The temporal architecture of eukaryotic growth

Abstract 

Coherence of the time structure of growing organisms depends on a metronome-like orchestration. In a continuously perfused culture of Saccharomyces cerevisiae the redox state of the cell shows a temperature-compensated oscillation manifest in respiratory cycles, which are measured by continuous and non-invasive electrodes of probes such as dissolved oxygen and probes such as fluorometric NAD(P)H. Although the entire transcriptome exhibits low-amplitude oscillatory behaviour, transcripts involved in the vast majority of metabolism, stress response, cellular structure, protein turnover, mRNA turnover, and DNA synthesis are amongst the top oscillators and their orchestration occurs by an intricate network of transcriptional regulators. Therefore cellular auto-dynamism is a function of a large ensemble of excitable intracellular components of that self-organized temporally and spatially that encompasses mitochondrial, nuclear, transcriptional and metabolic dynamics, coupled by cellular redox state.

Abbreviations: CCCP, m-chlorocarbonycyanide phenylhydrazone, S₁₃, 5-chloro-3-t-butyl-2-chloro-4′-salicylhydroxamic acid, ROS, reactive oxygen species

Keywords: Yeast, Redox regulation, Biological clock, Respiration, Mitochondrion