Sequences encoding a P2A self-cleavage sequence and GAL4 (" P2A::Gal4 ") are inserted in frame in place of the endogenous Tmem63 TAA stop codon. The presence of the P2A peptide allows the Tmem63 and GAL4 proteins to be expressed separately under the control of endogenous Tmem63 regulatory sequences, thereby generating a Tmem63 reporter in conjunction with a UAS line.