Data from: Local adaptation and oceanographic connectivity patterns explain genetic differentiation of a marine diatom across the North Sea-Baltic Sea salinity gradient
Sjöqvist, Conny, Åbo Akademi University
Godhe, Anna, University of Gothenburg
Jonsson, Per R., University of Gothenburg
Sundqvist, Lisa, University of Gothenburg
Kremp, Anke, Finnish Environmental Institute/Marine Research Centre; PB 140 00251 Helsinki Finland
Published Apr 23, 2015 on Dryad.
Cite this dataset
Sjöqvist, Conny et al. (2015). Data from: Local adaptation and oceanographic connectivity patterns explain genetic differentiation of a marine diatom across the North Sea-Baltic Sea salinity gradient [Dataset]. Dryad. https://doi.org/10.5061/dryad.j5cf0
Drivers of population genetic structure are still poorly understood in marine micro-organisms. We exploited the North Sea–Baltic Sea transition for investigating the seascape genetics of a marine diatom, Skeletonema marinoi. Eight polymorphic microsatellite loci were analysed in 354 individuals from ten locations to analyse population structure of the species along a 1500-km-long salinity gradient ranging from 3 to 30 psu. To test for salinity adaptation, salinity reaction norms were determined for sets of strains originating from three different salinity regimes of the gradient. Modelled oceanographic connectivity was compared to directional relative migration by correlation analyses to examine oceanographic drivers. Population genetic analyses showed distinct genetic divergence of a low-salinity Baltic Sea population and a high-salinity North Sea population, coinciding with the most evident physical dispersal barrier in the area, the Danish Straits. Baltic Sea populations displayed reduced genetic diversity compared to North Sea populations. Growth optima of low salinity isolates were significantly lower than those of strains from higher native salinities, indicating local salinity adaptation. Although the North Sea–Baltic Sea transition was identified as a barrier to gene flow, migration between Baltic Sea and North Sea populations occurred. However, the presence of differentiated neutral markers on each side of the transition zone suggests that migrants are maladapted. It is concluded that local salinity adaptation, supported by oceanographic connectivity patterns creating an asymmetric migration pattern between the Baltic Sea and the North Sea, determines genetic differentiation patterns in the transition zone.
This file contains data on growth rates (intrinsic rate of increase, µ) of Skeletonema marinoi strains isolated from the Baltic Sea and the Swedish west coast. The average values are based on measured growth rates of 10 monoclonal strains grown in f/4+Si for 5-7 days in +10 C in a light intensity of 40 µmol s-1 m-2. Strains were acclimatized to respective salinity during one week prior to the growth experiment.
Microsatellite genotypes (Skeletonema marinoi)
This file contains allelic information on 354 individuals (8 loci) of Skeletonema marinoi isolated from the Baltic Sea and NE North Sea.
This file contains the exact coordinates of the ten sampling stations in this study.
directional relative migration
This file contains the raw data for directional relative migration between the ten Skeletonema marinoi populations. More information in the ReadMe file.
This file contains matrices of oceanographic connectivity between the ten sampling stations. More information in the associated ReadMe file.