Kinetochore and ionomic adaptation to whole genome duplication

Whole genome duplication (WGD) brings challenges to key processes like meiosis but nevertheless is associated with diversification in all kingdoms. How is WGD tolerated, and what processes commonly evolve to stabilize the new polyploid lineage? Here we study this in Cochlearia spp., which have experienced multiple rounds of WGD in the last 300,000 years. We first generate a chromosome-scale genome and sequence 113 individuals from 33 diploid, tetraploid, hexaploid, and outgroup populations. We detect the clearest post-WGD selection signatures in functionally interacting kinetochore components and ion transporters. We structurally model these derived selected alleles, associating them with known WGD-relevant functional variation, and compare these results to independent recent post-WGD selection in Arabidopsis arenosa and Cardamine amara. Some of the same biological processes evolve in all three WGDs, but specific genes recruited are flexible. This points to a polygenic basis for modifyi...