1. Supplementary Figure We inserted three tandem repeats of wild-type and mutant E-boxes from the mPer1 gene, in front of the SV40 basic promoter driving a dLuc reporter, transfected the vector into Rat-1 cells and then monitored bioluminescence. The phase of SV40-driven dLuc reporters containing first E-box x3 and second E-box x3 was similar to that of mPer1 E(5)box SV40-dLuc (fifth E-box x3).