Egg-laying is an important trait in chickens, and it is affected by many factors, such as hormones regulated by the hypothalamic-pituitary axis and precursors synthesized by the liver. Recent studies showed that gut microbiota was associated with egg-laying, however, its underlying mechanism remains unclear. We comprehensively analyzed the host transcriptome, gut microbiota, and metabolome in broiler breeder hens during the pre-laying, peak-laying, and late-laying periods. The transcriptome analysis of the tissues related to the hypothalamic-pituitary-liver (HPL) axis revealed dynamic gene expression during egg-laying periods. Differentially expressed genes (DEGs) (i.e., PENK, NPY, AVP, PRL, RLN3, and FST) from the hypothalamus and pituitary gland were involved in female gonadal development, hormone secretion, response to endogenous stimulus, liver development, and amide metabolism. In liver, DEGs (i.e., FABP3, VTG1, LPL, APOA5, APOV1, and RBP5) were enriched in efferocytosis, sphingolipid metabolism, amide, and peptide biosynthesis. Alpha and beta diversity changed significantly in cecum microbiota during different laying periods. The abundance of Firmicutes was decreased and the abundance of Bacteroidota was increased during the peak-laying period. Functional analysis showed that the biosynthesis of secondary metabolites, amino acids, purine, and steroid hormones was altered during laying. The metabolome analysis from cecal contents showed that amino acid metabolism and steroid hormone biosynthesis changed during laying. Integrated analysis of the cecal microbiota and metabolites showed the genus Megasphaera was involved in amino acid metabolism, which included 3-phenyllatic acid, quinic acid, caffeic acid, and folic acid, and the genus Hungatella participated in steroid hormone biosynthesis through its strong correlation with estradiol. These results explored the dynamic changes in tissues related to the HPL axis and cecal microbiota and provided new insights into the interaction between the host and microbiota during egg-laying in chickens.

中文翻译：

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多组学分析揭示了鸡宿主基因表达、肠道微生物群和代谢物之间的关联


产蛋是鸡的一个重要特征，它受许多因素的影响，例如下丘脑-垂体轴调节的激素和肝脏合成的前体。最近的研究表明，肠道微生物群与产卵有关，但其潜在机制仍不清楚。我们全面分析了肉种鸡在产蛋前、产高峰和产蛋晚期的宿主转录组、肠道菌群和代谢组。与下丘脑-垂体-肝脏 （HPL） 轴相关的组织的转录组分析揭示了产卵期间的动态基因表达。来自下丘脑和垂体的差异表达基因 （DEGs） （即 PENK、NPY、AVP、PRL、RLN3 和 FST） 参与女性性腺发育、激素分泌、对内源性刺激的反应、肝脏发育和酰胺代谢。在肝脏中，DEGs （即 FABP3 、 VTG1 、 LPL 、 APOA5 、 APOV1 和 RBP5） 在胞吐作用、鞘脂代谢、酰胺和肽生物合成中富集。在不同产蛋期盲肠微生物群中 α 和 β 多样性发生显著变化。在产高峰期，厚壁菌门的丰度降低，拟杆菌门的丰度增加。功能分析表明，次生代谢物、氨基酸、嘌呤和类固醇激素的生物合成在产蛋过程中发生改变。盲肠内容物的代谢组分析表明，产蛋过程中氨基酸代谢和类固醇激素生物合成发生变化。 盲肠菌群和代谢物的综合分析显示，Megasphaera 属参与氨基酸代谢，包括 3-苯基酸、奎宁酸、咖啡酸和叶酸，Hungatella 属通过与雌二醇的强相关性参与类固醇激素的生物合成。这些结果探讨了与 HPL 轴和盲肠微生物群相关的组织的动态变化，并为鸡产蛋过程中宿主与微生物群之间的相互作用提供了新的见解。