Regulation of gene expression through production of unstable mRNA isoforms

Alternative splicing is universally accredited for expanding the information encoded within the transcriptome. In recent years, several tightly regulated alternative splicing events have been reported which do not lead to generation of protein products, but lead to unstable mRNA isoforms. Instead these transcripts are targets for NMD (nonsense-mediated decay) or retained in the nucleus and degraded. In the present review I discuss the regulation of these events, and how many have been implicated in control of gene expression that is instrumental to a number of developmental paradigms. I further discuss their relevance to disease settings and conclude by highlighting technologies that will aid identification of more candidate events in future.