UAS regulatory sequences drive expression of a cDNA that encodes full-length Hsap\ATXN3 with an expanded polyglutamine (polyQ) repeat of 80 residues (the polyQ repeats are encoded by CAGCAA doublet repeats, rather than a pure CAG tract, to avoid the possibility of repeat-associated non-ATG (RAN) translation and mRNA toxicity). The open reading frame is tagged with Tag:HA.