A 4.3kb sequence upstream of the transcription initiation site of tim is fused to tim coding sequence tagged at the C-terminal with YFP.
Expression of timT:Avic\GFP-YFP in a wild-type background has no effect on locomotor rhythm.
timYFP rescues tim01
Under conditions of constant darkness, wild-type locomotor activity is restored in tim01; timT:Avic\GFP-YFP flies.