不同放牧条件下绒山羊肌肉脂肪代谢和沉积变化的研究
Changes of Muscle Fat Metabolism and Deposition in Cashmere Goat under Different Grazing Conditions
-
摘要: 采用实时荧光定量多聚核苷酸链式反应(real-time quantitative polymerase chain reaction,RT-PCR)和气相色谱-质谱联用技术(gas chromatography-mass spectrometry,GC-MS)研究不同放牧条件下1.5岁绒山羊肌肉脂肪代谢和沉积的变化。结果表明,山地组肌内脂肪(intramuscular fat,IMF)含量显著高于草地组(p<0.05),不同放牧条件对肌肉中水分、灰分和蛋白质含量无显著影响(p>0.05)。山地组中多不饱和脂肪酸(polyunsaturated fatty acids,PUFA)显著含量高于草地组(p<0.05),并且α-亚麻酸、共轭亚油酸(conjugated linoleic acid,CLA)和二十二碳六烯酸(docosahexenoic acid,DHA)的含量均显著高于草地组(p<0.05)。通过相关性分析可知,硬脂酰辅酶A去饱和酶(stearoyl-CoA desaturase,SCD)和脂蛋白脂酶(lipoprteinlipase,LPL)基因高表达均有利于肌内脂肪的沉积,SCD基因的高表达有利于肌肉中单不饱和脂肪酸(monounsaturated fatty acids,MUFA)的沉积,而LPL基因的高表达会抑制肌肉中PUFA的沉积。Abstract: The aim of this study was to investigate the changes of fat metabolism and deposition of longissimus dorsi muscles in 1.5-year-old cashmere goat under different grazing conditions by the quantitative real-time PCR and gas chromatography-mass spectrometry(GC-MS).The results showed that the content of intramuscular fat(IMF)in hilly-graze group was significantly higher than that of pasture-graze group(p<0.05),different grazing conditions had no significant effect on water,ash,and protein content in muscle(p>0.05). The percentage of polyunsaturated fatty acids(PUFA)in hilly-graze group was significantly higher than that in pasture-graze group(p<0.05),and the contents of α-linolenic,CLA and DHA were significantly higher in hilly-graze group(p<0.05). Correlation analysis showed that high expression of SCD and LPL genes were beneficial to the deposition of intramuscular fat. The high expression of SCD gene facilitates the deposition of monounsaturated fatty acids(MUFA)in musclewhile high expression of the LPL gene inhibits the deposition of PUFA in longissimus dorsi muscles.