Mutator dynamics in sexual and asexual experimental populations of yeast.
Mutator dynamics in sexual and asexual experimental populations of yeast.
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DOI：
10.1186/1471-2148-11-158
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发表时间：
2011-06-07
影响因子：
3.4
通讯作者：
Sniegowski PD
中科院分区：
文献类型：
--
作者：
Raynes Y;Gazzara MR;Sniegowski PD
在无性种群中，突变体可能会与相关的有益突变搭便车。在有性种群中，预计重组会削弱这种关联，抑制突变搭便车。为了实验研究重组对突变子的影响，我们比较了酿酒酵母有性和无性群体中一个突变等位基因（msh2Δ）的频率动态。在所有的无性二倍体种群中，突变株的频率以牺牲野生型株的频率为代价而增加，有些在繁殖150代时接近固定。在同一时期内，在所有相应的有性繁殖的二倍体种群和无性繁殖的单倍体种群中，突变体都趋于消失。我们报告了在有性种群中突变动力学的第一个实验研究。我们发现，正如理论预测的那样，强突变体在有性种群中迅速下降，而在无性二倍体种群中搭便车到高频。我们还表明，msh2Δ突变体具有高而直接的实现成本，仅这一点就足以解释其在有性种群中的下降。我们假设这种成本是间接的；也就是说，它是由于非常高的隐性致死或强有害突变率。然而，我们不能排除msh2Δ对适应性也有未知的直接有害影响的可能性，并且这些影响可能在单倍体无性和有性种群之间有所不同。尽管存在这些保留意见，但我们的结果促使我们推测，在防止有性种群中的突变搭便车方面，高度有害的隐性突变的短期成本可能与重组一样重要。
In asexual populations, mutators may be expected to hitchhike with associated beneficial mutations. In sexual populations, recombination is predicted to erode such associations, inhibiting mutator hitchhiking. To investigate the effect of recombination on mutators experimentally, we compared the frequency dynamics of a mutator allele (msh2Δ) in sexual and asexual populations of Saccharomyces cerevisiae. Mutator strains increased in frequency at the expense of wild-type strains in all asexual diploid populations, with some approaching fixation in 150 generations of propagation. Over the same period of time, mutators declined toward loss in all corresponding sexual diploid populations as well as in haploid populations propagated asexually. We report the first experimental investigation of mutator dynamics in sexual populations. We show that a strong mutator quickly declines in sexual populations while hitchhiking to high frequency in asexual diploid populations, as predicted by theory. We also show that the msh2Δ mutator has a high and immediate realized cost that is alone sufficient to explain its decline in sexual populations. We postulate that this cost is indirect; namely, that it is due to a very high rate of recessive lethal or strongly deleterious mutation. However, we cannot rule out the possibility that msh2Δ also has unknown directly deleterious effects on fitness, and that these effects may differ between haploid asexual and sexual populations. Despite these reservations, our results prompt us to speculate that the short-term cost of highly deleterious recessive mutations can be as important as recombination in preventing mutator hitchhiking in sexual populations.
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影响因子：
14.8
作者：
Gietz, R. Daniel;Schiestl, Robert H.
通讯作者：
Schiestl, Robert H.
DOI：
10.1098/rspb.1999.0936
发表时间：
1999-12-07
影响因子：
4.7
作者：
Johnson, T
通讯作者：
Johnson, T
影响因子：
3.3
作者：
Joseph, SB;Hall, DW
通讯作者：
Hall, DW
影响因子：
56.9
作者：
Giraud, A;Matic, I;Taddei, F
通讯作者：
Taddei, F
影响因子：
3.3
作者：
André, JB;Godelle, B
通讯作者：
Godelle, B