NASHVILLE, Oct. 11 (UPI) -- A tiny virus called Wolbachia has managed to infect nearly half of all arthropod species. When a pair of scientists at Vanderbilt University sequenced the virus' genome, they found the DNA of the toxin used by black widow spiders, one of the virus' hosts.
"Discovering DNA related to the black widow spider toxin gene came as a total surprise because it is the first time that a phage -- a virus that infects bacteria -- has been found carrying animal-like DNA," Seth Bordenstein, an associate professor of biological sciences, said in a news release.
The bacterial parasite has shown promise as a weapon against dengue fever and Zika virus. Wolbachia, WO, stops the two viruses from replicating inside Aedes aegypti mosquitoes, the species that spreads the viruses.
If scientists can better understand how the WO phage works, they might be able to better engineer a Zika- and dengue-targeting viral weapon.
The discovery of black widow toxin DNA was surprising because most phages make a habit of ripping apart the defense systems of their targets.
"[But] the portion of DNA related to the black widow spider toxin gene is intact and widespread in the phage," said researcher Sarah Bordenstein.
The two researchers also found segments of other animal membrane DNA in the virus' genome. Its wholesale adoption of foreign DNA segments may be explained by its method of infection. When the phage invades its host, it must travel through various eukaryotic membranes then wrap itself inside a layer of the arthropod's membrane.
"We suspect it makes pores in the membranes of the arthropod cells that surround Wolbachia, thereby allowing the phage to overcome both the bacterial and arthropod membranes that surround it," Seth Bordenstein said. "That may be how it uses some of these proteins."
The researchers also believe it uses some of its stolen DNA to thwart immune system responses.
Researchers published their investigation of Wolbachia in the journal Nature Communications.