Transcriptome analysis reveals intestinal gene expression and metabolic pathways in yaks

The yak (Bos grunniens) is a typical high-altitude ruminant animal. It has long endured extreme environments such as low oxygen, low temperature, and strong ultraviolet radiation, and has become a key model for studying the physiological ecology of adaptation to high altitudes. The intestine is an important metabolic organ, playing a crucial role in environmental adaptation. Therefore, this study systematically compared and analyzed the transcriptional regulatory mechanisms of the yak's intestine to reveal its metabolic mechanisms for the high-altitude environment. The results showed that the expressions of several key metabolic genes such as IDO1, KYNU (tryptophan metabolism), ACSL1 (lipid metabolism), and ABCG2 (vitamin transport) in the small intestine of yaks were significantly upregulated, suggesting that they have stronger physiological potential in terms of small intestinal nutrient metabolism and barrier function. In the large intestine, the expressions of key genes in lipid metabolism (PLA2), detoxification reactions (UGT), cAMP signaling (ADCY, CREB3L), and bile secretion (ABCC) were significantly upregulated in yaks, indicating their unique physiological adaptive advantages in energy regulation and maintaining intestinal homeostasis. This study systematically expounded the metabolic mechanisms of the yak's intestine under extreme high-altitude conditions, providing a reference basis for in-depth analysis of the intestinal function of ruminants and molecular breeding.