Figure 1. Simplified schematic diagram of the molecular mechanisms of the circadian clock in mammals. See the main text for details. Positive and negative feedbacks are indicated by arrows with a + and a - sign, respectively. Genes and messenger ribonucleic acid (mRNA) are indicated by italics, proteins are in bold caps. C = CLOCK protein; N = NPAS2 protein; B = BMAL1 protein.
