sequence of FLAG-mCherry was replaced with the codon-optimized CAHS3 coding
sequence (Gene Universal) to express CAHS3-T2A-EGFP-T2A-neoR under the control
of Ac5 promoter. The empty vector was constructed by deleting FLAG-mCherry from
Ac5-STABLE2-neo, which was designed to express T2A-EGFP-T2A-neoR driven by the
same Ac5 promoter. Drosophila S2 cells were transfected using a
cationic liposome reagent Hilymax (Dojindo) with the expression construct or the
empty vector above. We established stably transfected cells by culturing for 6
weeks under the drug selection with G418 disulfate (2,000 μg/mL, Nacalai
Tesque).