牛肌内脂肪细胞是由胎儿骨骼肌间充质干细胞（MSCs）分化而来，其与肌细胞和成纤维细胞的形成存在竞争关系，因此调节胎儿骨骼肌MSCs成脂分化对肌内脂肪的形成具有重要意义。研究表明lncRNAs是控制MSCs成脂分化的重要调控分子，然而有关牛胎儿骨骼肌MSCs成脂分化相关的lncRNAs的研究至今未见报道。先前通过测序手段发现了一个在牛胎儿骨骼肌MSCs成脂分化前后表达上调的lncRNAlinc_000677，其基因位于脂肪生成相关转录因子EBF1上游，且二者表达模式相近。因此本研究以胎牛骨骼肌MSCs成脂分化为模型，利用RNA干扰、ChIP、荧光素酶报告基因等技术，探讨linc_000677与EBF1之间的调控关系及参与的细胞信号通路，揭示linc_000677在牛胎儿骨骼肌MSCs向脂肪分化过程中的调控机理，为进一步阐明牛肌内脂肪沉积的分子机制提供理论依据。

The intramuscular adipocytes are derived from the mesenchymal stem cells (MSCs) in fetal bovine skeletal muscle.There is a competition between adipogenesis and myogenesis,fibrogenesis.Therefore,modulating fetal bovine skeletal muscle MSCs adipogenesis differentiation is a potential way to increase intramuscular fat.It is suggested that lncRNAs is an important regulatory molecule during MSCs differentiation to adipocytes.Unfortunately, our knowledge of how fetal bovine skeletal muscle MSCs adipogenesis is under the lncRNAs control is limited.Previously,an up-regulated lncRNA named linc_000677 that was identified before and after adipocyte differentiation of fetal bovine skeletal muscle MSCs by sequencing, the genomic loci of linc_000677 locates at upstream of EBF1,which a transcription factor of regulating adipocyte differentiation,and both linc_000677 and EBF1 have similar expression patterns.Therefore in this research,using fetal bovine skeletal muscle MSCs adipogenesis as experiment model,the relationship between linc_000677and EBF1,and also the cell signaling pathway they were involved,were investigated using technologies including RNA interference,ChIP,dual luciferase report assay.Finally, the regulation mechanism of linc_000677 in fetal bovine skeletal muscle MSCs differentiation to adipocytes will be characterized.It will provide the theory basis to investigate molecular mechanism of intramuscular fat deposit in beef cattle.