Hall David W, Dawe R Kelly
Department of Genetics, University of Georgia, Athens, Georgia 30602-7223
Department of Genetics, University of Georgia, Athens, Georgia 30602-7223.
G3 (Bethesda). 2018 Jan 4;8(1):123-130. doi: 10.1534/g3.117.300073.
Autosomal drivers violate Mendel's law of segregation in that they are overrepresented in gametes of heterozygous parents. For drivers to be polymorphic within populations rather than fixing, their transmission advantage must be offset by deleterious effects on other fitness components. In this paper, we develop an analytical model for the evolution of autosomal drivers that is motivated by the neocentromere drive system found in maize. In particular, we model both the transmission advantage and deleterious fitness effects on seed viability, pollen viability, seed to adult survival mediated by maternal genotype, and seed to adult survival mediated by offspring genotype. We derive general, biologically intuitive conditions for the four most likely evolutionary outcomes and discuss the expected evolution of autosomal drivers given these conditions. Finally, we determine the expected equilibrium allele frequencies predicted by the model given recent estimates of fitness components for all relevant genotypes and show that the predicted equilibrium is within the range observed in maize land races for levels of drive at the low end of what has been observed.
常染色体驱动因子违反了孟德尔分离定律，因为它们在杂合亲本的配子中过度出现。为了使驱动因子在种群中保持多态性而非固定不变，它们的传递优势必须被对其他适合度成分的有害影响所抵消。在本文中，我们基于玉米中发现的新着丝粒驱动系统，开发了一个常染色体驱动因子进化的分析模型。特别地，我们对种子活力、花粉活力、由母本基因型介导的种子到成体的存活以及由后代基因型介导的种子到成体的存活的传递优势和有害适合度效应进行了建模。我们推导了四种最可能的进化结果的一般的、生物学上直观的条件，并讨论了在这些条件下常染色体驱动因子的预期进化。最后，我们根据所有相关基因型的适合度成分的近期估计值，确定了该模型预测的预期平衡等位基因频率，并表明预测的平衡处于玉米地方品种中所观察到的驱动水平低端的范围内。
