An ancient virus
The fact that its so widespread indicates that it probably isnt a particularly young virus, either.
Weve basically found it in every population weve looked at, Edwards said. As far as we can tell, its as old as humans are.
He and his team named the virus crAssphage, after the cross-assembly software program used to discover it.
Some of the proteins in crAssphages DNA are similar to those found in other well-described viruses. That allowed Edwards team to determine that their novel virus is one known as a bacteriophage, which infects and replicates inside bacteriaand using innovative bioinformatic techniques, they predicted that this particular bacteriophage proliferates by infecting a common phylum of gut bacteria known as Bacteriodetes.
Bacteriodetes bacteria live toward the end of the intestinal tract, and they are suspected to play a major role in the link between gut bacteria and obesity. What role crAssphage plays in this process will be a target of future research.
Further details about crAssphage have been difficult to come by. Its unknown how the virus is transmitted, but the fact that it was not found in very young infants fecal samples suggests that it is not passed along maternally, but acquired during childhood. The makeup of the viral DNA suggests that its circular in structure. Further laboratory work has confirmed that the viral DNA is a singular entity, but its proven difficult to isolate.
We know its there, but we cant capture it quite yet, Edwards said.
Once the virus is isolated, he hopes to delve into its role in obesity. Its possible the virus in some way mediates the activity of Bacteriodetes colonies, but whether crAssphage promotes or suppresses obesity-related processes in the gut remains to be seen.
|Contact: Natalia Elko|
San Diego State University