Evolution of the Clock from Yeast to Man by Period-Doubling Folds in the Cellular Oscillator

Dynamics of oscillatory phenotypes in Saccharomyces cerevisiae reveal a network of genome‐wide transcriptional oscillators

“…We are also interested in modeling the temporal organization of different phenotypes of redox cycles to help understand the mechanics of period changes. Changes in ultradian cycles also give clues to how cells have differentiated and evolved to adapt to environmental changes [1]. In our previous work, genome‐wide transcriptional oscillations were used to map a 3D attractor surface circling around the steady state through time after perturbation of the yeast strain IFO0233 with a drug that increased the redox period.…”

“…Day length on Earth, another oscillation, has increased at least threefold since the first photoautotrophs appeared. To adapt to the change in day length, the cell’s chemistry has evolved to coordinate with daily changes in the external environment [1].…”

Chronic treatment with a selective inhibitor of casein kinase I δ/ε yields cumulative phase delays in circadian rhythms

“…The global nature of this mechanism is indisputablenearly all organisms that experience the light of day exhibit circadian rhythms-and the molecular machinery that supports cycling in lower species is similar schematically to the one that supports it in mammals (Dunlap and Loros 2006;Yu and Hardin 2006;Klevecz and Li 2007;Rosbash et al 2007). A simple conclusion emerges that a healthy circadian timekeeping system is key to a healthy individual; conversely, a poorly functioning internal clock leads to significant health consequences.…”

Rhythms in Plants

“…But we stress that this phenomenon is not a special case, not a mere curiosity. The strict rhythmic self-organisation evident here is evident in another yeast (Kippert and Lloyd 1995), in mammalian cells (Brodsky 1975(Brodsky , 2006(Brodsky , 2014Lloyd and Gilbert 1998;Klevecz and Braly 1987) and probably in every living organism (Klevecz and Li 2007): its pervasive ubiquity emphasises its conserved central importance. In other yeasts, its period is different, as it is in protozoa (Table 14.1), in plants and in humans; the time base that the ultradian clock provides is a necessity for the synchrony and hence coherence of all life processes.…”

“…It has been suggested that evolutionary advantage may have accrued in an organism that could change period by changes in just one or a few genes as day length changed from 4 h in the prebiotic earth, through 8 h during the expansion of photoautotrophs, to the present 24 h (Klevecz and Li 2007). For all this time, evolution in a periodic environment has led to the development of organisms finely tuned to exploit all the possible advantages of rhythmic performance (Bünning 1964;Edmunds 1988;Lloyd and Rossi 1992;Dunlap 1999;Chandrashekaran 2005).…”