Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, UK.
Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.
Nat Ecol Evol. 2019 Mar;3(3):457-468. doi: 10.1038/s41559-019-0807-4. Epub 2019 Feb 25.
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.
倍性变化的物种允许直接推断染色体拷贝数对基本进化过程的影响。虽然大量的理论工作表明，多倍体应该会留下明显的群体基因组特征，但实证数据仍然很少。我们对来自 39 个拟南芥沙生种群的约 300 个个体进行了测序，这是一个自然的二倍体-同源四倍体物种。我们发现，多倍体对群体基因组过程的影响是微妙而普遍的，例如降低了纯化选择的效率、连锁选择的差异以及来自二倍体的猖獗基因流动。有害突变的初始屏蔽、核苷酸替换率的加快以及种间杂交的发生，可能共同塑造了多倍体的进化潜力。
