Pegueroles Queralt, Maria CintaFerrés Coy, AlbertMartí Solano, MariaAquadro, Charles F.Pascual, MartaMestres, Francesc2016-06-022016-06-022016Pegueroles C, Ferrés-Coy A, Martí-Solano M, Aquadro CF, Pascual M, Mestres F. Inversions and adaptation to the plant toxin ouabain shape DNA sequence variation within and between chromosomal inversions of Drosophila subobscura. Science reports. 2016; 6: 23754. DOI 10.1038/srep237542045-2322http://hdl.handle.net/10230/26803Adaptation is defined as an evolutionary process allowing organisms to succeed in certain habitats or conditions. Chromosomal inversions have the potential to be key in the adaptation processes, since they can contribute to the maintenance of favoured combinations of adaptive alleles through reduced recombination between individuals carrying different inversions. We have analysed six genes (Pif1A, Abi, Sqd, Yrt, Atpa and Fmr1), located inside and outside three inversions of the O chromosome in European populations of Drosophila subobscura. Genetic differentiation was significant between inversions despite extensive recombination inside inverted regions, irrespective of gene distance to the inversion breakpoints. Surprisingly, the highest level of genetic differentiation between arrangements was found for the Atpa gene, which is located outside the O1 and O7 inversions. Two derived unrelated arrangements (O3+4+1 and O3+4+7) are nearly fixed for several amino acid substitutions at the Atpa gene that have been described to confer resistance in other species to the cardenolide ouabain, a plant toxin capable of blocking ATPases. Similarities in the Atpa variants, conferring ouabain resistance in both arrangements, may be the result of convergent substitution and be favoured in response to selective pressures presumably related to the presence of plants containing ouabain in the geographic locations where both inversions are present.application/pdfeng© Nature Publishing Group. http://www.nature.com/articles/srep23754/n This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material.Drosòfila Genèticainfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/srep23754info:eu-repo/semantics/openAccess