Comparative Lipidomic Profiling of Camel and Cow Milk from a Shared Semi-Desert Pasture: Implications for Camel Adapta-tion to Arid Environments

opment in desert environments. Using UHPLC-MS/MS and targeted oxylipidomics, we compared milk from free-grazing camels and cows from the same region. We identi-fied 2,460 lipids across 44 subclasses and 11 oxygenated lipids in three groups. Glyc-erophospholipids (GP) were dominant in both. We found 498 differentially expressed lipids, including potential biomarkers such as phosphatidylinositol (PI 18:0/22:3), phosphatidylethanolamine (PE 18:0/22:3), and two triacylglycerol (TG) species. Camel milk was dominated by phosphatidylcholine (PC, approximately 49%) and PI (ap-proximately 22%), whereas cow milk was predominantly composed of TG (nearly 98%). Pathway analysis showed 11 key altered lipid pathways, mainly glycerophospholipid metabolism. These results define camel milk's unique lipid profile—linked to desert adaptation-and provide molecular insights into its role in supporting neonatal camels in arid environments.

沙漠环境中的适应性演化。本研究采用超高效液相色谱-串联质谱（Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry, UHPLC-MS/MS）与靶向氧脂组学（targeted oxylipidomics）技术，对比了同区域内自由放牧骆驼与奶牛的乳样脂质组成。我们在3个组别中共鉴定出覆盖44个亚类的2460种脂质，以及11种含氧脂质。两类乳样均以甘油磷脂（Glycerophospholipids, GP）为主。本研究共筛选出498种差异表达脂质，其中包含潜在生物标志物，如磷脂酰肌醇（phosphatidylinositol, PI 18:0/22:3）、磷脂酰乙醇胺（phosphatidylethanolamine, PE 18:0/22:3）以及两种三酰甘油（triacylglycerol, TG）亚型。骆驼乳以磷脂酰胆碱（phosphatidylcholine, PC，约49%）和磷脂酰肌醇（PI，约22%）为主要组成，而牛乳则几乎全部由三酰甘油（TG，近98%）构成。通路分析显示存在11条关键的差异脂质代谢通路，其中以甘油磷脂代谢通路为主。本研究明确了与沙漠适应相关的骆驼乳独特脂质谱，并为解析其在干旱环境中支撑新生骆驼存活的分子机制提供了新的见解。