Rewriting Nature: The Environmental Impacts of CRISPR/Cas9

CRISPR/Cas9 is a new technological advancement that has turned decades of “what ifs” into possible avenues of science. In 2020, Emmanuelle Charpentier and Jennifer Doudna were awarded the Nobel Prize in Chemistry for discovering CRISPR/Cas9 genetic scissors, opening a new world of genetic research. Unlike any genomic editing technology, this innovation allows for highly precise insertions and edits of genes in animals, plants, and microorganisms (Gustafsson et al., 2020). CRISPR/Cas9 has applications in any living organism, opening the doors to enhancing life while presenting risks of disrupting the global ecosystem. 

CRISPR, or clustered regularly interspaced palindromic repeats, is a naturally occurring defense mechanism to protect bacteria and archaea from infection. The genome of a bacteriophage, a virus that replicates within a host, can be inserted into a CRISPR DNA segment during a viral attack (Figure 1A and B). If the same virus infects the host (Figure 1C), the CRISPR DNA locus will be transcribed into an interfering piece of RNA that will degrade the bacteriophage genome when coupled with a Cas protein or CRISPR-associated protein (Figure 1D) (Piergentili et al., 2021). Doudna and Charpentier harnessed this mechanism to develop technology that can be engineered to modify specific genomic sequences, revolutionizing the infancy of gene editing. The dawn of CRISPR/Cas9 presents a unique opportunity to transform the world and reimagine global ecosystems. However, this innovation also bears the heavy weight of the future on its shoulders because a single change in heritable genes can catalyze ecological imbalances and worldwide catastrophes. From an environmental sustainability perspective, CRISPR/Cas9 could tip the scale toward restoration or devastation. 

CRISPR/Cas9 holds the power to improve crops, increase disease control, and create sustainable biofuels, painting a vision for a sustainable, healthy world that is improved by genome editing. In the agricultural sector, crop genes can be optimized to increase pest resistance, maximize crop yield, and prevent disease. Additionally, this technology has been used to make dairy products resilient against viruses, further the eradication of malaria-hosting mosquitoes, and improve smallpox vaccines, demonstrating the tremendous potential for CRISPR/Cas9 in preventing disease and death (Ayanoğlu et al., 2020). Scientists can accomplish this by introducing gene drives, a method of effectively transmitting genes throughout population generations. CRISPR/Cas9 also plays a role in bio-fuels, introducing yet another way that this technology will improve human life and save scarce resources on the planet (Piergentili et al., 2021). As climate change worsens, CRISPR/Cas9 presents an opportunity to make agriculture resistant to environmental stresses, improving resource yield and supporting community health around the globe. 

However, CRISPR/Cas9 may also introduce unforeseen consequences that will irreversibly threaten the survival of ecosystems and humanity. Recent reports have demonstrated how entire genome integrity can be compromised from off-target actions, where unintended mutations are caused due to mistakes in CRISPR/Cas9 implementation. These unexpected and dangerous chromosomal abnormalities have been found in embryos, which should act as a motion toward no-confidence as society tries to integrate genome editing in the world’s most significant sectors. Gene drives can spread a targeted gene amongst a population permanently and effectively, which may ultimately cause unintended mutations and species extinction (Piergentili et al., 2021). If one species becomes resistant to stressors, predators, or disease, it could outcompete natural species and possibly cause the proliferation of invasive species, putting other species at risk of extinction. Species extinction will cause ecological shifts as food chains are disrupted and shared habitats are changed. Additionally, spreading a gene mutation to all organisms in a species will decrease biodiversity, making a species and, eventually, the global ecosystem more vulnerable to environmental stresses. It is difficult and almost unfeasible to restore the ecosystem to its natural state after introducing hereditary genomic changes, so scientists and policymakers must ensure that regulations are written to protect Earth’s ecosystems.

Dr. Dana Zartner is a professor in the International Studies Department and School of Law at the University of San Francisco. On March 18, the International Studies Department gathered to celebrate the release of her book, Standing for Nature, which explores legal strategies to advocate for environmental justice. I had the opportunity to speak with Dr. Zartner about her work, and she shared her perspective on the importance and relevance of protecting nature: “Around the world, many people view nature as a commodity for us to use and abuse. However, we cannot measure the value of nature based on what it can provide for us. Nature is inherently important in and of itself. Particularly in the Global North, we have a habit of seeing a tree and measuring its worth by how much timber it gives us instead of appreciating how its root system is integral to the ecosystem. The tree has its place on Earth regardless of us. Nature has a right to exist and flourish without our interference. If we do interfere, we are fundamentally altering the holistic relationship between living things that depend on one another to be healthy.”

Dr. Zartner introduced the “Ego versus Eco” chart that visually displays two perspectives on the human-environment dynamic (Figure 2). We often view the world as a pyramid, where humans are at the apex and dominate over all other organisms–this is the “ego” view. However, a shift in perspective toward the “eco” view can illuminate how all living things exist within a circle. As Dr. Zartner advocates, “We all have the right to exist and flourish on this planet.” Earth is not just a resource center for humans–it is a home for all. 

In response to CRISPR-Cas9 technology and its potential to cause catastrophic ecological imbalances, Dr. Zartner hopes that scientists, policymakers, and innovators think carefully about the future of the world: “The Rights of Nature would say that we need to consider the environment. Nature is an independent living identity, and we need to respect that.” When regulating the innovation of CRISPR-Cas9, we must adopt an “eco” perspective that places humans among all other living organisms, not at the apex of a pyramid. 

As CRISPR/Cas9 and genome editing technology step into the spotlight, we must be proactive in assessing their moral significance, humanitarian potential, and environmental risks. As scientists and policymakers develop the future and decide whether we introduce restorative practices or destructive chaos, we must urge humanity to consider equity in the global ecosystem. 

 

References

Ayanoglu, Fatma Betul, et al. “Bioethical Issues in Genome Editing by the CRISPR/Cas9 Technology.” Turkish Journal of Biology, vol. 44, no. 2, Apr. 2020, pp. 110–20, https://doi.org/10.3906/biy-1912-52.

Coman, Mirela, and Bogdan Cioruța. “From Human-Environment Interaction to Environmental Informatics (III): The Social-Ecological Systems Dynamics in Knowledge-Based Society.” Magazine of Hydraulics, Pneumatics, Tribology, Ecology, Sensorics, Mechatronics, vol. Hidraulica 1/2019, June 2019.

Piergentili, Roberto, et al. “CRISPR-Cas and Its Wide-Ranging Applications: From Human Genome Editing to Environmental Implications, Technical Limitations, Hazards and Bioethical Issues.” Cells, vol. 10, no. 5, Apr. 2021, p. 969, https://doi.org/10.3390/cells10050969.

The Royal Swedish Academy of Sciences. “The Nobel Prize in Chemistry 2020.” NobelPrize.org, 7 Oct. 2020, www.nobelprize.org/prizes/chemistry/2020/press-release/.

Dr. Zartner’s book is available on Island Press: Standing for Nature: Legal Strategies for Environmental Justice.