Abstracts (first author)
The genetic basis of adaptation to ocean acidification in Emiliania huxleyi , a key phytoplankton species
Ocean acidification, the drop in seawater pH due to the uptake of anthropogenic CO2, is a major threat to marine calcifying organisms. In a long-term evolution experiment, we found that the biogeochemically important unicellular algae Emiliania huxleyi partly restored calcification and growth rates at elevated CO2 owing to adaptive evolution, compared to control lines kept at ambient CO2 levels. In order to unravel the genetic basis of adaptive change we re-sequenced replicated control and adapted populations to a high coverage. We identified SNPs and other polymorphisms that diverged with respect to CO2 selection treatments via mapping to the existing genome of E. huxleyi. We were particularly interested whether or not the same genes or metabolic pathways were affected, and how consistent these changes were across replicates. These data provide first insights into the dynamics and the parallelism of de novo mutations in an ecologically important phytoplankton species.