Loss of least-loaded class in asexual populations due to drift and epistasis
Loss of least-loaded class in asexual populations due to drift and epistasis
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DOI：
10.1534/genetics.108.089136
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发表时间：
2008-08-01
期刊：
影响因子：
3.3
通讯作者：
Jain, Kavita
中科院分区：
文献类型：
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作者：
Jain, Kavita
我们考虑一个非重组的单倍体种群的动态有限的大小，积累有害的突变不可逆的。这种类似棘轮的过程在不存在上位性的情况下以有限的速度发生，但是已经提出协同上位性可以停止棘轮。使用扩散理论，我们找到明确的解析表达式的棘轮的连续点击之间的典型时间为nonepistatic和epistatic健身功能。我们的计算表明，interclick时间是一个缩放形式，在没有上位性的情况下，给出了一个速度，这是由最小负载类的大小和选择系数。与协同作用，棘轮速度被发现迅速接近零任意上位性。我们的分析结果与数值模拟吻合得很好。
We consider the dynamics of a nonrecombining haploid population of finite size that accumulates deleterious mutations irreversibly. This ratchet-like process occurs at a finite speed in the absence of epistasis, but it has been suggested that synergistic epistasis can halt the ratchet. Using a diffusion theory, we find explicit analytical expressions for the typical time between successive clicks of the ratchet for both nonepistatic and epistatic fitness functions. Our calculations show that the interclick time is of a scaling form that in the absence of epistasis gives a speed that is determined by size of the least-loaded class and the selection coefficient. With synergistic interactions, the ratchet speed is found to approach zero rapidly for arbitrary epistasis. Our analytical results are in good agreement with the numerical simulations.