Abstract：
Breeding animals able to effectively respond to stress could be a long-term, sustainable, and affordable strategy to improve resilience and welfare in livestock systems. In the present study, the concentrations of 29 plasma biomarkers were used as candidate endophenotypes for metabolic stress response in single-SNP, gene- and haplotype-based GWAS using 739 healthy lactating Italian Holstein cows and 88,271 variants. Significant genetic associations were found in all the 3 GWAS approaches for plasma γ-glutamyl transferase concentration on BTA17, for paraoxonase on BTA4, and for alkaline phosphatase and zinc on BTA2. On these chromosomes, single-SNP and gene-based chromosome-wide association studies were performed, confirming GWAS findings. The signals identified for paraoxonase, γ-glutamyl transferase, and alkaline phosphatase were in proximity of the genes coding for them. The heritability of these 4 biomarkers ranged from moderate to high (from 0.39 to 0.54). Plasma biomarkers are known to undergo large changes in concentration during metabolic stress in the transition period, with an inter-individual variability in the rate of change and recovery time. Genetics may account in part for these differences. To assess this, we studied a subset of 139 periparturient cows homozygous at 3 SNPs known to be respectively associated with concentration of plasma ceruloplasmin, paraoxonase and γ-glutamyl transferase. We compared the immune-metabolic profile measured in plasma at -7, +5 and +30 d relative to calving between groups of opposite homozygotes. A significant effect of the genotype was found on paraoxonase and γ-glutamyl transferase plasma concentration at all the 3 time points. No evidence for genotype effect was detected for ceruloplasmin. Understanding the genetic control underlying metabolic stress response may suggest new approaches to foster resilience in dairy cows.
摘要：
能够有效应对压力的繁殖动物可能是一个长期的，可持续,和负担得起的战略，以提高牲畜系统的弹性和福利。在本研究中,29个血浆生物标志物的浓度被用作单SNP代谢应激反应的候选内表型，基于基因和单倍型的GWAS使用739头健康泌乳的意大利荷斯坦奶牛和88,271种变体。在BTA17上的血浆γ-谷氨酰转移酶浓度，BTA4上的对氧磷酶以及BTA2上的碱性磷酸酶和锌的所有3种GWAS方法中均发现了显着的遗传关联。在这些染色体上，进行了单SNP和基于基因的全染色体关联研究，确认GWAS的发现。对氧磷酶的信号鉴定，γ-谷氨酰转移酶，和碱性磷酸酶在编码它们的基因附近。这4种生物标志物的遗传力范围从中等到高(从0.39到0.54)。已知血浆生物标志物在过渡期的代谢应激期间经历大的浓度变化,在变化率和恢复时间方面存在个体差异。遗传学可以部分解释这些差异。为了评估这一点，我们研究了139只在3个SNP纯合的围产期母牛的子集，已知分别与血浆铜蓝蛋白浓度相关，对氧磷酶和γ-谷氨酰转移酶。我们比较了相对于相反纯合子组之间的产卵在-7、5和30d时在血浆中测量的免疫代谢谱。在所有3个时间点，基因型对对对氧磷酶和γ-谷氨酰转移酶血浆浓度均有显着影响。未检测到铜蓝蛋白的基因型效应的证据。了解代谢应激反应的遗传控制可能会提出新的方法来培养奶牛的韧性。
