The PBac{brp(FRT.Stop)GFP-2A-LexA-VP16} construct contains brp regulatory and coding sequences (genomic fragment of ~50kb) in which the stop codon has been replaced by an FRT cassette containing transcriptional and translational stop sequences, followed by a GFP tag, the 2A peptide and a lexA::VP16 driver sequence. Sequences downstream of the stop cassette are not translated, and thus the brp protein produced is not tagged and no lexA::VP16 protein is produced. In the presence of FLP recombinase the FRT cassette is excised. The brp protein produced is now tagged with GFP, and the presence of the 2A peptide allows the lexA::VP16 driver to be cotranslated as a separate protein, under the control of the brp regulatory sequences.