Feather pecking (FP) in laying hens reduces animal welfare and leads to economic losses for the layer industry. FP is considered a heritable condition that is influenced by dysregulation of neurotransmitter homeostasis, the gut microbiome, and the immune system. To identify genes and biological pathways responsible for FP behavior we compared the brain transcriptomes of 48 hens divergently selected for FP. In addition, we tested if high feather peckers (HFP) and low feather peckers (LFP) respond differently to light since light has been shown to trigger FP behavior. Of approximately 48 million reads/sample an average of 98.4% were mapped to the chicken genome (GRCg6a). We found 13,070 expressed genes in the analyzed brains of which 423 showed differential expression between HFP and LFP. Genes of uncertain function and non-coding RNAs were overrepresented among those transcripts. Functional analyses revealed the involvement of cholinergic signaling, postsynaptic activity, membrane channels, and the immune system. After the light stimulus, 28 genes were found to be differentially expressed. These included an interaction cluster of core components of the circadian clock. However, differences in the response to light between HFP and LFP were not detectable. Genes involved in cholinergic signaling, channel activity, synaptic transmission, and immune response were found to be involved in FP behavior. We propose a model in which the gut microbiota modulates the immune system, which in turn affects cholinergic signaling. This might have an influence on monoamine signaling with possible involvement of GABA or glutamate signaling.

中文翻译：

---

分析不同的产蛋母鸡行羽毛啄食过程中的脑转录组。

蛋鸡的啄羽（FP）会降低动物的福利，并给蛋鸡行业造成经济损失。FP被认为是一种遗传性疾病，受神经递质稳态，肠道微生物组和免疫系统失调的影响。为了确定负责FP行为的基因和生物学途径，我们比较了48只不同的FP母鸡的大脑转录组。此外，我们已经测试了高羽啄木鸟（HFP）和低羽啄木鸟（LFP）对光的反应是否不同，因为已经证明光会触发FP行为。在大约4800万次读取/样品中，平均98.4％被定位到了鸡基因组（GRCg6a）。我们在分析的大脑中发现了13070个表达基因，其中423个在HFP和LFP之间显示出差异表达。在这些转录物中，功能不确定的基因和非编码RNA的表达过多。功能分析表明胆碱能信号，突触后活动，膜通道和免疫系统的参与。在光刺激之后，发现28个基因被差异表达。其中包括生物钟的核心组成部分的相互作用簇。但是，无法检测到HFP和LFP之间对光的响应差异。发现与胆碱能信号传导，通道活性，突触传递和免疫反应有关的基因与FP行为有关。我们提出了一种模型，其中肠道菌群调节免疫系统，进而影响胆碱能信号传导。这可能对单胺信号传导有影响，可能涉及GABA或谷氨酸信号传导。