Evolutionary resurrection of flagellar motility via rewiring of the nitrogen regulation system

Taylor, T. B., Mulley, G. ORCID: https://orcid.org/0000-0003-0650-478X, Dills, A. H., Alsohim, A. S., McGuffin, L. J. ORCID: https://orcid.org/0000-0003-4501-4767, Studholme, D. J., Silby, M. W., Brockhurst, M. A., Johnson, L. J. ORCID: https://orcid.org/0000-0002-0006-1511 and Jackson, R. W. (2015) Evolutionary resurrection of flagellar motility via rewiring of the nitrogen regulation system. Science, 347 (6225). pp. 1014-1017. ISSN 0036-8075 doi: 10.1126/science.1259145

Abstract/Summary

A central process in evolution is the recruitment of genes to regulatory networks. We engineered immotile strains of the bacterium Pseudomonas fluorescens that lack flagella due to deletion of the regulatory gene fleQ. Under strong selection for motility, these bacteria consistently regained flagella within 96 hours via a two-step evolutionary pathway. Step 1 mutations increase intracellular levels of phosphorylated NtrC, a distant homologue of FleQ, which begins to commandeer control of the fleQ regulon at the cost of disrupting nitrogen uptake and assimilation. Step 2 is a switch-of-function mutation that redirects NtrC away from nitrogen uptake and towards its novel function as a flagellar regulator. Our results demonstrate that natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/39447
Identification Number/DOI	10.1126/science.1259145
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences > Biomedical Sciences Life Sciences > School of Biological Sciences > Ecology and Evolutionary Biology
Publisher	AAAS
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