Gene drive is both a promising and disturbing technology. It allows us to engineer a stretch of DNA that, once inserted in a specific location in an organism’s genome, will convert other versions of the gene so that they also carry the insert. Once started in a population, gene drive will convert the entire population within a relatively short number of generations.
That’s promising, in that it opens the door to editing mosquitos to cause sterility to spread through a population, eliminating the spread of diseases and a fair bit of itching. But it’s also a genie that, once out of the bottle, appears to be impossible to put back—and hence is disturbing. But so far, there has been a small consolation: it has only been shown to work in insects.
Now, a large research team at the University of California, San Diego, has managed to get it working in mice. Sort of. It turns out that the efficiency is much lower. While the gene drive DNA is inherited at rates well above normal Mendel-style inheritance, it’s nowhere near as effective as in insects, and it’s not clear we know how to fix it.