Hötzinger, Matthias
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
- University of Innsbruck
Abstract
Allopatric divergence is one of the principalmechanisms for speciation of macro-organisms. Microbes by comparison are assumed to disperse more freely and to be less limited by dispersal barriers. However, thermophilic prokaryotes restricted to geothermal springs have shown clear signals of geographic isolation, but robust studies on this topic for microbes with less strict habitat requirements are scarce. Furthermore, it has only recently been recognized that homologous recombination among conspecific individuals provides species coherence in a wide range of prokaryotes. Recombination barriers thus may define prokaryotic species boundaries, yet, the extent to which geographic distance between populations gives rise to such barriers is an open question. Here, we investigated gene flow and population structure in a widespread species of pelagic freshwater bacteria, Polynucleobacter paneuropaeus. Through comparative genomics of 113 conspecific strains isolated from freshwater lakes and ponds located across a North-South range of more than 3,000 km, we were able to reconstruct past gene flow events. The species turned out to be highly recombinogenic as indicated by significant signs of gene transfer and extensive genome mosaicism. Although genomic differences increased with spatial distance on a regional scale (
Keywords
pelagic freshwater bacteria; microbial evolutionary ecology; gene flow; homologous recombination; Polynucleobacter; allopatric speciation
Published in
Genome Biology and Evolution
2021, volume: 13, number: 3, article number: evab019
Publisher: OXFORD UNIV PRESS
SLU Authors
UKÄ Subject classification
Ecology
Publication identifier
- DOI: https://doi.org/10.1093/gbe/evab019
Permanent link to this page (URI)
https://res.slu.se/id/publ/111681