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Caulobacter crescentus intrinsic dimorphism provides a prompt bimodal response to copper stress


Stress response to fluctuating environments often implies a time-consuming reprogramming of gene expression. In bacteria, the so-called bet hedging strategy, which promotes phenotypic stochasticity within a cell population, is the only fast stress response described so far1. Here, we show that Caulobacter crescentus asymmetrical cell division allows an immediate bimodal response to a toxic metals-rich environment by allocating specific defence strategies to morphologically and functionally distinct siblings. In this context, a motile swarmer cell favours negative chemotaxis to flee from a copper source, whereas a sessile stalked sibling engages a ready-to-use PcoAB copper homeostasis system, providing evidence of a prompt stress response through intrinsic bacterial dimorphism.

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Figure 1: Cu detoxification response in Cu-treated ST cells.
Figure 2: Respective roles of PcoA and PcoB during the Cu detoxification response.
Figure 3: Cu-treated SW cells escape.
Figure 4: Model of the C. crescentus bimodal response.

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The authors thank C. Jacobs-Wagner, J. Collier, L. Shapiro, P. Viollier and J. Smit for providing strains and antibodies. The authors acknowledge the microscopy platform of the De Duve Institute (UCL) for allowing access to the Zen Observer Z.1 inverted microscope, and thank C. Staudt (URPhym, UNamur) for technical support regarding the oxygraph and R. Stephan from the GIGA Flow Cytometry Facility (ULg) for technical support with FACS cell counting. Finally, the authors thank C. Jacobs-Wagner, J.-F. Collet, G. Cornelis and X. De Bolle for critical reading of the manuscript and the URBM members for discussions. This work was supported by the University of Namur. E.L. and S.G. were supported by the Belgian Fund for Industrial and Agricultural Research Associate (FRIA).

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E.L., S.G., G.L., F.T., S.L.B. and P.C. performed the experiments. E.L., S.G. and G.L. analysed the data. E.L. and J.-Y.M. initiated and designed the research. E.L., S.G. and J.-Y.M. wrote the manuscript.

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Correspondence to Jean-Yves Matroule.

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The authors declare no competing financial interests.

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Supplementary Figures 1-15, Supplementary Text, Supplementary Tables 1 and 2, Supplementary References (PDF 27626 kb)

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Lawarée, E., Gillet, S., Louis, G. et al. Caulobacter crescentus intrinsic dimorphism provides a prompt bimodal response to copper stress. Nat Microbiol 1, 16098 (2016).

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