Search results for "mutagénèse"
showing 4 items of 4 documents
Massive presence of insertion sequences in the genome of SOPE, the primary endosymbiont of the rice weevil Sitophilus oryzae
2008
Bacteria that establish an obligate intracellular relationship with eukaryotic hosts undergo an evolutionary genomic reductive process. Recent studies have shown an increase in the number of mobile elements in the first stage of the adaptive process towards intracellular life, although these elements are absent in ancient endosymbionts. Here, the genome of SOPE, the obligate mutualistic endosymbiont of rice weevils, was used as a model to analyze the initial events that occur after symbiotic integration. During the first phases of the SOPE genome project, four different types of insertion sequence (IS) elements, belonging to well-characterized IS families from alpha-proteobacteria, were ide…
New insights into the pharmacology of the short-chain free fatty acid receptors 2 and 3
2011
Metabolic diseases, such as diabetes, dyslipidemia or obesity, are more and more weighing on public health expenses in developed countries. Despite active research, these widespread diseases remain difficult to handle. Promising new therapeutic strategies against metabolic diseases include the development of drugs targeting the free fatty acid receptors, as key players in metabolism homeostasis. In this context, the current PhD thesis focuses on the study of two G protein-coupled receptors, namely the short-chain free fatty acid receptors 2 (FFA2) and 3 (FFA3). First, we investigated the expression of the two receptors of interest in a variety of cell types. Then, in order to study the phar…
Conséquences de l’utilisation de variétés de tournesol tolérantes aux herbicides sur la flore des agrosystèmes
2022
The farming practices associated with the use of sunflower herbicide-tolerant varieties (HTVs) have raised concerns among public authorities, who have recommended monitoring the potential effects of HTVs on biodiversity. In this context, at the scale of three French departments, the vegetation of 239 sunflower fields and their margins was studied between 2017 and 2019. This lower weed diversity can be attributed to shorter crop rotations and higher herbicide use. Admittedly, the higher densities of A. artemisiifolia observed in plots with HTVs are the cause of the use of these varieties rather than the consequence of these practices. However, these practices do not seem to solve the problem…
Genetic and biochemical characterization by random and site-directed mutagenesis, repressors involved in stress response phenolic acids in Bacillus s…
2009
The aim of this work was to characterize the genetic and biochemical mechanisms involved in the PASR, the phenolic acid stress response induced by phenolic acids Bacillus subtilis. By genetics and molecular biology strategies, like reverse genetic, PCR or transposon random mutagenesis, gene deletion, complementation of strains, and gene expression, the main components of the PASR were identified and quantified. Site-directed and random mutagenesis of respectively the promoter of padC encoding the phenolic acid decaroxylase, and PadR, the repressor of the padC expression, allowed us to identify the site of binding of PadR with this promoter, as well as the amino-acid residues involved in the…