Mi{Trojan-GAL4DBD.2} represents a transgenic construct generated in vivo by using phiC31:int-mediated recombination to replace the attP cassette of a Mi{MIC} element insertion with an intron phase 2 'Trojan GAL4DBD' cassette from the pBS-KS-attB2-SA(2)-T2A-GAL4DBD-Hsp70 plasmid. The Trojan GAL4DBD cassette consists of a splice acceptor site followed by the T2A peptide, sequence encoding a GAL4(DBD)::Zip- hemidriver (component of the 'Split GAL4' system, contains the GAL4 DNA-binding domain) and an Hsp70 transcription termination signal. Integration of the cassette into a Mi{MIC} insertion in a coding intron (with the same phase) of a native Drosophila gene of interest will result in the cassette behaving as a 'Trojan' exon: the splice acceptor site ensures that the T2A-GAL4(DBD)::Zip- open reading frame is incorporated into the mRNA of the native Drosophila gene, while the T2A sequence truncates the native gene product and promotes the separate translation of the GAL4(DBD)::Zip- open reading frame. Thus the GAL4(DBD)::Zip- hemidriver should be expressed under the control of the regulatory sequences of the native Drosophila gene of interest in the resulting fly line.