QUAS regulates expression of a truncated form of Hsap\ATXN3, consisting of the normal length glutamine tract (27 repeats) flanked upstream by 12 amino acids and downstream by the carboxy terminal 43 amino acids of Hsap\ATXN3 and tagged at the N-terminus with Tag:HA. (cDNA was amplified from P{UAS-Hsap\MJD.tr-Q27} flies.)