# Resolving the Conflicts between Phenotypic Diversity and Collective Migration in Bacterial Populations

> **NIH NIH F32** · YALE UNIVERSITY · 2020 · $65,310

## Abstract

Project Summary
Cell populations often display substantial phenotypic diversity, even in homogeneous
environments. At the same time, biological functions are not typically carried out by isolated cells,
but rather by populations of varying functional abilities. The conflicts between phenotypic diversity
and collective behavior have scarcely been examined. This project will address the gap in our
understanding of these conflicts using Escherichia coli, a well-studied model system that exhibits
both individuality and collective behavior. Groups of E. coli in a uniform field of nutrient form
migrating bands mediated by the well-characterized chemotaxis system, which enables them to
chase a gradient of nutrient generated by their consumption. However, single cells in an isogenic
population of E. coli climb standing gradients with very different drift speeds, as recently
characterized by the Emonet lab. How are these cells able to migrate together? We recently
discovered a compensatory mechanism in which the fastest gradient-climbers localize to the front
of the traveling band where the gradient is shallow, and the weakest performers localize to the
back where the gradient is steep. But not all phenotypes are able to travel, indicating that
collective migration can limit the amount of phenotypic diversity in the population. Here, I will
examine the mechanisms by which bacteria resolve the conflicts between phenotypic diversity
and collective behavior. Aim 1 will determine how phenotypic diversity in the band shapes the
traveling gradient of attractant, and how receptor adaptation together with the shape of the
gradient in turn affect which phenotypes can travel. The results will produce a quantitative
understanding of how bacteria use spatial organization to resolve the conflicts between
phenotypic diversity and collective behavior. Aim 2 will determine how differential growth and
leakage of phenotypes off the back of the group affect collective migration. These studies will
deepen our understanding of the extent to which growth can counteract the effects of collective
behavior on population diversity.

## Key facts

- **NIH application ID:** 9844854
- **Project number:** 5F32GM131583-02
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** Henry H Mattingly
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $65,310
- **Award type:** 5
- **Project period:** 2019-01-01 → 2020-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9844854

## Citation

> US National Institutes of Health, RePORTER application 9844854, Resolving the Conflicts between Phenotypic Diversity and Collective Migration in Bacterial Populations (5F32GM131583-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9844854. Licensed CC0.

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