‘Selfish’ DNA flouts rules of inheritance
R2d2 can quickly spread to an entire mouse population despite its evolutionary disadvantage
DNA TAKEOVER A selfish bit of DNA called R2d2 was first discovered in mice in Maryland called Watkins Star Line B, or WSB (one shown). That selfish DNA can sweep through populations, distorting views of evolution.
Jackson Laboratory photo by Jennifer L. Torrance
In the Star Wars movies, the droid R2D2 is a heroic rebel. In living animals, a selfish bit of DNA called R2d2 is an outright lawbreaker. It violates laws of both genetic inheritance and Darwinian evolution. R2d2 can sweep through mouse populations by mimicking helpful mutations while actually damaging fertility, researchers report online February 15 in Molecular Biology and Evolution.
The new findings suggest that even genes that hurt an organism’s evolutionary chances can cheat their way to the top. That could be good news for researchers hoping to use engineered “gene drives” to eliminate mosquito-borne diseases and invasive species. But it’s also a cautionary tale for scientists looking for signs that natural selection has picked certain genes
