Flies expressing Unr1+2.Scer\UAS.P\T.T:Avic\GFP-EGFP under the control of Scer\GAL4Act5C.PI exhibit reduced viability compared to controls. Lethality occurs before the third instar larval stage and males are more severely affected than females. When the temperature is increased to 29[o]C the frequency of lethality increases. Lethality is not observed when Unr1+2.Scer\UAS.P\T.T:Avic\GFP-EGFP is expressed under the control of Scer\GAL4en.PU.