中文摘要：

环状RNA（circRNAs）是一类不同于线性RNA的内源非编码RNA,它是通过反向剪接形成的闭合环状RNA分子。circRNA不具有5′端帽子和3′端poly（A）尾巴结构,能够稳定存在于各种类型真核细胞中。对于circRNA的数量和丰度的检测,传统分子生物学方法的能效非常有限,因此一直以来circRNA被认为是RNA异常剪接的产物。随着生物信息学的快速发展和高通量测序技术的不断革新,目前已经在真核细胞中发现了大量内源性circRNA,其中一些circRNA表达丰度高并呈现出时空表达特异性和物种间保守性,说明circRNA可能在调节基因表达方面具有重要功能。本文综述了circRNA的特征、形成机制及生物学功能,并对近年来circRNA研究进展进行归纳总结,以期为真核生物基因表达调控研究、疾病检测等提供基础资料,并对circRNA在动物分子育种方面的研究进行展望。

英文摘要：

Circular RNAs（circRNAs）are a class of endogenous noncoding RNA,unlike linear RNAs,which form a covalently closed continuous loop by back-splicing.circRNA has no the 5′end cap and 3′end poly（A）tail structure,and exist steadily in many eukaryotic cells.Due to the limitation of traditional biological methods for circRNA detection in both species and abundance,circRNA is traditionally considered as the products of abnormal RNA splicing.With the development of bioinformatics and the innovation of high-throughput sequencing technology,the thousands of endogenous circRNA in mammalian cells were discovered,some of which are highly expressed in a tissue-and development stage-specific manner and display conservation across species,suggesting their potential regulating function on the gene expression.In combination with the characteristics,formation mechanism and biological function of circRNA,we summarize the research advance of circRNA in recent years,aiming to provide fundamental information for studying eukaryotic gene expression regulation and disease detection,and prospect circRNAs′research in animal molecular breeding.