家畜复杂性状稀有变异遗传研究

Study on Inheritance of Rare Variants of Complex Traits in Livestock

本研究通过模拟和基因组数据,使用群体遗传模型来预测稀有变异选择的预期特征,并比较不同SNP年龄估计方法的结果之间的异同。Wright-Fisher模型框架下,随着初始基因频率的增加,基因被固定的概率上升;与有效群体缩减Wright-Fisher模型相比,一般Wright-Fisher模型和有效群体扩增Wright-Fisher模型的基因被固定概率更高,但初始基因频率较高时,3种模型无明显差异。稀有变异基因的遗传方式为共显性、完全显性时,稀有变异基因可以在群体中达到很高的频率或固定,其中完全显性时基因频率在群体中达到0.5以上的概率更高;稀有变异基因的遗传方式为共显性时,不同有效群体含量随选择系数变化的规律与理论预测基本相同。SNP年龄估计依据不同假设条件,往往有不同估计结果。

This study uses population genetic models to predict the expected characteristics of rare variant selection through simulation and genomic data,and compares the similarities and differences between the results of different SNP age estimation methods.Under the framework of the Wright-Fisher model,with the increase of the initial gene frequency,the probability of the gene being fixed increases;compared with the effective population size contraction Wright-Fisher model,the fixed probability of gene frequency in the general Wright-Fisher model and the effective population expansion Wright-Fisher model is higher,but when the initial gene frequency is higher,there is no significant difference between the those models.When the genetic mode of the rare variant gene is codominance and completely dominant,the rare variant gene can reach a high frequency or fixation in the population.And when the genetic mode is completely dominant,the probability of gene frequency reaching 0.5 or more in the population is higher.When the genetic mode of rare variant genes is codominant,the law of the different effective populations size with the different selection coefficient is basically the same as the theoretical prediction.SNP age estimation methods based on different assumptions often have different estimation results.