G protein-coupled receptors (GPCRs) represent a family of seven-pass transmembrane protein receptors whose ligands include neuropeptides and small-molecule neuromodulators such as dopamine and serotonin. These neurotransmitters act at long distances and are proposed to define the ground state of the nervous system. The Drosophila genome encodes approximately 50 neuropeptides and their functions in physiology and behavior are now under intensive studies. Key information currently lacking in the field is the spatiotemporal activation patterns of endogenous GPCRs. Here we report application of the Tango system, a reporter assay to detect GPCR activity, to endogenous GPCRs in the fly genome. We developed a method to integrate the sensor component of the Tango system to the C-terminus of endogenous genes by using genome editing techniques. We demonstrate that Tango sensors in the Sex-peptide receptor (SPR) locus allow sensitive detection of mating-dependent SPR activity in the female reproductive organ. The method is easily applicable to any GPCR and will provide a way to systematically characterize GPCRs in the fly brain.

G蛋白偶联受体（GPCR）代表一族七遍跨膜蛋白受体，其配体包括神经肽和小分子神经调节剂（如多巴胺和血清素）。这些神经递质在很长的距离内起作用，并被提出来定义神经系统的基态。在果蝇基因组编码大约50种神经肽，目前它们在生理和行为上的功能正在深入研究中。该领域目前缺乏的关键信息是内源性GPCR的时空激活模式。在这里，我们报告了探戈系统的应用，这是一种检测GPCR活性的报告基因检测法，用于果蝇基因组中的内源性GPCR。我们开发了一种通过使用基因组编辑技术将Tango系统的传感器组件整合到内源基因C端的方法。我们证明了在性肽受体（SPR）中的探戈传感器）基因座可以灵敏地检测雌性生殖器官中依赖交配的SPR活性。该方法可轻松应用于任何GPCR，并将提供一种系统地表征苍蝇大脑中GPCR的方法。