UASp regulatory sequences drive expression of the Rif1 coding sequence, in which 15 Ser/Thr residues within candidate CDK or DDK phosphorylation sites have been mutated to Ala, to prevent their phosphorylation. The protein is tagged with Tag:FLAG.
Expression of Rif115a.UASp.Tag:FLAG under the control of Scer\GAL4ey.PH causes complete lethality, with pupae developing into headless nearly adult flies.