Hybrid fitness effects modify fixation probabilities of introgressed alleles.
Hybrid fitness effects modify fixation probabilities of introgressed alleles.
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DOI：
10.1093/g3journal/jkac113
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发表时间：
2022-07-06
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影响因子：
--
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中科院分区：
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杂交是自然种群中常见的现象，而基因渗入是遗传变异的主要来源。尽管适应性渐渗在进化中具有重要意义，但经典的群体遗传学理论并没有考虑到杂交适应度效应。具体来说，杂种优势（即杂种活力）和Dobzhansky-Muller不亲和性影响等位基因的渗入命运。在这里，我们明确地解释了多基因、非连锁杂交适应度效应，当跟踪一个罕见的渐渗入标记等位基因时。由于重复回交，这些杂交适应度效应会随着时间的推移而迅速衰减，从而实现了时间尺度分离方法。利用扩散和分支过程理论结合计算机模拟，我们形式化了混合适应度效应如何影响渐渗等位基因背后的直觉。研究发现，杂种适应度效应会显著阻碍或提高等位基因的固定概率，这取决于杂种优势的相对强度和Dobzhansky-Muller不亲和性效应。我们表明，在经典群体遗传学理论中加入校正因子（α，代表杂交适应度效应随时间的复合效应）可以产生准确的固定概率。尽管杂交适应度效应对固定的概率有很大的影响，但它只是微妙地改变了达到固定的渐渗等位基因的适应度效应的分布。虽然强Dobzhansky-Muller不亲和性效应可能加速渐渗等位基因的丢失，但固定时间在很大程度上不受杂交适应度效应的影响。
Hybridization is a common occurrence in natural populations, and introgression is a major source of genetic variation. Despite the evolutionary importance of adaptive introgression, classical population genetics theory does not take into account hybrid fitness effects. Specifically, heterosis (i.e. hybrid vigor) and Dobzhansky–Muller incompatibilities influence the fates of introgressed alleles. Here, we explicitly account for polygenic, unlinked hybrid fitness effects when tracking a rare introgressed marker allele. These hybrid fitness effects quickly decay over time due to repeated backcrossing, enabling a separation-of-timescales approach. Using diffusion and branching process theory in combination with computer simulations, we formalize the intuition behind how hybrid fitness effects affect introgressed alleles. We find that hybrid fitness effects can significantly hinder or boost the fixation probability of introgressed alleles, depending on the relative strength of heterosis and Dobzhansky–Muller incompatibilities effects. We show that the inclusion of a correction factor (α, representing the compounded effects of hybrid fitness effects over time) into classic population genetics theory yields accurate fixation probabilities. Despite having a strong impact on the probability of fixation, hybrid fitness effects only subtly change the distribution of fitness effects of introgressed alleles that reach fixation. Although strong Dobzhansky–Muller incompatibility effects may expedite the loss of introgressed alleles, fixation times are largely unchanged by hybrid fitness effects.
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影响因子：
64.5
作者：
Browning SR;Browning BL;Zhou Y;Tucci S;Akey JM
通讯作者：
Akey JM
DOI：
10.1007/978-3-319-16345-1_10
发表时间：
2015-01-01
期刊：
RETICULATE EVOLUTION: SYMBIOGENESIS, LATERAL GENE TRANSFER, HYBRIDIZATION AND INFECTIOUS HEREDITY
影响因子：
--
作者：
Arnold, Michael L.;Brothers, Amanda N.;Martin, Noland H.
通讯作者：
Martin, Noland H.
影响因子：
3.3
作者：
DOBZHANSKY, T;PAVLOVSKY, O
通讯作者：
PAVLOVSKY, O
影响因子：
3.3
作者：
Edmands, S
通讯作者：
Edmands, S
影响因子：
3.5
作者：
Geneva, Anthony;Garrigan, Daniel
通讯作者：
Garrigan, Daniel