Figure 2.

Endogenous core clock genes oscillate with a lower circadian amplitude at reduced Pol II-dependent transcription rates. Expression profiles of Bmal1, Rev-erbα, Dbp, Per1 and Per2 mRNA from untreated cells and cells pretreated with 3 μg/ml α-amanitin for 16 h. The cells were collected at the indicated time points after the addition of horse serum (time 0). The relative mRNA levels were determined by qRT–PCR analysis and normalized to genomic DNA (see Materials and methods).