# Vibrio fischeri as a Model for Bacterial Colonization

> **NIH NIH R37** · UNIVERSITY OF HAWAII AT MANOA · 2022 · $1

## Abstract

Project Summary/Abstract - The long-term goals of the proposed research program are to provide insight into
the complex dialogue that occurs each generation between humans and their microbiota during the critical
period following birth. Recent research has indicated a strong correlation between outcomes of these early
events and life-long health. However, the inaccessibility of colonized tissues and high diversity of the
microbiota renders an in-depth study of early colonization of human tissues extremely challenging. When faced
with such complex phenomena, biologists often turn to simpler model systems to provide insights into
evolutionarily conserved features and reveal basic principles. To decipher the cellular and molecular
mechanisms underlying the initiation of bacterial associations with apical surfaces of mucosal epithelia, the
proposed program exploits the binary symbiosis between the bacterium Vibrio fischeri and its squid host,
Euprymna scolopes. This relatively simple association has been studied for over two decades as a model for
the chronic colonization of mucosa by Gram-negative bacteria. As in humans, the squid-vibrio association
begins anew each generation, requiring a `winnowing' of other environmental bacteria that results in persistent
association restricted to the coevolved partners. In this system, the process of symbiosis initiation occurs
across ~100 microns over minutes to hours. It can be directly imaged in its entirety using confocal microscopy,
which offers the rare opportunity to define, with high temporal and spatial resolution, the reciprocal molecular
and biochemical dialogue that results in the establishment of a specific, life-long beneficial symbiosis. This
project brings together two collaborators, each with expertise in the biology of one of the symbiotic partners,
and introduces new technology to the study of host-microbe interactions, including: Nanoscale Secondary Ion
Mass Spectrometry (NanoSIMS), which allows precision tracking of symbiont molecules into host tissues;
Hybridization-Chain-Reaction Fluorescent In Situ Hybridization (HCR-FISH), which enables visualization of
rare transcripts in host and symbiont cells; NanoString, a new technology for simultaneous analysis of dozens
to hundreds of targeted transcripts; and high-efficiency RNAseq, which produces robust transcriptional libraries
from as little as 10 ng total RNA (~105 bacteria). Specific aims to be addressed are: (1) the examination of how
symbiotic bacterial strain variation affects symbiosis onset and persistence; (2) the characterization of outer
membrane vesicle (OMV) contents, their trafficking into host cells, and host responses to OMV cargo; and, (3)
the investigation of the roles of vibrio virulence determinants in a non-pathogenic association. An
understanding of the human microbiome is in its infancy, and this frontier field is currently at the stage of
building paradigms. Within this context, as the squid-vibrio system has in the pa...

## Key facts

- **NIH application ID:** 10338077
- **Project number:** 5R37AI050661-19
- **Recipient organization:** UNIVERSITY OF HAWAII AT MANOA
- **Principal Investigator:** MARGARET J MC FALL-NGAI
- **Activity code:** R37 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $1
- **Award type:** 5
- **Project period:** 2001-12-01 → 2022-02-02

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10338077

## Citation

> US National Institutes of Health, RePORTER application 10338077, Vibrio fischeri as a Model for Bacterial Colonization (5R37AI050661-19). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/10338077. Licensed CC0.

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