硬脂酰辅酶A去饱和酶1基因表达对草原安格斯牛血液脂肪酸组成的影响

研究硬脂酰辅酶A去饱和酶1（stearoyl-coenzyme A desaturase 1，SCD1）基因表达对草原安格斯牛血液脂肪酸组成的影响，采集38 头平均体质量（698±34） kg、48 月龄草原安格斯牛血液样品，测定其脂肪酸组成与含量，采用实时荧光定量聚合酶链式反应测定SCD1基因表达量，一代测序技术检测SCD1基因在C878T位点的突变对实验牛血液脂肪酸组成的影响，分析SCD1基因表达与脂肪酸组成间的相关性。结果表明：血液样品中共测得36 种主要脂肪酸，饱和脂肪酸（saturated fatty acids，SFA）以棕榈酸（C16:0）和硬脂酸（C18:0）为主，含量分别达22.53%和26.95%，单不饱和脂肪酸（monounsaturated fatty acids，MUFA）中油酸（C18:1 n-9c）含量最高（15.09%）；由SCD1基因表达与脂肪酸组成的显著性分析结果可知，SCD1基因表达对肉豆蔻酸（C14:0）、肉豆蔻油酸（C14:1）、C16:0、棕榈油酸（C16:1）、C18:0、C18:1 n-9c、亚油酸（C18:2 n-6c）、MUFA和MUFA/SFA以及C14指数、C18指数、脂肪酸总不饱和指数和伸长指数均影响显著；相关性分析结果显示，SCD1基因表达量与C16:0、C16:1、C18:0、C18:1 n-9c和MUFA含量均呈正相关；SCD1基因在878位点处出现了C/T突变，有CC、TT和CT 3 种基因型，不同基因型与脂肪酸组成之间均无显著相关性。综上所述，草原安格斯牛血液中的SCD1基因表达对其脂肪酸组成具有调控作用，可作为遗传标记参考基因。

Effects of Stearoyl-Coenzyme A Desaturease 1 Gene Expression on Blood Fatty Acid Composition of Pastured Angus Cattle

The purpose of this study was to investigate the effect of stearoyl-coenzyme desaturase 1 (SCD1) gene expression on blood fatty acid composition of Angus cattle raised on pasture. Blood samples of 38 pastured Angus cattle with average body mass of (698 ± 34) kg and at the age of 48 months were collected for fatty acid composition and content determination. The expression of the SCD1 gene was detected by real-time fluorescence quantitative polymerase chain reaction, and the influence of SCD1 gene mutation at C878T on fatty acid composition of blood samples of cattle was detected by firstgeneration sequencing technology. The correlation between SCD1 gene expression and fatty acid composition was further analyzed. The results showed the presence of 36 main fatty acids in blood samples, with the major saturated fatty acids (SFA) being palmitic acid (C16:0, 22.53%) and stearic acid (C18:0, 26.95%). Oleic acid (C18:1 n-9c) was identified as the most abundant monounsaturated fatty acid (MUFA) (15.09%). The significance analysis indicated that SCD1 gene expression had significant effects on myristic acid (C14:0), myristic acid (C14:1), C16:0, C16:1, C18:0, C18:1 n-9c, linoleic acid (C18:2 n-6c), MUFA and MUFA/SFA ratio as well as C14 index, C18 index, total unsaturation index and elongation index of fatty acids. Additionally, the correlation analysis results suggested that SCD1 gene expression was positively correlated with C16:0, palmitoleic acid (C16:1), C18:0, C18:1 n-9c and MUFA. SCD1 gene exhibited C/T mutation at the 878 site, yielding three genotypes: CC, TT and CT. No significant difference between different genotypes and fatty acid composition was found. Overall, the expression of SCD1 gene in the blood of pastured Angus cattle can regulate its fatty acid composition and thus can be used as a reference gene for genetic markers.