VATIS UPDATE Article

Applied mathematicians and physicists from Harvard University, the United States, and Princeton University, the United States, used mathematical modeling to guide the design and distribution of genetically modified (GM) genes that can both effectively replace wild mosquitoes and be safely controlled. In the normal course of evolution, any specific trait has only a modest chance of being inherited by offspring. The research has been published in the Proceedings of the National Academy of Sciences.

But, with the development of the CRISPR-Cas9 gene editing system, researchers can now design systems that increase the likelihood of inheritance of a desired trait to nearly 100 percent, even if that trait confers a selective disadvantage. These so-called gene drives could replace wild-type genes in short generations. Those powerful systems raise serious safety concerns, such as what happens if a genetically-engineered mosquito accidentally escapes from a lab?

“An accidental or premature release of a gene drive construct to the natural environment could damage an ecosystem irreversibly,” said Hidenori Tanaka, at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). To protect against such releases, Tanaka, along with co-authors David Nelson, the ­Arthur K. Solomon at Princeton, proposed a narrow range of selective disadvantages that would allow the genes to spread, but only after a critical threshold had been reached.