Using Genomics To Eradicate Mosquitos
Scientists recently developed an efficient tool for genome engineering that uses the CRISPR nuclease Cas9 to cut sequences specified by guide RNA molecules. This technique is in widespread use and has already engineered the genomes of more than a dozen species, reports The Scientist.
Scientists can use this technology to edit nearly any gene in sexually reproducing populations. One of the possible applications of this technology is to deliberately eradicate mosquitos which are deadly disease vectors. Every year they cause hundreds of millions of people suffer from mosquito-borne illnesses such as Dengue fever, West Nile virus and malaria.
A diverse group representing the scientific community published two studies, one in the journal Science and the other in eLife, discussing the feasibility of eradicating mosquitos and issues related to environmental consequences and security.
According to the studies, one option for destroying a natural population is the release of large numbers of sterilized males. Another option is to select a gene and cut it out using CRISPR, and introduce a gene with a desired trait.
Through homologous recombination, the genes are replaced with whatever altered form of the genes have been inserted into the mutant organism. This would reverse natural selection by placing unfit genes that would spread throughout a population.
Past methods for altering genes were notoriously cumbersome. The CRISPR approach is much easier to use and is cheap enough for many laboratories to afford, according to George Church of Harvard Medical School.
If this method of eradication is used, the team described a variety of ways the technology could be made safe and eco-friendly.
One concern is the unknown. It is uncertain how a new combination of genes in wild populations of mosquitos might act together. It is possible that undesirable emergent properties could occur. Another concern is what impact the eradication of mosquitos would have on various ecosystems.
In the Science paper, the researchers suggested that methods to reverse the gene alterations should be tested in tandem with any proposed gene changes.
David Gurwitz of Tel Aviv University responded to the team's eradication proposal arguing that such research should be classified to prevent its use in developing biological weapons.
In response, proposal co-authors Kenneth Oye of MIT and Kevin Esvelt at Harvard noted that "restricting information would be counter-productive, as it would impede research into containment and reversal."
As the scientists further research the areas of uncertainty, they urge the public to provide feedback regarding their environmental and security concerns. These discussions will inform regulations regarding risks and any policy gaps, and to determine if, when, and how the technology should be used.