RNA degradation plays a fundamental role in regulating gene expression. In order to characterize the spatiotemporal dynamics of RNA turnover in single cells, we developed a fluorescent biosensor based on dual-color, single-molecule RNA imaging that allows intact transcripts to be distinguished from stabilized degradation intermediates. Using this method, we measured mRNA decay in single cells and found that individual degradation events occur independently within the cytosol and are not enriched within processing bodies. We show that slicing of an mRNA targeted for endonucleolytic cleavage by the RNA-induced silencing complex can be observed in real time in living cells. This methodology provides a framework for investigating the entire life history of individual mRNAs from birth to death in single cells.

RNA降解在调节基因表达中起着基本作用。为了表征单细胞中RNA周转的时空动态，我们开发了一种基于双色，单分子RNA成像的荧光生物传感器，该传感器可将完整的转录本与稳定的降解中间体区分开。使用这种方法，我们测量了单个细胞中的mRNA衰减，发现单个降解事件独立地发生在细胞质内，并且在处理体中并未富集。我们显示，可以在活细胞中实时观察到由RNA诱导的沉默复合物靶向内切核酸的mRNA的切片。该方法学为研究单个mRNA从出生到死亡的整个mRNA的整个生命史提供了框架。