Old fish in a young lake: stone loach (Pisces: Barbatula barbatula) populations in Lake Constance are genetically isolated by distance (original) (raw)

Late glacial history of the cold-adapted freshwater fish Cottus gobio, revealed by microsatellites

Molecular Ecology, 2002

The distribution of genetic diversity at 10 highly polymorphic microsatellite loci within the European freshwater fish, Cottus gobio , L. was examined. The sampling range comprised a large geographical scale including lineages known to be highly divergent at both mitochondrial DNA (mtDNA) and allozymes. An analysis of genetic variability within populations showed that expected heterozygosity and allelic richness could be explained largely by current effective population sizes. Evidence was found, however, that historical processes predating the last major glaciation affected allelic richness. In addition to confirming the large-scale patterns from earlier studies, the microsatellite data revealed new insights into recent processes by analysing genetic structure within ancient lineages defined by mtDNA data.

Contemporary nuclear and mitochondrial genetic clines in a north temperate estuarine fish reflect Pleistocene vicariance

Marine Ecology Progress Series, 2011

Contemporary genetic spatial structure in north temperate marine species is likely the culmination of multiple vicariant and dispersive cycles. Here we evaluate spatial genetic structure in an estuarine fish, rainbow smelt Osmerus mordax, from coastal Newfoundland, Canada, using data from both mtDNA (ND5) sequences and nuclear loci (11 microsatellites). Sequence analysis of ND5 identified a previously unrecognized genetic discontinuity between 2 hypothesized glacial clades in southeastern Newfoundland. Microsatellite based tests for directional selection identified a locus (Omo11, p < 0.001) that mirrored mtDNA clades in the geographic distribution of its 2 common alleles but did not display elevated differentiation following correction for heterozygosity. Bayesian multilocus clustering of the remaining micro satellite loci supported the presence of 2 predominant groups, for which the spatial distribution was also largely consistent with those of the mtDNA and Omo11 clades. Taken together, the similarity in microsatellite and mtDNA clines supports the hypothesis that contemporary spatial structure in smelt reflects historical landscape isolation maintained by low dispersal and selective processes producing reinforcement between diverging populations. As genetic structure in northern marine and estuarine species may be largely determined by historical glacial cycles of vicariance, contemporary estimates of connectivity should be interpreted in the context of both past and present landscape structure.

Mitochondrial haplotype diversity among Portuguese brown trout Salmo trutta L. populations: relevance to the post-Pleistocene recolonization of northern Europe

Molecular Ecology, 2000

Mitochondrial haplotype diversity in seven Portuguese populations of brown trout, Salmo trutta L., was investigated by sequencing the 5 ′ end of the mitochondrial DNA (mtDNA) control region. Five new haplotypes were described for this species, each two to three mutational steps distant from the common north Atlantic haplotype. Significant population subdivision of mtDNA haplotypes was also apparent. Based on these results, as well as on published data describing the distribution of both mtDNA haplotypes and allozyme alleles throughout Europe, the postglacial recolonization of northern Europe was re-evaluated. It is argued that the available data do not support the contribution of two major glacial refugia (southwest Atlantic and Ponto-Caspian Basin) to this postglacial recolonization, as proposed in a recently published model. The unique genetic architecture of Portuguese brown trout within the Atlantic-basin clade of this species represents a highly valuable genetic resource that should be protected from introgression with nonendemic strains of hatchery fish.

Nuclear and mitochondrial DNA sequence data reveal the evolutionary history of Barbus (Cyprinidae) in the ancient lake systems of the Balkans

Molecular Phylogenetics and Evolution - MOL PHYLOGENET EVOL, 2010

Freshwater fauna of ancient lakes frequently contain endemic taxa thought to have originated during the long existence of these lakes, yet uncertainties remain as to whether they represent distinct genetic lineages with respect to more widespread relatives and to the relative roles of isolation and dispersal in their evolution. Phylogenetic analyses of sequence variation at nuclear and mitochondrial genes were used to examine these issues for the freshwater fish genus Barbus in two European ancient lake systems on the Balkan Peninsula. The nuclear and mitochondrial data yielded concordant phylogeographic patterns though incomplete sorting of nuclear haplotypes between some mitochondrial clades was detected. The distributions of two currently recognized species investigated here do not match the distributions of evolutionary lineages revealed by phylogenetic analyses. The Prespa barbel, Barbus prespensis, is not endemic to the lakes Prespa as previously thought but is instead found to be widespread in the southeastern Adriatic Sea basin, with a distribution largely corresponding to the basin of the now extinct Lake Maliq historically connected with Lake Prespa. On the other hand, a cryptic phylogenetic subdivision in a widespread species, B. rebeli, was discovered to be more distant from B. rebeli than from other Barbus species and to be endemic to the system of connected lakes Ohrid and Shkodra. The division coincides with the hydrogeographical boundary delimiting distributions of other freshwater fishes, and we suggest that this newly discovered evolutionary lineage represents a distinct species. These findings support the emerging pattern that endemic taxa have evolved not through isolation of individual lakes, but in systems of currently and historically interconnected lakes and their wider basins.

Admixture between old lineages facilitated contemporary ecological speciation in Lake Constance stickleback

Nature Communications, 2019

Ecological speciation can sometimes rapidly generate reproductively isolated populations coexisting in sympatry, but the origin of genetic variation permitting this is rarely known. We previously explored the genomics of very recent ecological speciation into lake and stream ecotypes in stickleback from Lake Constance. Here, we reconstruct the origin of alleles underlying ecological speciation by combining demographic modelling on genome-wide single nucleotide polymorphisms, phenotypic data and mitochondrial sequence data in the wider European biogeographical context. We find that parallel differentiation between lake and stream ecotypes across replicate lake-stream ecotones resulted from recent secondary contact and admixture between old East and West European lineages. Unexpectedly, West European alleles that introgressed across the hybrid zone at the western end of the lake, were recruited to genomic islands of differentiation between ecotypes at the eastern end of the lake. Our ...

The Effects of Paleoclimatic Events on Mediterranean Trout: Preliminary Evidences from Ancient DNA

PLOS ONE, 2016

In this pilot study for the first time, ancient DNA has been extracted from bone remains of Salmo trutta. These samples were from a stratigraphic succession located in a coastal cave of Calabria (southern Italy) inhabited by humans from upper Palaeolithic to historical times. Seven pairs of primers were used to PCR-amplify and sequence from 128 to 410 bp of the mtDNA control region of eleven samples. Three haplotypes were observed: two (ADcs-1 and MEcs-1) already described in rivers from the Italian peninsula; one (ATcs-33) belonging to the southern Atlantic clade of the AT Salmo trutta mtDNA lineage (sensu Bernatchez). The prehistoric occurrence of this latter haplotype in the water courses of the Italian peninsula has been detected for the first time in this study. Finally, we observed a correspondence between frequency of trout remains and variation in haplotype diversity that we related with ecological and demographic changes resulting from a period of rapid cooling known as the Younger Dryas.

Genetic variation over space and time: analyses of extinct and remnant lake trout populations in the Upper Great Lakes

… of the Royal …, 2003

Lake trout (Salvelinus namaycush) in the upper Laurentian Great Lakes of North America experienced striking reductions in abundance and distribution during the mid-twentieth century. Complete collapse of populations was documented for Lake Michigan, and a few remnant populations remained only in lakes Huron and Superior. Using DNA obtained from historical scale collections, we analysed patterns of genetic diversity at five microsatellite loci from archived historical samples representing 15 populations (range 1940-1959) and from three contemporary remnant populations across lakes Huron and Superior (total n = 893). Demographic declines in abundance and the extirpation of native lake trout populations during the past 40 years have resulted in the loss of genetic diversity between lakes owing to extirpation of Lake Michigan populations and a temporal trend for reduction in allelic richness in the populations of lakes Superior and Huron. Naturally reproducing populations in Lake Superior, which had been considered to be remnants of historical populations, and which were believed to be responsible for the resurgence of lake trout numbers and distribution, have probably been affected by hatchery supplementation.

Restricted gene flow at the micro- and macro-geographical scale in marble trout based on mtDNA and microsatellite polymorphism

Frontiers in Zoology, 2011

Background The genetic structure of the marble trout Salmo trutta marmoratus, an endemic salmonid of northern Italy and the Balkan peninsula, was explored at the macro- and micro-scale level using a combination of mitochondrial DNA (mtDNA) and microsatellite data. Results Sequence variation in the mitochondrial control region showed the presence of nonindigenous haplotypes indicative of introgression from brown trout into marble trout. This was confirmed using microsatellite markers, which showed a higher introgression at nuclear level. Microsatellite loci revealed a strong genetic differentiation across the geographical range of marble trout, which suggests restricted gene flow both at the micro-geographic (within rivers) and macro-geographic (among river systems) scale. A pattern of Isolation-by-Distance was found, in which genetic samples were correlated with hydrographic distances. A general West-to-East partition of the microsatellite polymorphism was observed, which was supported by the geographic distribution of mitochondrial haplotypes. Conclusion While introgression at both mitochondrial and nuclear level is unlikely to result from natural migration and might be the consequence of current restocking practices, the pattern of genetic substructuring found at microsatellites has been likely shaped by historical colonization patterns determined by the geological evolution of the hydrographic networks.

Mitochondrial DNA variation in sea trout from coastal rivers in the southern Baltic region

Sea trout (Salmo trutta m. trutta) populations are intensely stocked in Poland. It is estimated that over 90% of smolts migrating from rivers to the sea are offspring of locally caught spawners, artificially bred for over one year. Mitochondrial DNA variation in the populations of sea trout from six Polish rivers was investigated by RFLP analysis of PCR-amplified NADH-dehydrogenase 1 and 5/6 segments of mtDNA. Sixteen composite haplotypes were identified. Limited variation in the frequency of haplotypes between populations (?2=116.46, p<0.001) was observed. Only the Słupia River population differed from the other five. Close similarity between Vistula River and the Pomeranian Rega and Parset¸a rivers in a neighbour-joining tree indicates the presence of Pomeranian trout in the Vistula River system. In order to explain the possible causes of low differentiation of mtDNA among these sea trout populations, a comparison has been made to that found among populations from geographically close rivers in Bornholm Island, Denmark based on the literature data.

Genetic admixture of burbot (Teleostei: Lota lota) in Lake Constance from two European glacial refugia

Molecular Ecology, 2006

The burbot, Lota lota , is the only freshwater species of the codfish family and has a Holarctic distribution. Pleistocene glaciations caused significant geographical differentiation in the past, but its life history characterized by winter spawning migrations over large distances is likely to homogenize populations by contemporary gene flow. We investigated the population genetic structure of 541 burbots from Lake Constance and adjacent Rhine and Danube tributaries in Europe using the entire mitochondrial DNA (mtDNA) control region and 11 microsatellites. Microsatellites revealed considerable population divergence ( F ST = 0.26) and evidenced recent bottlenecks in two Central European rivers. In accordance to previous evidence two main phylogeographic lineages (Atlantic and Danubian) were found co-occurring at similar frequencies in Lake Constance, where they currently undergo random mating as indicated by microsatellites. The Danubian lineage contributed only a small proportion to the lake's mtDNA diversity, and probably expanded within the lake shortly after its formation ∼ ∼ ∼ ∼ 10 000 -15 000 BP . The larger Atlantic haplotype diversity suggested a population expansion older than the lake itself. Levels of admixture at microsatellite loci were less obvious due to their high variability, and coalescence methods were used to estimate past admixture proportions. Our results reinforce a model of a two-step colonization of Europe by burbot from an ancestral Danubian refuge, and confirm the persistence of a secondary Atlantic refuge, as proposed to exist for other freshwater fish. We conclude that the present-day burbot population in Lake Constance bears the genetic signature of both contemporary gene flow and historical separation events.