DOES RECOMBINATION CONSTRAIN NEUTRAL DIVERGENCE AMONG BACTERIAL TAXA
DOES RECOMBINATION CONSTRAIN NEUTRAL DIVERGENCE AMONG BACTERIAL TAXA
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DOI：
10.1111/j.1558-5646.1995.tb05968.x
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发表时间：
1995-02-01
期刊：
影响因子：
3.3
通讯作者：
COHAN, FM
中科院分区：
文献类型：
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作者：
COHAN, FM
本文提出了一种用于预测可区分为独立DNA序列簇的密切相关类群之间中性分歧命运的合并模型。该模型迭代地模拟了序列分歧和类群间性别隔离之间的正反馈，其中序列分歧的增加导致重组减少，而重组减少导致序列分歧的增加。该反馈的迭代被继续，直到序列发散收敛于稳定状态或达到失控过程。序列分歧的最终结果取决于四个可评估的群体遗传参数：预期的轴突内序列多样性、轴突内重组的基线速率、重组率对序列分歧的敏感性和中性突变率。该模型可以用来确定实际分类群之间的中性分歧是否注定要在平衡水平上停止，或者中性分歧是否会达到失控的过程。将该模型应用于含有枯草芽孢杆菌及其近亲的一组分类群，表明这些分类群彼此之间处于无界中性发散的轨道上。
A coalescence model for predicting the fate of neutral divergence among closely related taxa distinguishable as separate DNA sequence clusters is presented here. The model simulates iteratively the positive feedback between sequence divergence and sexual isolation among taxa, where increases in sequence divergence result in reduced recombination, and reduced recombination results in increased sequence divergence. Iteration of this feedback is continued until sequence divergence either converges on a steady state or reaches a runaway process. The eventual outcome of sequence divergence was shown to depend on four estimable population-genetic parameters: the expected intrataxon sequence diversity, the baseline rate of intrataxon recombination, the sensitivity of the recombination rate to sequence divergence, and the neutral mutation rate. The model can be used to determine whether neutral divergence among actual taxa is destined to stop at an equilibrium level, or whether neutral divergence will reach a runaway process. Application of the model to the group of taxa containing Bacillus subtilis and its closest relatives showed these taxa to be on a trajectory of unbounded neutral divergence from one another.