CRISPR is less like molecular scissors and more like molecular malware

CRISPR is less like molecular scissors and more like molecular malware

Last week I read an article about CRISPR, the latest tool scientists are using to edit DNA. It was a great piece – well researched, beautifully written, factually accurate. It covered some of the amazing projects scientist are working on using CRISPR, like bringing animals back from extinction and curing diseases. It also gave me the heebies, but not for the reason you might expect.

My unease was the echo of a feeling I’d had during the early days of my PhD, when some fellow malaria researchers made a discovery that was reported on the news. I was thrilled for them, but I understood the incremental nature of the work they were doing. I knew that in a real-world, drugs-in-the-clinic sense, we were no closer to a breakthrough than we’d been the day before. I thought the reporters had communicated that clearly. Five minutes later my Dad called to ask if I was out of a job, and what I was going to do now that malaria was cured.

I don’t pretend to understand all the myriad reasons for the gaping chasm between what scientists say and what the public hears. Lately though, I’m starting to think it might have something to do with the metaphors we use, and the way they shape our perception of the complexity involved.

Take CRISPR. It’s most often described as a pair of molecular scissors that can be used to modify DNA, the blueprint for life. And when we read that, I think most of us start imagining something like a child with her Lego bricks strewn in front of her, instruction booklet in one hand, scissors in the other. One set of pictograms, one model; one gene, one disease; one snip, one cure. We’re there in a blink. CRISPR seems like it can work miracles.

I want to stress that the molecular scissors metaphor is pretty damn accurate as far as it goes. But in focusing on the relatively simple relationship between CRISPR and DNA, we miss the far more complicated relationship between DNA and the rest of the body. This metaphor ignores an entire ecosystem of moving parts that are crucial for understanding the awe-inspiring, absolutely insane thing scientists are trying to do when they attempt gene editing.

I prefer the metaphor of malware

In my research I use CRISPR from time to time. To design experiments and interpret results effectively, I need a solid way to conceptualize what it can (and can’t) do. I do not think of CRISPR as molecular scissors.

Instead I imagine a city. The greater metropolis represents the body, the suburbs are organs, the buildings are cells, the people are proteins, and the internet is DNA.

In this metaphor CRISPR is malware. More precisely, CRISPR is malware that can search for any chosen 20-character line of code and corrupt it. This is not a perfect metaphor by any stretch, but it gets me closer to understanding than almost anything else.