UAS regulatory sequences drive expression of two coding regions separated by a 2A peptide sequence that are designed to be used to report neuromodulator release in vivo using the 'Tango' system (PMID:18165312). The upstream coding region encodes a tethered transcription factor which is composed of the Oamb receptor fused via a Tag:CS(TEVp) cleavage site to a lexA::UnkAD driver (the driver is tagged with the Tag:HA epitope) (this coding region is represented in FlyBase by the Oamb^UAS.Tango allele). The downstream coding region consists of Arr1 fused to the TEVp protease (this coding region is represented in FlyBase by the Arr1::TEV\NIa^UAS.Tango allele). Upon activation of the Oamb receptor by its ligand, the Arr1 ::TEVp protein is recruited, resulting in cleavage at the Tag:CS(TEVp) site. This allows the Tag:HA-tagged lexA::UnkAD driver to translocate to the nucleus, where it can drive expression of a reporter that is controlled by lexAop regulatory sequences.