Comparison of heritabilities of dairy traits in Australian Holstein-Friesian cattle from genomic and pedigree data and implications for genomic evaluations
Comparison of heritabilities of dairy traits in Australian Holstein-Friesian cattle from genomic and pedigree data and implications for genomic evaluations
复制标题
DOI：
10.1111/j.1439-0388.2013.01001.x
复制
发表时间：
2013-02-01
影响因子：
2.6
通讯作者：
Hayes, B. J.
中科院分区：
文献类型：
--
作者：
Haile-Mariam, M.;Nieuwhof, G. J.;Hayes, B. J.
基因组评估的可靠性取决于DNA标记所解释的遗传变异的比例。在这项研究中，我们估计了45 993个全基因组单核苷酸多态性（SNP）标记在29个性状上解释奶牛子性状偏差（dtd）的变异比例。我们将这些比例与来自谱系的可加关系矩阵解释的dtd中的方差比例进行比较，以及同时拟合谱系和标记信息解释的方差总和。相对于总遗传变异（同时拟合基因组关系和家系关系所解释的总遗传变异），dtd的遗传变异比例从生育力性状的32%到产奶量性状的约80%不等。当同时拟合基因组和家系关系时，与单独拟合任何一种性状相比，大多数性状总方差的dtd中未解释的方差（即残差）减少了，这表明效应之间不存在完全重叠。基因组关系所占遗传方差的比例可用于修正由直接基因组育种值（DGV）和亲本平均值计算基因组估计育种值（GEBV）的混合方程。我们的研究结果来自DTD的年轻奶牛群体，表明这种修改可以将GEBV的可靠性提高5%。
The reliability of genomic evaluations depends on the proportion of genetic variation explained by the DNA markers. In this study, we have estimated the proportion of variance in daughter trait deviations (DTDs) of dairy bulls explained by 45 993 genome wide single-nucleotide poly- morphism (SNP) markers for 29 traits in Australian Holstein-Friesian dairy cattle. We compare these proportions to the proportion of variance in DTDs explained by the additive relationship matrix derived from the pedigree, as well as the sum of variance explained by both pedigree and marker information when these were fitted simultaneously. The propor- tion of genetic variance in DTDs relative to the total genetic variance (the total genetic variance explained by the genomic relationships and pedigree relationships when both were fitted simultaneously) varied from 32% for fertility to approximately 80% for milk yield traits. When fitting genomic and pedigree relationships simultaneously, the variance unexplained (i.e. the residual variance) in DTDs of the total variance for most traits was reduced compared to fitting either individually, suggesting that there is not complete overlap between the effects. The proportion of genetic variance accounted by the genomic relationships can be used to modify the blending equations used to calculate genomic estimated breeding value (GEBV) from direct genomic breeding value (DGV) and parent average. Our results, from a validation population of young dairy bulls with DTD, suggest that this modification can improve the reliability of GEBV by up to 5%.