Circular RNAs (circRNAs) are a class of RNA molecules with a covalently closed loop structure formed by back-splicing of exon-exon junctions. The detection of circRNAs across many eukaryotic species, often with cell-type- and tissue-type-specific expression, has catalyzed a growing interest in understanding circRNA biogenesis and their potential functions. circRNAs are enriched in the brain, and accumulate upon neuronal differentiation and depolarization, suggesting that these RNAs are an integral component of the brain transcriptome, and may play functional roles. Here, we give an overview of the current understanding of circRNA biogenesis and function, discuss how circRNAs contribute to transcriptome complexity in the brain, and discuss recent data on the functional roles of circRNAs in the brain. We also discuss emerging data on the role of circRNAs in brain disorders and address common challenges of circRNA quantification in postmortem human brain.

中文翻译：

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环状RNA：大脑转录组完整循环

环状RNA（circRNA）是一类具有共价闭环结构的RNA分子，通过外显子-外显子连接的反剪接形成。在许多真核物种中检测 circRNA，通常具有细胞类型和组织类型特异性表达，这促使人们对理解 circRNA 生物发生及其潜在功能越来越感兴趣。circRNAs 在大脑中富集，并在神经元分化和去极化时积累，表明这些 RNAs 是大脑转录组的一个组成部分，可能发挥功能作用。在这里，我们概述了当前对 circRNA 生物发生和功能的理解，讨论了 circRNA 如何促进大脑中转录组的复杂性，并讨论了关于 circRNA 在大脑中的功能作用的最新数据。