Press release No. 212/2013
Bacterial policing: Why you’d better cooperate with your own family
Scientists from Göttingen University study social behavior of unicellular organisms
(pug) Bacteria are unicellular organisms that may show surprising levels of sociality. They can coordinate their behavior and cooperatively build enzymes or defence compounds that a single cell would not be able to produce in sufficient quantity. Such cooperative traits are extremely useful but at the same time vulnerable to social cheaters. Scientists from the University of Göttingen recently discovered that cooperating bacteria are able to produce toxins to defend themselves against social cheaters. However, this mechanism only functions among bacteria with close kin progeny. It turns unreliable when it comes to fighting social cheats from little related lineages. The study was published in Nature Communications.
The researchers analysed bacteria of the genus Pseudomonas, a widespread group that includes useful kinds as well as pathogenic germs. They grew multispecies communities in which social cheats rapidly evolved. The cheats were kept under control with the help of a clever mechanism: The cooperators produced toxins that left the cooperating bacteria unaffected and killed those who stopped doing so. However, the mechanism only works among closely related kin. It fails to control cheats from little related lineages.
“Bacteria exercise tight control over their clones,” leading author Dr. Alexandre Jousset from Göttingen Uni-versity’s Animal Ecology section explains. “Therefore, cooperation is only stable if all organisms within the community are closely related.” This finding about ‘bacterial partisanship’ might prove very useful with regard to curing diseases. The dangerousness of germs is often based on functioning cooperation among bacteria. “Injecting social cheats from little related lineages into communities might be a way to purposefully disturb cooperation and thus reduce the dangerousness of the disease,” says Jousset.
Original publication: Alexandre Jousset et al. Evolutionary history predicts the stability of cooperation in mi-crobial communities. Nature Communications 4:2573. Doi: 10.1038/ncomms3573.
Dr. Alexandre Jousset
Georg-August University Göttingen
Faculty of Biology and Psychology
Johann-Friedrich-Blumenbach-Institute für Anthropology and Zoology
Berliner Straße 28, 37073 Göttingen, Germany, Phone +49 (0)551 39-5448