The attP cassette in the Mi{MIC}ChAT^MI04508 insertion has been replaced with a Trojan GAL4DBD cassette that contains a splice acceptor site followed by the T2A peptide, the DNA-binding domain of Scer\GAL4 fused to the T:Zzzz\Zip- component of the SplitGAL4 system ("GAL4DBD") and an Hsp70 transcription termination signal. The insertion is in the correct orientation to gene trap ChAT. The splice acceptor ensures that the T2A-GAL4DBD 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 GAL4DBD open reading frame. Thus expression of the Scer\GAL4 DNA-binding domain fused to the T:Zzzz\Zip- component of the SplitGAL4 system is driven by the native ChAT regulatory sequences.

The GMR41A01 enhancer fragment regulates expression of the p65(AD)::Zip+ hemidriver.