Nov 23, 2017

Scientists have used cells as a recording device for the first time

Illustration: Rebecca Zisser / Axios

For the first time, scientists have used a cell to record what happens in the world around it. They were able to retrieve the information and read it in chronological order.

Why it matters: Changes in temperature and chemical levels inside the body can be recorded in a broad sense, but tools like this are the biological equivalent of using a microscope versus a magnifying glass. "It's the next generation of resolution," says study author Harris Wang, a synthetic biologist at Columbia University.

What it's called: Temporal Recording Arrays by CRISPR Expansion — or TRACE, for short.

How it works: CRISPR isn't just for editing genes. In bacterial cells, CRISPR is a part of the immune system. Some parts of the CRISPR suite cut and store information from the genomes of invading viruses to help bacteria defend against them in the future. Because they register that information in a sort of a stack, with the most recent on the top, it's possible to use CRISPR to record something chronologically.

What they did: The researchers programmed the cells to respond to a biological input by increasing or decreasing the amount of a certain piece of DNA. The DNA contains pre-programmed 'trigger spacers' that cause the CRISPR to start making the record. They found that they were able to accurately reconstruct a timeline of the cell's environment based on information recovered from the cell.

This builds on previous research, where scientists at Harvard used the same mechanism to store and recover a video from E. coli bacteria cells. At the time, they hoped it would serve as proof-of-concept for storing sequential information in bacteria. "The idea is that eventually we can have the cells go out and collect information, store it in their genome, and later we can interrogate the cells and figure out what they've captured," Seth Shipman, who conducted the research, told Axios. Four months later, they've done just that.

What's next: The information gathered in the most recent study was relatively simple, but the research shows complex information can be stored and recovered, if it can be recorded. These cells could record the ways a neuron reacts to a medication, or track changes in a gut during an infection or be placed in the environment to monitor the soil. The cells Wang and his colleagues created passively collect data —Wang hopes to create ones that actively record specific types of data and even respond to those changes.

Sci-fi level stuff:

On the extreme end, Wang imagines a future where bacteria throughout our body keep a running 'medical record' of sorts, ready for doctors to recover and read in the event of an illness. But there's still a lot work to be done."We're just starting to engineer bacteria to be able to do something truly useful associated with the human body," says Wang.

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