The gene editing tool known as CRISPR-Cas9 (CRISPR to its friends) was featured on several “top breakthroughs of the decade” lists as the 2020s came into view. It has been ogled for a broad spectrum of uses, from groundbreaking medical treatments to doubling animals' muscle mass. One of CRISPR’s creators, Jennifer Doudna, predicts the most significant impact will be in what we eat.
There’s a Party in My Petri Dish
CRISPR is used to modify the DNA of a living organism. Traditionally, GMOs have been created using “transgenic” engineering, which means that DNA from different species was implanted into a living organism. One infamous example was the tomato engineered to withstand frost by adding genes from an arctic flounder. (While this particular GMO tomato was never available to consumers, things that are unexpectedly fishy are surprising and memorable — and not in a good way — which makes the fish-tomato a compelling example.) Gene editing focuses on the intrinsic genetic material of a living thing, though transgenic methods can be used during this process (i.e. the technology that brought us the fish-tomato). Ultimately, the final product will not contain foreign DNA (i.e. fish-tomato that has been de-fished). This is an important distinction, because biotech companies are tying themselves in knots to differentiate newer gene editing from older GMOs, hoping to avoid the controversy and public rejection. However, that’s a load of bollocks. When the genetic material of a living organism is engineered in a lab for a desired outcome, that is genetic modification, and the products of that work are GMOs. The Non-GMO Project stands firmly with the United Nations and the European Court of Justice in our assertion that gene editing tools like CRISPR produce GMOs, and should be regulated as such.
What exactly is being manipulated during gene editing? Genes are the inherited material that determines how an organism appears, behaves, and reproduces. Our genetic material is an immensely complex system, and scientists are still learning about it. Currently, the purpose of about 1 in 5 genes in the human genome is unknown. The insight we have gained was mainly through trial and error: scientists use a gene editing tool to manipulate a particular gene and then observe the changes to the organism. It's a bit like clicking fuses on and off in a fusebox, one by one, to find out which fuse has blown: you'll get there eventually, and you’ll learn stuff along the way, but the internet will cut out and every clock in the house will need to reset. As a learning tool, there’s a lot to be said for trial and error. It’s been the bread and butter of many a dedicated and brilliant scientific mind. But, the lessons learned are inevitably subject to the interpretation of the observer. The scientific community at large uses ethical guidelines and The Precautionary Principle to mitigate the inherent risks of experimentation.
The Truth About Cats and Dogs
One of CRISPR’s main selling points has been its precision, inspiring comparisons such as “it’s like a pair of scissors” or “the search and replace function in a word processing program.” These are relatable images to the layperson, and I, for one, love a good simile. But the reality of CRISPR — and of word processing for that matter — is more complicated. Imagine you’ve written a story about a cat, but you decide later on to change the main character to a dog. You might use a “search and replace” function to change the text. The computer program will highlight and change text anywhere the letters C-A-T appear, including every non-feline word that contains those letters in that particular order: catapult, vacation, scathing. Plus, how will changing the protagonist affect the storyline? Everyone knows you can’t just swap out cats and dogs. They are different: different skill sets, different priorities. Search and replace alone won’t do it — you’ll need a major rewrite to avoid literary catastrophe. As a search and replace tool, CRISPR has similar limitations. The tool that guides the “cut” can be misled; the gene, once cut, will also work to repair itself, causing imprecise results even if the target area was correct; and, given our limited knowledge about how genes function, the process can lead to outcomes that were neither desired or intended.
In Search of Self-Governance
Accepting that mistakes can, and do, happen, what steps do scientists take to double-check their work? It depends. Some labs do tests to validate their work, others do not. Nicholas McCarty, writing for The Wire, explains how this uncertainty affects outcomes: “It means that dozens, or hundreds, of studies that used CRISPR/Cas9 to knock out genes, but failed to validate that the encoded protein was fully removed, could be incorrect or misleading.“ And science based on incorrect or misleading data is cause for concern. McCarty continues:
“The problem with major scientific developments, especially CRISPR/Cas9, is that experimental tools often explode in popularity before scientists and editors can implement standard procedures.”
The popularity of CRISPR has absolutely exploded. Today, enthusiasts and hobbyists alike can buy CRISPR kits online, conducting experiments in the comfort of their own homes.
CRISPR has opened as many practical and ethical rabbit holes as it has potential applications. The first CRISPR gene-edited babies have already been born, but neither the condemnation of this work by the scientific community nor the prison sentence ultimately handed down to Dr. He Jainkui — the scientist responsible — have quelled the ambition of others to follow in his footsteps. Molecular biologist Denis Rebrikov has passionately and publicly nominated himself as Dr. He’s successor.
These are not the words one wants to hear from a scientist.
From a professional wrestler, sure. Scientist, no.
Join us next week to find out where CRISPR technology can show up in your house!