By Paul Rincon Science editor, BBC News website
An image and short film has been encoded in DNA, using the units of inheritance as a medium for storing information.
Using a genome editing tool known as Crispr, US scientists inserted a gif – five frames of a horse galloping – into the DNA of bacteria.
Then the team sequenced the bacterial DNA to retrieve the gif and the image, verifying that the microbes had indeed incorporated the data as intended.
The results appear in Nature journal.
For their experiments, the team from Harvard University in Cambridge, Massachusetts, used an image of a human hand and five frames of the horse Annie G captured in the late 19th Century by the British photography pioneer Eadweard Muybridge.
In order to insert this information into the genomes of bacteria, the researchers transferred the image and the movie onto nucleotides (building blocks of DNA), producing a code that related to the individual pixels of each image.
The researchers then employed the Crispr platform, in which two proteins are used to insert genetic code into the DNA of target cells – in this case, those of E.coli bacteria.
For the gif, sequences were delivered frame-by-frame over five days to the bacterial cells.
The data were spread across the genomes of multiple bacteria, rather than just one, explained co-author Seth Shipman, from Harvard University in Massachusetts.
“The information is not contained in a single cell, so each individual cell may only see certain bits or pieces of the movie. So what we had to do was reconstruct the whole movie from the different pieces,” Dr Shipman told the BBC.
“Maybe a single cell saw a few pixels from frame one and a few pixels from frame four… so we had to look at the relation of all those pieces of information in the genomes of these living cells and say: can we reconstruct the entire movie over time?”
To “read” the information back, the researchers sequenced the bacterial DNA and used custom computer code to unscramble the genetic information, which spits out the images.
The team was able to achieve 90% accuracy: “We were really happy with how it came out,” Seth Shipman told me.
Eventually, the team wants to use the technique to create “molecular recorders”.
Dr Shipman says these are cells that can “encode information about what’s going on in the cell and what’s going on in the cell environment by writing that information into their own genome”.
This is why the researchers used images and a movie: images because they represent the kind of complex information the team would like to use in future, and movies because they have a timing component.
The timing component is important because it would be useful to track changes in a cell and its environment over time.