Long noncoding RNAs: from identification to functions and mechanisms

Abstract

The complex universe of RNA transcribed by mammalian cells includes thousands of large RNA molecules that do not encode for proteins. Despite their lack of coding capacity and relatively low conservation, many large noncoding RNA molecules (lncRNAs) have been shown to be functional, adding a new level of complexity on the structural organization, func-tion, and evolution of the genome. Here, we summarize the current knowledge of lncRNAs, starting from the methodologies that led to their identification to their genomic and evolutive features. We discuss the diverse mechanisms by which lncRNAs exert their functions, and the technical approaches for their study. Finally, we discuss the future directions of lncRNA research and the challenges involved. The advances in lncRNA research are definitively changing our conception of gene regulation.