Adenosine-to-inosine (A-to-I) RNA editing regulates miRNA biogenesis and function. To date, fewer than 160 miRNA editing sites have been identified. Here, we present a quantitative atlas of miRNA A-to-I editing through the profiling of 201 pri-miRNA samples and 4694 mature miRNA samples in human, mouse, and Drosophila. We identified 4162 sites present in ∼80% of the pri-miRNAs and 574 sites in mature miRNAs. miRNA editing is prevalent in many tissue types in human. However, high-level editing is mostly found in neuronal tissues in mouse and Drosophila. Interestingly, the edited miRNAs in neuronal and non-neuronal tissues in human gain two distinct sets of new targets, which are significantly associated with cognitive and organ developmental functions, respectively. Furthermore, we reveal that miRNA editing profoundly affects asymmetric strand selection. Altogether, these data provide insight into the impact of RNA editing on miRNA biology and suggest that miRNA editing has recently gained non-neuronal functions in human.

腺苷到肌苷（A到I）RNA编辑调节miRNA的生物发生和功能。迄今为止，已经鉴定出少于160个miRNA编辑位点。在这里，我们通过对人类，小鼠和果蝇中的201 pri-miRNA样品和4694个成熟miRNA样品进行分析，介绍了miRNA A-to-I编辑的定量图集。我们确定了约80％的pri-miRNA中存在4162个位点，而成熟miRNA中则有574个位点。miRNA编辑在人类的许多组织类型中普遍存在。但是，高级编辑通常在小鼠和果蝇的神经元组织中发现。有趣的是，人类神经元和非神经元组织中编辑的miRNA获得了两组新的新靶标，分别与认知和器官发育功能显着相关。此外，我们揭示了miRNA编辑会深刻影响不对称链的选择。总而言之，这些数据提供了RNA编辑对miRNA生物学的影响的洞察力，并表明miRNA编辑最近已在人类中获得非神经元功能。