Xiong Lin, Pei Jie, Wu Xiaoyun, Kalwar Qudratullah, Liang Chunnian, Guo Xian, Chu Min, Bao Pengjia, Yao Xixi, Yan Ping
Animal Science Department, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China.
Key Laboratory for Yak Genetics, Breeding, and Reproduction Engineering of Gansu Province, Lanzhou 730050, China.
Animals (Basel). 2020 Jul 7;10(7):1150. doi: 10.3390/ani10071150.
Long-term energy stress (ES) during the cold season is a serious problem for the breeding of yaks. In this paper, the response of fat metabolism in yaks to long-term ES during the cold season was studied. Gas chromatography (GC) analysis showed that the percentage of saturated fatty acids (SFAs) in the subcutaneous fat of the yaks in the ES group was 42.7%, which was less than the 56.6% in the CO group ( < 0.01) and the percentage of polyunsaturated unsaturated fatty acids (PUFAs) in the subcutaneous fat of the yaks in the ES group was 38.3%, which was more than the 26.0% in the CO group ( < 0.01). The serum analysis showed that fatty acid oxidation in yaks was increased under long-term ES. In the subcutaneous fat of yaks under long-term ES, the gene expression levels of glycerol-3-phosphate acyltransferase 4 (GPAT4), hormone-sensitive lipase (HSL), patatin-like phospholipase domain-containing protein 2 (PNPLA2), acyl-CoA dehydrogenase (ACAD), acyl-coenzyme A thioesterase 8 (ACOT8), facilitated glucose transporter (GLUT4), 3-oxoacyl-[acyl-carrier-protein] synthase (OXSM), oestradiol 17-beta-dehydrogenase 8 (HSD17B8) and malonate-Co-A ligase ACSF3 (ACSF3) were downregulated ( < 0.05), whereas the gene expression levels of aquaporin-7 (AQP7), long-chain-fatty-acid-CoA ligase (ACSL), elongation of very long chain fatty acids protein (ELOVL) and fatty acid desaturase 1 (FADS1) were upregulated ( < 0.05), indicating the inhibition of fat catabolism, fat anabolism, fatty acid oxidation, glucose (GLU) intake and SFA synthesis and the promotion of glycerinum (GLY) transportation and PUFA synthesis. Additional findings showed that the gene expression levels of leptin (LEP), adenosine 5'-monophosphate-activated protein kinase (AMPK) and phosphatidylinositol 3-kinase (PI3K) were upregulated ( < 0.05), whereas the gene expression levels of malonyl-CoA decarboxylase (MCD), sterol regulatory element-binding protein 1 (SREBF1), mammalian target of rapamycin (mTOR) and serine/threonine-protein kinase (AKT) were downregulated ( < 0.05), indicating that fat metabolism in the subcutaneous fat of yaks under ES was mainly regulated by AMPK signaling and mTOR and PI3K-AKT signaling were also involved. Energy consumption was inhibited in the subcutaneous fat itself. This study can provide a theoretical basis for the healthy breeding and genetic breeding of yaks.
寒冷季节的长期能量应激（ES）是牦牛养殖中的一个严重问题。本文研究了牦牛脂肪代谢在寒冷季节对长期ES的反应。气相色谱（GC）分析表明，ES组牦牛皮下脂肪中饱和脂肪酸（SFA）的百分比为42.7%，低于对照组的56.6%（<0.01）；ES组牦牛皮下脂肪中多不饱和脂肪酸（PUFA）的百分比为38.3%，高于对照组的26.0%（<0.01）。血清分析表明，长期ES下牦牛的脂肪酸氧化增加。在长期ES下的牦牛皮下脂肪中，甘油-3-磷酸酰基转移酶4（GPAT4）、激素敏感性脂肪酶（HSL）、含patatin样磷脂酶结构域蛋白2（PNPLA2）、酰基辅酶A脱氢酶（ACAD）、酰基辅酶A硫酯酶8（ACOT8）、易化葡萄糖转运蛋白（GLUT4）、3-氧代酰基-[酰基载体蛋白]合酶（OXSM）、雌二醇17-β-脱氢酶8（HSD17B8）和丙二酸单酰辅酶A连接酶ACSF3（ACSF3）的基因表达水平下调（<0.05），而水通道蛋白7（AQP7）、长链脂肪酸辅酶A连接酶（ACSL）、极长链脂肪酸延长蛋白（ELOVL）和脂肪酸去饱和酶1（FADS1）的基因表达水平上调（<0.05），表明脂肪分解代谢、脂肪合成代谢、脂肪酸氧化、葡萄糖（GLU）摄取和SFA合成受到抑制，甘油（GLY）转运和PUFA合成受到促进。另外的研究结果表明，瘦素（LEP）、腺苷5'-单磷酸激活蛋白激酶（AMPK）和磷脂酰肌醇3-激酶（PI3K）的基因表达水平上调（<0.05），而丙二酰辅酶A脱羧酶（MCD）、固醇调节元件结合蛋白1（SREBF1）、哺乳动物雷帕霉素靶蛋白（mTOR）和丝氨酸/苏氨酸蛋白激酶（AKT）的基因表达水平下调（<0.05），表明ES下牦牛皮下脂肪中的脂肪代谢主要受AMPK信号通路调控，mTOR和PI3K-AKT信号通路也参与其中。皮下脂肪自身的能量消耗受到抑制。本研究可为牦牛的健康养殖和遗传育种提供理论依据。
