Feedback Loops of the Mammalian Circadian Clock Constitute Repressilator
Fig 2
Effect of parameter alterations on the period (fraction of default value on logarithmic x-scale).
(A) Change of Per2 delay. (B) Change of Cry1 mRNA degradation rate. (C) Change of Cry1 inhibition strength on Per2. (D) Change of Bmal1 activation strength on Rev-erb-α. The default parameter values, corresponding to 1 on the x-axis, are: Per2 delay τ3 = 3.82, Cry1 degradation d4 = 0.2, Rev-erb-α activation by Bmal1 actn1,2 = 3.26 and Per2 inhibition by Cry1 inh4,3 = 0.37. Blue symbols refer to increasing parameters, whereas orange symbols refer to the reverse parameter variation (see S2 Appendix for details).