The QUAS regulatory sequence contains varying numbers of a 16bp repeat (consensus 5'-GGRTAARYRYTTAYCC-3', R is A/G, Y is C/T) that is specifically bound by the DNA-binding domain of Neurospora crassa QA-1F (UniProtKB:P11638). This property can be utilized to form a binary expression system to control the spatial and temporal expression of a gene of interest: a transgene or modified endogenous locus in which the target gene of interest is downstream of QUAS sequences can be combined with a transgene or modified endogenous locus encoding any 'QF driver' that includes the QA-1F DNA-binding domain plus a transcriptional activation sequence (FBrf0210697, reviewed in FBrf0214230, FBrf0233764).