畜牧兽医学报 ›› 2017, Vol. 48 ›› Issue (1): 60-67.doi: 10.11843/j.issn.0366-6964.2017.01.007

• 遗传繁育 • 上一篇    下一篇

基于显性模型的基因组选择中贝叶斯方法研究

王延晖,朱波,李俊雅*   

  1. (中国农业科学院北京畜牧兽医研究所,北京 100193)
  • 收稿日期:2016-10-27 出版日期:2017-01-23 发布日期:2017-01-23
  • 通讯作者: 李俊雅,研究员,E-mail:jl1@iascaas.net.cn
  • 作者简介:王延晖(1988-),女,甘肃景泰人,硕士,主要从事动物遗传育种与繁殖(数量遗传)研究,E-mail:wangyanhuiemail@126.com
  • 基金资助:

    现代农业(肉牛)产业技术体系岗位科学家(CARS-38);中国农业科学院科技创新工程-牛遗传育种(ASTIP-IAS03)

Bayesian Models including Dominant Effects for Genomic Selection

WANG Yan-hui, ZHU Bo, LI Jun-ya*   

  1. (Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193,China)
  • Received:2016-10-27 Online:2017-01-23 Published:2017-01-23

摘要:

本研究旨在探索显性效应对基因组育种值估计准确性的影响。基于贝叶斯A模型,根据加性效应和显性效应相关性,提出两种子模型:1)加性效应和显性效应相互独立的BayesAD1模型;2)显性系数(Dominant coefficients)与加性效应的绝对值相互独立,并且显性系数服从正态分布的BayesAD2模型。通过模拟数据比较加性效应模型BayesAD0和两种显性效应模型下基因组估计育种值(GEBV)的准确性,并且研究不同数量性状基因座(Quantitative trait locus, QTL)数、全同胞家系内个体数和加性方差与显性方差的比重对GEBV准确性的影响。结果表明,显性模型可以减缓随着世代变化GEBV的准确性降低的趋势。另外,显性方差的比重越大,对GEBV的准确性影响越大。当加性方差与显性方差之比达到0.25时,BayesAD2有较大优势,分别比BayesAD1和BayesAD0准确性高20.3%和28.4%。全同胞数越多,GEBV的准确性越高,QTL数目增多,GEBV估计的准确性随之下降。结果显示,对显性效应占较大比重即低遗传力的性状进行育种值估计时,考虑显性效应可以提高育种值估计准确性。

Abstract:

The aim of this study was to investigate the impact of dominant effects on the predictive accuracy of genomic breeding values. Based on the dependency between additive and dominant effects using BayesA model, we proposed two submodels:1) the additive effect and dominant effect were independent of each other in BayesAD1 model; 2) the dominant coefficient and absolute values of additive effect were independent of each other in BayesAD2 model, in which the dominant coefficient followed normal distribution. Using simulated datasets, we compared the predictive accuracy of genomic estimated breeding value (GEBV) among the additive model (BayesAD0) and dominant models (BayesAD1 and BayesAD2). We further investigated the effect of number of QTLs (quantitative trait loci), size of full-sibs family and ratio of additive variance to dominant variance on predictive accuracy of GEBV. The results showed that the dominant models slowed down the declining of the predictive accuracy of GEBV in subsequent generations. Moreover, the predictive accuracy of GEBV increased as the ratio of dominant variance increase. When the ratio of additive variance to dominant variance reached 0.25, BayesAD2 was 20.3% and 28.4% higher than the accuracy of the BayesAD1 and BayesAD0, respectively. In addition, the size of full-sibs family affected the predictive accuracy of GEBV positively. And an increase in the number of QTL was accompanied by a reduction on the predictive accuracy of GEBV. These results indicate that a better prediction of genetic values is intended, when the dominant variance are large just as low-heritability traits.

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