Animals Steal Toxins with Gene Transfer to Fight Bacteria
It turns out that some animals may be able to steal toxins in order to fight off bacteria. Scientists have found that ticks, mites and other animals have "stolen" microbe toxin genes in order to battle otherwise harmful bacteria.
The scientists actually discovered the animal toxins when they were working to find more bacterial competition toxins.
"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," said Matt Daugherty, one of the researchers, in a news release. "We immediately started wondering why they were there."
The researchers analyzed the toxins and found that they had jumped from bacteria into animals. In fact, the genes had become permanently incorporated into the genomes of these animals through a process known as horizontal gene transfer. This transfer caused the organisms carrying the bacterial toxins to better be able to fight off diseases. One species, in particular, was the deer tick, which is infamous for its ability to transfer Lyme disease.
"We were excited to see this in the deer tick, given the increasing prevalence of Lyme disease in North America," said Seemay Chou, co-author of the new study, in a news release. "Lyme disease is caused by a bacterium, so we speculated that the transferred antibacterial toxin might affect how the tick interacts with the Lyme disease agent."
Currently, how the toxins functions in organisms other than ticks still needs to be explored. Yet it's likely that the toxins have been repurposed by animals for antibacterial defense.
"Given the rate by which we are discovering new toxins, it would not surprise me at all if we find more that have been horizontally transferred," said Joseph Morgous, one of the researchers.
The findings are published in the journal Nature.