环状RNA（circular RNA，circRNA）是新发现的一类特殊的非编码RNA，在动物细胞增殖分化、器官发育、疾病发生等过程中发挥重要作用。然而，circRNA在绵羊骨骼肌中的表达和功能迄今尚不清楚。本项目将以产肉性能明显差异的萨福克羊和哈萨克羊为研究对象，利用高通量测序技术分别构建两个绵羊品种的胚胎期骨骼肌circRNA表达谱，经生物信息学和定量分析筛选出品种间显著差异表达的circRNA；利用荧光素酶基因报告系统分析circRNA与靶基因的互作；利用circRNA过表达和基因沉默技术研究circRNA在成肌细胞增殖和分化过程中的生物学功能。本研究可进一步丰富哺乳动物circRNA数据库，并为动物骨骼肌发育相关circRNA的生物学功能研究提供依据。circRNA可作为分子标记和候选功能基因应用于我国肉羊新品种培育。

Circular RNA (circRNA) in animals are an enigmatic class of RNA with unknown function, and play an important role in organ development, cell proliferation and differentiation, and disease etc. However, the expression and function of circRNA in sheep skeletal muscle is not clear yet. We will choose Suffolk sheep and Kazak sheep with obvious difference of meat performance as research object. circRNA expression will be analyzed in skeletal muscle of sheep embryo using high-throughput sequencing and bioinformatics analysis. The significantly differentially expressed circRNA will be filtered; The interactions between circRNA and target gene will be identified by using luciferase gene reporting system. Expression and biological function of circRNA in the process of muscle cell proliferation and differentiation will be analyzed by overexpression and gene silencing technology. Our study can further enrich the circRNA database of mammals, and provides the basis for research on development-related circRNA of skeletal muscle. CircRNA can be used as potential molecular markers and functional gene for application in breeding of the mutton sheep.