Pathogenesis of ruminant mycoplasmoses
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Interactions Hôtes-Agents Pathogènes, UMR, INRA, ENVT
23 chemin des Capelles
BP 87614 – 31076 Toulouse Cedex 3
France
Scientific Interest
Horizontal gene transfer (HGT) is a driving force of bacterial evolution and was long thought to be marginal in mycoplasmas, whose evolution was long thought to be only driven gene losses. Ten years ago, this dogma was challenged by our group and data collected since then indicate that mycoplasma genomes are indeed highly mobile. Our objective is to further decipher mechanisms evolved by these minimal bacteria to access a considerable reservoir of genetic resources distributed among a vast number of species. By combining classical mating experiments to comparative and functional genomics, integrative and conjugative elements (ICEs) have been identified as pivotal in horizontal gene flows within and among mycoplasma species. Indeed, mycoplasma conjugation is not restricted to ICE transmission, but also involves the transfer of chromosomal fragments, ranging from one SNP up to hundred kbs. From two parental cells, this phenomenon is capable of generating a multitude of offspring with mosaic genomes, each being unique. In addition to providing a new framework for understanding the acquisition and dissemination of new phenotypic traits in mycoplasmas, our studies extend the concept of the minimal cell to the broader context of the “open source” genome.
Horizontal gene transfer (HGT) is a driving force of bacterial evolution and was long thought to be marginal in mycoplasmas, whose evolution was long thought to be only driven gene losses. Ten years ago, this dogma was challenged by our group and data collected since then indicate that mycoplasma genomes are indeed highly mobile. Our objective is to further decipher mechanisms evolved by these minimal bacteria to access a considerable reservoir of genetic resources distributed among a vast number of species. By combining classical mating experiments to comparative and functional genomics, integrative and conjugative elements (ICEs) have been identified as pivotal in horizontal gene flows within and among mycoplasma species. Indeed, mycoplasma conjugation is not restricted to ICE transmission, but also involves the transfer of chromosomal fragments, ranging from one SNP up to hundred kbs. From two parental cells, this phenomenon is capable of generating a multitude of offspring with mosaic genomes, each being unique. In addition to providing a new framework for understanding the acquisition and dissemination of new phenotypic traits in mycoplasmas, our studies extend the concept of the minimal cell to the broader context of the “open source” genome.
Thematic