Adaptability of non-genetic diversity in bacterial chemotaxis

TL;DR

This study explores how genetic regulation mutations can lead to heritable behavioral diversity in bacterial chemotaxis, enabling adaptation to diverse and variable environments through phenotypic diversification.

Contribution

It demonstrates that mutations in gene regulation can produce heritable chemotactic diversity, facilitating adaptation without switching between multiple systems.

Findings

Different environments select for different chemotactic behaviors.

Behavioral diversification is advantageous when navigation time is limited.

Protein level distribution changes can produce heritable behavioral diversity.

Abstract

Bacterial chemotaxis systems are as diverse as the environments that bacteria inhabit, but how much environmental variation can cells tolerate with a single system? Diversification of a single chemotaxis system could serve as an alternative, or even evolutionary stepping-stone, to switching between multiple systems. We hypothesized that mutations in gene regulation could lead to heritable control of chemotactic diversity. By simulating foraging and colonization of E. coli using a single-cell chemotaxis model, we found that different environments selected for different behaviors. The resulting trade-offs show that populations facing diverse environments would ideally diversify behaviors when time for navigation is limited. We show that advantageous diversity can arise from changes in the distribution of protein levels among individuals, which could occur through mutations in gene regulation. We propose experiments to test our prediction that chemotactic diversity in a clonal population could be a selectable trait that enables adaptation to environmental variability.