Live Flash drive
The bacteria encoded a video of a galloping horse in the DNA
American scientists recorded a gif image in the form of a genetic code, embedded it in the genome of a bacterium and again counted from the genome with almost no loss of quality.
In recent decades, the role of DNA as a data carrier has been actively discussed. Moreover, we are talking not only about the genetic information that it contains initially, but also about other information that could theoretically be recorded in it. Due to the intensive development of technologies, there is a problem of big data (big data) and a place to store them. And here DNA turned out to be a suitable candidate, since the information recorded in it takes up a small amount and reproduces itself easily and quickly. In other words, there is an idea in the scientific community to make living USB flash drives out of cells.
Scientists from Boston and Cambridge decided to work out this technology on Escherichia coli bacteria – the well-known E. coli. To embed new information into the genome of bacteria, they used the CRISPR-Cas system, which is widely used now. The advantage of this method is that it allows you to efficiently and accurately embed new DNA fragments into an existing chain.
To begin with, the researchers experimented with a static image of the hand. They split the photo into pixels and built two models. In the first variant, the pixels were of four colors and each color corresponded to one DNA nucleotide (of which there are only four types). In another variant, the pixels were divided into 21 colors and encoded with three-nucleotide combinations (the same three-nucleotide combinations encode amino acids, of which there are about 20 in the cell). The first version of the code turned out to be simple and strict, the second – redundant.
Hand image: original (left) and read from the genome (right).
Here and below are photos of Seth Shipman.
Then the scientists recorded a photo of the hand in the form of a sequence of nucleotides, synthesized this sequence in a test tube, integrated it into the genome of bacteria, then multiplied the bacteria and the next day tried to read the information from the genome of the second generation. They managed to restore the picture, and it turned out that a more complex version of the code provides a clearer reproduction.
The authors of the study not only tested the technology on new material, but also worked on its improvement. They identified several traits that affect how well the DNA sequence integrates into the genome (length, composition, presence of repeats, etc.). Using redundant code helped them experiment with these traits and ensure that the integration was successful.
To test the effectiveness of their technique on a larger amount of information, the authors took a gif image of a galloping horse, made up of a series of pictures of one of the pioneers of photography – Edward Maybridge.
The original video (from Wikimedia Commons) – VM.
Five consecutive frames took up a volume of about 2.6 KB, which was also successfully recorded in the E. coli genome and extracted back. When comparing the initial and final images, it is clear that the accuracy of information transmission was high, scientists estimated it above 90%.
Gif image of a galloping horse: original (left)
and read from the genome of the bacterium (on the right)
The study is published in the journal Nature (Shipman et al., CRISPR–Cas encoding of a digital movie into the genomes of a population of living bacteria).
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13.07.2017