Department of Animal Sciences, Georg-August-University, 37077, Göttingen, Germany.
Institute of Animal Science, University of Hohenheim, 70599, Stuttgart, Germany.
BMC Genomics. 2024 Sep 19;25(1):880. doi: 10.1186/s12864-024-10782-5.
Reproductive performance plays an important role in animal welfare, health and profitability in animal husbandry and breeding. It is well established that there is a negative correlation between performance and reproduction in dairy cattle. This relationship is being increasingly considered in breeding programs. By elucidating the genetic architecture of underlying reproduction traits, it will be possible to make a more detailed contribution to this. Our study followed two approaches to elucidate this area; in a first part, variance components were estimated for 14 different calving and fertility traits, and then genome-wide association studies were performed for 13 reproduction traits on imputed sequence-level genotypes with subsequent enrichment analyses.
Variance components analyses showed a low to moderate heritability (h) for the traits analysed, ranging from 0.014 for endometritis up to 0.271 for stillbirth, indicating variable degrees of variation within the reproduction traits. For genome-wide association studies, we were able to detect genome-wide significant association signals for nine out of 13 analysed traits after Bonferroni correction on chromosome 6, 18 and the X chromosome. In total, we detected over 2700 associated SNPs encircling more than 90 different genes using the imputed whole-genome sequence data. Functional associations were reviewed so far known and potential candidate regions in the proximity of reproduction events were hypothesised.
Our results confirm previous findings of other authors in a comprehensive cohort including 13 different traits at the same time. Additionally, we identified new candidate genes involved in dairy cattle reproduction and made initial suggestions regarding their potential impact, with special regard to the X chromosome as a putative information source for further research. This work can make a contribution to reveal the genetic architecture of reproduction traits in context of trait specific interactions.
在畜牧业和繁殖中，繁殖性能对动物福利、健康和盈利能力起着重要作用。众所周知，奶牛的生产性能和繁殖性能呈负相关。这种关系在繁殖计划中越来越受到重视。通过阐明潜在繁殖性状的遗传结构，我们将有可能对此做出更详细的贡献。我们的研究采用了两种方法来阐明这一领域；在第一部分，对 14 种不同的产犊和繁殖性状进行了方差分量估计，然后对 13 种繁殖性状进行了全基因组关联研究，使用随后的富集分析对基于序列水平基因型的 imputed 进行了全基因组关联研究。
方差分量分析显示，所分析性状的遗传力（h）较低，从子宫内膜炎的 0.014 到死产的 0.271，表明繁殖性状的变异程度不同。对于全基因组关联研究，在对 6 号、18 号和 X 染色体进行 Bonferroni 校正后，我们能够检测到 13 个分析性状中的 9 个具有全基因组显著关联信号。利用 imputed 全基因组序列数据，总共检测到超过 2700 个与 90 多个不同基因相关的关联 SNP，围绕着这些基因。迄今为止，已经对功能关联进行了审查，并假设了与繁殖事件接近的潜在候选区域。
我们的结果在一个包含 13 个不同性状的综合队列中证实了其他作者的先前发现。此外，我们确定了新的候选基因参与奶牛繁殖，并对其潜在影响提出了初步建议，特别是对 X 染色体，因为它可能是进一步研究的信息来源。这项工作有助于揭示特定性状相互作用背景下繁殖性状的遗传结构。
