College of Liberal Arts & Sciences

Christian Ray

Assistant Professor
Primary office:


Critical points, fitness, and evolution in natural and synthetic biological networks

Physiological responses in growing organisms display tradeoffs between cost and benefit. In microbial metabolism, organismal fitness (often characterized by population growth rate) depends on networks of well-balanced metabolic fluxes. In gene regulation and signaling networks, physical limits on information flow play a decisive role in evolution. In either type of network, small-scale molecular mechanisms can have a powerful effect on larger-scale emergent physiology, creating critical transitions that determine cellular phenotypes and thus fitness.

In my laboratory we are using complementary theoretical and experimental methods to understand the relationship between the properties of critical transitions in single cells and evolutionary fitness. We use mathematical and computational methods to predict cellular dynamics and guide the design of experiments with bacteria. In the laboratory we directly measure the relationship between network dynamics and fitness, using either natural networks (such as the well-studied lac operon in E. coli) or synthetic constructs designed to test specific predictions.

Representative Publications

  • Wang H and Ray JCJ. (2017) Dynamical predictors of an imminent phenotypic switch in bacteria. Phys Biol 14(4):045007.
  • Ray JCJ. (2016) Survival of phenotypic information during cellular growth transitions. ACS Synth Biol 5(8):810-816.
  • Ray JCJ, Wickersheim ML, Jalihal AP, Adeshina YO, Cooper TF, and Balázsi G. (2016) Cellular growth arrest and persistence from enzyme saturation. PLoS Comp Biol 12(3):e1004825.
  • González C, Ray JCJ, Manhart M, Adams RM, Nevozhay D, Morozov AV, and Balázsi G. (2015) Stress-response balance drives the evolution of a network module and its host genome. Mol Sys Biol 11(8):827.

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