(In the image, fruit fly ovaries show wolbachia infection within.)
While analyzing genetic material taken from fruitflies, scientists at the University of Rochester and the J. Craig Venter Institute noticed that quite a few Wolbachia genes were mixed in.
Wolbachia is a prolific parasite, having carved out a niche for itself in some 70 percent of all invertebrate animals. But it's doing more than living in their cells: it's changing their very DNA in a way that could affect how scientists study genetics and evolution across the animal kingdom.
At first, the scientists thought they were doing something wrong. But after treating the flies with a parasite-killing antibiotic, the genes were still there. They realized that the flies had actually absorbed the Wolbachia genome into their own -- the most dramatic example yet of lateral gene transfer, in which genes pass between unrelated species.
Traditionally, biologists thought such transfer was limited to the simplest organisms. Since bacterial DNA is easy to spot, they'd throw it out if they found some while sequencing an organism's genome. The new findings suggest that this discarded "bacterial" DNA might often have been part of the genome being studied.
Fortunately, this doesn't appear to have happened with the human genome:
But even without that, the findings still challenge the idea of species evolution as something that happens strictly within a species: instead it appears to be a complicated, sticky, multi-level process of co-evolution, with organisms growing alongside and within each other, swapping DNA
and keeping it when the new DNA helps.
Life. It's messy.
One Species' Genome Discovered Inside Another's [Press Release]
