Phenotypic heterogeneity and bet hedging in chemotaxis of Escherichia coli

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Escherichia coli chemotaxis is one of the most analyzed model systems of simple behavioural re-sponse. Chemotaxis allows bacteria to follow gradients of nutrients and environmental stimuli to find conditions that are optimal for growth. It further plays an important role in cooperative behaviour of bacteria and in virulence. Experimental and theoretical studies established E. coli chemotaxis as an example of an evolutionary optimized cellular network and yielded many insights into such general network properties as signal amplification and robustness. The goal of this project is to investigate one of the little studied aspects of chemotaxis, namely the origins and consequences of concerted variation in expression of chemotaxis genes across the population, in E. coli and in other model bacteria. We further propose to investigate the ability of E. coli population to adjust its heterogeneity dependent on the environmental selection. Finally, we aim to analyze the interplay between such population heterogeneity and cooperative behaviour in E. coli chemotaxis, also by establishing an artificial cooperating system with tuneable cooperativity and heterogeneity. We expect this project to significantly advance our quantitative understanding of the origins and consequences of heterogeneity and cooperativity in microbial behaviour.