Metabolic activities are selective modulators for individual segmentation clock processes

A sequence of cellular and molecular processes unfolding during embryonic development prompts fundamental questions of how the tempo of multiple processes is coordinated and whether a common global modulator exists. The oscillation of the segmentation clock is a well-studied model of developmental tempo. While the clock period is known to scale with the kinetics of gene expression and degradation processes of the core clock gene Hes7 across mammalian species, how these key molecular processes are coordinated remains unclear. In this study, we investigated if metabolic activities act as a global modulator for the segmentation clock, finding that they are rather selective modulators. While several metabolic inhibitions extended the clock period, their effects on the key processes varied. Inhibition of glycolysis decelerated the protein degradation of Hes7 and extended the production delay but did not influence the intron delay. Electron transport chain inhibition extended Hes7 intron delay without influencing the other two processes. Combinations of distinct metabolic inhibitions exhibited synergistic effects. By contrast, temperature changes affected the clock period and all three key processes simultaneously. These results highlight the selective effects of metabolic activities on segmentation clock processes, hinting that their scaled kinetics across species may be achieved through combinations of multiple modulators.