UASt regulatory sequences drive expression of a mutated form of dco that carries the amino acid replacement K38R (producing a dominant negative protein). The protein is tagged at the C-terminal end with Tag:MYC and with the Tag:NLS(SV40-largeT) nuclear localisation signal.
The expression of dcoK38R.UAS.Tag:MYC,Tag:NLS(SV40-largeT) under the control of Scer\GAL4tim.PE leads to a decrease in circadian rhythmicity and to a significant increase in circadian period, as compared to controls.