Lower flight reaction is closely related to higher production in cattle, but the genetic basis of lower flight reaction is not clearly understood. Here, we sampled a total of 45 Brahman cattles and 166 Yunling cattles with flight distance (FD), and 73 Brahman cattles and 288 Yunling cattles with crush score (CS) and flight speed (FS), whereas there were 45 Brahman cattles and 161 Yunling cattles with all three traits. The FD, CS and FS in Brahman cattle were significantly lower than those in Yunling cattle. The flight reaction traits had negative correlation with conformational traits (e.g., body weight, withers height and body length). Based on SNPs derived from a subset of 162 whole genomes (25 Brahman genomes and 100 Yunling genomes with FD, 30 Brahman and 131 Yunling genomes with CS and FS), genome-wide association study with mixed linear model was performed to test potential associations between flight reaction traits and genomic variants. We identified five, two and two genomic loci suggestively associated with FD, CS and FS, respectively. Five out of five candidate genes for FD (LOC789753, LRP6, CTIF, SLC9A9 and ZEB1) were reported to be related to Alzheimer's disease representing cognitive impairment in human, which was consistent with the finding that cognitive-behavioural intervention decreased the FD of cows to human. In CS, a very strong association locus was assigned to CDH8, a cadherin involved in synaptic adhesion, axon outgrowth and guidance, whose deletion was associated with autism spectrum disorder. In FS, a very strong association locus was assigned to GABRG2, a gamma-aminobutyric acid (a major inhibitory neurotransmitter in brain) receptor, whose polymorphisms were associated with suicidal behaviour in schizophrenia patients. Our findings will provide targets for molecular-marker selection and genetic manipulation of cattle improvement to meeting the growing demand for lower flight reaction to human.

中文翻译：

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全基因组关联研究确定了与牛飞行反应相关的基因组位点

低飞行反应与牛的高产密切相关，但低飞行反应的遗传基础尚不清楚。在这里，我们总共采样了 45 头婆罗门牛和 166 头具有飞行距离（FD）的婆罗门牛和 73 头婆罗门牛和 288 头云岭牛，其中有粉碎分数（CS）和飞行速度（FS），而有 45 头婆罗门牛和 161具有全部三个特征的云岭牛。婆罗门牛的FD、CS和FS显着低于云岭牛。飞行反应性状与构象性状（如体重、马肩隆高度和体长）呈负相关。基于源自 162 个全基因组子集的 SNP（25 个婆罗门基因组和 100 个具有 FD 的婆罗门基因组，30 个婆罗门基因组和 131 个具有 CS 和 FS 的云岭基因组），使用混合线性模型进行全基因组关联研究，以测试飞行反应性状和基因组变异之间的潜在关联。我们分别确定了五个、两个和两个与 FD、CS 和 FS 相关的基因组位点。据报道，五分之五的 FD 候选基因（LOC789753、LRP6、CTIF、SLC9A9 和 ZEB1）与代表人类认知障碍的阿尔茨海默病有关，这与认知行为干预将奶牛的 FD 降低至人类。在 CS 中，一个非常强的关联位点被分配给 CDH8，这是一种参与突触粘附、轴突生长和引导的钙粘蛋白，其缺失与自闭症谱系障碍有关。在 FS 中，一个非常强的关联位点被分配给 GABRG2，一种γ-氨基丁酸（大脑中的主要抑制性神经递质）受体，其多态性与精神分裂症患者的自杀行为有关。我们的研究结果将为牛改良的分子标记选择和基因操作提供目标，以满足对人类低飞行反应不断增长的需求。