Cell type‐specific transcription is a key determinant of cell fate and function. An ongoing challenge in biology is to develop robust and stringent biochemical methods to explore gene expression with cell type specificity. This challenge has become even greater as researchers attempt to apply high‐throughput RNA analysis methods under in vivo conditions. TU‐tagging and EC‐tagging are in vivo biosynthetic RNA tagging techniques that allow spatial and temporal specificity in RNA purification. Spatial specificity is achieved through targeted expression of pyrimidine salvage enzymes (uracil phosphoribosyltransferase and cytosine deaminase) and temporal specificity is achieved by controlling exposure to bioorthogonal substrates of these enzymes (4‐thiouracil and 5‐ethynylcytosine). Tagged RNAs can be purified from total RNA extracted from an animal or tissue and used in transcriptome profiling analyses. In addition to identifying cell type‐specific mRNA profiles, these techniques are applicable to noncoding RNAs and can be used to measure RNA transcription and decay. Potential applications of TU‐tagging and EC‐tagging also include fluorescent RNA imaging and selective definition of RNA–protein interactions. TU‐tagging and EC‐tagging hold great promise for supporting research at the intersection of RNA biology and developmental biology.

中文翻译：

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通过TU标签和EC标签揭示基因表达和RNA代谢的细胞类型特异性复杂性。

细胞类型特异性转录是细胞命运和功能的关键决定因素。生物学方面的一项持续挑战是开发强大而严格的生化方法，以探索具有细胞类型特异性的基因表达。随着研究人员试图在体内条件下应用高通量RNA分析方法，这一挑战变得更加严峻。TU标签和EC标签是体内生物合成RNA标签技术，可在RNA纯化中提供时空特异性。通过特异性表达嘧啶挽救酶（尿嘧啶磷酸核糖转移酶和胞嘧啶脱氨酶）来实现空间特异性，而通过控制这些酶（4-硫尿嘧啶和5-乙炔基胞嘧啶）的生物正交底物的暴露来实现时间特异性。可以从动物或组织中提取的总RNA中纯化标记的RNA，并将其用于转录组谱分析。除了识别特定于细胞类型的mRNA谱外，这些技术还适用于非编码RNA，并可用于测量RNA转录和衰变。TU标签和EC标签的潜在应用还包括荧光RNA成像和RNA与蛋白质相互作用的选择性定义。TU标记和EC标记在支持RNA生物学和发育生物学交叉领域的研究方面具有广阔的前景。TU标签和EC标签的潜在应用还包括荧光RNA成像和RNA与蛋白质相互作用的选择性定义。TU标记和EC标记在支持RNA生物学和发育生物学交叉领域的研究方面具有广阔的前景。TU标签和EC标签的潜在应用还包括荧光RNA成像和RNA与蛋白质相互作用的选择性定义。TU标记和EC标记在支持RNA生物学和发育生物学交叉领域的研究方面具有广阔的前景。