The Evolution of Mass Cell Suicide in Bacterial Warfare
| Autor: | Elisa T. Granato, Kevin R. Foster |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Programmed cell death Lysis Bacterial Toxins colicins Biology medicine.disease_cause Article bacteriocins General Biochemistry Genetics and Molecular Biology collective behavior 03 medical and health sciences 0302 clinical medicine Bacteriocin Escherichia coli medicine kin selection social evolution 030304 developmental biology 0303 health sciences Reporter gene Natural selection Cell Death 030306 microbiology Toxin 16. Peace & justice biology.organism_classification Biological Evolution Cell biology 030104 developmental biology cell suicide Colicin warfare General Agricultural and Biological Sciences competition 030217 neurology & neurosurgery Bacteria |
| Zdroj: | Current Biology |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/j.cub.2020.05.007 |
| Popis: | Summary Behaviors that cause the death of an actor are typically strongly disfavored by natural selection, and yet many bacteria undergo cell lysis to release anti-competitor toxins [1, 2, 3, 4, 5]. This behavior is most easily explained if only a small proportion of cells die to release toxins and help their clonemates, but the frequency of cells that actually lyse during bacterial warfare is unknown. The challenge is finding a way to distinguish cells that have undergone programmed suicide from those that were simply killed by a competitor’s toxin. We developed a two-color fluorescence reporter assay in Escherichia coli to overcome this problem. This revealed conditions where nearly all cells undergo programmed lysis. Specifically, adding a DNA-damaging toxin (DNase colicin) from another strain induced mass cell suicide where ∼85% of cells lysed to release their own toxins. Time-lapse 3D confocal microscopy showed that self-lysis occurs locally at even higher frequencies (∼94%) at the interface between toxin-producing colonies. By exposing E. coli that do not perform lysis to the DNase colicin, we found that mass lysis occurs when cells are going to die anyway from toxin exposure. From an evolutionary perspective, this renders the behavior cost-free as these cells have zero reproductive potential. This helps to explain how mass cell suicide can evolve, as any small benefit to surviving clonemates can lead to this retaliatory strategy being favored by natural selection. Our findings have parallels to the suicidal attacks of social insects [6, 7, 8, 9], which are also performed by individuals with low reproductive potential. Graphical Abstract Highlights • A novel assay can detect Escherichia coli undergoing cell suicide to release toxins • This assay was used to follow the frequency of suicidal self-lysis during competition • Under some conditions, nearly all cells will self-lyse to release toxins • Self-lysis makes evolutionary sense as cells will die anyway from competitors’ toxins Granato and Foster show that Escherichia coli bacteria undergo mass cell suicide to release toxins during competitions and that this behavior is restricted to cells that are going to die from the competitor’s attack. Mass cell suicide makes evolutionary sense as a last-ditch attempt to counterattack by doomed cells. |
| Databáze: | OpenAIRE |
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