Multicellular Bacteria Evolve Defenses that Resemble the Immune System | The Scientist

Elizabeth Wilbanks, lead author on this study, is an MBL Whitman Fellow and a microbiologist at the University of California, Santa Barbara.

Bacterial superorganisms must evolve defenses to fight off infections, and microbiologists found that they use a weapons cache coincidentally similar to that of the human immune system.

The vast majority of bacteria are single-celled creatures that compete with one another for survival. However, some bacteria team up to build multicellular communities. While loner bacteria boast impressive genetic diversity, cooperating bugs are genetically similar to ensure that no members carry mutations that favor their own growth at the expense of the collective. Low genetic diversity increases the risk that the population could be wiped out by a bacteriophage outbreak, and multicellular bacteria need to evolve rapidly-adapting defenses to develop resilience. Now, researchers have found a mutagenesis system in bacterial communities that resembles the human immune system in more ways than one. Their findings, reported in Proceedings of the National Academy of Sciences, challenge the view that bacteria lack intricate defense systems to stave off invaders.

Scientists knew about this particular mutagenesis system, known as diversity-generating retroelements (DGR), for some time but had not unraveled its purpose. “No one really understood what bacteria or archaea were doing with them,” said Elizabeth Wilbanks, a microbiologist at the University of California, Santa Barbara and coauthor of the study. Read more on The Scientist website.

Source: Multicellular Bacteria Evolve Defenses that Resemble the Immune System | The Scientist