Bacterial chemotaxis in a microfluidic T-maze reveals strong phenotypic heterogeneity in chemotactic sensitivity

• Published in: Nature communications 2019-04, Vol.10 (1), p.1877-1877, Article 1877
• Main Authors: Salek, M. Mehdi, Carrara, Francesco, Fernandez, Vicente, Guasto, Jeffrey S., Stocker, Roman
• Format: Article
• Language: English
• Subjects: 101/62; 14/63; 631/326/41; 704/158/855; Bacteria; Bias; Cell division; Cell migration; Chemotaxis; Chemotaxis - genetics; Decision making; Dimethylpolysiloxanes - chemistry; E coli; Engineering; Environmental engineering; Escherichia coli; Escherichia coli - physiology; Gene expression; Heterogeneity; Humanities and Social Sciences; Intravital Microscopy - methods; Mathematical analysis; Mathematical models; Microfluidic Analytical Techniques - methods; Microfluidics; Microorganisms; Microscopy, Phase-Contrast - methods; Models, Biological; multidisciplinary; Organic chemicals; Phenotype; Population; Proteins; Science; Science (multidisciplinary); Sensitivity; Single-Cell Analysis - methods
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09521-2

Many microorganisms have evolved chemotactic strategies to exploit the microscale heterogeneity that frequently characterizes microbial habitats. Chemotaxis has been primarily studied as an average characteristic of a population, with little regard for variability among individuals. Here, we adopt a classic tool from animal ecology – the T-maze – and implement it at the microscale by using microfluidics to expose bacteria to a sequence of decisions, each consisting of migration up or down a chemical gradient. Single-cell observations of clonal Escherichia coli in the maze, coupled with a mathematical model, reveal that strong heterogeneity in the chemotactic sensitivity coefficient exists even within clonal populations of bacteria. A comparison of different potential sources of heterogeneity reveals that heterogeneity in the T-maze originates primarily from the chemotactic sensitivity coefficient, arising from a distribution of pathway gains. This heterogeneity may have a functional role, for example in the context of migratory bet-hedging strategies. Chemotaxis is usually considered as a trait of a species or population. Here, the authors use a microfluidics device to reveal that clonal E . coli show individual variation in a key aspect of chemotactic behavior.