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The lacoperon of Escherichia coliis a classic model for studying gene regulation. This study has uncovered features such as the environmental input logic controlling gene expression, as well as gene expression bistability and hysteresis. Most lacoperon studies have focused on a few lab strains, and it is not known how generally those findings apply to the diversity of E. colistrains. We examined the environmental dependence of lacgene regulation in 20 natural isolates of E. coliand found a wide range of regulatory responses. By transferring lacgenes from natural isolate strains into a common reference strain, we found that regulation depends on both the lacgenes themselves and on the broader genetic background, indicating potential for still-greater regulatory diversity following horizontal gene transfer. Our results reveal that there is substantial natural variation in the regulation of the lacoperon and indicate that this variation can be ecologically meaningful.

Computation is a useful concept far beyond the disciplinary boundaries of computer science. Perhaps the most important class of natural computers can be found in biological systems that perform computation on multiple levels. From molecular and cellular information processing networks to ecologies, economies and brains, life computes. Despite ubiquitous agreement on this fact going back as far as von Neumann automata and McCulloch–Pitts neural nets, we so far lack principles to understand rigorously how computation is done in living, or active, matter. What is the ultimate nature of natural computation that has evolved, and how can we use these principles to engineer intelligent technologies and biological tissues?