基于非靶向代谢组学分析放牧与舍饲条件下彭波半细毛羊代谢特征

Exploration on metabolic characteritics of Pengbo semi-wool sheep under the condition of grazing and barn feeding based on non-targeted metabonomics

放牧与舍饲环境下,因养分不同,会引起家畜相应生理机能和代谢机理变化。探究西藏彭波半细毛羊在两种环境下代谢通路的差异情况,为放牧条件下藏系绵羊合理补饲和全价舍饲养殖饲草配方提供可行的理论和方法。采用非靶向代谢组学方法,测定放牧与舍饲环境下彭波半细毛羊血清中代谢物的沉积量与变异关系,与人类代谢组学数据库(HMDB)和京都基因与基因组百科全书(KEGG)数据库进行比对,找出与之相对应的代谢通路,并分析其原因。结果发现24种代谢物存在显著性差异(P<0.05),其中放牧组血清沉积代谢物肌醇-1-磷酸盐、赖氨酸、非对称二甲基精氨酸、鸟氨酸-1,5-丙酰胺和鸟氨酸差异显著(P<0.01);舍饲组血清沉积代谢物3-乙基苯酚、3-羟基丁酸、4-羟基脯氨酸和多聚谷胺酸差异显著(P<0.01)。与24种显著代谢物关联的代谢通路有23种,两种模式存在8种显著差异的代谢通路(P<0.05)。采用原始数据差异性、Holm-Bonferroni差异性、错误发现率(FDR)及通路拓扑等分析法,发现低蛋白饲料主要影响放牧组的缬氨酸、亮氨酸和异亮氨酸生物合成代谢通路,对精氨酸和鸟氨酸代谢通路也存在影响,即蛋白合成与机体信使传导受到阻滞。对舍饲组的丙酮酸代谢、糖酵解和糖质新生代谢通路产生影响,即能量饲料供应过剩。

The physiological functions and metabolic mechanisms were changed for the nutrition caused by the condition between the grazing and barn feeding.The differences of metabolic pathways between grazing and barn feeding were researched,and supplied theories basis and technical support for supplementary feeding of Tibet sheep in the condition of grazing and reasonable feed formula in the condition of barn feeding.The method of non-targeted metabonomics were adopted in the experiment.The deposition and the variable relationship among metabolites in sheep serum were analyzed between the grazing group and barn feeding group,and compared directly with database of HMDB and KEGG to find out the corresponding metabolic pathways,and analyze its causes.The result showed that 24 metabolites have significant difference(P<0.05).The difference of myo-inositol-1-phosphate,lysine,ADMA,ornithine-1,5-lactam and ornithine in serum metabolites of grazing group were significant(P<0.01).Similarly,the difference of 3-ethylphenol,3-hydroxybutyric acid,4-hydroxyproline and proglutamic acid in serum of barn feeding group were significant(P<0.01).The 24 metabolites were significantly correlated with 23 metabolic pathways.8 of 24 metabolic pathways showed significant difference between grazing and bard feeding(P<0.05).The result of metabolic pathways were analyzed by methods of original pvalue,Holm-Bonferroni,FDR(false discovery rate)and pathway topology analysis,the results discovered that the low protein was the main factor causing protein synthesis and messenger transduction block in metabolic pathways of valine,leucine and isoleucine biosynthesis,also influence arginine and proline metabolism.Excess energy feed in the barn feeding should cause the disturbance of pyruvate metabolism and glycolysis or gluconeogenesis.