A TI{2A-GAL4(DBD)::Zip-} cassette has been inserted in-frame into the endogenous esg locus. The presence of the 2A peptide results in the GAL4(DBD)::Zip- hemidriver being expressed as a separate protein under the control of endogenous esg regulatory sequences. The TI{2A-GAL4(DBD)::Zip-} cassette was inserted via the CRISPR/Cas-9 drop-in technique. The sgRNA sequence used to target the gene was: CTCCACCAACATGTCTTCCA.