Editor’s summary
RNA is generally considered a short-lived mediator of genetic information. Zocher et al. discovered that certain nuclear RNAs produced during postnatal development can persist for years in a subset of cells in the mammalian brain (see the Perspective by Lawrence and Hall). The authors also showed that some of these long-lived RNAs play a crucial role in maintaining genome integrity and cellular plasticity. Because adult mammals have limited capacity to replace neurons, the longevity of these RNAs could be critical for lifelong function of the brain but might also contribute to its age-dependent decline. —Stella M. Hurtley
Abstract
Genomic DNA that resides in the nuclei of mammalian neurons can be as old as the organism itself. The life span of nuclear RNAs, which are critical for proper chromatin architecture and transcription regulation, has not been determined in adult tissues. In this work, we identified and characterized nuclear RNAs that do not turn over for at least 2 years in a subset of postnatally born cells in the mouse brain. These long-lived RNAs were stably retained in nuclei in a neural cell type–specific manner and were required for the maintenance of heterochromatin. Thus, the life span of neural cells may depend on both the molecular longevity of DNA for the storage of genetic information and also the extreme stability of RNA for the functional organization of chromatin.
