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.

中文翻译：

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核RNA在小鼠大脑中终生持续存在

哺乳动物神经元细胞核中的基因组 DNA 可以与生物体本身一样古老。核 RNA 对正常染色质结构和转录调控至关重要，但其寿命在成体组织中尚未确定。在这项工作中，我们鉴定并表征了小鼠大脑中出生后细胞子集中至少 2 年不会更新的核 RNA。这些长寿命的 RNA 以神经细胞类型特异性的方式稳定地保留在细胞核中，并且是维持异染色质所必需的。因此，神经细胞的寿命可能取决于用于存储遗传信息的DNA的分子寿命，以及用于染色质功能组织的RNA的极端稳定性。