Table 1_The integrative analysis of transcriptome and metabolome reveals differences in raw foie gras performance induced by different force-feeding intensities in male Tianfu meat geese.docx

We aimed to explore the influence of different force-feeding intensities on foie gras performance. Geese were force-fed with A (force-feeding four times per day and lasting 28 days) and B (force-feeding 5 times per day and lasting 18 days) at two levels of force-feeding intensities in this study. An integrative analysis of the liver transcriptome, amino acid metabolome, and long-chain fatty acid metabolome was performed. In serum, the levels of blood glucose, insulin, triglyceride (TG), and very low-density lipoprotein (VLDL) of the B group were significantly higher than those of the A group (p < 0.05). The B force-feeding intensity induced more severe steatosis in the goose liver. Transcriptome analysis showed that 948 upregulated differentially expressed genes (DEGs) and 519 downregulated DEGs were identified (A vs. B); key DEGs G6PD, IGF1, IGF2, and MLX were upregulated; LPL, IRS1, IRS4, and IGF1R were downregulated. Principal component analysis (PCA) indicated that there was clear separation and discrimination in liver free amino acids profiles and long-chain fatty acids profiles between the A and B groups, respectively. The Lys level of the B group was significantly higher than that of the A group (p < 0.05). The highest enrichment pathway of different amino acids was valine, leucine, and isoleucine biosynthesis, whereas alanine, aspartate, and glutamate metabolism was the pathway involved with the highest impact score. The levels of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), unsaturated fatty acids (UFAs), C14:0, C16:1, C16:0, C18:2n6c, C18:1n9c, and C18:0 of the B group were significantly higher than those of the A group (p < 0.05). The highest impact score pathway related to different fatty acids was linoleic acid metabolism, and the highest enrichment pathway involved in different fatty acids was biosynthesis of unsaturated fatty acids. In conclusion, liver DEGs involved in glucolipid metabolism, different free amino acids, and different fatty acids collectively shaped the foie gras performance difference induced by different force-feeding intensities.

本研究旨在探究不同填饲强度对鹅肥肝（foie gras）品质的影响。本研究设置两种填饲强度处理组：A组为每日填饲4次，持续28天；B组为每日填饲5次，持续18天。本研究对肝脏转录组、氨基酸代谢组以及长链脂肪酸代谢组进行了整合分析。血清检测结果显示，B组的血糖、胰岛素、甘油三酯（triglyceride, TG）与极低密度脂蛋白（very low-density lipoprotein, VLDL）水平均显著高于A组（p < 0.05）。B组填饲强度可诱导鹅肝脏产生更为严重的脂肪变性。转录组分析结果显示，相较于A组，B组中共鉴定出948个上调差异表达基因（differentially expressed genes, DEGs）与519个下调差异表达基因；其中关键差异表达基因G6PD、IGF1、IGF2及MLX呈上调表达，LPL、IRS1、IRS4与IGF1R呈下调表达。主成分分析（principal component analysis, PCA）结果表明，A组与B组的肝脏游离氨基酸谱及长链脂肪酸谱分别呈现出清晰的分离与区分效果。B组的赖氨酸（Lys）水平显著高于A组（p < 0.05）。差异氨基酸的最显著富集通路为缬氨酸、亮氨酸与异亮氨酸生物合成通路，而丙氨酸、天冬氨酸与谷氨酸代谢通路则拥有最高的影响得分。B组的饱和脂肪酸（saturated fatty acids, SFAs）、单不饱和脂肪酸（monounsaturated fatty acids, MUFAs）、不饱和脂肪酸（unsaturated fatty acids, UFAs）以及C14:0、C16:1、C16:0、C18:2n6c、C18:1n9c与C18:0水平均显著高于A组（p < 0.05）。与差异脂肪酸相关的最高影响得分通路为亚油酸代谢通路，而差异脂肪酸的最显著富集通路为不饱和脂肪酸生物合成通路。综上，参与糖脂代谢的肝脏差异表达基因、差异游离氨基酸以及差异脂肪酸共同塑造了不同填饲强度诱导的鹅肥肝品质差异。