0 avis
Chromosomal transfers in mycoplasmas: when minimal genomes go mobile
Archive ouverte
Edité par CCSD ; American Society for Microbiology -
International audience. Horizontal gene transfers (HGT) shape bacterial genomes and are key contributors to microbial diversity and innovation. One main mechanism involves conjugation, a process that allows the simultaneous transfer of significant amounts of DNA upon cell-to-cell contact. Recognizing and deciphering conjugal mechanisms are thus essential in understanding the impact of gene flux on bacterial evolution. We addressed this issue in mycoplasmas, the smallest and simplest self-replicating bacteria. In these organisms, HGT was long thought to be marginal. We showed here that nearly every position of the Mycoplasma agalactiae chromosome could be transferred via conjugation, using an unconventional mechanism. The transfer involved DNA blocks containing up to 80 genes that were incorporated into the host chromosome by homologous recombination. These findings radically change our views concerning mycoplasma evolution and adaptation with particularly far-reaching implications given that over 50 species are human or animal pathogens.IMPORTANCE: Horizontal gene transfers (HGT) shape bacterial genomes and are key contributors to microbial diversity and innovation. One main mechanism involves conjugation, a process that allows the simultaneous transfer of significant amounts of DNA upon cell-to-cell contact. Recognizing and deciphering conjugal mechanisms are thus essential in understanding the impact of gene flux on bacterial evolution. We addressed this issue in mycoplasmas, the smallest and simplest self-replicating bacteria. In these organisms, HGT was long thought to be marginal. We showed here that nearly every position of the Mycoplasma agalactiae chromosome could be transferred via conjugation, using an unconventional mechanism. The transfer involved DNA blocks containing up to 80 genes that were incorporated into the host chromosome by homologous recombination. These findings radically change our views concerning mycoplasma evolution and adaptation with particularly far-reaching implications given that over 50 species are human or animal pathogens.
Consulter en ligne
Suggestions
Du même auteur
