High degree of genetic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus)
| Autor: | Jacquelin DeFaveri, Juha Merilä, Yukinori Shimada, Takahito Shikano |
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| Rok vydání: | 2013 |
| Předmět: |
Genetic Markers
0106 biological sciences Candidate gene Oceans and Seas Population Adaptation Biological Gasterosteus Environment Biology 010603 evolutionary biology 01 natural sciences Gene flow 03 medical and health sciences Gene Frequency Genetics Animals Cluster Analysis 14. Life underwater Selection Genetic Allele education Allele frequency Ecology Evolution Behavior and Systematics 030304 developmental biology 0303 health sciences education.field_of_study Genetic Variation Bayes Theorem biology.organism_classification Smegmamorpha Genetics Population Genetic marker Microsatellite Microsatellite Repeats |
| Zdroj: | Molecular Ecology. 22:4811-4828 |
| ISSN: | 0962-1083 |
| Popis: | Populations of widespread marine organisms are typically characterized by a low degree of genetic differentiation in neutral genetic markers, but much less is known about differentiation in genes whose functional roles are associated with specific selection regimes. To uncover possible adaptive population divergence and heterogeneous genomic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus), we used a candidate gene-based genome-scan approach to analyse variability in 138 microsatellite loci located within/close to (6 kb) functionally important genes in samples collected from ten geographic locations. The degree of genetic differentiation in markers classified as neutral or under balancing selection-as determined with several outlier detection methods-was low (F(ST) = 0.033 or 0.011, respectively), whereas average FST for directionally selected markers was significantly higher (F(ST) = 0.097). Clustering analyses provided support for genomic and geographic heterogeneity in selection: six genetic clusters were identified based on allele frequency differences in the directionally selected loci, whereas four were identified with the neutral loci. Allelic variation in several loci exhibited significant associations with environmental variables, supporting the conjecture that temperature and salinity, but not optic conditions, are important drivers of adaptive divergence among populations. In general, these results suggest that in spite of the high degree of physical connectivity and gene flow as inferred from neutral marker genes, marine stickleback populations are strongly genetically structured in loci associated with functionally relevant genes. |
| Databáze: | OpenAIRE |
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