miR-23a/27a/24-2簇调控牛肌内前体脂肪细胞增殖分化的协作机制

项目名称： miR-23a/27a/24-2簇调控牛肌内前体脂肪细胞增殖分化的协作机制

项目编号： No.31501937

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 畜牧学与草地科学

项目作者： 张莺莺

作者单位： 西北农林科技大学

项目金额： 20万元

中文摘要： 肌内脂肪含量是影响牛肉品质的重要因素之一。小鼠上已证实miR-27a靶向PPARγ调控前脂肪细胞成脂分化，但miR-27a所在的miR-23a/27a/24-2簇在脂肪生成中的协作效应机制尚未见报道。前期工作初步表明，该簇基因序列在牛及其它物种之间高度保守，它的3个成员可能通过直接或间接的方式影响PPARγ表达，相互协作参与调控牛肌内脂肪代谢，其分子机制有待进一步阐明。因此，本项目拟采用基因过表达、沉默技术，明确 miR-23a/27a/24-2簇在牛肌内前体脂肪细胞增殖分化中的具体作用；利用miRNA报告基因系统，鉴定其下游靶基因，同时探讨该miRNA簇对下游信号通路的调控机制。研究结果将阐明miR-23a/27a/24-2簇调控牛肌内脂肪细胞增殖分化的协作机制，为肌内脂肪沉积的分子调控网络解析和肉牛分子育种提供理论依据。

中文关键词： 肉牛；前体脂肪细胞；细胞增殖和分化；miRNA；簇；肌间脂肪

英文摘要： Intramuscular fat (IMF) or marbling positively affects meat palatability such as tenderness, juiciness. Studies on the mice have confirmed that miR-27a regulated adipogenesis by targeting PPARγ gene. However, the effects of miR-23a/27a/24-2 cluster on adipogenesis are not yet reported. Preview research found that the gene sequences of this miRNA cluster are highly conserved between bovine and other species, this cluster might regulate adipogenesis by influencing the expression of PPARγ directly or indirectly. But the function of miR-23a/27a/24-2 cluster and its cooperation mechanism are still unclear. The program is about to figure out the effects of miR-23a/27a/24-2 cluster on bovine intramuscular preadipocyte proliferation and differentiation by the gene over expression and RNAi methods, then explore the downstream targets of miR-23a/27a/24-2 cluster. Meantime, analyze the role of this miRNA cluster on downstream signaling pathways. This study can not only illuminate the cooperation mechanism of miR-23a/27a/24-2 cluster in regulating proliferation and differentiation of bovine intramuscular predipocytes, as well as help us to better understand molecular regulation network in intramuscular fat deposition, but also provide a theoretical basis for molecular breeding of beef cattle.

英文关键词： beef cattle;Preadipocytes;Cell proliferation and differentiation;miRNA cluster;IMF