Venom-stealing viruses sound like something plucked straight from a horror film, but a recent paper published in Nature Communications has discovered exactly that.
Husband-and-wife team Seth and Sarah Bordenstein at Vanderbilt University, USA, found snippets of animal DNA within a bacteria-infecting virus. Gene stealing in viruses is not a new phenomenon but these findings are the first time a transfer of genetic information between an animal and a bacterial virus has been seen.
Viruses are the most abundant and diverse biological entities in the environment and are split into three distinct domains: eukaryotic (the group of life in which animals, plants and fungi belong), archael and bacterial. Usually eukaryotic viruses co-opt eukaryotic genes and bacterial viruses, known as bacteriophages, steal bacterial genes. Until the Bordenstein’s discovery it was known that viruses steal DNA but this discovery is the first time bacteriophages have assimilated eukaryotic genes into their own genetic material.
‘Like many other viruses, WO lives within its host, multiplying in number until it bursts out, killing the host.’
In their experiment the Bordensteins sequenced the DNA of WO bacteriophages and discovered the presence of a stolen eukaryotic gene coding for latroxin, the poison used by black widow spiders. As WO bacteriophages must cross both bacterial and animal membranes, it is thought the poison is used to help punch the virus into its destination host cell. Like many other viruses, WO lives within its host, multiplying in number until it bursts out, killing the host. The Bordensteins suspect the toxin may be used both for entry into and exit from its host cell and has been stolen by the bacteriophage as a survival gene.
Luckily for us, these venom-stealing viruses won’t be infecting us with Black Widow venom anytime soon. WO bacteriophage only infect the Wolbachia bacteria, which in turn infect insects, spiders, woodlice and other arthropods.
Thanks to the DNA sequencing efforts of the Bordensteins, scientists believe WO bacteriophages could be used to assist in the ongoing efforts to genetically engineer Wolbachia to prevent mosquitos spreading dengue fever, Zika, yellow fever and other deadly diseases. Wolbachia has already been shown to prevent disease-causing viruses such as Zika replicating in mosquitos. As we now know the specific genetic sequence of WO that allows it to insert its genome into the Wolbachia chromosome, scientists believe it could provide a basic toolkit for the genetic engineering of the bacterium, aiding the efforts to prevent the spread of insect-borne diseases.