# Heterogeneity in bacterial quorum sensing during infection

> **NIH NIH R01** · PENNSYLVANIA STATE UNIVERSITY, THE · 2021 · $319,574

## Abstract

Quorum sensing describes the cell-signaling systems that facilitate intercellular interactions among bacteria
and coordinate population-level behaviors. Quorum sensing typically alters cellular behavior by regulating
gene expression. Bacteria also use quorum sensing to regulate factors important for infecting humans and
other animals. There is a gap in understanding how quorum-sensing systems are integrated into the infection
process. Addressing this knowledge gap is important to gain basic insight into how pathogens and beneficial
microbes form stable host-microbe associations, which will inform strategies designed to control these
associations through modulating quorum sensing. The overall objective of this proposal is to determine how
the bacterium Vibrio fischeri uses gene-regulatory networks associated with quorum sensing during infection of
its natural host, the Hawaiian squid. V. fischeri infections initially assemble within the light organ of juvenile
animals, which are un-colonized at the time of hatching. V. fischeri uses quorum sensing to regulate
bioluminescence, which is its symbiotic function within the squid host. The genes necessary for
bioluminescence are regulated by quorum sensing. The small RNA Qrr1 is a component of this regulatory
network and negatively controls bioluminescence. Guided by preliminary data, this proposal investigates how
V. fischeri uses this network during host colonization by addressing three aims: 1) Understand regulation of
qrr1 transcription in V. fischeri, 2) Examine V. fischeri aggregates for phenotypic heterogeneity, and 3)
Evaluate how aggregation during symbiosis establishment impacts the quorum-sensing pathway. All three
aims will take advantage of the innovative platform afforded by the symbiosis: fluorescence microscopy will be
used to directly examine the infection process and molecular biology tools to dissect the associated quorum-
sensing systems. The proposed research is significant because it will reveal important basic principles of how
quorum-sensing networks function at different infection stages, which is knowledge that has broad applicability
to other host-microbe interactions and provides critical insight into strategies designed to control these
associations through modulating quorum sensing.

## Key facts

- **NIH application ID:** 10217194
- **Project number:** 5R01GM129133-04
- **Recipient organization:** PENNSYLVANIA STATE UNIVERSITY, THE
- **Principal Investigator:** Timothy Miyashiro
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $319,574
- **Award type:** 5
- **Project period:** 2018-08-01 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10217194

## Citation

> US National Institutes of Health, RePORTER application 10217194, Heterogeneity in bacterial quorum sensing during infection (5R01GM129133-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10217194. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*