele of the homeodomain transcription factor Prospero (prosVoila1,V1), presents several developmental defects including abnormal growth and altered taste responses. In addition, many neural tracts connecting the AMC to the central nervous system (CNS) were affected. Our earlier reports on larval AMC did not argue in favour of a role ofprosin cell fate decision, but strongly suggested thatproscould be involved in the control of other aspect of neuronal development. In order to identify these fu…
Listeria monocytogenes EGD-e biofilms: no mushrooms but a network of knitted chains.
2008
ABSTRACT Listeria monocytogenes is a food pathogen that can attach on most of the surfaces encountered in the food industry. Biofilms are three-dimensional microbial structures that facilitate the persistence of pathogens on surfaces, their resistance toward antimicrobials, and the final contamination of processed goods. So far, little is known about the structural dynamics of L. monocytogenes biofilm formation and its regulation. The aims of this study were, by combining genetics and time-lapse laser-scanning confocal microscopy (LSCM), (i) to characterize the structural dynamics of L. monocytogenes EGD-e sessile growth in two nutritional environments (with or without a nutrient flow), and…
Evaluation of acyl coenzyme A oxidase (Aox) isozyme function in the n- alkane-assimilating yeast Yarrowia lipolytica
1999
ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n -alkane-assimilating yeast Yarrowia lipolytica , encoded by the POX1 through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to …
A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio. Role of an intronic sequence in transcriptional a…
2004
0962-1075 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between i…
Using a Multi-Locus Microsatellite Typing method improved phylogenetic distribution of Candida albicans isolates but failed to demonstrate associatio…
2012
EA MERS CT3 Enjeu 3; International audience; The dimorphic yeast Candida albicans is a component of the normal microflora at the mucosal surfaces of healthy individuals. It possesses an array of phenotypic properties considered as virulence traits that contribute to pathogenicity of the yeast in immuno-compromised patients. We addressed the question of the pathogenicity of lineages of C. albicans with regard to their genotype in three series of C. albicans isolates (a series of commensal isolates collected in healthy individuals, a group of bloodstream isolates and a group of non-bloodstream clinical isolates) using a Multi-Locus Microsatellite Typing (MLMT) approach based on the analysis o…
Smoking and FOS expression from blood leukocyte transcripts in patients with coronary artery disease.
2011
International audience; OBJECTIVE: Analysis of the leukocyte transriptome, in particular the Finkel-Biskis-Jinkins Osteosarcoma (c-Fos) gene, which has a prominent role in inflammation, provides new insights into atherosclerosis mechanisms. Although smoking is a major risk factor, the links between smoking status and coronary artery disease (CAD) remains unclear. We aimed to analyze the relationship between smoking status and c-Fos expression in circulating leukocytes of patients with CAD. METHODS: c-Fos expression was measured by RT-Q-PCR, from blood leukocytes of 239 consecutive patients after acute myocardial infarction (MI). The patients were asked about their smoking status and stratif…