Figure 3.

Unraveling the Circadian Clock.

(A) The initial model for the circadian clock involved interaction between TOC1 and LHY /CCA1.

(B) To account for discrepancies between the model and data, an additional component in the network was proposed (gene X), which mediates LHY/TOC1 activation.

(C) Further comparison between new experimental data and the model indicated that the circadian clock involves two interlocking feedback loops, this comprising the original loop and feedback between putative gene Y and TOC1.

(D) While GI was proposed as a candidate for Y, even further experimental validation revealed that this only fulfils part of the role. Furthermore, gene X has subsequently been proposed to reflect TOC1 modification or protein binding.