Forget your old zipper case of DVDs, and pendrives. How about storing movies in a Petri dish of bacterial colony?
In a rather bizarre sequence of events, scientists embedded a short film- specifically a gif- into the DNA of living bacteria cells.
In 1872, Eadweard Muybridge captured a series of photos of a running horse. His images settled a debate about whether the animal ever lifted all four feet off the ground at once—it did. And this formed the basis of one of the first motion pictures.
Now, Seth Shipman, from Harvard Medical School, has immortalized the running horse in a new and very different medium: the genomes of bacteria!
Shipman has encoded a series of images and a GIF and then inserted those strands into living microbes using CRISPR.
CRISPR has existed for billions of years ago in bacteria as technique they use to defend themselves against viruses. The bacteria grab the DNA of invading viruses, incorporating it into their own genomes. That viral DNA always gets inserted in the same place, and new sequences get added after old ones; they later use these archives to guide an enzyme called Cas9, which cuts and disables any viral DNA that matches the stored
sequences.CRISPR is a technique best known for as a tool for editing genes by cutting strands of DNA at precise locations. But it has another trait that’s often been overlooked: It’s an amazing tool for recording information. CRISPR is a kind of genetic memory—a system for storing information. And that information doesn’t have to be the DNA of viruses.
Scientists have encoded digital files in the form of DNA, by converting the ones and zeroes of binary code into As, Cs, Gs, and Ts of the double helix. Thereby, encoding an image and a movie in a colony of bacteria. They also included a code that indicated where in the frame each pixel belonged. They did not encode the order of the frames, however.
In the end, each frame consisted of 104 DNA sequences that the team inserted into a population of bacteria cells using a process called electroporation. Basically, they zapped the cells with electricity, which caused pores in their membrane to open, allowing the synthesized DNA to pass into them.
Once the DNA pieces were in, they used CRISPR to grab the free-floating pixel codes and insert them into the bacteria’s genome. Later they “uploaded” their movie into the bacteria’s DNA at a rate of one frame each day.
After the entire movie had been inserted into the genome, the authors boiled the cells to extract the DNA and then sequenced the regions where they thought the encoded movie frames would be. They ran the extracted sequences through a computer program and found they were able to play back their movie with 90% accuracy.
It turns out that the bacteria’s DNA conveniently stores new information in the order it is received, Shipman said. He added that when the group uploaded the movie backward and then extracted it, they were able to watch the horse run in reverse.
“It was one of the first examples of a moving image, it was captured with a technology that was very new at the time, and it answered some relevant questions,” shipman says. And for the image, he chose a simple black-and-white photo of a hand. “It harkens back to the first images that humankind put in the natural world—handprints on cave walls. We’re putting images into the natural world in a different way.”
Shipman says, as a neuroscientist who found it vexingly hard to study what happens as our brains develop—which genes are activated when, and where, and in which neurons? Plans to take this project further by turning these bacteria into microscopic video cameras, observing you and the world around you “We want cells to go out and record environmental or biological information that we don’t already know.” It might sound a little creepy, but it would also be incredibly useful.
