The idea is bold and seems to have worked fine. By using a DNA cutting enzyme to disrupt the X chromosome, researchers succeeded in distorting the sex ratio of offsprings, eventually leading to the all-male populations collapse. Andrea’s Crisanti and colleagues at the Imperial College London did it to caged Anopheles gambiae mosquitoes in their quest for a genetic strategy to beat malaria. Please see their paper in Nature Biotechnology and the Imperial College press release.
In a past experiment, Cristanti’s team targeted a gene called doublesex to make females develop intersex characteristics, fail to bite and do not lay eggs. The new all-male approach, however, leads to population crashes faster than the female-infertility method and reduces the proportion of biting females at an earlier stage.
This is the first successful sex-distorter gene drive ever created, and “outperforms other anopheline gene drives, combining efficacy, resistance management, and robustness, and it is well suited as an anti-malaria intervention,” they write in the paper’s closing remarks. The next step will be to test the male-biased mosquitoes into larger and more realistic cage trials.