Impact of dominance and epistasis on the genetic make-up of simulated populations under selection: A model development
Impact of dominance and epistasis on the genetic make-up of simulated populations under selection: A model development
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DOI：
10.1111/j.1439-0388.1997.tb00502.x
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发表时间：
1997-06-01
期刊：
影响因子：
--
通讯作者：
Essl, A
中科院分区：
文献类型：
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作者：
Fuerst, C;James, JW;Essl, A
用双基因座遗传模型模拟了不同水平的加性、显性和逐加性遗传效应。表型选择性状受位于不同染色体上的30对双等位基因座控制。所有基因座的初始基因频率均设置为0.5，相邻基因座之间的重组概率为0.20。广义遗传力在0.03、0.30和0.60水平上变化。在建立了一个由200只雄性和400只雌性组成的随机交配种群后，每年选出的表型最好的个体都是经过200年(约.35个世代重叠)，保持种群规模恒定。模拟结果表明，具有相同初始遗传力的8个模型之间存在极大差异，但加性、显性和逐个加性方差分量的数量不同。具有相同初始大小的加性、显性和加性-加性方差，以及负显性和正的加性-加性效应的模型，导致所有模拟遗传力的长期遗传反应最高。加性模型在短期内表现出最佳的选择进度。在选择期间，一些最初的显性和逐个加性的方差被转化为加性遗传方差，这反过来又有助于选择反应。
A two-locus genetic model was used to simulate different levels of additive, dominance, and additive-by-additive genetic effects. The character under phenotypic selection was controlled by 30 pairs of diallelic loci, located on different chromosomes. Initial gene frequencies were set to 0.5 for all loci and the recombination probability was 0.20 between adjacent loci. The broad-sense heritability was varied at levels of 0.03, 0.30, and 0.60. After building up a random mating population with 200 males and 400 females, the phenotypic best individuals per year were selected over 200 years (approx. 35 overlapping generations), keeping the population size constant. The results of the simulations showed extreme differences between eight models with the same initial heritability, but different amounts of additive, dominance, and additive-by-additive variance components. A model with additive, dominance, and additive-by-additive variance at the same initial magnitude, and negative dominance and positive additive-by-additive effect, led to the highest genetic response in the long term for all heritabilities simulated. The additive model showed the best selection advance in the short term. Some of the initial dominance and additive-by-additive variance was converted to additive genetic variance during the selection period, which in turn contributed to the selection response.