A group of researchers just encoded a movie into the DNA of a bacteria and even retrieved it back to play back the movie. The study, the first of its kind, was published Wednesday in the journal Nature.
The researchers used the five frames from a classic 1870s movie of a racehorse, broke the frames down into pixels and used DNA to create different codes for each pixel. Then, they used a CRISPR system to insert the encoded DNA into E.coli, a common type of bacteria often found in food, environments, or the intestines of people and animals.
Once the DNA gif was inserted into the bacteria, the E. coli incorporated the fragments into their genome, and the scientists were able to sequence the bacterial DNA to reconstruct the gif with 90 percent accuracy.
‘Molecular ticker tape’ allowed scientists to encode gif into bacteria
The researchers from Harvard University of the new study –which was funded by the National Institutes of Health- said their findings are a significant step toward a “molecular recorder” that one day could make it possible to get read-outs, for instance, of the internal shifting states of neurons.
“We want to turn cells into historians,” said neuroscientist Seth Shipman, a post-doctoral fellow at Harvard Medical School, according to a statement from the National Institutes of Health. “We envision a biological memory system that’s much smaller and more versatile than today’s technologies, which will track many events non-intrusively over time.”
Jeff Nivala, co-author of the study and geneticist at Harvard, told Wired the E. coli is just a proof of concept to show what “cool things” you can do using the CRISPR system. The Crispr-Cas9 is a molecular tool that combines RNA molecules and special proteins to precisely cut and edit DNA. The system was originally discovered in bacteria, which actually use it as kind of immune system to defend against viral attackers.
Nivala noted their real goal is to enable cells to gather data about themselves and to store it in their genome for scientists to look at later. The concept was dubbed the “molecular ticker tape.” Nivala and Shipman also worked with Harvard Drs. George Church and Jeffrey Macklis to transfer the encoded DNA into the bacteria.
CRISPR system allows bacteria to store foreign DNA in its own genome
The researchers said that recording sequential events like a movie at a molecular level is key to the idea of reinventing the concept and foundations of recording using molecular engineering. They believe that using the method, cells themselves could be induced to record molecular events –like changes in gene expression over time- in their own genomes. Then, just like they did in their experiment, the data could be retrieved simply by sequencing the genomes of the cells it is stored in.
“If we had those transcriptional steps, we could potentially use them like a recipe to engineer similar cells,” noted Shipman. “These could be used to model disease – or even in therapies.”
The Crispr-Cas9 system –which is also funded by the NIH- allowed them to store the information into E. coli. In the molecular tool, Cas9 is the protein that edits the DNA, while the Cas1 and Cas2 (other proteins in the system) are the ones that indicate Cas9 where to do the “cutting.”
Church told Wired that he plans to use Crispr to get human brain cells to show how exactly they turn into neurons. Nivala believes they’ll be able to perform that experiment thanks to Cas1 and Cas2. When there’s a foreign invasion on any given bacteria, the proteins cut a part of the attacker’s DNA, and CRISPR then includes it into the bacterial genome for another enzyme to turn into a matching guide RNA. But Cas1 and Cas2 don’t just do this randomly, as they are in charge of adding DNA in the order in which it arrives, thus making the cell’s genome into a chronological record.
Researchers hope to use the technology to study the brain
According to Shipman, the sequential nature of CRISPR makes it an appealing system for recording events over time. After the researchers successfully inserted the movie DNA into the E. coli, they spent the following five days sequentially treating bacteria with a frame of translated DNA.
Then they were able to reconstruct the racehorse movie with 90 percent accuracy by sequencing the bacterial DNA.
While this new technology could be used for many things, the research team hopes that it will allow them to study the human brain.
“We want to use neurons to record a molecular history of the brain through development,” said Shipman. “Such a molecular recorder will allow us to eventually collect data from every cell in the brain at once, without the need to gain access, to observe the cells directly, or disrupt the system to extract genetic material or proteins.”
Source: National Institutes of Health