UPLC-QTOF/MS-based metabolomic analysis of plasma reveals altitude effects on yaks (Bos grunniens)

Abstract

The yak is an ideal animal model for the study of adaptation to hypoxia at high altitudes. Its blood metabolites are an important reference index for research regarding adaptation to high-altitude hypoxia and can reflect cellular activity, antioxidant capacity and the metabolic capacity of yaks, thus highlighting the adaptability of the yak to hypoxic environments. The aim of our study was to evaluate differences in the global metabolic profiles of plasma in high- and low-altitude yaks (average age: 3 years old; live weight (LW): 300 ± 50 kg) using untargeted metabolomics. 52 differential metabolites were identified; 13 metabolites such as choline and trimethylamine N-oxide showed upregulated expression and 39 different metabolites such as L-carnitine and oleic acid were downregulated. Most of them were involved in energy, lipid and amino acid metabolism pathways. After analysis, the lysosome, citrate cycle, histidine metabolism and fatty acid biosynthesis changed significantly. The results demonstrate that there were differences in the metabolomes of high- and low-altitude yaks. As altitude increases, the critical pathways involve lysosomes, citrate cycle, histidine metabolism, fatty acid biosynthesis and biosynthesis of unsaturated fatty acids.