| 1. |
- Jansson, E., et al.
(författare)
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Genetic study reveals local differentiation persisting in the face of high connectivity and a genomic inversion likely linked with sexual antagonism in a common marine fish
- 2023
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Ingår i: Ices Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 8:4, s. 1103-12
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable harvest of wild populations requires knowledge of the underlying population structure. The focus of this study is on goldsinny wrasse (Ctenolabrus rupestris), a small marine fish inhabiting coastal waters of the north-eastern Atlantic. This species is caught in large numbers to serve as cleaner fish in salmonid aquaculture. We genotyped 2073 goldsinny wrasse from 43 sites along the Scandinavian coastline with 143 SNPs. Seven of the SNPs were linked and likely reside within a large genomic inversion dominated by one haplotype. The heterokaryotype of the putative inversion displayed sex-specific growth patterns, potentially resolving sexual antagonism for this trait. The unlinked 134 SNPs showed modest isolation-by-distance with samples from the northernmost locations showing highest divergence, whereas sites farther south were much more interconnected. Genetic divergence (F-ST) was highly variable among sites within regions, suggesting a varying degree of connectivity and local divergence. We conclude that despite a high degree of gene-flow mediated through pelagic dispersal in early life stages, regional and some local population structure remains due to limited adult movement in addition to other unidentified factors. Consequently, the species might be more vulnerable to local disturbances than previously anticipated.
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| 2. |
- Albert, F. W., et al.
(författare)
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Targeted resequencing of a genomic region influencing tameness and aggression reveals multiple signals of positive selection
- 2011
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Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 107:3, s. 205-214
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Tidskriftsartikel (refereegranskat)abstract
- The identification of the causative genetic variants in quantitative trait loci (QTL) influencing phenotypic traits is challenging, especially in crosses between outbred strains. We have previously identified several QTL influencing tameness and aggression in a cross between two lines of wild-derived, outbred rats (Rattus norvegicus) selected for their behavior towards humans. Here, we use targeted sequence capture and massively parallel sequencing of all genes in the strongest QTL in the founder animals of the cross. We identify many novel sequence variants, several of which are potentially functionally relevant. The QTL contains several regions where either the tame or the aggressive founders contain no sequence variation, and two regions where alternative haplotypes are fixed between the founders. A re-analysis of the QTL signal showed that the causative site is likely to be fixed among the tame founder animals, but that several causative alleles may segregate among the aggressive founder animals. Using a formal test for the detection of positive selection, we find 10 putative positively selected regions, some of which are close to genes known to influence behavior. Together, these results show that the QTL is probably not caused by a single selected site, but may instead represent the joint effects of several sites that were targets of polygenic selection.
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| 3. |
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| 4. |
- Jansson, E., et al.
(författare)
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Genome wide analysis reveals genetic divergence between Goldsinny wrasse populations
- 2020
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Ingår i: Bmc Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Marine fish populations are often characterized by high levels of gene flow and correspondingly low genetic divergence. This presents a challenge to define management units. Goldsinny wrasse (Ctenolabrus rupestris) is a heavily exploited species due to its importance as a cleaner-fish in commercial salmonid aquaculture. However, at the present, the population genetic structure of this species is still largely unresolved. Here, full-genome sequencing was used to produce the first genomic reference for this species, to study population-genomic divergence among four geographically distinct populations, and, to identify informative SNP markers for future studies. Results: After construction of a de novo assembly, the genome was estimated to be highly polymorphic and of similar to 600Mbp in size. 33,235 SNPs were thereafter selected to assess genomic diversity and differentiation among four populations collected from Scandinavia, Scotland, and Spain. GlobalF(ST)among these populations was 0.015-0.092. Approximately 4% of the investigated loci were identified as putative global outliers, and similar to 1% within Scandinavia. SNPs showing large divergence (F-ST > 0.15) were picked as candidate diagnostic markers for population assignment. One hundred seventy-three of the most diagnostic SNPs between the two Scandinavian populations were validated by genotyping 47 individuals from each end of the species' Scandinavian distribution range. Sixty-nine of these SNPs were significantly (p < 0.05) differentiated (meanF(ST_173_loci) = 0.065, F-ST_69_loci = 0.140). Using these validated SNPs, individuals were assigned with high probability (>= 94%) to their populations of origin. Conclusions: Goldsinny wrasse displays a highly polymorphic genome, and substantial population genomic structure. Diversifying selection likely affects population structuring globally and within Scandinavia. The diagnostic loci identified now provide a promising and cost-efficient tool to investigate goldsinny wrasse populations further.
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| 5. |
- Seljestad, G. W., et al.
(författare)
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"A cleaner break": Genetic divergence between geographic groups and sympatric phenotypes revealed in ballan wrasse (Labrus bergylta)
- 2020
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:12, s. 6120-6135
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Tidskriftsartikel (refereegranskat)abstract
- Capture and long-distance translocation of cleaner fish to control lice infestations on marine salmonid farms has the potential to influence wild populations via overexploitation in source regions, and introgression in recipient regions. Knowledge of population genetic structure is therefore required. We studied the genetic structure of ballan wrasse, a phenotypically diverse and extensively used cleaner fish, from 18 locations in Norway and Sweden, and from Galicia, Spain, using 82 SNP markers. We detected two very distinct genetic groups in Scandinavia, northwestern and southeastern. These groups were split by a stretch of sandy beaches in southwest Norway, representing a habitat discontinuity for this rocky shore-associated benthic egg-laying species. Wrasse from Galicia were highly differentiated from all Scandinavian locations, but more similar to northwestern than southeastern locations. Distinct genetic differences were observed between sympatric spotty and plain phenotypes in Galicia, but not in Scandinavia. The mechanisms underlying the geographic patterns between phenotypes are discussed, but not identified. We conclude that extensive aquaculture-mediated translocation of ballan wrasse from Sweden and southern Norway to western and middle Norway has the potential to mix genetically distinct populations. These results question the sustainability of the current cleaner fish practice.
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