Fig. 1.

Model structure. (A) Gene regulation scheme for the mouse circadian clock. Per1, Per2, and Rev-erbα are activated at E-Boxes by CLK/BMAL1 and deactivated when PER/CRY also binds. Clk and Bmal1 are activated by RORc and deactivated by REV-ERBα at RORE. Cry1, Cry2, and Rorc have both an E-Box and a RORE and are regulated accordingly. (B) Schematic of the mouse circadian clock model incorporating genetic regulation at Per1, Per2, Cry1, Cry2, Rev-erbα, Clk, Bmal1, and Rorc, the degradation of mRNAs, the translation of mRNAs to protein, the formation and dissociation of PER/CRY and CLK/BMAL1, and the degradation of PER1, PER2, CRY1, CRY2, REV-ERBα, CLK, BMAL1, and RORc. The loops involving Rev-erbα and Rorc are shown in red.