脂肪和肥胖相关基因、瘦素与阿勒泰大尾羊脂肪沉积的联系及调控机制研究

项目名称： 脂肪和肥胖相关基因、瘦素与阿勒泰大尾羊脂肪沉积的联系及调控机制研究

项目编号： No.31460646

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 农业科学

项目作者： 王金泉

作者单位： 新疆农业大学

项目金额： 50万元

中文摘要： 新疆肉用绵羊多为脂臀型品种，虽肉用性能良好，但尾脂过大，有些品种的尾脂甚至占体重的17%以上。如何降低尾脂而又不影响肌内脂肪含量，一直是困扰新疆绵羊优良肉质性状种质资源利用的关键问题，而解决的关键是深入了解其各部位脂肪沉积的规律及其关键调节因子对脂肪调控的机制。FTO是第一个与普通肥胖相关的基因，与脂肪沉积相关，在能量平衡和脂肪代谢中起有重要作用，摄食可导致FTO表达改变。Leptin由脂肪组织分泌，可调节摄食，分解脂肪。目前，FTO、leptin和脂肪沉积间的联系并不清楚。因此，本课题选用生长快系和慢系阿勒泰大尾羊通过限饲和高脂饮食试验，采用组织学和分子生物学等技术，比较同日龄生长快系与慢系，正常、限饲与高脂饮食组绵羊FTO表达及脂肪沉积的差异，及FTO、leptin与脂肪代谢相关激素和基因表达水平间的相关性，阐明FTO、leptin与脂肪沉积之间的联系，探讨FTO调控脂肪沉积分子机制。

中文关键词： 脂肪和肥胖相关基因；瘦素；脂肪沉积；调控机制

英文摘要： Altay sheep is an indigenous sheep breed in Xin Jiang. Meat quality of Altay sheep is very delicious. However, their tail fat tissue is too big, even more than 17% of body weight. How to reduce tail fat weight and does not affect intramuscular fat content，which hat has been a key problem of economic trait improvement of sheep in Xin Jiang. Fat mass and obesity associated gene (FTO) is the first gene related common obesity, and is related fatty deposition and metabolism. Evidence to date suggests that the association between SNPs in FTO and BMI is predominantly driven by increased energy intake. Subjects homozygous for the obesity-risk A allele of rs9939609 exhibit overall increased adlibitum food-intake, particularly fat consumption, and impaired satiety. FTO play a key role in regulating energy homeostasis. FTO is highly expressed in brain regions controlling feeding and energy expenditure, such as the hypothalamus. Hypothalamic FTO expression is modulated by fasting and restricted access to food, although both up-regulation and down-regulation have been reported, apparently depending on the severity of caloric restriction. Exposure to a high-fat diet also modulates hypothalamic FTO expression, with down-regulation reported with short-term exposure and up-regulation with more prolonged exposure. FTO gene mRNA expression was significantly different between skeletal muscle and fat tissues. Leptin is a peptide hormone expressed, synthesized and secreted by adipose tissue in proportion to its mass. This hormone circulates in blood and acts on the hypothalamus to regulate food intake and energy expenditure. When fat mass falls, plasma leptin levels fall stimulating appetite and suppressing energy expenditure until fat mass is restored. At present, the space-time of FTO gene expression have not been adequately addressed in sheep, and furthermore, little is known about correlation between FTO gene,leptin, and fatty deposition of the sheep. In the present study, we used Altay sheep as model to delineate a link of FTO gene,leptin,and fatty deposition by fasting and high-fat diet. FTO expression and leptin in different old and body weight sheep will be measured by RT-PCR and Western blot. Hormone levels, such as growth hormone and insulin, in serum will be measured.

英文关键词： Fat mass and obesity associated gene;Leptin;Fatty deposition;Regulation