A TI{KozakGAL4} DNA cassette has been inserted into Qsox3, replacing the coding sequence (coordinates of deleted sequence are 3R:21911816..21913527 , release 6 genome). This results in a simultaneous knock-out of Qsox3 plus a knock-in of GAL4 that is expected to be expressed under the control of the endogenous regulatory sequences of Qsox3 (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 a 3' homology arm of length 200bp and a 5' homology arm extended to restore the promoter. The sgRNA sequences used to target the gene were: TCATCGGTCTTGAGATAAAATGG and CAAGTAAAAATTGGTTCATGCGG.