Genome Evolution in Bacteria Isolated from Million-Year-Old Subseafloor Sediment.

ABSTRACT: Beneath the seafloor, microbial life subsists in isolation from the surface world under persistent energy limitation. The nature and extent of genomic evolution in subseafloor microbes have been unknown. Here, we show that the genomes of Thalassospira bacterial populations cultured from million-year-old subseafloor sediments evolve in clonal populations by point mutation, with a relatively low rate of homologous recombination and elevated numbers of pseudogenes. Ratios of nonsynonymous to synonymous substitutions correlate with the accumulation of pseudogenes, consistent with a role for genetic drift in the subseafloor strains but not in type strains of Thalassospira isolated from the surface world. Consistent with this, pangenome analysis reveals that the subseafloor bacteri

SUBMITTER: Orsi WD 

PROVIDER: S-EPMC8406185 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature