Animals steal defenses from bacteria

http://www.eurekalert.org/pub_releases/2014-11/uowh-asd112114.php

PUBLIC RELEASE DATE: 24-Nov-2014

Contact: Leila Gray
University of Washington Health Sciences/UW Medicine

Animals steal defenses from bacteria
Microbe toxin genes have jumped to ticks, mites and other animals

It's a dog eat dog world, and bacteria have been living in it for a long time. It's of no surprise that bacteria have a sophisticated arsenal to compete with each other for valuable resources in the environment. In 2010, work led by University of Washington Department of Microbiology Associate Professor Joseph Mougous uncovered a weaponry system used in this warfare between bacteria. The combatants inject deadly toxins into rival cells.

Now, in a surprising twist, Mougous and colleagues have found that many animals have taken a page from the bacterial playbook. They steal these toxins to fight unwanted microbes growing in or on them. The researchers describe their findings in a report to be published online Nov. 24 in the journal Nature.

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"When we started digging into genome databases, we were surprised to find that toxin genes we thought were present only in bacteria were also in several animals," explained co-author Matt Daugherty, a postdoctoral fellow in the Malik lab. "We immediately started wondering why they were there."

Their analyses revealed that these genes had jumped from bacteria into animals. These genes had become permanently incorporated into the genomes of these animals through a process known as horizontal gene transfer. While such transfer events are common between microbes, very few genes have been reported to jump from bacteria to more complex organisms.

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