As the main digestive organ, the small intestine plays a vital role in the digestion of animals. At present, most of the research on animal feeding habits focuses on carnivores and herbivores. However, the mechanism of feeding and digestion in omnivores remains unclear. This study aims to reveal the molecular basis of the omnivorous adaptive evolution of Melinae by comparing the transcriptome of the small intestines of Asian Badgers (Meles leucurus) and Northern Hog Badgers (Arctonyx albogularis). We obtained high-quality small intestinal transcriptome data from these two species. Key genes and signalling pathways were analysed through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and other databases. Research has mainly found that orthologous genes related to six enzymes have undergone adaptive evolution. In addition, the study also found three digestion-related pathways (cGMP-PKG, cAMP, and Hippo). They are related to the digestion and absorption of nutrients, the secretion of intestinal fluids, and the transport of food through the small intestine, which may help omnivorous animals adapt to an omnivorous diet. Our study provides insight into the adaptation of Melinae to omnivores and affords a valuable transcriptome resource for future research.

小肠作为主要的消化器官，在动物的消化过程中起着至关重要的作用。目前，对动物摄食习性的研究大多集中在肉食动物和草食动物。然而，杂食动物的摄食和消化机制仍不清楚。本研究旨在通过比较亚洲獾（ Meles leucurus）和北方猪獾（Arctonyx abogularis ）小肠的转录组，揭示Melinae杂食性适应性进化的分子基础。我们从这两个物种获得了高质量的小肠转录组数据。通过基因本体论（GO）、京都基因和基因组百科全书（KEGG）等数据库对关键基因和信号通路进行分析。研究主要发现与六种酶相关的直系同源基因发生了适应性进化。此外，研究还发现了三种消化相关途径（cGMP-PKG、cAMP和Hippo）。它们与营养物质的消化吸收、肠液的分泌以及食物通过小肠的运输有关，这可能有助于杂食动物适应杂食性饮食。我们的研究深入了解了 Melinae 对杂食动物的适应，并为未来的研究提供了宝贵的转录组资源。