UASt regulatory sequences drive expression of the pros open reading frame, tagged at the C-terminal end with the N-m9Venus split fluorescent protein fragment. Designed for use in a bimolecular fluorescence complementation (BiFC) assay. The pros ORF is flanked by a pair of incompatible FRT sites (FRT5 and FRT2), which allows for future in vivo exchange of either the promoter or the C-terminal tag sequence. A linker of 24 residues separates the FRT2 and N-m9Venus sequences.