Department of Microbiology and Immunology
Dynamics and evolution of the bacterial genome Dominique Schneider
Our group’s primary interest is to study the traits that determine the fit between organisms and their environment and the evolution of these traits by natural selection. Evolution is inherently complex owing to the high dimensionality of genomes and the multitude of interactions between genes, gene products, metabolites, and environmental factors including resources.To understand many adaptations, one must investigate changes in entire genomes and examine their consequences for global expression and organismal performance.
The work of our group is therefore integrative and multidisciplinary and at the frontier of ecology, evolution, microbiology and genetics, including the fields of experimental evolution, microbial genetics and population genetics. We use an experimental evolution strategy consisting in 12 evolving populations of Escherichia coli, all founded from the same ancestor and propagated in the same environment for more than 30,000 generations. Competition assays indicate substantial adaptation, manifest as increased fitness in the defined environment. We analyze the molecular-genetic and phenotypic bases of adaptation in this bacterial model that has evolved for 30,000 generations in a defined environment. Several mutations have been identified with complex effects on global gene expression, including widespread pleiotropy and epistasis, indicative of important changes in regulatory networks. We move and introduce these mutations, alone and in various combinations, across time and space in different genetic backgrounds. This allow us to have a set of unique isogenic strains. These experiments offer unique opportunities to quantify dynamics in a complex adaptive system and elucidate the interplay among these regulatory mutations.
National & international cooperations
- Réseau ColiScope de séquençage de génome (Erick Denamur, Hôpital Bichat, Paris)
- Laboratoire Ingénierie des Systèmes Macromoléculaires, UPR 9027, Marseille
- Prof. Richard Lenski (Michigan State University, USA)
- Prof. Margaret Riley (University of Massachussetts, USA)
- Prof. Michael Cashel (National Institute of Health, USA)
- Dr Tim Cooper (University of Auckland, Nouvelle-Zélande
- Dr. Jérôme Garin ( INSERM ERIT, M 0201, CEA)