Category Archives: DNA

Michael Harper for redOrbit.com Your Universe Online

Despite its status as a best selling novel and blockbuster hit, it turns out Jurassic Park was based on a fundamentally flawed premisebad news for dinoDNA researchers.

After drilling through some old bird bones, palaeogeneticists in Copenhagen and Australia have discovered DNA can hardly survive 1,000 years, let alone make it through the millions of years that separate us from our reptilian overlords.

Led by Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, a group of palaeogeneticists studied many bones from a Moa bird fossil to understand just how feasible it is to clone a Raptor these days.

Weve been permanently plagued by this Jurassic Park myth thats been kicking around since the early nineties, Bunce told the Sydney Morning Herald, reports the Telegraph. The myth is still out there. Even other scientists ask whether it is possible.

Each of the 158 Moa bones were gathered relatively close to one another in New Zealand, (about 3 miles or so apart) were preserved in near identical environments, and are estimated by the team to be anywhere between 600 and 8,000 years old.

After drilling into the core of these bones and examining them, the researchers estimated that DNA actually has a half-life of about 521 years. This means that after an estimated span of 521 years, half of the nucleotides in the samples backbone break. In another 521 years, half of the remaining nucleotides also break, and so on.

Even though half of the nucleotides are destroyed after just 521 years, the research team suggests that, under the best conditions, every strand in that DNA would be destroyed after, at most, 6.8 million years. Further crushing Crichton fans, these researchers also suggest that while this DNA could technically exist for upwards of 6 million years, it becomes mostly useless after only 1.5 million years. After the first millennia (1,000 years), the strands of DNA become far too short to read.

There are many variables to be considered, of course. As soon as a creature, say, a terrifying pterodactyl, passes on, everything in its body begins to die and decay. As cells die, enzymes begin to eat away at the nucleotide backbone of DNA as other micro-organisms speed the process along. Once only bone is left, groundwater becomes the worst enemy of any existing DNA, and though it can be a stubborn contender, DNA, just like the walls of the Grand Canyon, will eventually lose its fight with water. The speed at which groundwater destroys this DNA depends on variables such as temperatures, microbial attacks and oxygen, according to the team of palaeogeneticists.

Therefore, even under the best conditions, Dino DNA simply hasnt been able to stand the test of time.

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DNA Discrepancy: Bad News For Jurassic Genetics

They're called discreet DNA samples, and the Elk Grove, California, genetic-testing company easyDNA says it can handle many kinds, from toothpicks to tampons.

Blood stains from bandages and tampons? Ship them in a paper envelope for paternity, ancestry or health testing. EasyDNA also welcomes cigarette butts (two to four), dental floss ("do not touch the floss with your fingers"), razor clippings, gum, toothpicks, licked stamps and used tissues if the more standard cheek swab or tube of saliva isn't obtainable.

If the availability of such services seems like an invitation to mischief or worse - imagine a discarded tissue from a prospective employee being tested to determine whether she's at risk for an expensive disease, for instance - the Presidential Commission for the Study of Bioethical Issues agrees.

On Thursday it released a report on privacy concerns triggered by the advent of whole genome sequencing, determining someone's complete DNA make-up. Although sequencing "holds enormous promise for human health and medicine," commission chairwoman Amy Gutmann told reporters on Wednesday, there is a "potential for misuse of this very personal data."

"In many states someone can pick up your discarded coffee cup and send it for (DNA) testing," said Gutmann, who is the president of the University of Pennsylvania.

"It's not a fantasy to think about how, without baseline privacy protection, people could use this in a way that would be really detrimental," such as by denying someone with a gene that raises their risk of Alzheimer's disease long-term care insurance, or to jack up life insurance premiums for someone with an elevated genetic risk of a deadly cancer that strikes people in middle age.

"Those who are willing to share some of the most intimate information about themselves for the sake of medical progress should be assured appropriate confidentiality, for example, about any discovered genetic variations that link to increased likelihood of certain diseases, such as Alzheimer's, diabetes, heart disease and schizophrenia," Gutmann said.

The commission took on the issue because whole genome sequencing is poised to become part of mainstream medical care, especially by personalizing medical treatments based on a patient's DNA.

$1,000 genome

That has been driven in large part by dramatic cost reductions, from $2.5 billion per genome in the Human Genome Project of the 1990s and early 2000s to $1,000 soon. Several companies, including Illumina Inc. and Life Technology's Ion Torrent division, sell machines that can sequence a genome for a few hundred dollars, but that does not include the analysis to figure out what the string of 3 billion DNA "letters" means.

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US panel urges end to secret DNA testing over privacy concerns

In "Jurassic Park," scientists extract 80-million-year-old dino DNA from the bellies of mosquitoes trapped in amber. Researchers may never be able to extract genetic material that old and bring a T. rex back to life, but a new study suggests DNA can survive in fossils longer than previously believed.

The oldest DNA samples ever recovered are from insects and plants in ice cores in Greenland up to 800,000 years old. But researchers had not been able to determine the oldest possible DNA they could get from the fossil record because DNA's rate of decay had remained a mystery.

Now scientists in Australia report they've been able to estimate this rate based on a comparison of DNA from 158 fossilized leg bones from three species of the moa, an extinct group of flightless birds that once lived in New Zealand. The bones date between 600 and 8,000 years old and importantly all come from the same region.

Science news from NBCNews.com

Science editor Alan Boyle's blog: Next year, the committee behind the Nobel Prize for physics could have a huge Higgs hassle on its hands. And maybe that's a good thing.

Temperatures, oxygenation and other environmental factors make it difficult to detect a basic rate of degradation, researcher Mike Bunce, from Murdoch University's Ancient DNA lab in Perth, explained in a statement.

"The moa bones however have allowed us to study the comparative DNA degradation because they come from different ages from a region where they have all experienced the same environmental conditions," Bunce said.

Based on this study, Bunce and his team put DNA's half-life at 521 years, meaning half of the DNA bonds would be broken down 521 years after death, and half of the remaining bonds would be decayed another 521 years after that, and so on. This rate is 400 times slower than simulation experiments predicted, the researchers said, and it would mean that under ideal conditions, all the DNA bonds would be completely destroyed in bone after about 6.8 million years.

"If the decay rate is accurate then we predict that DNA fragments of sufficient length will preserve in frozen fossil bone of around one million years in age," Bunce said.

But he cautioned that more research is needed to examine the other variables in the breakdown of DNA.

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How long can DNA last? A million years

A man was arrested Wednesday after he was linked through DNA to the sexual assault of an 8-year-old Santa Ana girl in her bunk bed, police said. The assailant climbed in through an unlocked window of her home.

Damien Anthony Reyes was arrested at his home in the 1300 block of North King Street after detectives were told there was a positive match on the DNA left at the scene of the June attack.

Reyes was booked at the Santa Ana Jail on suspicion of burglary, child molestation by force with enhancements that could lead to a potential life sentence upon conviction. He is being held in lieu of $1 million bail.

Authorities did not say how Reyes' DNA got into the state or federal DNA database. In most cases an arrest or conviction leads to a DNA sample being taken.

The noise woke up the girl's 13-year-old sister, who was asleep on the bottom bed, police said. Both girls screamed and woke up their father, who ran to their aid.

Detectives said the man immediately fled the house through the same window and was last seen running south.

Man found with body bags, smoke grenade at LAX investigated

Hazing probe launched after Fresno State fraternity pledge dies

-- Richard Winton

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DNA leads to arrest in sexual assault of Santa Ana girl

Researchers in New Zealand found that DNA decays far quicker than previously considered, making it impossible to salvage usable genetic material from dinosaurs.

Don't worry, we won't have to worry about this scenario in the future.

Countless childhood dreams dissolved today upon the news that the calculated half-life of DNA figures out to around 521 years, all but invalidating the chances of a real-life "Jurassic Park."

The DNA fact-finding project involved a team of palaeogeneticists testing 158 leg bones belonging to three species of extinct giant moa birds ranging from 600 to 8,000 years old.

After running a series of comparisons between the age of the various bones and DNA degradation within each specimen, the researchers estimated that DNA's half-life works out to about 521 years after being kept in a swamp with an average temperature of 13.1 Celsius (55 Fahrenheit). Even a more ideal preservation temperature of minus 5 Celsius (23 Fahrenheit) would only result in readable DNA from specimens up to 1.5 million years old, meaning there is no possible way we can see a 65-million-year-old T-Rex waving its tiny arms about in this time frame.

DNA breaks down for a variety of reasons, including degradation from external influences such as temperature, water, soil chemistry, and so on. After half a millennium, the researchers assume that DNA continues to degrade as the nucleotide bonds within break in half. Each 521-year segment serves as another chapter of nucleotide structure breakdown and carries on until the bonds no longer exist. However, science has yet to determine the breakdown speed of DNA in environments that are more supportive of preservation, such as permafrost.

Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, worked with a large team on the findings, which were published today in the Proceedings of the Royal Society B science journal.

(Via Nature)

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DNA decay rate makes 'Jurassic Park' impossible

10 October 2012 Last updated at 12:37 ET

DNA representing a one-in-a-billion match to that of a retired teacher and the man accused of her murder was found on her hand, a court has heard.

A "full DNA profile" of Stephen Farrow, 48, was found on a swab taken from the back of Betty Yates's left hand following the discovery of her body.

Farrow denies the murders of Mrs Yates, in Worcestershire, and the Rev John Suddards, in South Gloucestershire.

He claims he saw 77-year-old Mrs Yates two days before she was killed.

She was found stabbed to death in her cottage, in Bewdley, on 4 January, having been killed two days earlier.

Farrow, of no fixed address, claims he saw Mrs Yates on 30 December, but Bristol Crown Court heard the location the DNA sample was found would make it "extremely rare" to get such a strong profile days later.

Forensic scientist Christopher McKenzie told the jury: "The DNA profile obtained showed a mixture of DNA from two people which matched the corresponding DNA profiles of Mrs Yates and Stephen Farrow.

"We found that it is a billion times more likely to have come from Betty Yates and Stephen Farrow than from Betty Yates and someone other than Stephen Farrow."

Mr McKenzie said given the strength of the DNA profile he would expect there to have been either direct physical contact between Mrs Yates and Farrow or for it to have come from a bodily fluid - potentially saliva or sweat.

More here:
Murder accused's DNA 'on victim'

NEW YORK (Reuters) - They're called discreet DNA samples, and the Elk Grove, California, genetic-testing company easyDNA says it can handle many kinds, from toothpicks to tampons.

Blood stains from bandages and tampons? Ship them in a paper envelope for paternity, ancestry or health testing. EasyDNA also welcomes cigarette butts (two to four), dental floss ("do not touch the floss with your fingers"), razor clippings, gum, toothpicks, licked stamps and used tissues if the more standard cheek swab or tube of saliva isn't obtainable.

If the availability of such services seems like an invitation to mischief or worse - imagine a discarded tissue from a prospective employee being tested to determine whether she's at risk for an expensive disease, for instance - the Presidential Commission for the Study of Bioethical Issues agrees.

On Thursday it released a report on privacy concerns triggered by the advent of whole genome sequencing, determining someone's complete DNA make-up. Although sequencing "holds enormous promise for human health and medicine," commission chairwoman Amy Gutmann told reporters on Wednesday, there is a "potential for misuse of this very personal data."

"In many states someone can pick up your discarded coffee cup and send it for (DNA) testing," said Gutmann, who is the president of the University of Pennsylvania.

"It's not a fantasy to think about how, without baseline privacy protection, people could use this in a way that would be really detrimental," such as by denying someone with a gene that raises their risk of Alzheimer's disease long-term care insurance, or to jack up life insurance premiums for someone with an elevated genetic risk of a deadly cancer that strikes people in middle age.

"Those who are willing to share some of the most intimate information about themselves for the sake of medical progress should be assured appropriate confidentiality, for example, about any discovered genetic variations that link to increased likelihood of certain diseases, such as Alzheimer's, diabetes, heart disease and schizophrenia," Gutmann said.

The commission took on the issue because whole genome sequencing is poised to become part of mainstream medical care, especially by personalizing medical treatments based on a patient's DNA.

$1,000 GENOME

That has been driven in large part by dramatic cost reductions, from $2.5 billion per genome in the Human Genome Project of the 1990s and early 2000s to $1,000 soon. Several companies, including Illumina Inc. and Life Technology's Ion Torrent division, sell machines that can sequence a genome for a few hundred dollars, but that does not include the analysis to figure out what the string of 3 billion DNA "letters" means.

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Citing privacy concerns, U.S. panel urges end to secret DNA testing

A DNA match made this year on items recovered at the scene of 2005 homicide in Brentwood has led Prince Georges County police to charge one man in connection with the fatal stabbing, officials said Wednesday.

Marcus Levi Brown, 41, was arrested Tuesday afternoon in the District and will be charged with second-degree murder in the fatal stabbing of Reginald Bruce Taborn, a 49-year-old National Institutes of Health employee found dead on the floor of his apartment on May 17, 2005.

The match that led to the Mr. Browns arrest was made this year after Mr. Browns DNA was entered into the FBIs DNA database of convicted offenders, said Capt. Joseph Hoffman, of the police departments homicide unit. DNA evidence was originally recovered from the scene of the homicide from several items in close proximity to the victim, Capt. Hoffman said. A confirmation DNA sample was analyzed by Prince Georges County officials and also produced a match, he said.

It was not immediately clear what criminal conviction led to Mr. Browns DNA being entered into the FBI database. Officers found Taborn dead in his apartment, located on the 3300 block of Buchanan Street, after they were called to check on his welfare when he failed to show up to work, according to police reports at the time. No weapon was recovered from the scene, Capt. Hoffman said.

Taborn was last seen alive on May 15, 2005, the same day that witnesses reported hearing mens voices yelling at the apartment, Capt. Hoffman said. There was no forced entry to Taborns apartment and police investigators believe the two men knew one another.

Homicide detectives have interviewed Mr. Brown about Taborns death, but Capt. Hoffman declined to discuss anything said during interviews.

D.C. court records show Mr. Brown is currently being held in the District where he was detained as a fugitive. He will be officially charged with second-degree murder once he is extradited to Prince Georges County, according to police.

Contact information for relatives of Mr. Brown could not be immediately located and no attorney is listed as representing him in D.C. court records.

Copyright 2012 The Washington Times, LLC. Click here for reprint permission.

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DNA IDs suspect in 2005 murder

DNA from two home-invasion robbery suspects who allegedly stole a truck and then got into a fatal hit-and-run crash will be pivotal evidence in their trial, which started Tuesday, the prosecutor said.

Curtis Travis, 35, and Stephen Stowers, 24, both of Fresno, are on trial for murder, robbery and hit-and-run in the death of Heliodoro Anthony Ruvalcaba, 50, of Fresno, who was killed in January 2011.

Ruvalcaba was on his way home from his janitorial job when he was struck by a truck that Travis and Stowers allegedly stole minutes earlier.

The pair had been at a friend's apartment at 4111 N. Blythe Ave. about 1 a.m. on Jan. 5, 2011.

A short time later, they forced their way into another apartment at the complex, taking a laptop computer, two cellphones, $10 and keys to the resident's pickup, police reports state.

David Ruiz testified Tuesday that he was asleep in the apartment with his wife and two children when Travis and Stowers entered by breaking a window.

After hearing the noise, he went into his living room to investigate and was ordered by the two men to hand over his keys, cash, laptop computer and cellphones. Ruiz said he did so because he feared for the lives of his wife and daughters.

Ruiz described the men as light-skinned and dark-skinned, and he identified Travis as the man who made most of the demands. He could not positively identify Stowers. Travis is white and Stowers is black.

The pair left in Ruiz's 1994 Chevrolet Silverado, running two red lights before speeding about 60 mph eastbound on Ashlan Avenue near Highway 99, police said.

Travis, reportedly the driver, ran red lights at Ashlan and the Highway 99 offramp and hit Ruvalcaba's northbound 1998 Ford Taurus, killing him, police said.

Original post:
DNA links Fresno robbery suspects to fatal crash

A new analysis confirms the widely held suspicion that DNA from dinosaurs and ancient insects trapped in amber cannot be recovered to make a 'Jurassic Park'-style theme park

By Matt Kaplan and Nature magazine

Palaeogeneticist Morten Allentoft used the bones of extinct moa birds to calculate the half-life of DNA. Image: M. Mhl

Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...

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From Nature magazine

Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest and putting paid to hopes of cloning a Tyrannosaurus rex.

After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Determining that rate has been difficult because it is rare to find large sets of DNA-containing fossils with which to make meaningful comparisons. To make matters worse, variable environmental conditions such as temperature, degree of microbial attack and oxygenation alter the speed of the decay process.

But palaeogeneticists led by Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, examined 158 DNA-containing leg bones belonging to three species of extinct giant birds called moa. The bones, which were between 600 and 8,000 years old, had been recovered from three sites within 5 kilometres of each other, with nearly identical preservation conditions including a temperature of 13.1 C. The findings are published today in Proceedings of the Royal Society B.

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Dinos' DNA Demise: Genetic Material Has a 521-Year Half-Life