UNASSIGNED: This study aimed to assess the impact of non-additive effects (dominance and epistasis) on the estimation of genetic parameters for body weight traits in sheep.
UNASSIGNED: This study used phenotypic and genotypic belonging to 752 Scottish Blackface lambs. Three live weight traits considered in this study were included in body weight at 16, 20, and 24 weeks). Three genetic models including additive (AM), additive + dominance (ADM), and additive + dominance + epistasis (ADEM), were used.
UNASSIGNED: The narrow sense heritability for weight at 16 weeks of age (BW16) were 0.39, 0.35, and 0.23, for 20 weeks of age (BW20) were 0.55, 0.54, and 0.42, and finally for 24 weeks of age (BW24) were 0.16, 0.12, and 0.02, using the AM, ADM, and ADEM models, respectively. The additive genetic model significantly outperformed the non-additive genetic model (p < 0.01). The dominance variance of the BW16, BW20, and BW24 accounted for 38, 6, and 30% of the total phenotypic, respectively. Moreover, the epistatic variance accounted for 39, 0.39, and 47% of the total phenotypic variances of these traits, respectively. In addition, our results indicated that the most important SNPs for live weight traits are on chromosomes 3 (three SNPS including s12606.1, OAR3_221188082.1, and OAR3_4106875.1), 8 (OAR8_16468019.1, OAR8_18067475.1, and OAR8_18043643.1), and 19 (OAR19_18010247.1), according to the genome-wide association analysis using additive and non-additive genetic model.
UNASSIGNED: The results emphasized that the non-additive genetic effects play an important role in controlling body weight variation at the age of 16-24 weeks in Scottish Blackface lambs.
UNASSIGNED: It is expected that using a high-density SNP panel and the joint modeling of both additive and non-additive effects can lead to better estimation and prediction of genetic parameters.
■本研究旨在评估非加性效应(优势和上位性)对绵羊体重性状遗传参数估算的影响。
■这项研究使用了属于752只苏格兰黑脸羔羊的表型和基因型。本研究中考虑的三个活重性状包括在16、20和24周的体重中)。三种遗传模型包括加性(AM)、加法+优势(ADM),加性+优势+上位性(ADEM),被使用。
■16周龄(BW16)体重的狭义遗传力为0.39、0.35和0.23,20周龄(BW20)为0.55、0.54和0.42,最后24周龄(BW24)为0.16、0.12和0.02,ADM,和ADEM模型,分别。加性遗传模型显著优于非加性遗传模型(p<0.01)。BW16,BW20和BW24的优势变异占总表型的38%,6%和30%,分别。此外,上位性变异占这些性状总表型变异的39、0.39和47%,分别。此外,我们的结果表明,活重性状最重要的SNP在3号染色体上(三个SNPS,包括s12606.1,OAR3_221188082.1和OAR3_4106875.1),8(OAR8_16468019.1、OAR8_18067475.1和OAR8_18043643.1),和19(OAR19_18010247.1),根据全基因组关联分析,采用加性和非加性遗传模型。
■结果强调,非加性遗传效应在控制苏格兰黑脸羔羊16-24周龄时的体重变化中起着重要作用。
■预期使用高密度SNP面板以及加性效应和非加性效应的联合建模可以导致对遗传参数的更好估计和预测。