The Relation Between Reproductive Value and Genetic Contribution
The Relation Between Reproductive Value and Genetic Contribution
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DOI：
10.1534/genetics.111.127555
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发表时间：
2011-08-01
期刊：
影响因子：
3.3
通讯作者：
Etheridge, Alison M.
中科院分区：
文献类型：
--
作者：
Barton, Nicholas H.;Etheridge, Alison M.
是什么决定了一个人对后代的遗传贡献？在双亲繁殖的情况下，每个个体都会留下一个由种群中双亲关系决定的后代“谱系”。一个人的血统限制了其每个基因的血统。一个个体的生殖价值是其每个基因的预期拷贝数，这些基因以其血统为条件传递给遥远的后代。对于最简单的双亲繁殖模型（类似于赖特-费舍尔模型），个体的繁殖值在近似10代内确定，与种群大小无关。部分自交和细分不会大大减缓这种收敛。我们的主要结论是，基因存活的概率与携带该基因的个体的生殖价值成正比，而且，在存活的条件下，经过几十代之后，存活的拷贝数的分布对于所有个体都是相同的，无论它们的生殖价值如何。这些结果可以推广到祖先基因组的幸存块的联合分布。在遗传背景中对非连锁位点的选择可能会大大增加繁殖值的方差，但上述结果仍然成立。生存概率和繁殖值之间的几乎线性关系也适用于弱优势等位基因。因此，后代的复杂谱系对个体对种群的遗传贡献的影响可以通过一个数字来概括：它的生殖价值。
What determines the genetic contribution that an individual makes to future generations? With biparental reproduction, each individual leaves a "pedigree" of descendants, determined by the biparental relationships in the population. The pedigree of an individual constrains the lines of descent of each of its genes. An individual's reproductive value is the expected number of copies of each of its genes that is passed on to distant generations conditional on its pedigree. For the simplest model of biparental reproduction (analogous to the Wright-Fisher model), an individual's reproductive value is determined within similar to 10 generations, independent of population size. Partial selfing and subdivision do not greatly slow this convergence. Our central result is that the probability that a gene will survive is proportional to the reproductive value of the individual that carries it and that, conditional on survival, after a few tens of generations, the distribution of the number of surviving copies is the same for all individuals, whatever their reproductive value. These results can be generalized to the joint distribution of surviving blocks of the ancestral genome. Selection on unlinked loci in the genetic background may greatly increase the variance in reproductive value, but the above results nevertheless still hold. The almost linear relationship between survival probability and reproductive value also holds for weakly favored alleles. Thus, the influence of the complex pedigree of descendants on an individual's genetic contribution to the population can be summarized through a single number: its reproductive value.