EPISTASIS AND THE EFFECT OF FOUNDER EVENTS ON THE ADDITIVE GENETIC VARIANCE
EPISTASIS AND THE EFFECT OF FOUNDER EVENTS ON THE ADDITIVE GENETIC VARIANCE
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DOI：
10.1111/j.1558-5646.1988.tb04151.x
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发表时间：
1988-05-01
期刊：
影响因子：
3.3
通讯作者：
GOODNIGHT, CJ
中科院分区：
文献类型：
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作者：
GOODNIGHT, CJ
创始人事件的模型集中在创始人事件后遗传变异的减少。然而，最近的工作（Bryant等人，一九八六年;晚安，1987年）表明，当有上位性遗传变异的人口，总的遗传变异内demes实际上可能增加后，创始人事件。由于加性遗传方差是群体的统计特性，并且可以随着近交水平而变化，因此在建立者事件期间，一些上位性遗传方差可以转换为加性遗传方差。这里提出的模型表明，一些加性的加性上位性遗传方差转换为加性遗传方差的创始人事件。此外，上位性转化为加性遗传方差的量是重组率和繁殖体大小的函数。对于两个个体的单个创始者事件，祖先群体中多达75%的上位性方差可能在创始者事件之后变为加性遗传方差。对于两个自由重组个体的奠基者事件，上位性对奠基者事件后加性遗传方差的相对贡献等于其在奠基者事件前总遗传方差中的比例。与适合度密切相关的性状预期具有相对较小的加性遗传方差，但可能具有相当大的非加性遗传方差。创始人事件在适应性性状的进化中可能很重要，不是因为它们导致遗传方差的减少，而是因为它们导致加性遗传方差的增加。
Models of founder events have focused on the reduction in the genetic variation following a founder event. However, recent work (Bryant et al., 1986; Good night, 1987) suggests that when there is epistatic genetic variance in a population, the total genetic variance within demes may actually increase following a founder event. Since the additive genetic variance is a statistical property of a population and can change with the level of inbreeding, some of the epistatic genetic variance may be converted to additive genetic variance during a founder event. The model presented here demonstrates that some of the additive-by-additive epistatic genetic variance is converted to additive genetic variance following a founder event. Furthermore, the amount of epistasis converted to additive genetic variance is a function of the recombination rate and the propagule size. For a single founder event of two individuals, as much as 75% of the epistatic variance in the ancestral population may become additive genetic variance following the founder event. For founder events involving two individuals with free recombination, the relative contribution of epistasis to the additive genetic variance following a founder event is equal to its proportion of the total genetic variance prior to the founder event. Traits closely related to fitness are expected to have relatively little additive genetic variance but may have substantial nonadditive genetic variance. Founder events may be important in the evolution of fitness traits, not because they lead to a reduction in the genetic variance, but rather beause they lead to an increase in the additive genetic variance.