The per CRS (circadian regulatory sequence) and a basal Hsp70 promoter are fused upstream of sequences encoding the per coding region (a hybrid of cDNA and genomic sequences). The genomic portion includes the 3' UTR, including the 3' terminal intron. XhoI and KpnI sites have been introduced flanking this 3' terminal intron.
The P{dmpi8WT} construct, which contains wild type per regulatory and coding regions, also contains the entire wild type dyw locus.