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The Danger of Gene Drives


Source: 21stcentech.com
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Biotechnology is becoming increasingly important to humanity. The modification of DNA and proteins for practical uses is now widespread due to the expanded availability of biotechnology tools, such as CRISPR-cas9 gene editing technology. Using CRISPR-cas9, scientists have created the gene drive, a mechanism that spreads a certain gene through a population of organisms via sexual reproduction over several generations. In a paper published in Nature in September 2018, a team of scientists at the Imperial College of London led by Andrea Crisanti described how they were able to use gene drives to render all the females in a caged mosquito population infertile, leading to elimination of the population within seven to eleven generations. Gene drives are still a highly theoretical technology and have not been used in the wild. While gene drives have the potential for good, scientists warn that they could have catastrophic outcomes if released.

One obvious application of gene drives is crippling mosquitoes’ ability to transmit diseases such as malaria and dengue fever. Although the removal of mosquito-borne diseases would save hundreds of thousands of lives, doing so may cause unintended ecological side effects, according the Science Magazine article by Oye et al., “Regulating gene drives”. For example, a population of animals previously kept in check by mosquitoes might overpopulate because of the gene drive. Furthermore, cross-breeding of different populations of mosquitoes in the wild could allow the gene drives to spread around the world. The gene drives could then mutate, possibly giving mosquito populations an even more harmful trait than they have today.

Another proposed use for gene drives is combating invasive organism populations. However, if an invasive organism with the gene drive somehow travels to the species’ native range and reproduces with a native organism, the gene drive could spread throughout the species’ native population, as well as the invasive population. If the gene drive’s purpose was to kill off the invasive population, then the whole species might be driven to extinction because of the gene drive’s spread. According to Webber et al., researchers at the University of Western Australia, this risk is especially high if the invasive species in question is a marine animal, like the lionfish in the Atlantic Ocean and Caribbean Sea, or an effective terrestrial disperser like some species of grass.

The potency of gene drives worries security experts, such as former Director of National Intelligence James Clapper, who wrote in his address to the Senate Arms Services Committee that “misuse [of genome editing technologies] might lead to far-reaching… national security implications”. For example, gene drives could genetically modify agricultural plants or animals. While this could be used beneficially, Oye et al. note that malicious actors could spread detrimental genes in agricultural organisms, especially in developing countries that do not use commercial seed production or artificial insemination of livestock. This could result in a food security and safety problem.

Currently, scientists have theorized some technologies to control and limit the spread of gene drives effectively. According to Oye et al., these technologies include different types of gene drives: reversal, precision, daisy, immunizing drives. Reversal drives overwrite unwanted changes introduced by initial drive or restore the original DNA sequences in organisms affected by the gene drive. Immunizing drives preemptively alter organisms’ DNA sequences that would be targeted by the gene drive, thus blocking the effects of the gene drive. Precision drives target a very specific DNA sequence so that organisms that lack that specific sequence would not be affected. In addition, Wired science writer Megan Molteni reports that Harvard biologist Kevin Esvelt has developed a daisy drive, which allows for “temporary, controlled gene editing of a local species” by making the engineered change disappear after a while.

Oye et al. have encouraged scientists to pursue benefit/risk analysis in deciding whether to implement a gene drive in the wild and to create accurate testing environments for gene drives. The National Academies of Sciences, Engineering, and Medicine, the scientific advisory organization for the U.S. government, has endorsed the latter option, calling for “carefully controlled field trials”. However, actions by scientists have not been sufficient to guarantee the safe usage of gene drives, as the aforementioned precautions are voluntary. Thus, an unscrupulous or careless scientist could cause lasting damage by releasing a harmful gene drive into the wild.

The U.S. government has made a small effort to help mitigate the dangers of gene drives. The Defense Advanced Research Projects Agency, an agency of the DoD, started the Safe Genes program in 2016, supplying $65 million in funding to seven teams of scientists and seeking to enable temporal, spatial, and reversible control of gene drives, develop methods to protect the integrity of original genomes of organisms in the wild, and find ways to eliminate undesired gene drives in the environment.

In addition, in the “Plant and Animal Biotechnology Innovation Action Plan”, the FDA states that it has taken some action regarding gene drives, including modernizing regulatory frameworks, increasing public outreach, and cooperating with domestic and international partners.

As the U.S. government agency tasked with defending public health, the FDA has immense authority over gene drives. Furthermore, actions by the FDA would set an example to other U.S. and foreign governmental organizations. However, the FDA’s current action on gene drives are insufficient. Modernizing regulatory frameworks, increasing public outreach, and cooperating with other governmental organizations are all necessary steps to take, but they do not accomplish much on their own.

In order to adequately deal with the risks of gene drives, the FDA should increase regulations on the development and usage of gene drives. This includes requiring scientists to extensively test and provide technological safeguards for gene drives during development and usage phases, and publish test results afterwards. After gene drives are developed and ready to be used, the FDA needs to analyze and approve each specific case of gene drive usage before the gene drive is released into the wild.

Gene drives have the potential to hurt public health, having widespread ecological, economic, and security risks and the possibility of misuse by malicious actors. These actions would alleviate the urgent dangers of gene drives. However, if the FDA does not act immediately to regulate gene drives, then it places public health and national security in jeopardy.

 

Works Cited

https://www.dni.gov/files/documents/SASC_Unclassified_2016_ATA_SFR_FINAL.pdf

https://www.nature.com/articles/nbt.4245

https://www.wired.com/story/this-gene-editing-tech-might-be-too-dangerous-to-unleash/

http://science.sciencemag.org/content/345/6197/626.full

https://www.fda.gov/downloads/Safety/Biotechnology/UCM624517.pdf

https://www.darpa.mil/news-events/2016-09-07

https://www.pnas.org/content/112/34/10565.full

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