An elav promoter drives expression of ewg. The 5' end of ewg is derived from cDNA sequence, while the 3' end is derived from genomic DNA (intron sequences from intron 4 onwards are present). A Tag:VSV-G epitope and a Tag:HA epitope have been added at the end of the open reading frames resulting from intron 6 spliced and unspliced mRNAs respectively.