Description du projet
Cartographie de l’évolution du génome microbien
La compréhension des mécanismes à l’origine des principaux groupes de procaryotes reste limitée. L’origine des espèces et des taxons supérieurs parmi les procaryotes devrait entraîner des interactions écologiques avec l’environnement combinées à une variation génétique naturelle impliquant des innovations génétiques spécifiques à la lignée et des acquisitions génétiques spécifiques à la lignée. Toutefois, les études phylogénomiques ne peuvent pas prédire le contenu génétique de 99 % du génome en raison du rôle du transfert horizontal de gènes (THG). Le projet eMicrobevol, financé par le CER, utilisera toutes les données évolutives que les génomes ont à offrir — arbres génétiques, distributions de gènes et distributions fractionnées à travers des ensembles d’arbres — pour cartographier l’histoire de la composante 99 % de l’évolution du génome microbien et expliquer le rôle du THG dans l’origine des taxons microbiens supérieurs.
Objectif
From the primordial emergence of the earliest cells to the ongoing diversification of modern microbiota, the mechanisms that underlie the origin of major prokaryotic groups are still poorly understood. In principle, the origin of both species and higher taxa among prokaryotes should entail similar mechanisms — ecological interactions with the environment paired with natural genetic variation involving lineage-specific gene innovations and lineage-specific gene acquisitions. Because eukaryotes started out as a prokaryote lineage, the same holds true at the prokaryote-eukaryote transition. Prokaryotic higher taxa are currently circumscribed by phylogenomic studies encompassing 30-40 proteins for information processing that are universal to all genomes, or nearly so. The core is useful in taxonomy but comprises only about 1% of an average genome. It does not predict gene content in the remaining 99% of the genome, because of the role of lateral gene transfer (LGT) in generating diversity within and between prokaryotic groups. Especially in groups with large pangenomes or broad ecological diversity, the core itself does not reveal which gene innovations underlie the origin of major groups, but gene distributions might. This proposal aims to harness all the evolutionary data that genomes have to offer — gene trees, gene distributions, and split distributions across sets of trees — to chart the history of the 99% component of microbial genome evolution and the role of LGT in the origin of higher microbial taxa. The focus is on three important questions: i) What are the quantitative and lineage specific relative contributions of gene transfer from endosymbionts vs. gene transfers from other prokaryotes during eukaryotic genome evolution, ii) Are there significant differences in verticality in comparisons of genome evolution in prokaryotes vs. eukaryotes and how can we statistically better quantify them, and iii) What was the biological nature of the earliest prokaryotes.
Champ scientifique
- medical and health sciencesmedical biotechnologygenetic engineeringgene therapy
- humanitieshistory and archaeologyhistory
- natural sciencescomputer and information sciencesdata sciencedata processing
- natural sciencesbiological sciencesgeneticsgenomesprokaryotic genomes
- natural sciencesbiological sciencesgeneticsgenomeseukaryotic genomes
Programme(s)
Thème(s)
Régime de financement
ERC-ADG - Advanced GrantInstitution d’accueil
40225 Dusseldorf
Allemagne