BACKGROUND Inbreeding is caused by mating between related individuals and its most common consequence is inbreeding depression. Several studies have detected heterogeneity in inbreeding depression among founder individuals, and recently a procedure for predicting hidden inbreeding depression loads associated with founders and the Mendelian sampling of non-founders has been developed. The objectives of our study were to expand this model to predict the inbreeding loads for all individuals in the pedigree and to estimate the covariance between the inbreeding loads and the additive genetic effects for the trait of interest. We tested the proposed approach with simulated data and with two datasets of records on weaning weight from the Spanish Pirenaica and Rubia Gallega beef cattle breeds. RESULTS The posterior estimates of the variance components with the simulated datasets did not differ significantly from the simulation parameters. In addition, the correlation between the predicted and simulated inbreeding loads were always positive and ranged from 0.27 to 0.82. The beef cattle datasets comprised 35,126 and 75,194 records on weights between 170 and 250 days of age, and pedigrees of 308,836 and 384,434 individual-sire-dam entries for the Pirenaica and Rubia Gallega breeds, respectively. The posterior mean estimates of the variance of inbreeding depression loads were 29,967.8 and 28,222.4 for the Pirenaica and Rubia Gallega breeds, respectively. They were larger than those of the additive variance (695.0 and 439.8 for Pirenaica and Rubia Gallega, respectively), because they should be understood as the variance of the inbreeding depression achieved by a fully inbred (100%) descendant. Therefore, the inbreeding loads have to be rescaled for smaller inbreeding coefficients. In addition, a strong negative correlation (- 0.43 ± 0.10) between additive effects and inbreeding loads was detected in the Pirenaica, but not in the Rubia Gallega breed. CONCLUSIONS The results of the simulation study confirmed the ability of the proposed procedure to predict inbreeding depression loads for all individuals in the populations. Furthermore, the results obtained from the two real datasets confirmed the variability in the inbreeding depression loads in both breeds and suggested a negative correlation of the inbreeding loads with the additive genetic effects in the Pirenaica breed.

中文翻译：

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具有直接加性和近亲抑郁负荷效应的多元分析。

背景技术近亲繁殖是由相关个体之间的交配引起的，其最普遍的后果是近亲沮丧。几项研究已经发现创始人之间的近亲抑郁症存在异质性，并且最近开发了一种预测与创始人和非创始人的孟德尔抽样相关的隐性近亲抑郁负荷的程序。我们研究的目的是扩展该模型，以预测谱系中所有个体的近交负荷，并估计近交负荷与相关性状的附加遗传效应之间的协方差。我们用模拟数据和两个来自西班牙比雷牛属和鲁比亚·加利加（Rubia Gallega）肉牛品种的断奶体重的记录数据集对提出的方法进行了测试。结果模拟数据集的方差成分的后验估计与模拟参数没有显着差异。此外，预测和模拟近交负载之间的相关性始终为正，范围为0.27至0.82。肉牛数据集包括体重在170至250天之间的35,126和75,194条记录，以及比雷牛和卢比娅·盖勒加（Rubia Gallega）犬种的分别为308,836和384,434个个体父系血统的谱系。Pirenaica和Rubia Gallega品种近交抑郁负荷的后验均值分别为29,967.8和28,222.4。它们大于加性方差（Pirenaica和Rubia Gallega分别为695.0和439.8），因为它们应被理解为完全近交（100％）后代实现的近交沮丧感的变化。因此，对于较小的近交系数，必须重新调整近交负载。此外，在皮雷纳科发现了加性效应与近交负载之间的强负相关（-0.43±0.10），而在卢比亚·盖勒加（Rubia Gallega）品种中则没有。结论仿真研究的结果证实了所提出的方法能够预测人群中所有个体的近交抑郁负荷。此外，从两个真实数据集获得的结果证实了两个品种近交凹陷负荷的变异性，并表明近交载荷与比雷牛属品种的加性遗传效应呈负相关。