Gene drives are natural or artificial processes that favor the inheritance of certain genes throughout a population.

Gene drives operate by using CRISPR to insert a genetic modification into a population and spreading it at higher-than-normal rates of inheritance. Offspring from an organism carrying a gene drive inherit the drive from the engineered parent on one chromosome and a normal gene from the other parent on the other chromosome. During early development, the CRISPR drive cuts the other copy and replaces it with a copy of the drive, producing an organism with two copies of the genetic modification. Thus, while a mutation spread through Mendelian inheritance can propagate to only 50% of descendants with each generation, a modification spread through gene drives (or "super-Mendelian" inheritance) is passed on to virtually all descendants within a single generation.^[1]

Applications to malaria control

Two applications of gene drives to the control of malaria have been proposed. One is to modify the relevant mosquito species to make it incapable of carrying the malaria parasite. The other is to significantly reduce the population of those mosquito species.^[2] Once the gene drives are released, the relevant mutation could be propagated through the entire population of interest in a period of just a few years. In 2016, a group of researchers at Imperial College and other universities genetically engineered the Anopheles gambiae mosquito—the primary mosquito species that spreads the malaria parasite—rendering it capable of passing the genetic modification to over 99% of offspring.^[1]

Target Malaria is one organization currently working on these applications.

Other applications

Gene drives have also been suggested for reducing wild-animal suffering. For example, transhumanist philosopher David Pearce proposes CRISPR-based gene drives for promoting low-pain alleles in sexually reproducing wild animals.^[2] The leader of the MIT Media Lab’s Sculpting Evolution group Kevin M. Esvelt also has written favorably about engineered gene drives for reducing wild-animal suffering.^[3]

External links

Sculpting Evolution. Many additional resources on this topic.