Ploidy-variable species allow direct inference of the effects of chromosome copy number on fundamental evolutionary processes. While an abundance of theoretical work suggests polyploidy should leave distinct population genomic signatures, empirical data remains sparse. We sequenced ~300 individuals from 39 populations of Arabidopsis arenosa, a naturally diploid-autotetraploid species. We find that the impacts of polyploidy on population genomic processes are subtle yet pervasive, such as reduced efficiency of purifying selection, differences in linked selection and rampant gene flow from diploids. Initial masking of deleterious mutations, faster rates of nucleotide substitution and interploidy introgression likely conspire to shape the evolutionary potential of polyploids.
Bibliographical noteFunding Information:
The authors thank E. Záveská, M. Lučanová and S. Španiel for help with fieldwork and J. Brookfield and S. Martin for helpful comments on versions of the manuscript. Computational resources were provided by the CESNET LM2015042 and the CERIT Scientific Cloud LM2015085, provided under the programme Projects of Large Research, Development, and Innovations Infrastructures, and by SNIC through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under Project SNIC 2017/7–174. L.Y. acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement 679056) and the UK Biological and Biotechnology Research Council (BBSRC) via grant BB/P013511/1 to the John Innes Centre. K.B. acknowledges European Research Council Consolidator grant CoG EVO-MEIO 681946 and US National Science Foundation IOS-1146465. Additional support was provided by Czech Science Foundation (project 16–10809S to K.M. and 17–20357Y to F.K.), Charles University (project Primus/SCI/35 to F.K.), and a SNSF Early Postdoc Mobility fellowship (P2ZHP3_158773 to C.S.).
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.