You can thank your parents for your DNA. Because humans share genes through sexual reproduction, passing DNA from parent to child. It's known as the 'vertical transfer' of DNA.
Now imagine if you could share just one or two bits of your DNA with an unrelated stranger, through a handshake, or other incidental contact—and that stranger inserted your DNA into their genome. No sex. No offspring either. That's called the 'horizontal transfer' of DNA. It's obviously not how humans do it. But it's a mainstay of single-celled organisms like bacteria, which use the process to share antibiotic resistance genes, for example.
And now French scientists have found that horizontal DNA transfer could be a lot more common than we thought in multicellular organisms, too—insects, in this case. Because by analyzing 195 insect genomes, they found more than 2,200 cases of horizontal DNA transfer between unrelated species of flies and butterflies, beetles and wasps.
That total quadruples the number of horizontal DNA transfers previously described in all animals, plants and fungi. The study is in the Proceedings of the National Academy of Sciences. [Jean Peccoud et al., Massive horizontal transfer of transposable elements in insects]
How exactly this genetic transfer happens is still a mystery. Might be viruses, or parasites, doing the DNA delivery. But whatever the cause, it suggests that the evolution of insects, on a molecular level at least, may be something more of a shared success story.
—Christopher Intagliata
