Genetic Variability and Structuring of Arctic Charr (Salvelinus alpinus) Populations in Northern Fennoscandia - PubMed (original) (raw)

Genetic Variability and Structuring of Arctic Charr (Salvelinus alpinus) Populations in Northern Fennoscandia

Takahito Shikano et al. PLoS One. 2015.

Abstract

Variation in presumably neutral genetic markers can inform us about evolvability, historical effective population sizes and phylogeographic history of contemporary populations. We studied genetic variability in 15 microsatellite loci in six native landlocked Arctic charr (Salvelinus alpinus) populations in northern Fennoscandia, where this species is considered near threatened. We discovered that all populations were genetically highly (mean FST ≈ 0.26) differentiated and isolated from each other. Evidence was found for historical, but not for recent population size bottlenecks. Estimates of contemporary effective population size (Ne) ranged from seven to 228 and were significantly correlated with those of historical Ne but not with lake size. A census size (NC) was estimated to be approximately 300 individuals in a pond (0.14 ha), which exhibited the smallest Ne (i.e. Ne/NC = 0.02). Genetic variability in this pond and a connected lake is severely reduced, and both genetic and empirical estimates of migration rates indicate a lack of gene flow between them. Hence, albeit currently thriving, some northern Fennoscandian populations appear to be vulnerable to further loss of genetic variability and are likely to have limited capacity to adapt if selection pressures change.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1

Fig 1. Sampling locations of the six Arctic charr populations.

The current situation is presented in black, in which Lakes Kilpisjärvi, Urtas-Riimmajärvi and Somasjärvi belong to the watercourse draining into the Baltic Sea and the other lakes belong to the watercourse draining into the Atlantic Ocean. Gray shading indicates the historical (ca. 10 000 years ago) situation, when all lakes were involved in two separate watercourses draining into the Atlantic Ocean. All studied populations are landlocked at the present day.

Fig 2

Fig 2. An unrooted neighbor-joining tree based on D A distances among the six Arctic charr populations.

Bootstrap support (>50%) is given at each node.

Fig 3

Fig 3. Bayesian clustering analyses for the six Arctic charr populations based on STRUCTURE and BAPS.

(A) Likelihood estimates for K = 1–9 in STRUCTURE. (B) Estimated delta K for K = 2–8 in STRUCTURE. (C) Individual assignment at K = 6 in STRUCTURE. (D) Individual assignment at K = 6 in BAPS. Each individual is shown in a vertical bar in the same sequence (C and D).

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References

    1. DeWoody JA, Avise JC (2000) Microsatellite variation in marine, freshwater and anadromous fishes compared with other animals. J Fish Biol 56: 461–473.
    1. Merilä J (2014) Lakes and ponds as model systems to study convergent and parallel evolution. J. Limnol 73: 33–45.
    1. Frankham R, Ballou JD, Briscoe DA (2002) Introduction to Conservation Genetics. Cambridge: Cambridge University Press.
    1. Hewitt G (2000) The genetic legacy of the Quaternary ice ages. Nature 405: 907–913. - PubMed
    1. Hewitt GM (2004) The structure of biodiversity–insights from molecular phylogeography. Front Zool 1: 1–16. - PMC - PubMed

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Grants and funding

This research was supported by grants from Academy of Finland (to JM) and Ministry of Agriculture and Forestry (to KKK).

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