绒山羊次级毛囊周期性发育过程关键甲基化基因的表达调控机制研究

哺乳动物毛囊的周期性发育过程受一系列遗传因子和表观遗传因子的共同调控，以基因甲基化为主的DNA表观遗传修饰对毛囊周期性发育的表达调控机理尚不清楚。在前期获得的陕北白绒山羊次级毛囊不同发育时期转录组（RNA-Seq）数据的基础上，本项目以生长期、退行期和休止期陕北白绒山羊皮肤为试验材料，借助甲基化DNA免疫沉淀-高通量测序（MeDIP-Seq），构建绒山羊皮肤DNA甲基化谱；通过DNA甲基化数据与转录组数据的联合分析，筛选和鉴定启动子区域发生甲基化且基因表达水平降低，并与绒山羊毛囊发育调控通路相关的关键基因；通过构建荧光素酶报告基因系统，在细胞水平验证基因启动子区CpG岛的甲基化对基因表达的影响，揭示DNA甲基化对绒山羊次级毛囊的周期性发育的表达调控机制。本项目的研究结果对于从表观遗传学水平揭示动物毛囊周期性发育的调控机制具有重要意义，为人工调控山羊绒毛生长提供科学依据。

Hair renewal features with periodic hair cycles of growth (anagen), regression (catagen) and rest (telogen). This process is controlled by both genetic and epigenetic factors， however, little is known about the regulation of DNA methylation changes during the hair follicle cycling in mammals. This project conducts MedIP-Seq by using the skin samples of cashmere goats from anagen, catagen and telogen stages, in an attempt to identify differentially methylated genes on a genome-wide scale. Key hypermethylated genes, with downregulated gene expression, and were involved in the hair follicle cycling pathways will be identified by integration analysis of DNA methylation and RNA-Seq data, which we have conducted previously. Finally, the function of selected methylated genes will be verified through luciferase reporter assay based on the dermal papilla cell lines derived from cashmere goats. Our results will provide evidence for the regulation of periodic changes of hair development and cycling at the epigenetic level, as well as helpful for manipulating hair and cashmere growth in goats for fiber production.