高、低乳脂率哈萨克马血浆代谢组比较分析

Comparative Analysis of Plasma Metabolome of Kazakh Horses with High and Low Milk Fat Rates

本研究旨在分析不同乳脂率哈萨克马血浆代谢物的差异,筛选出高乳脂率哈萨克马血浆中的标志代谢物,为高乳脂率哈萨克马的选育提供数据支撑。选取年龄、胎次、体况相近,饲养管理条件一致的泌乳期哈萨克马12匹,采集产后第30~105天的乳样和血样各288份。根据测定的乳脂率结果,将乳脂率高(≥1.84%)的6匹哈萨克马的血样组成高乳脂率组,乳脂率低(≤0.90%)的6匹哈萨克马的血样组成低乳脂率组。之后,通过非靶向液相色谱-质谱(LC-MS)代谢组学技术分析血样本中的血浆代谢物。结果显示:从高、低乳脂率哈萨克马血浆中共检测出53种差异代谢物。高乳脂率哈萨克马血浆中花生四烯酸、D-赤式-1-磷酸鞘氨醇、前列腺素、5-羟基吲哚-3-乙酸、血栓素B2、尿酸等36种物质的浓度显著高于低乳脂率哈萨克马(P<0.05),L-焦谷氨酸、D-果糖-6-磷酸、生物素和D-高半胱氨酸等17种物质的浓度显著低于低乳脂率哈萨克马(P<0.05)。这些差异代谢物主要富集在花生四烯酸代谢、亚油酸代谢、嘌呤代谢、半乳糖代谢及甘氨酸、丝氨酸和苏氨酸代谢等代谢途径。本研究结果可为深层次探究乳脂的合成以及进一步提升马乳品质提供理论基础。

The purpose of this study was to analyze the differences in plasma metabolites of Kazakh horses with different milk fat rates,and to screen out the marker metabolites in plasma of Kazakh horses with high milk fat rate,so as to provide data support for the breeding of Kazakh horses with high milk fat rate.Twelve Kazakh horses with similar age,parity,body condition,and feeding and management conditions during lactation were selected,and 288 milk samples and blood samples were collected from Kazakh horses during days 30 to 105 after delivery.According to the determination results of milk fat rate,six Kazakh horses with high milk fat rate(≥1.84%)were selected,and their blood samples were divided into high milk fat rate group(HF group);six Kazakh horses with low milk fat rate(≤0.90%)were selected,and their blood samples were divided into low milk fat rate group(LF group).Subsequently,plasma metabolites in blood samples were analyzed by non-targeted liquid chromatography-mass spectrometry(LC-MS)metabolomics technique.The results showed that a total of 53 differential metabolites were detected in the plasma of high and low milk fat rate Kazakh horses.The concentrations of 36 substances such as arachidonic acid,D-erythro-sphingosine-1-phosphate,prostaglandin,5-hydroxyindole-3-acetic acid,thromboxane B2,uric acid and so on in the plasma of the high milk fat rate Kazakh horses were significantly higher than those of the low milk fat rate Kazakh horses(P<0.05),while the concentrations of 17 substances such as L-pyroglutamic acid,D-fructose-6-phosphate,biotin and D-homocysteine and so on in the plasma of the high milk fat rate Kazakh horses were significantly lower than those of the low milk fat rate Kazakh horses(P<0.05).These differential metabolites were mainly enriched in metabolic pathways such as arachidonic acid metabolism,linoleic acid metabolism,purine metabolism,galactose metabolism,glycine,serine and threonine metabolism,etc.The results of this study provide a theoretical basis for further exploring the synthesis of milk fat and further improving the quality of mare’s milk.