Category Archives: Genome

The sequencing of DNA from the earliest known North American remains has provided the first genetic confirmation of Native American ancestry, quashed a controversial alternative theory and hinted at possible migration patterns that may revise our understanding of population dispersal from modern-day Alaska to the southern tip of Chile.

Whew. Pretty impressive achievements for a baby.

Researchers today announced the successful whole-genome sequencing of Anzick-1, the remains of an infant boy who lived roughly 12,600 years ago. The remains were discovered in central Montana in 1968 during a construction project. Anzick-1 was a crucial find for archaeologists even before scientists completed the DNA analysis the childs remains are the oldest known burial in North America and the only human remains ever found that are definitively associated with the Clovis people, the continents first known indigenous culture.

Anzick-1s DNA allowed researchers to confirm genetically, for the first time, that all native peoples of North and South America descended from ancestors who arrived via land bridges from East Asia, possibly in a single migration. While there has been ample archeological evidence of the East Asian origin of Native Americans, conclusive proof based on DNA had been absent until now. Even a recent study comparing the genes of ancient Siberian remains with those of modern Native Americans had not been as conclusive.

The sequencing of Anzick-1s genome, however, revealed the child was part of a line that was directly ancestral to 80 percent of all American native peoples, and close cousins to the remaining 20 percent.

In addition, analysis of the childs mitochondrial DNA indicated Anzick-1 belonged to whats known as the D4h3a haplogroup, or lineage. The finding is important and surprising, according to researchers because the D4h3a line is considered to be a founder lineage, belonging to the first people to arrive in the Americas. Although rare in most Native Americans in the U.S. and Canada today, D4h3a genes are found more commonly in native people of South America, far from the Montana cliff beneath which Anzick-1 was laid to rest.

Placing Anzick-1 in the D4h3a haplogroup suggests greater genetic complexity among Native Americans than previously believed, including an early divergence in genetic lineage 13,000 years ago or more. One theory had suggested that after crossing into North America from Siberia, one group of early Americans, with the D4h3a lineage, moved south along the Pacific coast and eventually, over thousands of years, to Central and South America. Other groups may have moved inland, east of the Rockies, as ice sheets retreated.

Finding Anzick-1s D4h3a lineage in central Montana casts doubt on that theory, though researchers were quick to caution that we shouldnt draw conclusions about migration patterns more than 10,000 years ago by comparing one ancient genome with that of modern people. Only the discovery and genetic sequencing of other remains as old as Anzick-1 will clarify how and when populations spread from the far northwest of the Americas.

Anzick-1 was estimated to be 12-18 months old at the time of his death; a cause of death has not been identified. He was covered in red ochre, a natural pigment, and apparently buried with several tools made of bone or stone in the style of the Clovis people. The Clovis people are generally believed to be the first wholly indigenous culture of North America, though there is archaeological evidence some of it contentious of an earlier human presence in the Americas.

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Earliest American Genome Proves Siberian Origins of Native Peoples

The burial mound in Montana where the skeleton was found.

Texas A&M University

The peopling of the Americas via the Bering Sea land bridge is one of the more confusing events in recent history. Some of the earliest signs of human occupancy are actually in Chile. After that, the first distinct toolmaking culture, the Clovis people, appeared in the interior of North America and rapidly swept across the continent. There are also indications that a separate migration occurred down the Pacific Coast, possibly associated with people who had distinctive skeletal features, while the Inuit seem to be relatively recent arrivals.

The sudden appearance of the Clovis toolset has caused some people to suggest that the Clovis were a distinct migration by a passage between ice sheets directly into North America's interior. Others have even suggested that they arrived from Europe, brought by people who crossed the ice through Greenland (an idea that's favored by a certain Bigfoot researcher). Now, researchers have completed the genome of an individual who was buried with Clovis tools in Montana 12,500 years ago. The results suggest that the migration into North America was more unified than some thought.

Although Clovis tools are relatively common at many North American sites, they're generally not associated with skeletal remains. And there have been no distinctive skeletal features that label remains as belonging to a distinctive Clovis ethnic group. All of which makes Montana's Anzick site exceptional: it contains remains that were placed with Clovis tools, unambiguously tagging the skeleton as belonging to this group.

Completing a genome from a bone of this age is no longer big news. The DNA showed the expected signs of age-associated damage, and careful controls needed to be done to show that the contamination with modern DNA is minimal. In this case, the skeleton was male, which means it has a single X chromosome. Therefore, any DNA variation on the X would be a sign of contamination. By this and other measures, 99 percent of the DNA came from the individual in question.

The researchers used the resulting data to reconstruct the mitochondrial genome. And, already, the results brought a bit of clarity to the migrations of our ancestors. Its DNA sequence belongs to a type that now is almost exclusively distributed along the Pacific Coast, a distribution that some have suggested indicates the migration of a distinct group of humans, who arrived separately from those who settled the continents' interiors. The new result shows that the interiors and coasts were settled by the same people.

The Clovis genome also lacks many of the variants that are present in the modern populations, placing it at the base of the tree. The authors conclude that these results should serve as a caution against reading too much into the modern distribution of DNA variants.

The Y chromosome showed a similar story, placing it closer to all existing native populations than any sequences from Eurasia. The main genome is also consistent with the Clovis population being ancestral to most Native American populations.

But the results don't entirely argue for a single migration into North America. That's because the Clovis genome is more closely related to genomes from South America than it is to a few groups in Northern Canada and the Canadian Arcticincluding some groups that speak languages from the main Amerind group. That suggests that there might have been a second distinct migration along the interior of the ice sheets, one that left the northern populations of North America a bit more mixed than those of more southerly locations.

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Skeleton from one of the earliest Americans yields its genome

Social insects, which usually have specialized behavioral groups (also called castes), are important models for social evolution and behavior researches. How division of labor in insect societies is regulated is an outstanding question and not fully understood yet. However, in many social insect species, experimental control over important factors that regulate division of labor, such as genotype and age, is limited. In a study published online on February 6th in Current Biology, researchers from Rockefeller University and BGI-Shenzhen have sequenced the genome of the queenless clonal raider ant Cerapachys biroi, a new model system to study the molecular mechanisms of social behaviors.

Ants of the genus Cerapachys are myrmecophagous and raid the nests of other ants. It belongs to the dorylomorph clade of ants, which also includes the infamous army ants. Since the early 1900s, introduced populations of C. biroi have become established on tropical and subtropical islands around the world, probably as a consequence of human traffic and trade. Like in many other army ants, colonies of C. biroi undergo two phases in their life cycles: one is for reproduction and the other for foraging and brood care. And more interestingly, colonies of C. biroi uniquely consist entirely of totipotent workers, all of which reproduce asexually.

The authors noted one of the most interesting findings of this study is that nestmates in a colony are almost clonally related and reproduce via an asexual way called automixis with central fusion, which was also found in the Cape honeybees. Asexual reproduction usually leads to loss of genomic heterozygosity, which is harmful in the long run. However, that genomic heterozygosity in C. biroi is lost extremely slowly. "It is not yet clear whether maintaining heterozygosity in C. biroi is through reduced recombination during meiosis, via selection against homozygous individuals, or both." said Dr. Peter Oxley, co-first author of this study, in Laboratory of Insect Social Evolution, Rockefeller University.

Nestmates of C. biroi can synchronously alternate between reproduction and brood care. The authors also found expression patterns of the genes associated with division of labor in other social insects are conserved in C. biroi and dynamically regulated during the colony cycle. "This suggests that the gene networks underlying reproduction and brood care in C. biroi are likely to be the same conserved networks underlying caste-specific behavior in other eusocial insects." said Dr. Daniel Kronauer, co-senior author of this study and head of Laboratory of Insect Social Evolution in Rockefeller University.

Because C. biroi colonies have totipotent workers and no queens, it is easy to conduct colony propagation and control the composition of arbitrarily sized experimental colonies. In addition, the colony cycle of C. biroi allows for precise selection of age-matched workers and experimental control over colony demography. "Ants represent one of the most successful exclusively eusocial insects, with at least 15,000 species have been recorded, they have evolved innumerous diversity. This is the fourth ant genome published in our group. The clonal raider ant is unique in many aspects compared to other ants. There are still many interesting questions related to the development and evolution of the queenless and reproductive cycle in this system that we don't know yet. The availability of this genome could pave the road for these future studies." said Dr. Guojie Zhang, co-senior author of this study, from China National Genebank, BGI-Shenzhen and Centre for Social Evolution in University of Copenhagen.

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The above story is based on materials provided by BGI Shenzhen. Note: Materials may be edited for content and length.

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Genome of clonal raider ant provides promising model to study social evolution and behavior

Robert L. Walker

Humans from the Clovis culture used characteristic stone points (brown) and rod-shaped bone tools.

The remains of a young boy, ceremonially buried some 12,600years ago in Montana, have revealed the ancestry of one of the earliest populations in the Americas, known as the Clovis culture.

Published in this issue of Nature, the boys genome sequence shows that todays indigenous groups spanning North and South America are all descended from a single population that trekked across the Bering land bridge from Asia (M.Rasmussen et al. Nature 506, 225229; 2014). The analysis also points to an early split between the ancestors of the Clovis people and a second group, whose DNA lives on in populations in Canada and Greenland (see page162).

But the research underscores the ethical minefield of studying ancient Native American remains, and rekindles memories of a bruising legal fight over a different human skeleton in the 1990s.

To avoid such a controversy, Eske Willerslev, a palaeobiologist at the University of Copenhagen who led the latest study, attempted to involve Native American communities. And so he embarked on a tour of Montanas Indian reservations last year, talking to community members to explain his work and seek their support. I didnt want a situation where the first time they heard about this study was when its published, he says.

Source: Montana Office of Public Instruction

Construction workers discovered the Clovis burial site on a private ranch near the small town of Wilsall in May 1968 (see Ancient origins). About 100 stone and bone artefacts, as well as bone fragments from a male child aged under two, were subsequently recovered.

The boys bones were found to date to the end of the Clovis culture, which flourished in the central and western United States between about 13,000 and 12,600 years ago. Carved elk bones found with the boys remains were hundreds of years older, suggesting that they were heirlooms. The ranch, owned by Melvyn and Helen Anzick, is the only site yet discovered at which Clovis objects exist alongside human bones. Most of the artefacts now reside in a museum, but researchers returned the human remains to the Anzick family in the late 1990s.

At that time, the Anzicks daughter, Sarah, was conducting cancer and genome research at the National Institutes of Health in Bethesda, Maryland, and thought about sequencing genetic material from the bones. But she was wary of stoking a similar debate to the one surrounding Kennewick Man, a human skeleton found on the banks of the Columbia River in Kennewick, Washington, in July 1996. Its discovery sparked an eight-year legal battle between Native American tribes, who claimed that they were culturally connected to the individual, and researchers, who said that the roughly 9,000-year-old remains pre-dated the tribes.

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Ancient genome stirs ethics debate

If the genome sequencing is a success, it will make Richard III the first historical figure to have his DNA mapped in this way, according to CNN. Little is known about the 15th-century monarchs appearance, aside from artists renditions of him that were done long after his death in 1485. The project could reveal intricate details about the face behind the legend, right down to the color of his eyes and hair.

"There are no contemporary portraits of Richard," Turi King, a geneticist at the University of Leicester who will lead the project, said in a statement. "All the portraits that exist postdate his death by about 40 to 50 years onwards. So it's going to be interesting to see what the genetic information provides in relation to what we know from the portraits."

As CNN noted, many portraits of Richard III were painted in an unflattering light. He was branded after his death as a Machiavellian villain whose ascension to power was marked by bloodshed, including the murder of his two little nephews. This image was fueled by pro-Tudor propaganda that sought to legitimize his successors right to the throne.

Mapping the kings genome will give us an idea of just how accurate the centuries-old portraits really were.

Geneticists have previously sequenced the genomes of several ancient people, including Otzi the iceman, whose 5,000-year-old remains were discovered in 1991 on the Alpine border between Italy and Austria. As The BBC notes, scientists also mapped the DNA of a 4,000-year-old Greenland Inuit, a 7,000-year-old Spanish hunter-gatherer and several Neanderthals.

Sequencing Richard IIIs genome will not only give us a unique insight into the past, but have a profound impact on the way we think about disease and heredity in our own genomic age, Dan OConnor, head of medical humanities at the Wellcome Trust, which is funding the project, said in a statement. By making this genome available to all, we will ensure that we can continue to learn about Richards past both personal and historic even once his remains have been interred.

Sequencing King Richard IIIs genome will cost about 100,000, or about $165,000 USD. Thats just a fraction of what it cost to sequence the DNA of the first human genome in the 1990s. That project took 13 years and came with a price tag of about $1 billion, according to Live Science.

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Genome Of King Richard III Will Create Contemporary Portrait Of 15th Century Monarch

While there are few answers concerning the remains of a 12,600-year-old toddler found in the American Rockies, analysis of the boys genome may shed light on how the first Americans came to the New World.

The remains of the 1-year-old boy underwent a full genome sequence, which revealed, as expected, that the first human settlers in North America came from Asia and not Europe. Not only that, these tribes are the direct ancestors of todays Native Americans. The findings, published in Nature, add weight to the longstanding theory that the first Americans came to the New World by walking over a land bridge across the Bering Strait from Siberia.

"It's crazy," Eske Willerslev of the University of Copenhagen in Denmark, who led the genomic analysis told New Scientist. "Finding someone who is directly ancestral to the entire population of a continent that just does not happen. I don't think it would ever happen in Europe, or in Siberia. There are very few places where this could happen."

The skeletal remains, called Anzick-1, were found in 1968 near a rock cliff in central Montana, in an area called Anzick after the family that owned the land. At the time, the 1-year-old boys remains were found buried with a cache of sharpened flints and a bone tool that had been passed down for 150 years. The skeleton and burial artifacts were covered with red ochre, a type of mineral used in prehistoric times as a pigment in burials.

Spear points found at the burial site. Texas A&M University

Scientists believe the boy belonged to the Clovis culture (named after stone tools found in New Mexico), the first widespread prehistoric people that appeared about 13,000 years ago. The latest findings that link the toddlers skeletal remains to this prehistoric people may help settle differences between some anthropologists and Native Americans that have argued the first people originated in Europe, casting into doubt their origin stories and artifacts on ancestral lands, Reuters reports.

We hope that this study leads to more cooperation between Native Americans and scientists. This is just one human genome. We need to know the genetic story of modern Native peoples and derive more genetic data from ancient remains to fully understand the origins and movements of the First Americans and their descendants, Michael Waters, director of the Center for the Study of First Americans at Texas A&M, said in a statement.

Willerslev and his colleagues extracted DNA from the boys bones to sequence his genome. They compared the results with DNA samples from 43 modern non-African populations, including 52 South American, Central American and Canadian tribes. The results showed the boy was most closely and equally related to modern tribes in Central and South America.

Willerslev says the results act as the missing link between the first Americans and todays tribes. The new findings have settled the long-standing debate about the origins of the Clovis," according to Willerslev. "We can say the Solutrean theory suggesting Clovis originated from people in Europe doesn't fit our results."

Experts remain divided on just how the first Americans arrived and how large of a group first settled in the New World.

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Genome Of 12,600-Year-Old Clovis Boy May Be Missing Link In Native American Ancestry [PHOTOS]

Over the last decade, as DNA-sequencing technology has grown ever faster and cheaper, our understanding of the human genome has increased accordingly. Yet scientists have until recently remained largely ham-fisted when theyve tried to directly modify genes in a living cell. Take sickle-cell anemia, for example. A debilitating and often deadly disease, it is caused by a mutation in just one of a patients three billion DNA base pairs. Even though this genetic error is simple and well studied, researchers are helpless to correct it and halt its devastating effects.

Now there is hope in the form of new genome-engineering tools, particularly one called CRISPR. This technology could allow researchers to perform microsurgery on genes, precisely and easily changing a DNA sequence at exact locations on a chromosome. Along with a technique called TALENs, invented several years ago, and a slightly older predecessor based on molecules called zinc finger nucleases, CRISPR could make gene therapies more broadly applicable, providing remedies for simple genetic disorders like sickle-cell anemia and eventually even leading to cures for more complex diseases involving multiple genes. Most conventional gene therapies crudely place new genetic material at a random location in the cell and can only add a gene. In contrast, CRISPR and the other new tools also give scientists a precise way to delete and edit specific bits of DNAeven by changing a single base pair. This means they can rewrite the human genome at will.

It is likely to be at least several years before such efforts can be developed into human therapeutics, but a growing number of academic researchers have seen some preliminary success with experiments involving sickle-cell anemia, HIV, and cystic fibrosis (see table below). One is Gang Bao, a bioengineering researcher at the Georgia Institute of Technology, who has already used CRISPR to correct the sickle-cell mutation in human cells grown in a dish. Bao and his team started the work in 2008 using zinc finger nucleases. When TALENs came out, his group switched quickly, says Bao, and then it began using CRISPR when that tool became available. While he has ambitions to eventually work on a variety of diseases, Bao says it makes sense to start with sickle-cell anemia. If we pick a disease to treat using genome editing, we should start with something relatively simple, he says. A disease caused by a single mutation, in a single gene, that involves only a single cell type.

In little more than a year, CRISPR has begun reinventing genetic research.

Bao has an idea of how such a treatment would work. Currently, physicians are able to cure a small percentage of sickle-cell patients by finding a human donor whose bone marrow is an immunological match; surgeons can then replace some of the patients bone marrow stem cells with donated ones. But such donors must be precisely matched with the patient, and even then, immune rejectiona potentially deadly problemis a serious risk. Baos cure would avoid all this. After harvesting blood cell precursors called hematopoietic stem cells from the bone marrow of a sickle-cell patient, scientists would use CRISPR to correct the defective gene. Then the gene-corrected stem cells would be returned to the patient, producing healthy red blood cells to replace the sickle cells. Even if we can replace 50 percent, a patient will feel much better, says Bao. If we replace 70 percent, the patient will be cured.

Though genome editing with CRISPR is just a little over a year old, it is already reinventing genetic research. In particular, it gives scientists the ability to quickly and simultaneously make multiple genetic changes to a cell. Many human illnesses, including heart disease, diabetes, and assorted neurological conditions, are affected by numerous variants in both disease genes and normal genes. Teasing out this complexity with animal models has been a slow and tedious process. For many questions in biology, we want to know how different genes interact, and for this we need to introduce mutations into multiple genes, says Rudolf Jaenisch, a biologist at the Whitehead Institute in Cambridge Massachusetts. But, says Jaenisch, using conventional tools to create a mouse with a single mutation can take up to a year. If a scientist wants an animal with multiple mutations, the genetic changes must be made sequentially, and the timeline for one experiment can extend into years. In contrast, Jaenisch and his colleagues, including MIT researcher Feng Zhang (a 2013 member of our list of 35 innovators under 35), reported last spring that CRISPR had allowed them to create a strain of mice with multiple mutations in three weeks.

Genome GPS

The biotechnology industry was born in 1973, when Herbert Boyer and Stanley Cohen inserted foreign DNA that they had manipulated in the lab into bacteria. Within a few years, Boyer had cofounded Genentech, and the company had begun using E. coli modified with a human gene to manufacture insulin for diabetics. In 1974, Jaenisch, then at the Salk Institute for Biological Studies in San Diego, created the first transgenic mouse by using viruses to spike the animals genome with a bit of DNA from another species. In these and other early examples of genetic engineering, however, researchers were limited to techniques that inserted the foreign DNA into the cell at random. All they could do was hope for the best.

It took more than two decades before molecular biologists became adept at efficiently changing specific genes in animal genomes. Dana Carroll of the University of Utah recognized that zinc finger nucleases, engineered proteins reported by colleagues at Johns Hopkins University in 1996, could be used as a programmable gene-targeting tool. One end of the protein can be designed to recognize a particular DNA sequence; the other end cuts DNA. When a cell then naturally repairs those cuts, it can patch its genome by copying from supplied foreign DNA. While the technology finally enabled scientists to confidently make changes where they want to on a chromosome, its difficult to use. Every modification requires the researcher to engineer a new protein tailored to the targeted sequencea difficult, time-consuming task that, because the proteins are finicky, doesnt always work.

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Genome Surgery

Image Caption: Beating-heart cells derived from iPS cells are shown. A single DNA base-pair of the PRKAG2 gene was edited using the method developed by Drs. Miyaoka and Conklin. Credit: Luke Judge/Gladstone Institutes

Anne D. Holden, PhD Gladstone Institutes

Gladstones innovative technique in stem cells to boost scientists ability to study and potentially cure genetic disease

Sometimes biology is cruel. Sometimes simply a one-letter change in the human genetic code is the difference between health and a deadly disease. But even though doctors and scientists have long studied disorders caused by these tiny changes, replicating them to study in human stem cells has proven challenging. But now, scientists at the Gladstone Institutes have found a way to efficiently edit the human genome one letter at a time not only boosting researchers ability to model human disease, but also paving the way for therapies that cure disease by fixing these so-called bugs in a patients genetic code.

Led by Gladstone Investigator Bruce Conklin, MD, the research team describes in the latest issue of Nature Methods how they have solved one of science and medicines most pressing problems: how to efficiently and accurately capture rare genetic mutations that cause disease as well as how to fix them. This pioneering technique highlights the type of out-of-the-box thinking that is often critical for scientific success.

Advances in human genetics have led to the discovery of hundreds of genetic changes linked to disease, but until now weve lacked an efficient means of studying them, explained Dr. Conklin. To meet this challenge, we must have the capability to engineer the human genome, one letter at a time, with tools that are efficient, robust and accurate. And the method that we outline in our study does just that.

One of the major challenges preventing researchers from efficiently generating and studying these genetic diseases is that they can exist at frequencies as low as 1%, making the task of finding and studying them labor-intensive.

For our method to work, we needed to find a way to efficiently identify a single mutation among hundreds of normal, healthy cells, explained Gladstone Research Scientist Yuichiro Miyaoka, PhD, the papers lead author. So we designed a special fluorescent probe that would distinguish the mutated sequence from the original sequences. We were then able to sort through both sets of sequences and detect mutant cellseven when they made up as little one in every thousand cells. This is a level of sensitivity more than one hundred times greater than traditional methods.

The team then applied these new methods to induced pluripotent stem cells, or iPS cells. These cells, derived from the skin cells of human patients, have the same genetic makeup including any potential disease-causing mutations as the patient. In this case, the research team first used a highly advanced gene-editing technique called TALENs to introduce a specific mutation into the genome. Some gene-editing techniques, while effective at modifying the genetic code, involve the use of genetic markers that then leave a scar on the newly edited genome. These scars can then affect subsequent generations of cells, complicating future analysis. Although TALENs, and other similarly advanced tools, are able to make a clean, scarless single letter edits, these edits are very rare, so that new technique from the Conklin lab is needed.

Our method provides a novel way to capture and amplify specific mutations that are normally exceedingly rare, said Dr. Conklin. Our high-efficiency, high-fidelity method could very well be the basis for the next phase of human genetics research.

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Engineering The Human Genome One Letter At A Time

Sometimes biology is cruel. Sometimes simply a one-letter change in the human genetic code is the difference between health and a deadly disease. But even though doctors and scientists have long studied disorders caused by these tiny changes, replicating them to study in human stem cells has proven challenging. But now, scientists at the Gladstone Institutes have found a way to efficiently edit the human genome one letter at a time -- not only boosting researchers' ability to model human disease, but also paving the way for therapies that cure disease by fixing these so-called 'bugs' in a patient's genetic code.

Led by Gladstone Investigator Bruce Conklin, MD, the research team describes in the latest issue of Nature Methods how they have solved one of science and medicine's most pressing problems: how to efficiently and accurately capture rare genetic mutations that cause disease -- as well as how to fix them. This pioneering technique highlights the type of out-of-the-box thinking that is often critical for scientific success.

"Advances in human genetics have led to the discovery of hundreds of genetic changes linked to disease, but until now we've lacked an efficient means of studying them," explained Dr. Conklin. "To meet this challenge, we must have the capability to engineer the human genome, one letter at a time, with tools that are efficient, robust and accurate. And the method that we outline in our study does just that."

One of the major challenges preventing researchers from efficiently generating and studying these genetic diseases is that they can exist at frequencies as low as 1%, making the task of finding and studying them labor-intensive.

"For our method to work, we needed to find a way to efficiently identify a single mutation among hundreds of normal, healthy cells," explained Gladstone Research Scientist Yuichiro Miyaoka, PhD, the paper's lead author. "So we designed a special fluorescent probe that would distinguish the mutated sequence from the original sequences. We were then able to sort through both sets of sequences and detect mutant cells -- even when they made up as little one in every thousand cells. This is a level of sensitivity more than one hundred times greater than traditional methods."

The team then applied these new methods to induced pluripotent stem cells, or iPS cells. These cells, derived from the skin cells of human patients, have the same genetic makeup -- including any potential disease-causing mutations -- as the patient. In this case, the research team first used a highly advanced gene-editing technique called TALENs to introduce a specific mutation into the genome. Some gene-editing techniques, while effective at modifying the genetic code, involve the use of genetic markers that then leave a 'scar' on the newly edited genome. These scars can then affect subsequent generations of cells, complicating future analysis. Athough TALENs, and other similarly advanced tools, are able to make a clean, scarless single letter edits, these edits are very rare, so that new technique from the Conklin lab is needed.

"Our method provides a novel way to capture and amplify specific mutations that are normally exceedingly rare," said Dr. Conklin. "Our high-efficiency, high-fidelity method could very well be the basis for the next phase of human genetics research."

"Now that powerful gene-editing tools, such as TALENs, are readily available, the next step is to streamline their implementation into stem cell research," said Dirk Hockemeyer, PhD, assistant professor of molecular and cellular biology at the University of California, Berkeley, who was not involved in this study. "This process will be greatly facilitated by the method described by Dr. Conklin and colleagues."

"Some of the most devastating diseases we face are caused by the tiniest of genetic changes," added Dr. Conklin. "But we are hopeful that our technique, by treating the human genome like lines of computer code, could one day be used to reverse these harmful mutations, and essentially repair the damaged code."

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Genome editing goes hi-fi: Innovative stem cell technique

February Edition Teaser - The Incomplete Map of the Cosmic Genome
A look inside the upcoming Feb edition of Cosmic Genome which is a special space edition featuring black holes, parallel universes, stargazing and more. Incl...

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February Edition Teaser - The Incomplete Map of the Cosmic Genome - Video