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Updated: Jun 11, 2026
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Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Genome-scale dissection of phase-variable gene function in Campylobacter jejuni using a stabilized phasotype library
Shouji Yamamoto1, Ken-Ichi Lee1, Akiko Kubomura1
1Department of Bacteriology I, National Institute of Infectious Diseases, Japan Institute for Health Security, Shinjuku City, Tokyo, Japan.
Msphere
|June 10, 2026
Summary
Phase variation allows bacteria like Campylobacter jejuni to adapt by changing surface structures. A new tool, PV-GenShift, stabilizes these changes to reveal how specific gene combinations improve survival and colonization.
Area of Science:
- Microbiology
- Genetics
- Bacterial Pathogenesis
Background:
- Phase variation (PV) enables bacterial pathogens to adapt to changing environments and evade host immunity.
- In *Campylobacter jejuni*, simple sequence repeat (SSR)-mediated PV controls surface molecules crucial for host interaction and immune resistance.
- The inherent randomness of PV has hindered systematic analysis of individual phase-variable genes (PVGs) and their combinatorial effects.
Purpose of the Study:
- To develop a scalable platform, PV-GenShift, for genetically stabilizing and analyzing phase-locked variants of *C. jejuni*.
- To systematically investigate the functional impact of specific combinations of PVG states (phasotypes) on bacterial adaptation under selective pressures.
- To identify specific phasotypes associated with enhanced survival in host environments, such as serum exposure and murine colonization.
Main Methods:
- Creation of a genetically stabilized library of phase-locked *C. jejuni* variants.
- Utilizing multiplex genome editing via natural transformation to fix the ON/OFF states of 15 SSR-containing PVGs.
- Applying the PV-GenShift platform to models of human serum exposure, murine colonization, and chicken gut passage to analyze distinct phasotypes.
Main Results:
- Identified distinct phasotypes linked to enhanced serum resistance and enrichment during mouse colonization.
- Observed that capsular polysaccharide modifications, specifically *O*-methyl phosphoramidation and methylation, were associated with successful murine colonization.
- Found heterogeneous PVG expression patterns during chicken gut passage, suggesting weak or non-specific selection in this environment.
Conclusions:
- The combinatorial expression states of multiple PVGs significantly influence bacterial adaptation and host colonization.
- PV-GenShift provides a versatile and scalable framework for dissecting PV-driven phenotypic diversity in bacterial pathogens.
- The findings have implications for developing novel vaccines, diagnostics, and therapeutics targeting bacterial adaptation strategies.
