1. The Global Transcription Factor Lrp Controls Virulence Modulation in Xenorhabdus nematophila.
- Author
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Hussa, Elizabeth A., Casanova-Torres, Ángel M., and Goodrich-Blair, Heidi
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TRANSCRIPTION factors , *XENORHABDUS nematophilus , *MICROBIAL virulence , *INSECT larvae , *STEINERNEMA carpocapsae - Abstract
The bacterium Xenorhabdus nematophila engages in phenotypic variation with respect to pathogenicity against insect larvae, yielding both virulent and attenuated subpopulations of cells froman isogenic culture. The global regulatory protein Lrp is necessary for X. nematophila virulence and immunosuppression in insects, as well as colonization of themutualistic host nematode Steinernema carpocapsae, and mediates expression of numerous genes implicated in each of these phenotypes. Given the central role of Lrp in X. nematophila host associations, as well as its involvement in regulating phenotypic variation pathways in other bacteria, we assessed its function in virulencemodulation.We discovered that expression of lrp varies within an isogenic population, in amanner that correlates withmodulation of virulence. Unexpectedly, although Lrp is necessary for optimal virulence and immunosuppression, cells expressing high levels of lrp were attenuated in these processes relative to those with low to intermediate lrp expression. Furthermore, fixed expression of lrp at high and low levels resulted in attenuated and normal virulence and immunosuppression, respectively, and eliminated population variability of these phenotypes. These data suggest that fluctuating lrp expression levels are sufficient to drive phenotypic variation in X. nematophila. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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