Cell-to-cell variability serves as information not noise

Abstract Multicellular organisms can adapt to the environment despite heterogeneous responses by individual cells. Heterogeneity in cellular responses has been regarded as noise that reduces accurate information transmission. Cellular heterogeneity consists of intracellular variation, referred to as “intrinsic” noise, which is caused by stochasticity of biochemical reactions, and of intercellular variation, “extrinsic” noise, which is caused by differences in amounts of molecules. We found that intercellular variation increases the gradualness of the multicellular dose-response, a phenomenon that we termed the “response diversity effect.” The result is an increase in the capacity of the system to transmit information. This response diversity effect is a previously unappreciated mechanism enabling multicellular organisms to use cell-to-cell variability as information, not noise.