Microbial and Plant Genetics Institute, University of Minnesota, St Paul, MN 55108, USA.
Biol Lett. 2020 Feb;16(2):20190796. doi: 10.1098/rsbl.2019.0796. Epub 2020 Feb 26.
Searching for population genomic signals left behind by positive selection is a major focus of evolutionary biology, particularly as sequencing technologies develop and costs decline. The effect of the number of chromosome copies (i.e. ploidy) on the manifestation of these signals remains an outstanding question, despite a wide appreciation of ploidy being a fundamental parameter governing numerous biological processes. We clarify the principal forces governing the differential manifestation and persistence of the selection signal by separating the effects of polyploidy on the rates of fixation versus rates of diversity (i.e. mutation and recombination) using coalescent simulations. We explore the major consequences of polyploidy, finding a more localized signal, greater dependence on dominance and longer persistence of the signal following fixation, and discuss what this means for within- and across ploidy inference on the strength and prevalence of selective sweeps. As genomic advances continue to open doors for interrogating natural systems, simulations such as this aid our ability to interpret and compare data across ploidy levels.
搜索正选择留下的群体基因组信号是进化生物学的主要焦点，特别是随着测序技术的发展和成本的降低。尽管多倍体是控制许多生物过程的基本参数，但多倍体对这些信号表现的影响仍然是一个悬而未决的问题。我们使用合并模拟将多倍体对固定率与多样性率（即突变和重组）的影响分开，澄清了控制选择信号差异表现和持续的主要力量。我们探索了多倍体的主要后果，发现信号更局部化，对显性的依赖性更大，以及在固定后信号的持久性更长，并讨论了这对在不同倍性水平上推断选择清扫的强度和普遍性意味着什么。随着基因组学的进步继续为研究自然系统开辟道路，这种模拟有助于我们提高解释和比较不同倍性水平数据的能力。
