Category Archives: Genome

In a paper published in the journal Genome Biology and Evolution, University of Houston Professor Dan Graur says that the functional portion of the human genome probably falls between 10% and 15%, with an upper limit of 25%. These figures are very different from one (about 80%) given in 2012 by the Encyclopedia of DNA Elements (ENCODE) project, but more optimistic than the 2014 estimate (8.2%) by Rands et al.

According to Professor Graur, the functional fraction within the human genome cannot exceed 25%, and is probably considerably lower.

Professor Graur took a deceptively simple approach to determining how much of the genome is functional, using the deleterious mutation rate that is, the rate at which harmful mutations occur and the replacement fertility rate.

Both genome size and the rate of deleterious mutations in functional parts of the genome have previously been determined, and historical data documents human population levels.

With that information, the researcher developed a model to calculate the decrease in reproductive success induced by harmful mutations, known as the mutational load, in relation to the portion of the genome that is functional.

The functional portion of the genome is described as that which has a selected-effect function, that is, a function that arose through and is maintained by natural selection.

Protein-coding genes, RNA-specifying genes and DNA receptors are examples of selected-effect functions.

In Professor Graurs model, only functional portions of the genome can be damaged by deleterious mutations; mutations in nonfunctional portions are neutral since functionless parts can be neither damaged nor improved.

Because of deleterious mutations, each couple in each generation must produce slightly more children than two to maintain a constant population size.

Over the past 200,000 years, replacement-level fertility rates have ranged from 2.1 to 3 children per couple; global population remained remarkably stable until the beginning of the 19th century, when decreased mortality in newborns resulted in fertility rates exceeding replacement levels, Professor Graur said.

If 80% of the genome were functional, unrealistically high birth rates would be required to sustain the population even if the deleterious mutation rate were at the low end of estimates.

For 80% of the human genome to be functional, each couple in the world would have to beget on average 15 children and all but two would have to die or fail to reproduce.

If we use the upper bound for the deleterious mutation rate (2108 mutations per nucleotide per generation), then the number of children that each couple would have to have to maintain a constant population size would exceed the number of stars in the visible Universe by ten orders of magnitude.

_____

Dan Graur. An upper limit on the functional fraction of the human genome. Genome Biol Evol, published online July 11, 2017; doi: 10.1093/gbe/evx121

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Only 10-25% of Human Genome is Functional, New Estimate Says - Sci-News.com

NEW YORK (GenomeWeb) Genome editing continues to be one of the most compelling trends in biological research as investigators maintain a steady pace of studies and papers on new CRISPR-Cas systems, innovative research tools, and various uses for the technology.

But academia is certainly not alone in its enthusiasm for CRISPR industry is joining in as various companies are either setting out to develop new tools based on the genome editing technology or find CRISPR-based applications for tools that already exist.

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Bio-Rad Laboratories Aims to Create Genome Editing Tools Pipeline, Starting With ddPCR - GenomeWeb

At least three quarters of the human genome consists of non-functional, 'junk DNA', according to a new study, and the actual proportion is likely to be even greater than that.

Ever since Watson and Crick discovered the double helix structure of DNA back in the 1950s, scientists have been debating what extent of the genome is responsible for making you you and now an evolutionary biologist says the answer to the riddle lies in some basic math.

Dan Graur from the University of Houston calculates that the functional portion of the human genome probably constitutes only about 10 to 15 percent of our overall DNA, with an upper limit of 25 percent.

The rest of our genome somewhere between around 75 to 90 percent of our DNA is what's called junk DNA: not necessarily harmful or toxic genetic matter, but useless, garbled nucleotide sequences that aren't functional in terms of encoding proteins that spur all the important chemical reactions going off inside our bodies.

The rationale for Graur's model is based on the way mutations creep into DNA, and how as a species we weed these mutations out for the benefit of all.

These kinds of genetic variants, called deleterious mutations, appear in our genome over time, subtly shifting or reordering the four chemical bases that make up DNA adenine, cytosine, guanine and thymine in parts of our genetic code.

When mutations take place in junk DNA, they're considered neutral since that genetic code doesn't do anything, anyway but when mutations occur to our functional, defining DNA, they can often be harmful and even ultimately lethal, as they mess up the instructions that code for healthy tissue and biological processes.

On that basis, it's better for our evolutionary prospects if less of our DNA is functional, because less of it is then exposed to the risk of mutation and the increased chances of early death it invites.

In Graur's calculations, given the risk of deleterious mutations to the survival of the species on one hand and the known stability of population and reproduction rates throughout human history on the other the limit of functional DNA has to be very low.

Otherwise dangerous mutations would keep stacking up, meaning we'd have to produce impossibly huge numbers of offspring for the small percentage of healthy bubs to survive.

"Under the assumption of 100 percent functionality and the range of deleterious mutation rates used in this paper, maintaining a constant population size would necessitate that each couple on average produce a minimum of 24 and a maximum of 5 1053 children," he writes in his paper.

Of course, nobody really other than creationists is suggesting that we carry around zero junk DNA, but a huge 2012 study called the Encyclopaedia of DNA Elements (ENCODE) project did claim that as much as 80 percent of human DNA was functional.

That study was controversial partly because many scientists claimed that the ENCODE definition of 'functional' was too broad.

In Graur's use of the term where functional DNA is code that's evolved to be useful in terms of its evolutionary effects the 80 percent figure just doesn't add up.

"For 80 percent of the human genome to be functional, each couple in the world would have to beget on average 15 children and all but two would have to die or fail to reproduce," he writes.

It's more likely then that only about 10 to 25 percent isn't junk DNA, Graur thinks.

While his is unlikely to be the last word on the subject the new results do coincide somewhat neatly with the findings of a separate 2014 study and could help focus vital scientific efforts on researching a smaller window of uncontested, 'functional' DNA.

"We need to know the functional fraction of the human genome in order to focus biomedical research on the parts that can be used to prevent and cure disease," Graur says.

"There is no need to sequence everything under the sun. We need only to sequence the sections we know are functional."

The findings are reported in Genome Biology and Evolution.

See more here:
New research suggests at least 75% of the human genome is junk ... - ScienceAlert

Head and shoulders of a sculpted model of a female Neanderthal.

Keeping pace with new developments in the field of human evolution these days is a daunting prospect. It seems as though every few weeks theres an announcement of exciting new findings from hominin fossils, or the recovery of an ancient genome that significantly impacts our understanding of our species history.

The best way to keep up is by regularly revisiting and reassessing a few core questions. When and where did our species first appear? How and where did we migrate? What was our relationship to our (now-extinct) hominin relatives? What evolutionary and cultural factors influenced our histories? How do new findings change the answers to these questions? Are they generally accepted by the relevant community of experts, or are they provisional or controversial?

This months challenge is to understand the significance of a recently published Neanderthal mitochondrial genome from a femur that was excavated in 1937 from the Hohlenstein-Stadel (HST) cave site in southwestern Germany. This new genome brings the total number of Neanderthals from whom we have genetic information to eighteen.

Reconstructing past population history accurately requires temporal and geographic diversity in sampling. Its tremendously important. Someday we will have so many archaic genomes sequenced that a new one isnt a big deal and doesnt add very much to the panoply. But that day isnt here yet, and so the recovery of genetic data from each new individual has the potential to make a huge difference in how we understand evolutionary history.

This is the case with the new HST Neanderthal mitochondrial genome, which is strikingly different to all others sequenced thus far so much so that it nearly doubles the known genetic diversity of Neanderthal populations.

The HST genome may resolve a longstanding point of confusion regarding the evolutionary relationships between modern humans, Neanderthals, and Denisovans. We actually get different histories for the three groups depending on whether we analyze their mitochondrial (maternally inherited) or nuclear (bi-parentally inherited) genomes. Nuclear DNA indicates that Neanderthals and Denisovans were more closely related to one another than to humans, and that the three groups last shared a common ancestor sometime between 765-550,000 years ago. Neanderthals and Denisovans diverged later (probably by 430,000 years ago) into genetically and geographically distinct groups.

However, mitochondrial DNA (inherited exclusively maternally) shows a different pattern: humans and Neanderthals appear to be more closely related to each other, and the Denisovans are a more distant cousin group.

The nuclear DNA story is most likely the correct one, as nuclear genomes give us a much more robust glimpse into the past by allowing us to look at the independent histories of thousands of genetic markers. But why does the mitochondrial DNA disagree?

One explanation for these results is that Neanderthal mitochondrial genomes may actually derive from gene flow with another group of hominins from Africa, ancestral or closely related to modern humans, whose maternal lineages effectively replaced the older Denisovan-like lineages. Indeed, the 430,000 year old hominins from the Sima de los Huesos site in Spain, who physically resemble the ancestors of Neanderthals, have early Neanderthal-like nuclear genomes but more Denisovan-like mitochondrial genomes, suggesting that the early Neanderthal populations had maternal lineages very unlike those found in later populations. If there was gene flow into Neanderthal population from female hominins from Africa, its possible that there could have been a complete replacement of the maternal lineages in this population without obscuring the histories reflected in the nuclear genome.

The HST genome has now provided a good chance to test this hypothesis, because it is quite old about 124,000 years, according to an estimate based on the molecular clock (in contrast to most other published Neanderthal genomes, which are much more recent). HSTs mitochondrial lineage is distinct from all other Neanderthal mitochondrial genomes sequenced thus far, and is basal (very ancient) relative to them. Using this new mitochondrial genome in their analyses, researchers found it was indeed plausible that some hominins may have migrated out of Africa and interbred with Neanderthals sometime between 413,000 and 270,000 years ago, perhaps in the Middle East. This event would have significantly predated the major Out-of-Africa human migration, which is currently thought to have occurred around 75,000 years ago. There is other evidence to suggest that early human populations were much more mobile than we had previously thought, such as the recent classification of hominin fossils in Morocco dating to 300,000 years ago as early pre-modern H. sapiens. These data may give indirect support for early small-scale migrations before the major spread of human populations out of Africa.

The HST mitochondrial genome adds more important details to our ever-expanding understanding of hominin evolution and allows us to be a bit more confident in one model that resolves seemingly contradictory genetic results. While nuclear DNA from the HST fossil would tell us even more, unfortunately the endogenous Neanderthal DNA in the fossil is not well preserved. Of the ~240,000 unique sequence reads recovered from the femur, only about 1,110 were from the Neanderthal. The rest were from other organisms such as soil bacteria and modern humans. These high contamination and low endogenous DNA levels mean that it will be difficult to obtain a nuclear genome from this bone.

I feel like every time I write about ancient DNA its an exercise in expectation lowering, since so few remains ever yield their genetic secrets. So here I want to emphasize that what we have learned about our histories from this single fossil really is remarkable. The brand new editions of textbooks that many of us are planning on using for our courses next term are already completely out of date, and Im hopeful there are even more surprises to come in the near future. Im sure I speak for the whole biological anthropology community when I say that we couldnt be happier about the pace of discoveries these days, even if it does feel overwhelming.

Further reading

Posth C., et al. 2017. Deeply divergent archaic mitochondrial genome provides lower time boundary for African gene flow into Neanderthals. Nature Communications. doi:10.1038/ncomms16046

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Did human women contribute to Neanderthal genomes over 200000 years ago? - The Guardian

An evolutionary biologist at the University of Houston has published new calculations that indicate no more than 25 percent of the human genome is functional. That is in stark contrast to suggestions by scientists with the ENCODE project that as much as 80 percent of the genome is functional.

In work published online in Genome Biology and Evolution, Dan Graur reports the functional portion of the human genome probably falls between 10 percent and 15 percent, with an upper limit of 25 percent. The rest is so-called junk DNA, or useless but harmless DNA.

Graur, John and Rebecca Moores Professor of Biology and Biochemistry at UH, took a deceptively simple approach to determining how much of the genome is functional, using the deleterious mutation rate that is, the rate at which harmful mutations occur and the replacement fertility rate.

Both genome size and the rate of deleterious mutations in functional parts of the genome have previously been determined, and historical data documents human population levels. With that information, Graur developed a model to calculate the decrease in reproductive success induced by harmful mutations, known as the mutational load, in relation to the portion of the genome that is functional.

The functional portion of the genome is described as that which has a selected-effect function, that is, a function that arose through and is maintained by natural selection. Protein-coding genes, RNA-specifying genes and DNA receptors are examples of selected-effect functions. In his model, only functional portions of the genome can be damaged by deleterious mutations; mutations in nonfunctional portions are neutral since functionless parts can be neither damaged nor improved.

Because of deleterious mutations, each couple in each generation must produce slightly more children than two to maintain a constant population size. Over the past 200,000 years, replacement-level fertility rates have ranged from 2.1 to 3.0 children per couple, he said, noting that global population remained remarkably stable until the beginning of the 19th century, when decreased mortality in newborns resulted in fertility rates exceeding replacement levels.

If 80 percent of the genome were functional, unrealistically high birth rates would be required to sustain the population even if the deleterious mutation rate were at the low end of estimates, Graur found.

For 80 percent of the human genome to be functional, each couple in the world would have to beget on average 15 children and all but two would have to die or fail to reproduce, he wrote. If we use the upper bound for the deleterious mutation rate (2 108 mutations per nucleotide per generation), then the number of children that each couple would have to have to maintain a constant population size would exceed the number of stars in the visible universe by ten orders of magnitude.

In 2012, the Encyclopedia of DNA Elements (ENCODE) announced that 80 percent of the genome had a biochemical function. Graur said this new study not only puts these claims to rest but hopefully will help to refocus the science of human genomics.

We need to know the functional fraction of the human genome in order to focus biomedical research on the parts that can be used to prevent and cure disease, he said. There is no need to sequence everything under the sun. We need only to sequence the sections we know are functional.

This article has been republished frommaterialsprovided by The University of Houston. Note: material may have been edited for length and content. For further information, please contact the cited source.

Reference

Graur, D. (2017). An upper limit on the functional fraction of the human genome. Genome Biology and Evolution.

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Study Indicates 75% of Human Genome is Non-functional - Technology Networks

DNA is a hugely promising medium for storing data. Consider that a cell nucleus can hold the instructions for an organism as complex as a human. So far efforts to store non-genetic data in DNA have been carried out in test tubes, but now scientists have encoded a GIF into the genome of living bacteria.

The scientists from Harvard University used the CRISPR genome-editing tool to store a picture of a hand and an animation of a running horse adapted from Eadweard Muybridges 1878 photographic study Human and Animal Locomotion in the genome of E. coli bacteria.

More importantly, they were able to retrieve the image of the hand perfectly and the GIF with 90 percent accuracy by sequencing the bacterial genomes. Their results were published in the journal Nature on Wednesday.

Efforts to store unconventional data in DNA have been going on for years thanks to DNAs incredible compactness and long shelf life. Properly stored, it can keep data intact for at least 100,000 years. Just a couple of months ago Microsoft said it planned to incorporate a DNA storage system in one of its data centers by the end of the decade.

Typically, though, this has been done by translating the bits that encode books, images or audio recordings into DNA sequences and then synthesizing them artificially. By using CRISPR instead, the Harvard team, led by renowned geneticist George Church, was able to hijack the genomes of E. coli bacteria to store the information.

The CRISPR system is actually a natural defense mechanism that bacteria use to develop immunity to invading viruses by recording snippets of the attackers DNA in the bacterias genome. These snippets are then used to guide the enzyme Cas9 to find and destroy invasive DNA next time the virus attacks.

The CRISPR/Cas9 system has been re-purposed by scientists to edit genomes by re-engineering it so it chops DNA sequences at a specific location. This then allows them to remove existing genes or add new ones.

In this new study, though, the researchers instead re-purposed the lesser-known Cas1 and Cas2 proteins responsible for inserting viral DNA into the bacterias genome. We found that if we made the sequences we supplied look like what the system usually grabs from viruses, it would take what we give, Seth Shipman, a neuroscience researcher at Harvard and study co-author, told The Verge.

Importantly, Cas1 and Cas2 insert new pieces of DNA in the order they arrive, which is what made it possible for the researchers to encode an animation. The data was actually encoded in 600,000 cells to help boost accuracy because the process is not precise, but modern sequencing tools mean its fairly quick to retrieve the data.

The amount of data stored in the cells is considerably less than whats been achieved with the synthesis route. Last year researchers from Microsoft and the University of Washington stored 200 megabytes of data in a smear of DNA smaller than a pencil tip.

That means the approach is unlikely to supplant synthesized DNA for the kind of long-term data storage that has piqued the interest of IT firms. But the ability to record data directly into a cells genome does open up a host of new potential applications.

The one the researchers themselves are most interested in is the prospect of turning cells into recording devices that can track changes in both their internal workings and their environment over time. They think this could help us to understand the developmental processes that govern how neurons morph into specialized cells over time or help track which neurons are talking to each other.

Further into the future, it may be possible to effectively create black boxes for cells in the human body, Church told The New York Times. Bacteria could be made to record the activity of cells over time, and when someone gets ill doctors could extract the bacteria and sequence their DNA to play it back.

Its also possible to imagine the approach could be a useful new tool for synthetic biologists who are already using gene circuits to build tiny computers inside cells that can carry out logic functions by providing a form of memory.

Banner Image Credit:Eadweard Muybridge/Wikimedia Commons

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A Living Hard Drive: This GIF Was Stored in the DNA of Bacteria - Singularity Hub

LONDON (Reuters) - The malaria parasite owes its devastating success to a finely tuned genome that can survive attacks and evade human immune defense because it retains only the bare essential genes it needs to thrive, scientists have found.

In a detailed study analyzing more than half the genes in the genome of the parasite that cause malaria - Plasmodium - researchers found that two thirds of those genes are essential for survival. This is the largest proportion of essential genes found in any organism studied to date, they said.

Importantly for researchers trying to develop vaccines and drugs against the disease, the scientists discovered that the parasite often disposes of genes that produce proteins that give its presence away to its host's immune system.

This allows malaria to swiftly change its appearance to the human immune system and hence build up resistance to a vaccine, posing problems for the development of effective shots.

"Our study found that below the surface the parasite is more of a Formula 1 race car than a clunky people carrier: The parasite is fine-tuned and retains the absolute essential genes needed for growth," said Julian Rayner, who co-led this study at Britain's Wellcome Trust Sanger Institute.

He said this discovery, published on Thursday in the journal Cell, had both positive and negative implications.

"The bad news is it can easily get rid of the genes behind the targets we are trying to design vaccines for, but the flip side is there are many more essential gene targets for new drugs than we previously thought," he said.

Malaria kills around half a million people a year, the vast majority of them children and babies in the poorest parts of sub-Saharan Africa. And beyond that, almost half the world's population is at risk of becoming infected with malaria and more than 200 million people fall sick with it each year, according to World Health Organization figures.

Despite decades of scientific endeavor, the genetics of Plasmodium parasites have proved tricky to decipher.

This is partly because they are ancient organisms and around half their genes have no similar genes homologs in any other organism, Rayner's team explained, making it difficult for scientists to find clues to their function.

Francisco Javier Gamo, a malaria expert at GlaxoSmithKline, a British drugmaker active in this field of research, said the "Holy Grail" for malaria scientists would be to discover genes that are essential across all of the parasite lifecycle stages.

"If we could target those with drugs it would leave malaria with nowhere to hide," he said.

Reporting by Kate Kelland, editing by Mark Heinrich

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Malaria genome study reveals savvy, finely tuned parasite - Reuters

The potential for artificial intelligence in precision medicine is big, according to conclusions of a new study by the New York Genome Center and IBM.

The results, published in the July 11 issue of Neurology Genetics, a journal of the American Academy of Neurology, showed that researchers at the New York Genome Center, Rockefeller University and other institutions along with IBM verified the potential of IBM Watson for Genomics to analyze complex genomic data from state-of-the-art DNA sequencing of whole genomes.

[Also:IBM Watson, Illumina partner to deliver precision oncology on a large scale]

This study documents the strong potential of Watson for Genomics to help clinicians scale precision oncology more broadly, Vanessa Michelini, Watson for Genomics Innovation Leader for IBM Watson Health, said in a statement. Clinical and research leaders in cancer genomics are making tremendous progress towards bringing precision medicine to cancer patients, but genomic data interpretation is a significant obstacle, and thats where Watson can help.

The proof of concept study compared multiple techniques used to analyze genomic data from a glioblastoma patients tumor cells and normal healthy cells, putting to work a beta version of Watson for Genomics technology to help interpret whole genome sequencing data for one patient.

[Also:IBM Watson, FDA align to boost public health with blockchain]

Watson provided a report of potential clinically actionable insights within 10 minutes, compared to 160 hours of human analysis and curation typically required to reach similar conclusions, according to researchers.

The study also showed that whole-genome sequencing, or WGS, identified more clinically actionable mutations than the current standard of examining a limited subset of genes, known as a targeted panel. WGS requires significantly more manual analysis, so combining this method with artificial intelligence could help doctors identify potential therapies for more patients in less time, researchers concluded.

This informatics challenge is often a critical bottleneck when dealing with deadly cancers such as glioblastoma, with a median survival of less than 15 months following diagnosis, researchers noted.

Twitter: @Bernie_HITN Email the writer: bernie.monegain@himssmedia.com

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AI can speed up precision medicine, New York Genome Center-IBM ... - Healthcare IT News

The researchers used next-generation sequencing technology to count those barcodes, and hence measure the growth of each genetically modified malaria parasite. If the switched-off gene was not essential, the parasite numbers shot up, but if the knocked-out gene was essential, the parasite disappeared.

This work was made possible by a new method that enabled us to investigate more than 2500 genes in a single studymore than the entire research community has studied over the past two decades, explained co-senior study investigator Oliver Billker, Ph.D., senior group leader at Sanger. We believe that this method can be used to build a deep understanding of many unknown aspects of malaria biology and radically speed up our understanding of gene function and prioritization of drug targets."

The researchers systematically showed that the malaria parasite can easily dispose of the genes that produce proteins that give away its presence to the host's immune system. This poses problems for the development of malaria vaccines, as the parasite can quickly alter its appearance to the human immune system, and, as a result, the parasite can build resistance to the vaccine.

"We knew from previous work that on its surface the malaria parasite has many dispensable parts, remarked co-senior study investigator Julian Rayner, Ph.D., senior group leader and director of Wellcome Genome Campus Connecting Science. Our study found that below the surface the parasite is more of a Formula 1 race car than a clunky people carrier. The parasite is fine-tuned and retains the absolute essential genes needed for growth. This is both good and bad: The bad news is it can easily get rid of the genes behind the targets we are trying to design vaccines for, but the flip side is there are many more essential gene targets for new drugs than we previously thought."

The authors stressed that the factors influencing gene function go well beyond the realm of basic science research, concluding that the level of genetic redundancy in a single-celled organism may thus reflect the degree of environmental variation it experiences. In the case of Plasmodium parasites, this helps rationalize both the relative successes of drugs and the greater difficulty of making an effective vaccine.

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Malaria Genome Analysis Reveals an Abundance of Potential New ... - Genetic Engineering & Biotechnology News (blog)

Photos from Eadweard Muybridges study of a galloping horse have been recorded in bacterial DNA

Eadweard Muybridge/The LIFE Picture Collection/Gett

By Douglas Heaven

Life is an open book and were writing in it. A team at Harvard University has used the CRISPR genome-editing tool to encode video into live bacteria demonstrating for the first time that we can turn microbes into librarians that can pass records on to their descendants and perhaps to ours.

The technique could even let us create populations of cells that keep their own event logs, making records as biological processes like disease or brain development happen.

DNA is one of the best media for storing data we know of. Researchers have already crammed large amounts of information from books to digital images into tiny amounts of biological material. In theory, a gram of single-stranded DNA can encode 455 exabytes, or roughly 100 billion DVDs.

Most previous DNA storage work has used artificial DNA: digital information is translated into a DNA sequence that is then synthesized.

However, using CRISPR lets you cut and paste the digital information directly into the DNA of a live organism, in this case a large population of E. coli.

Bacteria use the CRISPR/Cas9 system to record information in their DNA about viruses they encounter. And this machinery has been co-opted by researchers to enable us to precisely edit genomes.

In bacteria, each new entry gets stored upstream of the last one, which makes it possible to read off a history of events in the order they happened. Previous groups have created lifelogging cells by using CRISPR/Cas9 to mark the genome when a particular event occurs. But these marks just provide a tally of how many times something happens.

Seth Shipman at Harvard University and his colleagues have now used a version of CRISPR with a different enzyme, called CRISPR/Cas1-Cas2. This let them add a message to the genome rather than simply cut a notch.

The message was a recorded image of a human hand and five images showing a galloping horse, taken from Eadweard Muybridges 1878 photographic study of the animals motion, which has since been animated.

Seth Shipman

To get the DNA sequences encoding this data inside the cells, the team applied an electrical current that opened channels in the cells walls and the DNA flowed in. Once inside, CRISPR got to work.

To read the data back again, the team sequenced the DNA of more than 600,000 cells. The large number is necessary because most cells will not have edited their genome entirely accurately. Every cell isnt going to acquire every piece of information we throw at it, says Shipman. The more cells that are sampled, the better the reconstruction of the data. Fortunately, with modern sequencing tools, reconstruction is quick.

The five frames of a horse in motion showed that it is possible to capture data chronologically and replay them as a video. You get a physical record of events over time, says Shipman. For a long time we wanted to have some way of storing timing information inside cells, says Shipman. The CRISPR system is perfectly adapted to that.

This is a really neat paper, says Yaniv Erlich at Columbia University in New York. The team didnt store that much data and it is not clear that the CRISPR technique can compete with the storage capacity of synthetic DNA. But inserting information into living cells opens up a lot of possibilities, he says.

For a start, it lets you add to or change the stored information later. And because the data is written into the bacterial genomes, it gets passed down between generations. Mutations happen, but not nearly as many as you think, says Shipman certainly not enough to corrupt the data stored across a large population of cells.

Storing data in bacteria could even be a way to make important information survive a nuclear apocalypse. You could useDeinococcus radiodurans, a species that maintains its genome in extreme radiation conditions, says Erlich.

Shipman wants to turn cells into recording devices that document what takes place inside themselves. He is excited about the possibility of keeping a log book of events inside a living brain as it develops, showing how different brain cells acquire their distinct identities.

Its hard to understand what events make brain cells fully defined, says Shipman. You cant easily get in there to take a look. Taking a brain apart disrupts the whole process.

You could also get a cell to diarise what happens as it changes from healthy to diseased. Now that would be an account worth reading.

Journal reference: Nature, DOI: 10.1038/nature23017

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Video stored in live bacterial genome using CRISPR gene editing ... - New Scientist