Chapter 14 - Circular RNAs Expression, Function, and Regulation in Neural Systems

Abstract

Initially discovered in viroids and Archea, circular RNAs recently emerged as a large class of eukaryotic transcripts with important biological features. Being widely produced by the spliceosome through a particular reaction called back-splicing, their synthesis can be regulated by intronic sequences in cis and RNA-binding proteins in trans. Expression of circular RNAs is strongly tissue- and cell-specific, with a particular enrichment in the nervous system of metazoans. They can be highly expressed, localized at particular foci, and play disparate molecular functions, including sequestering microRNAs. In this chapter, we will review the current knowledge about circular RNAs, from the principles of their biogenesis, through the enigma of their turnover, to their known and possible functions in development and physiology. Although trying to summarize most of the recent advances in this field, our focus will be primarily directed to the expression and impact of circular RNAs in neural tissues.