The attP cassette in the Mi{MIC}ChAT^MI04508 insertion has been replaced with a Trojan QF2 cassette that contains a splice acceptor site followed by the T2A peptide, the QF2 variant of Ncra\QF and an Hsp70 transcription termination signal. The insertion is in the correct orientation to gene trap ChAT. The splice acceptor ensures that the T2A-QF2 open reading frame is incorporated into the ChAT mRNA, while the T2A sequence is expected to truncate the native ChAT gene product and promotes the separate translation of the QF2 open reading frame. Thus expression of QF2 is driven by the native ChAT regulatory sequences.