Freshwater protists do not go with the flow: Population structure in Gonyostomum semen independent of connectivity among lakes.
Author
Summary, in English
Many recent studies have found genetically differentiated populations in microorganisms despite potentially high dispersal. We designed a study to specifically examine the importance of physical dispersal barriers, i.e. geographic distance and lack of hydrological connectivity, in restricting gene flow and enhancing divergence in limnic microorganisms. We focused on the nuisance microalga Gonyostomum semen, which has recently expanded in northern Europe and differentiated into genetically distinct populations. Gonyostomum semen was sampled from six lakes distributed in two adjacent watersheds, which thereby comprised, both connected and non-connected lakes. The individual isolates were genotyped by Amplified Fragment Length Polymorphism. Several lake populations were differentiated from each other, but connectivity within watersheds could not explain the observed population genetic pattern. However, isolation by distance was moderate and might limit the gene flow among distant populations. In addition, we found low, but significant linkage disequilibrium, which indicates regular sexual recombination in this species, despite its high degree of asexual reproduction. Therefore, we conclude that the genetic properties of microalgae with occasional sexual reproduction essentially mirror regularly recombining species. Furthermore, the data indicated bottlenecks supporting the hypothesized recent range expansion of this species.
Department/s
Publishing year
2015
Language
English
Pages
5063-5072
Publication/Series
Environmental Microbiology
Volume
17
Issue
12
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Ecology
Status
Published
Research group
- Aquatic Ecology
ISBN/ISSN/Other
- ISSN: 1462-2920