Stowaway Genes

Science Daily reports on some very strange behavior found in bacterial DNA – one parasite’s entire genome is replicated by the host’s body. And, the researchers believe, is causing the host to change:

“For several months, I thought I was just failing,” says Clark. “I kept administering antibiotics, but every single Wolbachia gene I tested for was still there. I started thinking maybe the strain had grown antibiotic resistance. After months of this I finally went back and looked at the tissue again, and there was no Wolbachia there at all.”

Clark had cured the fly of the parasite, but a copy of the parasite’s genome was still present in the fly’s genome.


Werren and Clark are now looking further into the huge insert found in the fruitfly, and whether it is providing a benefit. “The chance that a chunk of DNA of this magnitude is totally neutral, I think, is pretty small, so the implication is that it has imparted of some selective advantage to the host,” says Werren. “The question is, are these foreign genes providing new functions for the host? This is something we need to figure out.”

Evolutionary biologists will certainly take note of this discovery, but scientists conducting genome-sequencing projects around the world also may have to readjust their thinking.

(Story ganked from reddit, where there’s an even more interesting discussion brewing about wasps that manufacture their own viruses to inject into hosts.)