Single-cell genomics reveal low recombination frequencies in freshwater bacteria of the SAR11 clade.

ABSTRACT:

Background

The SAR11 group of Alphaproteobacteria is highly abundant in the oceans. It contains a recently diverged freshwater clade, which offers the opportunity to compare adaptations to salt- and freshwaters in a monophyletic bacterial group. However, there are no cultivated members of the freshwater SAR11 group and no genomes have been sequenced yet.

Results

We isolated ten single SAR11 cells from three freshwater lakes and sequenced and assembled their genomes. A phylogeny based on 57 proteins indicates that the cells are organized into distinct microclusters. We show that the freshwater genomes have evolved primarily by the accumulation of nucleotide substitutions and that they have among the lowest ratio of recombination to mutation estimated for bacteria. In contrast

SUBMITTER: Zaremba-Niedzwiedzka K 

PROVIDER: S-EPMC4053759 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature