The attP cassette of the Mi{MIC} element has been replaced with an artificial exon that contains: 1) splice acceptor sequence, 2) Sema1a coding sequence, 3) FRT-stop-FRT, 4) sequences encoding 3xTag:V5, 5) 2A peptide, 6) lexA::p65, and 7) 3' UTR of Sema1a. In the absence of FLP, a transcription termination sequence prevents expression of tagged Sema1a, but when FLP is expressed the stop sequence is excised, allowing a Tag:V5 epitope to be added to the endogenous Sema1a protein, along with co-transcription of lexA::p65 and Sema1a.