BioEd Online

Entire mosquito populations can be rapidly wiped out with the help of a gene-editing technique, laboratory tests reveal.

Andrea Crisanti and his colleagues at Imperial College London used the gene-editing technology CRISPR–Cas9 to disrupt the doublesex gene in embryos of Anopheles gambiae mosquitoes, which transmit the malaria parasite to humans. Mosquitoes with one disrupted copy of the gene rapidly drove the spread of the genetic modification, transmitting it to more than 95% of their offspring.

Females with two disrupted copies of the gene lacked fully developed reproductive organs, and even grew some male-like structures; they also could not bite or produce eggs.

In one cage that initially contained 600 mosquitoes, the population failed to produce any eggs by the eighth generation. In another cage, population failure occurred by the twelfth generation.

In the past, similar ‘gene drive’ strategies have been stymied by the evolution of resistant mosquitoes: natural variation in target genes can, over time, select for tamper-resistant versions. Crisanti’s team found minimal variation in doublesex, perhaps because of its crucial role in sex development. This feature makes it an attractive candidate for larger tests, the authors say.