FoxO1参与牛骨骼肌细胞增殖和分化的表观遗传调控机制

叉头转录因子O1（FoxO1）作为PI3K/AKT通路的直接下游信号分子，参与脂代谢、细胞自噬和多种器官及肌肉组织的发育，但其调控牛骨骼肌生长发育的分子机制尚不清。申请人前期通过多组学技术筛选到FoxO1基因与秦川牛生长性状密切相关。在线软件预测到牛FoxO1基因启动子区有3个CpG岛及大量与肌肉生长发育和甲基化敏感性相关的转录因子结合位点。因此，我们推测FoxO1在骨骼肌细胞增殖和分化过程中具有重要的表观遗传调控作用。本项目拟在此基础上，探究FoxO1基因在不同牛品种肌肉中表达情况，进一步干扰和过表达FoxO1基因，明确其对牛骨骼肌细胞增殖和分化作用。结合转录组测序、启动子转录调控、DNA甲基化、组蛋白甲基化、免疫荧光及染色质免疫共沉淀等方法，探究FoxO1基因在骨骼肌细胞增殖和分化过程中表观遗传调控机制，为我国牛遗传改良及分子育种奠定理论基础。

As a direct downstream signaling pathway of PI3K/AKT, the forkhead box O1 (FoxO1) gene involved in regulation of the lipid metabolism, autophagy and the development of various organs and muscle tissues. However, the molecular mechanism of FoxO1 in regulating cattle skeletal muscle growth and development is unclear. Our prophase research has demonstrated that FoxO1 gene was closely related to growth traits of Qinchuan cattle based on multi-omics analysis results. Furthermore, three CpG islands and many potential muscle-specific and methylation sensitivity transcription factor binding sites were predicted in the promoter region of FoxO1 gene by using online software. Therefore, we speculated that FoxO1 gene could play a major role in the proliferation and differentiation of skeletal myoblast. On this basis, this project aims to determine the effects on overexpression and interference FoxO1 gene in bovine skeletal myoblast. Meanwhile, we will explore the expression pattern of FoxO1 gene in muscles at different cattle breeds. The epigenetic mechanisms of FoxO1 gene in regulating bovine skeletal myoblast proliferation and differentiation will be further identified by transcriptome sequencing, promoter transcriptional regulation, DNA and histone methylation, immunofluorescence and chromatin immunoprecipitation. This study will elucidate the epigenetic mechanisms of FoxO1 gene during skeletal myoblast proliferation and differentiation and provided useful information for molecular breeding programmes of cattle.