Genetic architecture in a marine hybrid zone: comparing outlier detection and genomic clines analysis in the bivalve Macoma balthica
Luttikhuizen, P.C.; Drent, J.; Peijnenburg, K.T.C.A.; van der Veer, H.W.; Johannesson, K. (2012). Genetic architecture in a marine hybrid zone: comparing outlier detection and genomic clines analysis in the bivalve Macoma balthica. Mol. Ecol. 21(12): 3048-3061. dx.doi.org/10.1111/j.1365-294X.2012.05586.x
In: Molecular Ecology. Blackwell: Oxford. ISSN 0962-1083; e-ISSN 1365-294X, more
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| Author keywords |
admixture mapping; ecological speciation; FST outliers; genomic clines;population genomics |
| Authors | | Top |
- Luttikhuizen, P.C., more
- Drent, J., more
- Peijnenburg, K.T.C.A.
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- van der Veer, H.W., more
- Johannesson, K.
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| Abstract |
The role of natural selection in speciation has received increasing attention and support in recent years. Different types of approaches have been developed that can detect genomic regions influenced by selection. Here, we address the question whether two highly different methodsFST outlier analysis and admixture analysisdetect largely the same set of non-neutral genomic elements or, instead, complementary sets. We study genetic architecture in a natural secondary contact zone where extensive admixture occurs. The marine bivalves Macoma balthica rubra and M. b. balthica descend from two independent trans-Arctic invasions of the north Atlantic and hybridize extensively where they meet, for example in the KattegatDanish StraitsBaltic Sea region. The KattegatDanish Straits region forms a steep salinity cline and is the only entrance to the recently (ca. 8000 years ago) established brackish water basin the Baltic Sea. Salinity along the contact zone drops from 30 parts per thousand (Skagerrak, M.b.rubra) to 3 parts per thousand(Baltic, M.b.balthica). Both outlier analysis and genomic clines analysis suggest that large parts of the genome are influenced by non-neutral effects. Contrasting samples from well outside the hybrid zone, outlier analysis detects 16 of 84 amplified fragment length polymorphism markers as significant FST outliers. Genomic clines analysis detects 31 of 84 markers as non-neutral inside the hybrid zone. Remarkably, only three markers are detected by both methods. We conclude that the two methods together identify a suite of markers that are under the influence of non-neutral effects. |
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