Comparing effective population sizes of dominant marine alphaproteobacteria lineages. Issue 2 (5th December 2013)

• Record Type: Journal Article
• Authors: Luo, Haiwei; Swan, Brandon K.; Stepanauskas, Ramunas; Hughes, Austin L.; Moran, Mary Ann
• Is Part Of: Environmental microbiology reports. Volume 6:Issue 2(2014)
• Page Start: 167
• Page End: 172
• Publication Date: 2013-12-05
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; Electronic journals; 579.17
• DOI: 10.1111/1758-2229.12129
• Languages: English
• ISSNs: 1758-2229

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>A fundamental question in marine microbial ecology is how microbes adapt to ocean environments. Although numerically dominant populations are typically considered more successful, higher census population sizes (N<sub>c</sub>) do not equate directly to a greater capability for adaptation. Instead, effective population size (N<sub>e</sub>) determines the fate of deleterious and favourable mutations, and thus is a key parameter for determining the adaptive potential of a population. In the case of the SAR11 and Roseobacter lineages, two abundant heterotrophic bacteria in ocean surface waters with contrasting life history strategies, culture‐independent population surveys suggest that SAR11s have greater N<sub>c</sub> than Roseobacters. To determine relative N<sub>e</sub>, we compared the ratio of nonsynonymous to synonymous substitution rates (ω) of recently diverged lineages of these taxa. Values of ω associated with several of the Roseobacter subclades were lower than for SAR11 subclades, suggesting greater N<sub>e</sub> in these cases. Most Roseobacter lineages also had smaller ω values compared with an atypical basal Roseobacter lineage with a large N<sub>c</sub>. This finding provides insight into variability in N<sub>e</sub> across two important marine bacterial lineages, and provides an evolutionary context for considering how heterotrophic marine bacteria may differ in their ability to adapt to changing ocean habitats.</p> </abstract>