The P{UAS-Flybow.1.0} construct allows stochastic expression of one of two fluorescent proteins from a single transgene using excision mediated by the FLPm5 recombinase variant (which targets mFRT71 sites). It contains UAS regulatory sequences fused upstream of an invertible cassette flanked by inward-facing mFRT71 sites. The cassette contains sequence encoding a pair of fluorescent proteins (mCherry in the forward orientation and Cerulean in the reverse orientation) with each open reading frame followed by a polyadenylation signal. Each fluorescent protein sequence is tagged with Tag:M(mCd8a) to target it to the membrane and the Cerulean sequence is additionally tagged with Tag:V5. In the absence of FLPm5 activity the mCherry protein is adjacent to the UAS sequences and is in the correct orientation to be expressed. In the presence of the FLPm5 recombinase, the cassette is inverted, placing the Cerulean variant adjacent to the UAS sequences and in the correct orientation to be expressed.