Gene flow's effect on the genetic architecture of a local adaptation and its consequences for QTL analyses
Gene flow's effect on the genetic architecture of a local adaptation and its consequences for QTL analyses
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DOI：
10.1038/sj.hdy.6800822
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发表时间：
2006-06-01
期刊：
影响因子：
3.8
通讯作者：
Griswold, C. K.
中科院分区：
文献类型：
--
作者：
Griswold, C. K.
本文使用计算机模拟来确定种群之间的基因流如何影响（1）局部适应的遗传结构和（2）数量性状基因座（QTL）作图种群中分离的等位基因的特性。结果表明，随着迁移率的增加，导致群体之间表型差异的等位基因的平均量级下降，但随着迁移率的增加，较大量级的等位基因会按比例导致群体之间更多的表型差异。 QTL 研究中使用的群体之间的基因流往往会导致作图群体中等位基因的平均幅度和解释方差百分比 (PVE) 增加。因此，尽管导致差异的等位基因的平均量值随着迁移而下降，但QTL作图群体中等位基因的平均量值或PVE可能会增加。原因是 QTL 作图群体的等位基因被采样的概率与其频率成正比，并且随着迁移的增加，较大量级的等位基因往往比效应较小的等位基因以相对更高的频率分离。随着群体之间基因流动速率的增加，由 QTL 作图群体中分离的等位基因解释的表型差异的比例（因此可能被检测到）减少。最后，结果表明，只要群体之间的分化时间不太长或群体的最佳值相距不太远，大效应（> 20% PVE）的 QTL 等位基因应该是常见的。
This paper uses computer simulations to determine how gene flow between populations affects (1) the genetic architecture of a local adaptation and (2) properties of alleles segregating in quantitative trait locus (QTL) mapping populations. Results suggest that the average magnitude of an allele that causes a phenotypic difference between populations declines as the migration rate increases, but with an increase in migration, alleles of larger magnitude cause proportionally more of the phenotypic difference between populations. Gene flow between populations that are used in a QTL study tends to cause the average magnitude and percent variance explained (PVE) of an allele in a mapping population to increase. Thus, although the average magnitude of an allele causing a difference declines with migration the average magnitude or PVE of an allele in a QTL mapping population may increase. The reason is that the probability an allele is sampled for a QTL mapping population is in direct proportion to its frequency and alleles of larger magnitude tend to segregate at relatively higher frequencies than alleles of smaller effect with an increased migration. As the rate of gene flow between populations increases, the proportion of the phenotypic difference explained by alleles that are segregating in a QTL mapping population (and therefore potentially detected) decreases. Lastly, results suggest QTL alleles of large effect (> 20% PVE) should be commonly found, provided the divergence time between populations is not too long or optima of populations are not too far apart.