You can take the flagella out of the bacteria, but you can’t take the flagella out of the bacteria’s genetic arsenal.
By deleting a gene that controls flagella growth, Tiffany Taylor of the University of Reading in England and colleagues engineered the soil bacteria Pseudomonas fluorescens so they lacked their tiny tails. Bacteria that can move around and find food are more likely to survive, and after a mere 96 hours in a low-food environment, the bacteria were once again growing flagella.
How did the bacteria manage such a swift feat? Two mutations in regulatory genes jump-started flagella production, suggesting that natural selection can rewire genetic networks with a few key mutations, the researchers report February 26 in Science.