PDF(Pubmed)
Abstract：
Polyploidy, the result of whole-genome duplication (WGD), is a major driver of eukaryote evolution. Yet WGDs are hugely disruptive mutations, and we still lack a clear understanding of their fitness consequences. Here, we study whether WGDs result in greater diversity of genomic structural variants (SVs) and how they influence evolutionary dynamics in a plant genus, Cochlearia (Brassicaceae). By using long-read sequencing and a graph-based pangenome, we find both negative and positive interactions between WGDs and SVs. Masking of recessive mutations due to WGDs leads to a progressive accumulation of deleterious SVs across four ploidal levels (from diploids to octoploids), likely reducing the adaptive potential of polyploid populations. However, we also discover putative benefits arising from SV accumulation, as more ploidy-specific SVs harbor signals of local adaptation in polyploids than in diploids. Together, our results suggest that SVs play diverse and contrasting roles in the evolutionary trajectories of young polyploids.
摘要：
多倍体,全基因组复制（WGD）的结果，是真核生物进化的主要驱动力。然而，WGD是巨大的破坏性突变，我们仍然对他们的健身后果缺乏清晰的了解。这里,我们研究WGD是否会导致基因组结构变异（SV）的更大多样性，以及它们如何影响植物属的进化动力学，耳蜗（十字花科）。通过使用长读数测序和基于图形的pangenome，我们发现WGD和SV之间既有消极的相互作用，也有积极的相互作用。由于WGD引起的隐性突变的掩盖导致有害SV在四个倍性水平（从二倍体到八倍体）的逐步积累，可能会降低多倍体种群的适应性潜力。然而,我们还发现了SV积累带来的推定益处，与二倍体相比，多倍体特异性SVs具有更多的局部适应信号。一起,我们的结果表明，SVs在年轻多倍体的进化轨迹中起着不同的作用。
