Hybrid models for the interconnection of circadian and genetic cycles in cyanobacteria

This paper will discuss the coupling of two oscillators in cyanobacteria. The circadian rhythm of cyanobacteria is thought to be driven by an oscillator based on an ordered sequence of phosphorylations of a protein (KaiC). At the same time, as the cyanobacterial cell grows and divides, the amount of protein KaiC itself is regulated by a transcription/ translation cycle. Our goals are to study: (i) the robustness of the circadian rhythm with respect to the perturbations inherent to the noisy environment of the cell, including cell growth and division; and (ii) to what extent the growth curves of cyanobacterial colonies, under different external light conditions, are modulated by the circadian cycle.