Upregulation of Per2 and delayed phases in oscillations of clock genes in Ksrp−/− hepatocytes, and downregulation of Per2 restores the phase shift in oscillations of circadian clock genes in Ksrp−/− hepatocytes. A: Oscillations of Per2, Rev-erba, Bmal1, and Per1 in wild-type hepatocytes transfected with a control siRNA (siCon) and in Ksrp−/− hepatocytes transfected with siCon or Per2 siRNAs (siPer2). * P < 0.05 between Ksrp+/+ (siCon) and Ksrp−/− (siCon) at each time point. B: Oscillations of Per2, Rev-erba, Bmal1, and Per1 in wild-type hepatocytes transfected with siCon or siPer2. C: Oscillations of Cry1, Cry2, Clock, and Dbp in wild-type and Ksrp−/− hepatocytes. All data are mean ± SEM from three independent preparations of hepatocytes (n = 6).