Category Archives: DNA

Scientists at the University of Manchester have developed a new type of self-replicating computer that uses DNA to make calculations, a breakthrough that could make computing far more efficient.

Computing with DNA was first proposed in 1994 as a way to solve problems faster than with normal computers. DNA has a number of advantages over silicon that makes it ideal for problem solving, namely that it's extremely small and highly stable.

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But the biggest advantage of DNA is that it can copy itself. In computing terms, this means that a DNA computer can run an arbitrary number of calculations at the same time, which is very important for solving complex problems. While a typical computer might have to do a billion calculations one after another, a DNA computer can just make a billion copies of itself and do all the calculations at once.

In fact, that's just what the University of Manchester researchers did with their DNA computer. Theirs is the first physical demonstration of this concept, and they hope that a DNA computer could be used to solve complex problems faster than current computers, or even the quantum computers of the future.

Source: University of Manchester

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Scientists Build New Computer Made of DNA - Popular Mechanics

Alaska Dispatch News

DNA leads to Anchorage cabbie's conviction in 2014 sexual assault Alaska Dispatch News Assistant District Attorney Gustaf Olson, who prosecuted the case, said Wednesday the victim, who immediately reported the attack, was assessed by a sexual assault specialist. DNA samples taken during the investigation were submitted to the state ...

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DNA leads to Anchorage cabbie's conviction in 2014 sexual assault - Alaska Dispatch News

Jeffrey Denny(Photo: Wisconsin Department of Correcti)

The Wisconsin Supreme Court has reversed a Court of Appeals decision that would have allowed DNA testing of evidence from a 1982 Ozaukee County homicide case, and set aside its own prior precedent in the process.

The decision concluded that Jeffrey Denny, who is represented by the Innocence Project, did not meet the statutory threshold for testing old evidence with new science, even at his own expense, and in the process overruled a unanimous 2005 decision interpreting the statute on post-conviction DNA testing.

The ruling Tuesday was 4-3 to deny the testing, but 5-2 to overrule the court's prior case, Wisconsin v. Moran. In all, the court put out 88 pages of the majority, concurring and dissenting opinions.

In a strong dissent, Justice Ann Walsh Bradley concluded, "Making several missteps along the way, the majority limits the contours of this search (for truth)," and legislates from the bench.

Denny and his brother Kent were convicted of killing Christopher Mohr in Grafton. Another man reported to police that he had shown up at Mohr's house and found him dead, and assumed it was suicide. But an autopsy showed Mohr had been beaten with a bong and stabbed repeatedly. Several people later testified that Kent and Jeffrey Denny admitted to killing Mohr, and about hiding blood-stained clothes from the crime.

Supreme Court Justice Ann Walsh Bradley(Photo: Milwaukee Journal Sentinel)

The brothers were sentenced to life in prison. Kent Denny died in 2012.

After other appeals failed, JeffreyDenny in 2014 sought to have numerous items from the crime scene tested for DNA that he suggested might match other people alreadyin the state or federaldatabase, or exclude him, and tend to prove he was innocent.

In 2015, Ozaukee County Circuit Judge Joseph Voiland denied the request and in 2016, the Court of Appeals reversed Voiland and ordered the forensic DNA testing.

But the high court majority rejected Denny's contention that he may not have been prosecuted or convicted if the DNA testing had been available. The court overruledits own precedent that would have held that Denny would be entitled to the testing if he paid for it himself.

Otherwise, the court now says, it would allow "post-convictionfishing expeditions in attempts to cast doubt uponand upset" convictions.

And in Denny's case, the majority found, there was too much evidence to overcome, even ifDNA testing revealed none of his was on the evidenceand even if other known offenders' DNA was found on the evidence.

"The ideathat the DNA results Denny seeks would tip the scales and causepolice or a jury to reject the substantial evidence againstDennyis simply conjecture,"Justice Annette Ziegler wrote for the majority.

Chief Justice Patience Roggensack wrote separately, concurring that the 2005 case, Moran, should be overruled, but dissenting to say she would allow Denny to test the evidence.

Supreme Court Justice Annette Ziegler.(Photo: Associated Press)

In her dissent, Bradley condemned the majority for legislating from thebench. "Throwing caution (as well as any semblance of judicial restraint) to the wind, the majority steps in to perform the Legislature's job," she wrote.

She noted that even though the 2005 Moran decision clearly invited the Legislature to address issues raised then, it did not, and the law on post-conviction DNA testing has been perfectly functional since then.

"Only the makeup of this court has changed," she wrote.

Thequestion is not whether there is strong evidenceof guilt. Rather, the question is whether the Legislature haswritten a statute that gives Denny the opportunity to testevidence that has the potential toexonerate him."

Justice Shirley Abrahamson joined Bradley's dissent, and wrote a separate dissent regarding the appellate procedures that landed the case before the court.

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Supreme Court denies DNA testing in 1982 Ozaukee murder case - Milwaukee Journal Sentinel

Morgan Reynolds and Jennisara Sumiri are looking forward to a future together after a DNA test matched them together.

CBS San Francisco

REDWOOD CITY, Calif. -- Bound by blood but separated by fate, two sisters met in the Bay Area on Tuesday for the first time after a lifetime apart.

The two sisters never knew each other. But each had an emptiness in their hearts they said that only the other could fill.

Since I was 10, I knew that I had a sibling, Morgan Reynolds told CBS San Francisco. But I also knew that I would never ever see her.

That was then. But no more, thanks to a DNA test -- through MyHeritage DNA -- that changed the lives of Reynolds and her sister Jennisara Sumiri.

Now, more than six decades later, they were united for the first time.

The moment I heard her voice on the phone, something clicked inside of me and I started crying, said Sumiri.

They share the same father -- Ray Edward Reynolds -- a gas station owner from Washington state.

He was married to Morgans mother but had an affair that produced Jennisara before Morgan was born.

This is what he looked like when he met your mother, said Reynolds, showing a photo of their father as a young man.

I so dont blame her! laughed Sumiri.

Jennisaras birth mom put her up for adoption and Ray Reynolds eventually left Morgan and her mom.

The sisters lived separate lives until last month when Jennisaras son bought a MyHeritage DNA kit.

He said mom, I think I may have found your sister. I said, What? No...WHAT? exclaimed Sumiri.

It matched up with Reynolds, who had also joined the registry, as a possible relative.

Her son Ted found...he found us, said Reynolds. After seeing he was my nephew, it just made sense that my fathers daughter was here.

I found a sister when I least expected to, said Sumiri.

Its been a rush of emotions. And things now certain make sense, like Jennisaras special talent.

He sang, said Reynolds.

And I sing and I always wondered where that connection was, said Sumiri.

Their father and mothers have passed away, but now the sisters are looking forward to the future together.

And for the first time, this year they cant wait to celebrate each others birthdays.

One other twist to the story: Sumiri was originally named Jennifer-Raye as a hint to her natural fathers name. But that name was later changed to Jennisara by her adoptive parents.

2017 CBS Interactive Inc. All Rights Reserved.

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Siblings meet for first time in 6 decades thanks to DNA test - CBS News

Worcester County District Attorney Joseph Early speaks to the public at a press conference.

PRINCETON Its been nearly seven months since Vanessa Marcotte left her mothers Princeton home for an afternoon jog and never returned. More than half a year since her body was found in the woods off Brooks Station Road, her murder remains unsolved.

Investigators are still searching for her killer, but in the months that have passed that search has gotten narrower, and last week, Worcester County District Attorney Joseph Early announced that that hunt has gotten a step closer. They do not know the name of the man who killed Vanessa, but they do know another key to his identity: they have his DNA.

In a press conference outside of the Princeton Town Hall Annex, a tiny parking lot usually filled with municipal employee cars, Early stood before reporters and television news cameras last Thursday to announce a new development in the case that the mans DNA, combined with with information from more than 1,300 tips that have poured in since August, have led to some key clues as to who Vanessas murderer is.

Early said that they have narrowed their search and are looking for a Hispanic or Latino male with light to medium complexion, of average height and with an athletic build. At the time of the murder, he had a shaved head or very short hair. He is approximately 30 years old and would have sustained scratches around the face, neck, arms, hands and upper body on Aug. 7 and dates forward of that, Early said.

Sifting through more than 1,000 tips and a very precise science yielded the new description of the person of interest in the case the first major development thats been announced since police said they were looking for a dark SUV in connection with the murder last November. Along with testing at Massachusetts State Police labs, the DNAwas sent for more detailed testing at Parabon NanoLabs, a small Virginia-based company whose DNA engineers are performing groundbreaking work.

Staffed by a team of scientists and technologists, Parabon is leveraging the enormous power of DNA with recent advances in DNA sequencing, processing and manufacturing technologies. They offer a forensic DNA analysis service that predicts the physical appearance and ancestry of an unknown person from DNA, used by law enforcement across the country for generating investigative leads, narrowing suspect lists, and identifying unknown remains.

DNA carries the genetic instruction set for an individuals physical characteristics, producing the wide range of appearances among people, according to their description of DNA phenotyping. By determining how genetic information translates into physical appearance, it is possible to reverse-engineer DNA into a physical profile. Snapshot reads tens of thousands of genetic variants (genotypes) from a DNA sample and uses this information to predict what an unknown person looks like.

Were very confident in our description that weve given you today that this is our person of interest, Early said at last weeks press conference. Since it is an active investigation, Early said he was limited in the questions he could take, but emphasized the coming up with the physical description is a very significant development in the case.

Indeed, similar clues have been a turning point in other unsolved cases. Just last week, police investigating a 20-year-old cold-case rape and killing in Costa Mesa, California, used DNA phenotyping to pinpoint the identity of a suspect.

Early would not say if Marcotte was specifically targeted, nor exactly where the DNA was collected. He said police officials have been able to rule out a connection to the murder of a female jogger in Queens around the same time.

We are asking the publics help in locating this particular person of interest, Early said, but cautioned that the man should

not be confronted. Im here today to urge the public to please, if you think you have something, give a call on the tipline.

Vanessa Marcottes naked and partially burned body was found in the woods not far from her home on Brooks Station Road. She worked for Google and lived in New York City, but was home that weekend visiting her family. Marcotte, 27, went out for a jog several hours before she was due to catch a bus to New York. When she did not return, a search was undertaken. Early thanked police chief Michele Powers, MSP detective lieutenant Dennis Hunt, Colonel Richard McKeon and Secretary of Public Safety Dan Bennett for their efforts, assistance and resources in this investigation.

State police detectives, Mass. State Police and Princeton Police are continuing to follow every tip and every lead they get in this case, Early said.

After the news conference, Vanessa Marcottes uncle, Steve Therrien, released the following statement: The family of Vanessa Marcotte wishes to thank the District Attorney, his staff, the detectives of the Mass State Police assigned to the case, and the Princeton Police Department for their relentless efforts and the tremendous support that they have shown us throughout this ordeal.

The family thinks that this development of a profile of a person of interest will be very helpful in getting the public to rethink and re-examine the events of Aug. 7, 2016 and help identify an individual who might have been on Brooks Station Rd on that day and subsequently had scratches and cuts that were clearly visible on his person. No tip is too small to call in.

Vanessa went for a walk on the lovely afternoon of Aug. 7, 2016. She did nothing wrong. She deserves justice.

Anyone knowing a man fitting the description is asked to call the MSP tipline at 508-453-7589. The tipline is anonymous.

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DNA yields new clues in Marcotte murder case - The Landmark

In 1953, we found the double-helix shape of DNA, the building block of all life as we know it. In 2003, humans finally sequenced our own DNA, which was a huge milestone in understanding ourselves. But today, with a few clicks, we can order a DNA testing kit to see what these blocks build for each of us.

A, T, C, and G are the base compounds of DNA, and they come in pairs. There are about three billion pairs in each DNA strand. So many, that we can only sample a few. Scientists do research all the time to identify specific groups of these pairs called genes. Genes can cause blue eyes, thick earwax, or even tell where you're really from.

As scientists get more and more DNA samples they'll be able to compare more and more people to find these genetic components that make up our lives by comparing all these different genomes. When you get tested, you can elect to add your DNA to the world-wide database of humanity.

To learn more about how DNA testing really works, check out the video above.

Read More:

BBC:How does DNA testing work?

U.S. National Library of Medicine:How is genetic testing done?

Nature:The family history: the first genetic test, and still useful after all those years?

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We Got Our DNA Tested, Here's How It Actually Works - Seeker

Last August, scientists injected a potential vaccine for Zika virus into a human being just 3 months after they had decided exactly what molecular recipe to use.

In the world of vaccine development, 3 months from design to injection is warp speed, says vaccine researcher Nelson Michael of the Walter Reed Army Institute of Research in Silver Spring, Md. Clinical trials can take years and epidemics can burn out before vaccines make it to doctors shelves. Even vaccine creation is typically sluggish.

But in this case, the vaccine is a bit of DNA, which means scientists can get moving fast. Unlike some traditional methods, DNA vaccines dont use dead or weakened viruses. Instead, they rely on a snippet of genetic material. This naked DNA carries, for example, the blueprints for Zika proteins. Its just a long sequence of DNA blocks.

With DNA vaccines, its easy to move very quickly, says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in Bethesda, Md. All you need to do is get the right sequence, and Bingo! youre there.

Historically, though, DNA vaccines have been deviled with drawbacks. They work absolutely fantastically in mice, says infectious diseases physician Anna Durbin of Johns Hopkins Bloomberg School of Public Health. But they fail miserably when we use them in humans.

Researchers at the infectious diseases institute will soon begin the second phase of human clinical trials for a DNA vaccine candidate for Zika, vaccine clinical researcher Julie Ledgerwood said February 6 in Washington, D.C., at an American Society for Microbiology meeting on biothreats. The virus made headlines last year as it continued its tear through the Americas, and scientists confirmed its link to birth defects, including microcephaly (SN: 12/24/16, p. 19). Ledgerwood hopes to see efficacy data on the vaccine by the end of 2018.

Ultimately, we want a vaccine that can prevent congenital Zika infection, she said. We think the DNA vaccine platform is an opportunity to do things safely and very quickly.

Government researchers arent betting everything on DNA, though, Fauci points out. Weve got multiple shots on goal here, he says. A slew of other vaccine candidates, based on both traditional and new techniques, are also in the works. But the DNA vaccine has stepped up to the plate first, and the world will soon see if it can deliver.

If it works, Durbin says, weve hit a home run.

Making a DNA vaccine is simple, in principle. Scientists synthesize genes from a pathogen, insert them into a circular strand of DNA called a plasmid, make lots of copies and then inject the purified plasmid into a person. You can literally build a DNA vaccine in weeks, says Dan Barouch, an immunologist at Beth Israel Deaconess Medical Center and Harvard Medical School. The approach is flexible, too, he adds. Researchers can tinker with the DNA building blocks in the plasmid, adding bits from other viruses that might ultimately enhance the immune response.

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For a DNA vaccine against Zika, scientists insert genes for Zika proteins into a circular piece of DNA called a plasmid. Many copies of the plasmid are injected into muscle. Some of the DNA travels into cells nuclei, where it is used to make messenger RNA. After exiting the nucleus, mRNA helps build Zika proteins, which can form viruslike particles that trigger the immune system to make antibodies.

Barouchs team was the first to report a Zika DNA vaccine that offered protection in mice in a study published last June in Nature. Five weeks later, he and colleagues reported in Science that the vaccine, and two others created via different strategies, worked well in monkeys, too. And in September, a team led by government scientists, and including Barouch as a coauthor, came out with two additional DNA vaccine candidates, described in Science.

Its one of those additional candidates, called VRC 5283, that the infectious diseases institute plans to test in a Phase II trial. The trial will help researchers figure out the precise dose and number of injections to use. VRC 5283 includes the blueprints for making two Zika virus proteins, as well as DNA from Japanese encephalitis virus.

When the vaccine is injected into the body, a small amount of DNA makes its way into cells and on into the cell nucleus. There, molecular machinery reads the DNA and writes a message in RNA. When the message leaves the nucleus, it serves as a how-to guide for making Zika proteins. The proteins assemble into viruslike particles that trigger alarm bells in cells, which marshal their defenses. Cells then know the face of the enemy and are ready to fight if Zika invades.

At least, thats the idea. DNA vaccines are hardly a new concept, Barouch says. People have been calling them the vaccines of the future for decades. But they havent yet lived up to the hype.

Scientists have created DNA vaccines for dozens of pathogens, but so far, not one has been licensed for use in humans. One problem is that scientists need massive doses of DNA to provoke an immune response a few milligrams or so. That is a god-awful amount of plasmid DNA, Michael says. Its so much DNA that the liquid of each dose is viscous, he says. Its like syrup.

Naked DNA doesnt readily travel into the nucleus, so scientists dump a lot in the bloodstream to ensure that some winds up inside. The Phase II trial of VRC 5283 will test both four and eight milligrams of DNA, and people will receive three immunizations, each spaced weeks apart, Ledgerwood said. The best dosing regimen then will be used in the second part of the trial a test to see how VRC 5283 performs in thousands of participants in regions likely to see Zika outbreaks.

But even if the vaccine eventually ends up in clinics, ensuring that patients come back for multiple doses wont be easy, says University of Pennsylvania immunologist Drew Weissman. Giving people one shot is hard enough, he says. Giving them two more immunizations is an absolute nightmare.

Weissman and colleagues at the infectious diseases institute and elsewhere are working on a different kind of vaccine that could make multiple doses moot. Like the DNA vaccine for Zika, Weissmans uses genetic material. But instead of DNA, his vaccine relies on modified versions of messenger RNA that how-to guide for making proteins.

Unlike DNA vaccines, those made of messenger RNA dont have to stop in the nucleus first. That makes these vaccines more efficient, Fauci says. The modified Zika RNA vaccine was enough to protect monkeys from the virus five weeks after vaccination, Weissman and colleagues reported online February 2 in Nature. The dose was just 50 micrograms roughly a hundredth as much as a single dose of the DNA vaccine.

On February 17, a different team of researchers reported online in Cell even more RNA vaccines for Zika. The vaccines protected mice from the virus, and some even reduced the severity of a subsequent dengue infection.

Scientists still need to test RNA vaccines in humans to gauge how they stack up against other candidates, Michael says. But the bottom line is this: If a single shot works and lasts a long time, that would be a game changer.

One of the RNA vaccines reported in Cell began a clinical trial in December, but trials for Weissmans vaccine are still 12 to 18 months away. In the meantime, other vaccines are charging forward. The biotech company Inovio Pharmaceuticals, for example, has begun human trials with yet another DNA vaccine for Zika. (It comes with a little zap of electricity, which blasts tiny holes in cell membranes to help DNA slip in, researchers reported November 10 in NPJ Vaccines.)

And Michaels team at Walter Reed has partnered with Sanofi Pasteur on a more traditional approach. Researchers grow vats of virus, kill it, purify it and then use the killed virus in the vaccine. Its the same way Jonas Salk tackled polio in the 1950s. These inactivated virus vaccines are generally very safe, Nelson says, because the virus is as dead as a doornail. Nelson expects data from three Phase I clinical trials for the vaccine, called ZPIV, in early April.

But for a vaccine with both durability and efficacy, Fauci says, the gold standard is a live-attenuated vaccine. Such vaccines, like the one for measles, mumps and rubella, use weakened rather than killed viruses to rile up the immune system.

Its the broadest, best type of protection lifelong, we think, says Durbin, who is part of a team developing a live-attenuated vaccine for Zika. The downside is that scientists have to make sure that the weakened vaccine is harmless. Even then, Durbin says, we would never consider giving a live-attenuated vaccine to a pregnant woman.

When exactly scientists have a working Zika vaccine ready for use is totally dependent on the outbreak situation in South America and Puerto Rico, Fauci says. If new infections dont crop up over the coming spring and summer, scientists may have to wait years to collect the efficacy data needed for vaccine approval.

But the race to make a Zika vaccine probably wont come down to just one winner, he says. Having several kinds of vaccines in play would give public health officials flexibility: more weapons to fight the virus and an opportunity to tailor the response to different populations.

In fact, the fevered quest for a Zika vaccine isnt really a race at all, Barouch says. Were all working together.

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DNA may offer rapid road to Zika vaccine | Science News - Science News

February 28, 2017 Male billy goat from a feral herd in Mulranny, Co. Mayo, Ireland. Credit: John Joyce

Intensive selective breeding over the past 200 years and high extinction rates among feral populations has greatly reduced the genetic diversity present in domestic goat breeds. The effect these pressures have had on Irish and British goat populations has been explored in a landmark DNA study that compared modern-day domestic and feral goats with museum specimens from years gone by.

A collaborative team led by geneticists from Trinity College Dublin compared the mitochondrial DNA (mtDNA) of 15 historical taxidermy specimens from Britain and Ireland and nine modern samples taken from Irish dairy and feral populations.

The team has just published their results in the Royal Society journal Biology Letters. Their work provides the first example in which DNA from taxidermy specimens is used to answer questions about livestock genetics.

Lara Cassidy, a researcher from Trinity's School of Genetics and Microbiology, is the first author of the journal article. She said: "There is an amazing wealth of genetic information locked away in taxidermic collections of animals that were - and still are - important for agricultural reasons. As such these collections are invaluable in helping us study the population history of these domesticated animals."

"Studying these specimens and comparing them with modern-day animals also helps to pinpoint existing populations that have retained some of the past genetic diversity, much of which has been lost to industrialized breeding. Retaining this diversity as an option for future breeding is very important, but some of these populations are being pushed to extinction."

The geneticists' study highlights an endangered feral herd living in Mulranny, Co. Mayo, as one such unique population in need of protection. Mulranny goats show a genetic similarity to extinct 'Old Goat' populations that lived on the Isle of Skye in the 1800s. They can therefore be considered among the last remaining 'Old Irish' goats.

The 'Old Goat' populations of Britain and Ireland were once ubiquitous throughout the islands but today have been replaced in agriculture by improved Swiss breeds. The native 'Old Goats' are now only found in small feral herds, whose existence is under constant threat from habitat loss, culling and the ongoing impact of Swiss introgression.

The geneticists sampled a number of different 'Old Goat' herds among the 15 taxidermy specimens. The results showed these goats formed two genetic groupings, distinct from other European breeds. Importantly, all of the modern-day Irish dairy goats fell into a genetic groupings outside these two.

Dr Valeria Mattiangeli, one of the study's lead researchers, said: "This highlights the impact that transportation and mass importation of continental breeds has had on Ireland's goat populations, and underlines how selective breeding for agricultural purposes can impact the genetic diversity of animals."

Sen Carolan of the Old Irish Goat Society, who is a co-author of the journal article, said: "We hope this study will play a key role in saving what was and still is a diminutive creature that is both resilient and charismatic and that represents our cultural and pastoral history."

Explore further: Experiment shows goats capable of recognizing other goats by sight and sound

More information: Capturing goats: Documenting two hundred years of mitochondrial DNA diversity among goat populations from Britain and Ireland, Biology Letters, rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2016.0876

(Phys.org)A small team of researchers with Queen Mary University of London has found that goats are able to recognize their stable mates by both sight and sound. In their paper published in the journal Royal Society Open ...

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Geneticists and anthropologists previously suspected that ancient Africans domesticated cattle native to the African continent nearly 10,000 years ago. Now, a team of University of Missouri researchers has completed the genetic ...

The ancestry of domesticated cattle proves more complex than previously thought, reports a paper published today in the open access journal Genome Biology. The first nuclear genome sequence from an ancient wild ox reveals ...

Intensive selective breeding over the past 200 years and high extinction rates among feral populations has greatly reduced the genetic diversity present in domestic goat breeds. The effect these pressures have had on Irish ...

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A University of Florida study shows that mollusk fossils provide a reliable measure of human-driven changes in marine ecosystems and shifts in ocean biodiversity across time and space.

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The Zika virus taking hold of the inner organelles of human liver and neural stem cells has been captured via light and electron microscopy. In Cell Reports on February 28, researchers in Germany show how the African and ...

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DNA from taxidermy specimens explains genetic structure of British and Irish goats - Phys.Org

James Raynor, who is serving 37 years in prison for shooting a man and participating in the gang-related murder of another, is now in the cross hairs of cold case investigators working on another Hartford homicide.

Detectives obtained a search warrant to get a sample of Raynor's DNA for their case.

Raynor, 33, was in court Tuesday because he objected to providing a DNA sample.

His lawyer, J. Patten Brown III, told Hartford Superior Court Judge Julia D. Dewey that his client's position was the state had obtained a DNA sample from him in 2014 and that he feared investigators will get his DNA and put it on the evidence they have.

"He thinks they want to smear his DNA on evidence to frame him," Brown said.

Dewey told Brown and Raynor that the search warrant is a lawful court order to Raynor to provide the DNA. She held him in contempt of court for refusing to provide it, and told him that detectives were authorized to use force to obtain the sample.

In Connecticut, investigators may legally use reasonable force to obtain DNA samples from inmates. The law was upheld by the state Supreme Court in 2016.

Detectives did obtain a sample before Raynor left the courthouse on Tuesday.

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Man Serving 37 Years For Shooting, Homicide Balks At Providing DNA For Another Homicide Case - Hartford Courant

DNAs ability to act like an electrical wire plays a part in how it replicates,new research shows.

In the early 1990s, Jacqueline Barton, professor of chemistry at Caltech, discovered an unexpected property of DNAthat it can act like an electrical wire to transfer electrons quickly across long distances. Later, she and colleagues showed that cells take advantage of this trait to help locate and repair potentially harmful mutations to DNA.

Now, Bartons lab has shown that this wire-like property of DNA is also involved in a different critical cellular function. When cells divide and replicate themselves in our bodiesfor example in the brain, heart, bone marrow, and fingernailsthe double-stranded helix of DNA is copied. DNA also copies itself in reproductive cells that are passed on to progeny.

The new study, based on work by graduate student Elizabeth OBrien in collaboration with Walter Chazins group at Vanderbilt University, offers evidencethat a key protein required for replicating DNA depends on electrons traveling through DNA.

Nature is the best chemist and knows exactly how to take advantage of DNA electron-transport chemistry, says Barton.

The electron transfer process in DNA occurs very quickly, says OBrien, lead author of the study in Science. It makes sense that the cell would utilize this quick-acting pathway to regulate DNA replication, which necessarily is a very rapid process.

The researchers found their first clue that DNA replication might involve the transport of electrons through the double helix by taking a closer look at the proteins involved. Two of the main players in DNA replication, critical at the start of the process, are the proteins DNA primase and DNA polymerase alpha. DNA primase typically binds to single-stranded, uncoiled DNA to begin the replication process. It creates a primer made of RNA to help DNA polymerase alpha start its job of copying the single strand of DNA to create a new segment of double-helical DNA.

DNA primase and DNA polymerase alpha molecules both contain iron-sulfur clusters. Barton and her colleagues previously discovered that these metal clusters are crucial for DNA electron transport in DNA repair. In DNA repair, specific proteins send electrons down the double helix to other DNA-bound repair proteins as a way to test the line, so to speak, and make sure there are no mutations in the DNA. If there are mutations, the line is essentially broken, alerting the cell that mutations are in need of repair. The iron-sulfur clusters in the DNA repair proteins are responsible for donating and accepting traveling electrons.

Barton and her group wanted to know if the iron-sulfur clusters were doing something similar in the DNA-replication proteins.

We knew the iron-sulfur clusters must be doing something in the DNA-replication proteins, otherwise why would they be there? Iron can damage the DNA, so nature would not have wanted the iron there were it not for a good reason, says Barton.

Through a series of tests in which mutations were introduced into the DNA primase protein, the researchers showed that this protein needs to be in an oxidized statewhich means it has lost electronsto bind tightly to DNA and participate in DNA electron transport. When the protein is reducedmeaning it has gained electronsit does not bind tightly to DNA.

The electronic state of the iron-sulfur cluster in DNA primase acts like an on/off switch to initiate DNA replication, says OBrien.

Whats more, the researchers demonstrated that electron transport through DNA plays a role in signaling DNA primase to leave the DNA strand. (Though DNA primase must bind to single-stranded DNA to kick off replication, the process cannot begin in earnest until the protein pops back off the strand).

The scientists propose that the DNA polymerase alpha protein, which sits on the double helix strand, sends electrons down the strand to DNA primase. DNA primase accepts the electrons, becomes reduced, and lets go of the DNA. This donation and acceptance of electrons is done with the help of the iron-sulfur clusters.

You have to get the DNA primase off the DNA quicklythat really starts the whole replication process, says Barton. Its a hand off of electrons from one cluster to the other through the DNA double helix.

Many proteins involved in DNA reactions also contain iron-sulfur clusters and may also play roles in DNA electron transport chemistry, Barton says. What began as a fundamental question 25 years ago about whether DNA could support migration of electrons continues to lead to new questions about the chemical workings of cells. Thats the wonder of basic research, she says. You start with one question and the answer leads you to new questions and new areas.

Funding for the work came from the National Institutes of Health.

Source: Caltech

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DNA acts like electrical wire to replicate itself - Futurity: Research News