Koch, Eva L.; Morales, Hernán E.; Larsson, Jenny; Westram, Anja MIST Austria ; Faria, Rui; Lemmon, Alan R.; Lemmon, E. Moriarty; Johannesson, Kerstin; Butlin, Roger K.
Chromosomal inversions have long been recognized for their role in local adaptation. By suppressing recombination in heterozygous individuals, they can maintain coadapted gene complexes and protect them from homogenizing effects of gene flow. However, to fully understand their importance for local adaptation we need to know their influence on phenotypes under divergent selection. For this, the marine snail Littorina saxatilis provides an ideal study system. Divergent ecotypes adapted to wave action and crab predation occur in close proximity on intertidal shores with gene flow between them. Here, we used F2 individuals obtained from crosses between the ecotypes to test for associations between genomic regions and traits distinguishing the Crab‐/Wave‐adapted ecotypes including size, shape, shell thickness, and behavior. We show that most of these traits are influenced by two previously detected inversion regions that are divergent between ecotypes. We thus gain a better understanding of one important underlying mechanism responsible for the rapid and repeated formation of ecotypes: divergent selection acting on inversions. We also found that some inversions contributed to more than one trait suggesting that they may contain several loci involved in adaptation, consistent with the hypothesis that suppression of recombination within inversions facilitates differentiation in the presence of gene flow.
We are very grateful to Irena Senčić for technical assistance and to Michelle Kortyna and Sean Holland at the Center for Anchored Phylogenomics for assistance with data collection. RKB was funded by the Natural Environment Research Council and by the European Research Council. KJ was funded by the Swedish Research Councils VR and Formas (Linnaeus Grant: 217‐2008‐1719). JL was funded by a studentship from the Leverhulme Centre for Advanced Biological Modelling. AMW was funded by the European Union's Horizon 2020 research and innovation program under Marie Skłodowska‐Curie Grant agreement no. 797747. RF was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska‐Curie Grant agreement No. 706376 and by FEDER Funds through the Operational Competitiveness Factors Program—COMPETE and by National Funds through FCT—Foundation for Science and Technology within the scope of the project “Hybrabbid” (PTDC/BIA‐EVL/30628/2017‐ POCI‐01‐0145‐FEDER‐030628). We are grateful to other members of the Littorina research group for helpful discussions. We thank Claire Mérot and an anonymous referee for insightful comments on an earlier version.
Koch EL, Morales HE, Larsson J, et al. Genetic variation for adaptive traits is associated with polymorphic inversions in Littorina saxatilis. Evolution Letters. 2021. doi:10.1002/evl3.227
Koch, E. L., Morales, H. E., Larsson, J., Westram, A. M., Faria, R., Lemmon, A. R., … Butlin, R. K. (2021). Genetic variation for adaptive traits is associated with polymorphic inversions in Littorina saxatilis. Evolution Letters. Wiley. https://doi.org/10.1002/evl3.227
Koch, Eva L., Hernán E. Morales, Jenny Larsson, Anja M Westram, Rui Faria, Alan R. Lemmon, E. Moriarty Lemmon, Kerstin Johannesson, and Roger K. Butlin. “Genetic Variation for Adaptive Traits Is Associated with Polymorphic Inversions in Littorina Saxatilis.” Evolution Letters. Wiley, 2021. https://doi.org/10.1002/evl3.227.
E. L. Koch et al., “Genetic variation for adaptive traits is associated with polymorphic inversions in Littorina saxatilis,” Evolution Letters. Wiley, 2021.
Koch EL, Morales HE, Larsson J, Westram AM, Faria R, Lemmon AR, Lemmon EM, Johannesson K, Butlin RK. 2021. Genetic variation for adaptive traits is associated with polymorphic inversions in Littorina saxatilis. Evolution Letters.
Koch, Eva L., et al. “Genetic Variation for Adaptive Traits Is Associated with Polymorphic Inversions in Littorina Saxatilis.” Evolution Letters, Wiley, 2021, doi:10.1002/evl3.227.
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