Positive Selection Inhibits Plasmid Coexistence in Bacterial Genomes.

ABSTRACT: Plasmids play an important role in bacterial evolution by transferring niche-adaptive functional genes between lineages, thus driving genomic diversification. Bacterial genomes commonly contain multiple, coexisting plasmid replicons, which could fuel adaptation by increasing the range of gene functions available to selection and allowing their recombination. However, plasmid coexistence is difficult to explain because the acquisition of plasmids typically incurs high fitness costs for the host cell. Here, we show that plasmid coexistence was stably maintained without positive selection for plasmid-borne gene functions and was associated with compensatory evolution to reduce fitness costs. In contrast, with positive selection, plasmid coexistence was unstable despite compensatory evolution.

SUBMITTER: Carrilero L 

PROVIDER: S-EPMC8262885 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature