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Invasive cyprinid fish in Europe originate from the single introduction of an admixed source population followed by a complex pattern of spread.

Simon A, Britton R, Gozlan R, van Oosterhout C, Volckaert FA, Hänfling B - PLoS ONE (2011)

Bottom Line: A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range.Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity.Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

View Article: PubMed Central - PubMed

Affiliation: Evolutionary Biology Group, Department of Biological Sciences, University of Hull, Hull, United Kingdom. a.simon@2007.hull.ac.uk

ABSTRACT
The Asian cyprinid fish, the topmouth gudgeon (Pseudorasbora parva), was introduced into Europe in the 1960s. A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range. Here we analyse a 700 base pair fragment of the mitochondrial cytochrome b gene to examine different models of colonisation and spread within the invasive range, and to investigate the factors that may have contributed to their invasion success. Haplotype and nucleotide diversity of the introduced populations from continental Europe was higher than that of the native populations, although two recently introduced populations from the British Isles showed low levels of variability. Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity. This suggests that these populations are not in mutation-drift equilibrium, but rather that the relative inflated level of nucleotide diversity is consistent with recent admixture. This study elucidates the colonisation patterns of P. parva in Europe and provides an evolutionary framework of their invasion. It supports the hypothesis that their European colonisation was initiated by their introduction to a single location or small geographic area with subsequent complex pattern of spread including both long distance and stepping-stone dispersal. Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

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Estimates of effective population size (theta) of native populations based equilibrium assumptions.
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pone-0018560-g002: Estimates of effective population size (theta) of native populations based equilibrium assumptions.

Mentions: DNaSP v. 4.5 [44] was used to estimate within population diversity (nucleotide diversity, π; haplotype diversity, Hs). Standardised measures of genetic diversity were calculated by resampling data sets 1000 times using a bootstrapping procedure [45], [46] based on the size of the smallest sample (6 individuals). Differences in genetic diversity between native and invasive populations were tested using a Mann-Whitney test. The invasive population PU was excluded from the comparison of π because it contained one highly divergent haplotype which is suspected to be derived from hybridisation with Gobio gobio. Coalescent based simulations as implemented in DNaSP were used to predict the expected relationship between haplotype diversity (H) and nucleotide diversity (π) under drift-mutation equilibrium and constant population size [47]. Effective population size of native populations assuming mutation-drift equilibrium and absence of migration among watersheds was estimated using MIGRATE-n v. 2.5 (Figure 2) [48]. The option Bayesian inference was used with the default search strategy settings. The rationale of this analysis was to estimate the populations size required to maintain the amount of genetic diversity found in the each population assuming mutation-drift-equilibrium.


Invasive cyprinid fish in Europe originate from the single introduction of an admixed source population followed by a complex pattern of spread.

Simon A, Britton R, Gozlan R, van Oosterhout C, Volckaert FA, Hänfling B - PLoS ONE (2011)

Estimates of effective population size (theta) of native populations based equilibrium assumptions.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108587&req=5

pone-0018560-g002: Estimates of effective population size (theta) of native populations based equilibrium assumptions.
Mentions: DNaSP v. 4.5 [44] was used to estimate within population diversity (nucleotide diversity, π; haplotype diversity, Hs). Standardised measures of genetic diversity were calculated by resampling data sets 1000 times using a bootstrapping procedure [45], [46] based on the size of the smallest sample (6 individuals). Differences in genetic diversity between native and invasive populations were tested using a Mann-Whitney test. The invasive population PU was excluded from the comparison of π because it contained one highly divergent haplotype which is suspected to be derived from hybridisation with Gobio gobio. Coalescent based simulations as implemented in DNaSP were used to predict the expected relationship between haplotype diversity (H) and nucleotide diversity (π) under drift-mutation equilibrium and constant population size [47]. Effective population size of native populations assuming mutation-drift equilibrium and absence of migration among watersheds was estimated using MIGRATE-n v. 2.5 (Figure 2) [48]. The option Bayesian inference was used with the default search strategy settings. The rationale of this analysis was to estimate the populations size required to maintain the amount of genetic diversity found in the each population assuming mutation-drift-equilibrium.

Bottom Line: A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range.Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity.Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

View Article: PubMed Central - PubMed

Affiliation: Evolutionary Biology Group, Department of Biological Sciences, University of Hull, Hull, United Kingdom. a.simon@2007.hull.ac.uk

ABSTRACT
The Asian cyprinid fish, the topmouth gudgeon (Pseudorasbora parva), was introduced into Europe in the 1960s. A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range. Here we analyse a 700 base pair fragment of the mitochondrial cytochrome b gene to examine different models of colonisation and spread within the invasive range, and to investigate the factors that may have contributed to their invasion success. Haplotype and nucleotide diversity of the introduced populations from continental Europe was higher than that of the native populations, although two recently introduced populations from the British Isles showed low levels of variability. Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity. This suggests that these populations are not in mutation-drift equilibrium, but rather that the relative inflated level of nucleotide diversity is consistent with recent admixture. This study elucidates the colonisation patterns of P. parva in Europe and provides an evolutionary framework of their invasion. It supports the hypothesis that their European colonisation was initiated by their introduction to a single location or small geographic area with subsequent complex pattern of spread including both long distance and stepping-stone dispersal. Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

Show MeSH
Related in: MedlinePlus