Separating signal from noise in living cells

A mathematician from the University of Bristol has teamed up with a biologist from the University of Edinburgh to address a major problem in molecular biology. Clive Bowsher, Lecturer at the School of Mathematics, and Professor Peter Swain at Synthetic and Systems Biology Edinburgh co-authored a paper in the Proceedings of the National Academy of Sciences showing how to separate 'signal' from 'noise' when studying the mechanisms of living cells. Cells make decisions in fluctuating environments using inherently noisy biochemical mechanisms. Such effects create considerable, unpredictable variation - known as 'stochasticity'- both over time and between genetically identical cells. To understand how cells exploit and control these biochemical fluctuations, scientists must identify the sources of stochasticity, quantify their effects, and distinguish variation that carries information about the biological environment from confounding noise. In their PNAS paper, Bowsher and Professor Swain show how to decompose the fluctuations of biochemical networks into multiple components and how to design experimental 'reporters' to measure these components in living cells. 'The mathematics provides variance decomposition techniques for dynamic systems,' said Bowsher.