Mitochondrial and nuclear DNA phylogeography of European grayling (Thymallus thymallus): evidence for secondary contact zones in central Europe

Abstract

Mitochondrial and microsatellite DNA markers were applied to infer the phylogeography, intraspecific diversity and dynamics of the distributional history of European grayling (Thymallus thymallus) with focus on its central and northern European distribution range. Phylogenetic and nested clade analyses revealed at least four major mtDNA lineages, which evolved in geographical isolation during the Pleistocene. These lineages should be recognized as the basic evolutionary significant units (ESUs) for grayling in central and northern Europe. In addition, and in contrast to previous work on grayling, the results of Bayesian analysis of individual admixture coefficients, two-dimensional scaling analysis and spatial analysis of molecular variance provided evidence for a high level of admixture among major lineages in contact zones between drainages (e.g. the low mountain range of Germany), most likely resulting from glacial perturbations and ancient river connections between drainages during the Pleistocene glaciations. Even within river systems, a high level of differentiation among populations was revealed as indicated by the microsatellite data. Grayling sampled from 29 sites displayed high levels of differentiation (overall F(ST) = 0.367), a high number of private alleles and high bootstrap support for the genetic distance-based population clusters across 12 loci. We specifically discuss our results in context of phylogeograpic studies on other European freshwater fish species with habitat preferences similar to those of grayling. Our study shows that both large-scale phylogeographical and detailed genetic analyses on a fine scale are mandatory for developing appropriate conservation guidelines of endangered species.

Good news for conservation: mitochondrial and microsatellite DNA data detect limited genetic signatures of inter-basin fish transfer inThymallus thymallus(Salmonidae) from the Upper Drava River

“…As expected, CR haplotypes of reference samples from the Sava populations OBR and RAD entirely clustered into the SV clade (Da22, Da23, Weiss et al, 2002;Da34, Meraner and Gandolfi, 2012), while the Rhine River reference sample was fixed for RH genetic variants (At14, Weiss et al, 2002; AT26, GenBank acc. n. AY841359, in Gum et al, 2005;At27, Meraner and Gandolfi, 2012; At29, new haplotype, Genbank accession: JX961600) (see Online Resource 1). The At29 haplotype sequence was characterised by the occurrence of a four-fold 82 bp repeat in the right domain of the control region, as previously described for different RH haplotypes from the same drainage (Weiss et al, 2002;Gum et al, 2005).…”

“…n. AY841359, in Gum et al, 2005;At27, Meraner and Gandolfi, 2012; At29, new haplotype, Genbank accession: JX961600) (see Online Resource 1). The At29 haplotype sequence was characterised by the occurrence of a four-fold 82 bp repeat in the right domain of the control region, as previously described for different RH haplotypes from the same drainage (Weiss et al, 2002;Gum et al, 2005). Such a feature has been reported as being common among different salmonids (Sell and Spirkovski, 2004).…”

Keynote Address: Conservation Genetics of Freshwater Organisms

“…This means that many organisms display complex phylogeographic structure with respect to current drainage patterns (e.g. ŠLECHTOVA et al, 2004, GUM et al, 2005. While this makes the region zoogeographically interesting, it also can cause some problems in trying to distinguish between natural and human-related mechanisms responsible for the distribution of genetic variation within and among river systems (WEISS et al, , 2002a.…”

Mitochondrial haplotype diversity of Gyrodactylus thymalli (Platyhelminthes; Monogenea): extended geographic sampling in United Kingdom, Poland, and Norway reveals further lineages

“…The European grayling is widely distributed in northern and continental Europe from the Ural mountains to the British Isles (Northcote 1995), and its phylogeography has been studied intensively analysing both mitochondrial data and microsatellites (Koskinen et al 2000(Koskinen et al , 2002Gum et al 2005). Koskinen et al (2000) found three main assemblages of mitochondrial haplotypes that diverged before the late Pleistocene, and it was concluded that Northern Europe was colonized from at least two ancient refugia.…”

“…Koskinen et al (2000) found three main assemblages of mitochondrial haplotypes that diverged before the late Pleistocene, and it was concluded that Northern Europe was colonized from at least two ancient refugia. Grayling populations in the UK were shown to be closely related to haplotypes from the River Rhine, Germany (Gum et al 2005).…”