A TI{KozakGAL4} DNA cassette has been inserted into key, replacing the coding sequence (coordinates of deleted sequence are 2R:24785571..24787065 , release 6 genome). This results in a simultaneous knock-out of key plus a knock-in of GAL4 that is expected to be expressed under the control of the endogenous regulatory sequences of key (predicted to gene trap all annotated transcripts of the gene). The TI{KozakGAL4} cassette was inserted via the CRISPR/Cas-9 drop-in technique, using a dsDNA donor vector with homology arms of length 200bp. The sgRNA sequences used to target the gene were: GTTGTCGCGGTAGCAATGGCGGG and GAGTCACGTTAACGATTGTTTGG. The 3' end of the deletion associated with the insertion is 29 bp downstream of the 3' end of the CG3589 gene and may affect the proper 3' end formation of its transcripts.