Employment opportunities for non-coding RNAs.

Analysis of the genomes of several higher eukaryotic organisms, including mouse and human, has reached the striking conclusion that the mammalian transcriptome is constituted in large part of non-protein-coding transcripts. Conversely, the number of protein-coding genes was initially at least overestimated. A growing number of studies report the involvement of non-coding transcripts in a large variety of regulatory processes. This review examines the different types of non-coding RNAs (ncRNAs) and discusses their putative mode of action with particular reference to large ncRNAs and their role in epigenetic regulation.