The P{UAS-Flybow.2.0} construct is designed to facilitate sparse cell labelling. It contains UAS regulatory sequences fused upstream of three cassettes. The first cassette is flanked by canonical FRT sites and contains the Lam open reading frame (ORF) tagged with two copies of Tag:HA and followed by two polyadenylation signals. This "stop" cassette is followed by two adjacent invertible cassettes, each flanked by inward-facing mFRT71 sites and each containing a pair of fluorescent proteins in opposing orientations. The first cassette contains EGFP in the forward orientation and Citrine in the reverse orientation and the second cassette contains mCherry in the forward orientation and Cerulean in the reverse orientation. Each fluorescent ORF is tagged with a membrane-targeting signal (Tag:M(mCd8a) in all cases except for the Citrine protein, which is tagged with Tag:MyrPalm(mLyn)) and is followed by a polyadenylation signal. The Cerulean sequence is additionally tagged with Tag:V5. In the absence of recombinase activity the Lam ORF is expressed and no fluorescent proteins are expressed. In the presence of the canonical FLP recombinase alone, the "stop" cassette containing Lam is removed and EGFP is expressed. If the FLPm5 variant (which targets mFRT71 sites) is also present in addition to canonical FLP, and also depending on which of the two invertible mFRT71 cassettes are excised/inverted, any one of the downstream coding regions can become juxtaposed with the UAS sequence, resulting in expression of that protein.