Description du projet
Étudier les facteurs de réussite du transfert horizontal de gènes chez les bactéries
Un certain nombre de facteurs peuvent influencer la réussite ou l’échec du transfert horizontal de gènes (THG), le processus par lequel le matériel génétique est transféré entre différents organismes. Le THG est un élément important de l’évolution des bactéries, mais son étude s’avère complexe. Financé par le Conseil européen de la recherche, le projet HorizonGT apportera un éclairage sur les forces sélectives à l’origine de la réussite du THG au sein des populations bactériennes. Plus précisément, le projet consiste à mettre au point une technologie génétique destinée à mesurer l’aptitude de milliers d’événements THG. Ce faisant, il identifiera les contraintes qui affectent la réussite du THG et examinera le rôle du contexte génomique dans l’aptitude de l’hôte. Ces conclusions nous permettront de mieux comprendre un mécanisme important qui sous-tend l’écologie et l’évolution des bactéries.
Objectif
Horizontal gene transfer (HGT) –the movement of genetic material between individuals– is a significant force fueling bacterial evolution. Through HGT, bacteria acquire new traits, develop new metabolic capabilities and learn to withstand harsh environmental conditions. However, in some cases, HGT brings genetic information that is not advantageous to its host. Despite its crucial relevance for bacterial ecology and evolution, understanding the selective forces that drive the success (or failure) of HGT remains a major challenge. Previous studies addressing this challenge ignored the fact that not all HGT events are alike: incoming DNA can be integrated into the host genome (e.g. transposons, integrons), or it can stand as a physically separated, autonomous DNA molecule (e.g. plasmids). This difference in genomic context poses several mechanistic constraints that are likely to alter the evolutionary outcome of HGT.
Here, I will present a conceptually novel approach that explicitly considers genomic context to uncover the selective drivers of HGT in bacterial populations. First, I will develop a new genetic technology to obtain high-throughput fitness measurements of thousands of HGT events. Then, I will use these data to identify and quantify the constraints that determine the success of HGT, both considering the intrinsic effects of the transferred DNA and the role of genomic context on host fitness. Specifically, I will measure the fitness effects of genetic transfers mediated by plasmids (Obj. 1) or integrated into the chromosome and, in the latter case, in different regions of the chromosome (Obj. 2). Finally, I will leverage the rules derived from these analyses to reconstruct the role of HGT in the evolution of a relevant human pathogen (Obj. 3). This project will provide a quantitative and mechanistic understanding of the selective forces driving HGT, expanding horizons in evolutionary microbiology.
Champ scientifique
Programme(s)
- HORIZON.1.1 - European Research Council (ERC) Main Programme
Thème(s)
Régime de financement
HORIZON-ERC - HORIZON ERC GrantsInstitution d’accueil
28046 MADRID
Espagne