What could this upstream control system be? Pourqui\u00e9 and Diaz Cuadros pondered which system could potentially affect a variety of cellular processes \u2014 and they landed on metabolism, driven by mitochondria. Mitochondria produce ATP, the energy currency of the cell, as well as a host of metabolites essential for building proteins and DNA, regulating the genome, and performing other critical processes.<\/p>\n

To test that idea, they devised genetic and pharmacological methods to speed up and then slow down the metabolic rates of their stem cells. If mitochondria were indeed setting the cellular tempo, they expected to see their experiments alter the rhythm of the segmentation clock.<\/p>\n