Integrative Population and Physiological Genomics Reveals Mechanisms of Adaptation in Killifish
| Autor: | Man Van La, Patricia M. Schulte, Andrew Whitehead, Heather J. Bryant, Timothy M. Healy, Reid S. Brennan |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Population Adaptation Biological Genomics Genome-wide association study 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Fundulidae Genetics Animals 14. Life underwater Selection Genetic education Association mapping Molecular Biology Ecology Evolution Behavior and Systematics Local adaptation education.field_of_study Natural selection biology Phenotypic trait biology.organism_classification Biological Evolution Fundulus 030104 developmental biology Phenotype Evolutionary biology Genome-Wide Association Study |
| Zdroj: | Molecular biology and evolution. 35(11) |
| ISSN: | 1537-1719 |
| Popis: | Adaptive divergence between marine and freshwater (FW) environments is important in generating phyletic diversity within fishes, but the genetic basis of this process remains poorly understood. Genome selection scans can identify adaptive loci, but incomplete knowledge of genotype-phenotype connections makes interpreting their significance difficult. In contrast, association mapping (genome-wide association mapping [GWAS], random forest [RF] analyses) links genotype to phenotype, but offer limited insight into the evolutionary forces shaping variation. Here, we combined GWAS, RF, and selection scans to identify loci important in adaptation to FW environments. We utilized FW-native and brackish water (BW)-native populations of Atlantic killifish (Fundulus heteroclitus) as well as a naturally admixed population between the two. We measured morphology and multiple physiological traits that differ between populations and may contribute to osmotic adaptation (salinity tolerance, hypoxia tolerance, metabolic rate, body shape) and used a reduced representation approach for genome-wide genotyping. Our results show patterns of population divergence in physiological capabilities that are consistent with local adaptation. Population genomic scans between BW-native and FW-native populations identified genomic regions evolving by natural selection, whereas association mapping revealed loci that contribute to variation for each trait. There was substantial overlap in the genomic regions putatively under selection and loci associated with phenotypic traits, particularly for salinity tolerance, suggesting that these regions and genes are important for adaptive divergence between BW and FW environments. Together, these data provide insight into the mechanisms that enable diversification of fishes across osmotic boundaries. |
| Databáze: | OpenAIRE |
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