Evolution. Evolutionary resurrection of flagellar motility via rewiring of the nitrogen regulation system.
Studholme, David J.
American Association for the Advancement of Science
This is the accepted version of the article published in Science 27 February 2015: 347 (6225), 1014-1017. DOI:10.1126/science.1259145
Reason for embargo
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 homolog 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 toward its novel function as a flagellar regulator. Our results demonstrate that natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps.
University of York
U.S. Department of Agriculture’s National Institute of Food and Agriculture Microbial Functional Genomics Program
types: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.
Copyright © 2015, American Association for the Advancement of Science.
Vol. 347, Issue 6225, pp. 1014 - 1017
Place of publication