Institute of Animal Sciences, University of Bonn, Endenicher Allee 15, Bonn, 53115, Germany.
BHZP GmbH, An der Wassermühle 8, Dahlenburg-Ellringen, 21368, Germany.
BMC Genomics. 2021 Oct 5;22(1):717. doi: 10.1186/s12864-021-07997-1.
In recent years, animal welfare and health has become more and more important in pig breeding. So far, numerous parameters have been considered as important biomarkers, especially in the immune reaction and inflammation. Previous studies have shown moderate to high heritabilities in most of these traits. However, the genetic background of health and robustness of pigs needs to be extensively clarified. The objective of this study was to identify genomic regions with a biological relevance for the immunocompetence of piglets. Genome-wide Association Studies (GWAS) in 535 Landrace (LR) and 461 Large White (LW) piglets were performed, investigating 20 immune relevant traits. Besides the health indicators of the complete and differential blood count, eight different cytokines and haptoglobin were recorded in all piglets and their biological dams to capture mediating processes and acute phase reactions. Additionally, all animals were genotyped using the Illumina PorcineSNP60v2 BeadChip.
In summary, GWAS detected 25 genome-wide and 452 chromosome-wide significant SNPs associated with 17 immune relevant traits in the two maternal pig lines LR and LW. Only small differences were observed considering the maternal immune records as covariate within the statistical model. Furthermore, the study identified across- and within-breed differences as well as relevant candidate genes. In LR more significant associations and related candidate genes were detected, compared with LW. The results detected in LR and LW are partly in accordance with previously identified quantitative trait loci (QTL) regions. In addition, promising novel genomic regions were identified which might be of interest for further detailed analysis. Especially putative pleiotropic regions on SSC5, SSC12, SSC15, SSC16 and SSC17 are of major interest with regard to the interacting structure of the immune system. The comparison with already identified QTL gives indications on interactions with traits affecting piglet survival and also production traits.
In conclusion, results suggest a polygenic and breed-specific background of immune relevant traits. The current study provides knowledge about regions with biological relevance for health and immune traits. Identified markers and putative pleiotropic regions provide first indications in the context of balancing a breeding-based modification of the porcine immune system.
近年来，动物福利和健康在养猪业中变得越来越重要。到目前为止，许多参数已被认为是重要的生物标志物，尤其是在免疫反应和炎症中。以前的研究表明，大多数这些性状都具有中等到高度的遗传力。然而，猪的健康和稳健性的遗传背景需要广泛阐明。本研究的目的是确定与仔猪免疫能力具有生物学相关性的基因组区域。对 535 头长白猪（LR）和 461 头大白猪（LW）仔猪进行了全基因组关联研究（GWAS），研究了 20 个免疫相关性状。除了完整和差异血细胞计数的健康指标外，还记录了所有仔猪及其生物母猪的 8 种不同细胞因子和触珠蛋白，以捕捉介导过程和急性期反应。此外，所有动物均使用 Illumina PorcineSNP60v2 BeadChip 进行基因分型。
总之，GWAS 在两个母系猪种 LR 和 LW 中检测到与 17 个免疫相关性状相关的 25 个全基因组和 452 个染色体宽显著 SNP。在统计模型中，考虑到母体免疫记录作为协变量，仅观察到很小的差异。此外，该研究还确定了跨品种和品种内的差异以及相关的候选基因。与 LW 相比，在 LR 中检测到更多的显著关联和相关的候选基因。在 LR 和 LW 中检测到的结果部分与以前确定的数量性状基因座（QTL）区域一致。此外，还确定了有前途的新基因组区域，这些区域可能是进一步详细分析的兴趣所在。特别是 SSC5、SSC12、SSC15、SSC16 和 SSC17 上的假定多效性区域与免疫系统的相互作用结构有关。与已确定的 QTL 进行比较表明，与影响仔猪存活率和生产性状的性状存在相互作用。
总之，结果表明免疫相关性状具有多基因和品种特异性背景。本研究提供了与健康和免疫性状具有生物学相关性的区域的知识。鉴定的标记和假定的多效性区域在平衡猪免疫系统的基于育种的修饰方面提供了初步指示。
