Mammoth hair produces DNA bounty

A rapid technique for isolating DNA in hair has yielded a mass of new information about woolly mammoths.

An international research team says the process should work on other extinct animals, allowing their genetics to be studied in detail for the first time.

The mammoth DNA was taken from the hair shaft which was long thought to be a poor source for the "life molecule".

But the group tells Science magazine that the shaft's keratin material slows degradation and limits contamination.

"The idea has been that all the DNA is in the root and that the shaft is DNA-void, or of much lower quality," explained co-worker Dr Tom Gilbert from the University of Copenhagen, Denmark.

"This is why when we screened a whole load of mammoths, we thought we might be lucky if we took enough hair from one of them. Basically, for every mammoth we tried, it worked. That blew us away," he told.

Hair and hooves

The traditional route to DNA in ancient samples is through bones and preserved muscle, but any genetic material usually falls apart very soon after death and is prone to contamination from bacteria.

Having a new route to large quantities of well-preserved DNA should be a real boon to scientific research, Gilbert and colleagues say.

The team read the DNA using an established technology known as "sequencing-by-synthesis" - but its application to hair in the context of ancient samples is novel.

"The reason we think hair is so great comes down to the fact that as a structure, hair is made out of this material called keratin," explained Dr Gilbert, who works out of Copenhagen's Center for Ancient Genetics.

"It's a kind of protein that in a very simplistic sense can be viewed as a plastic that the DNA gets embedded in and surrounded by and protected by."

The scientists think the approach will also work for other items built from the durable protein, such as horns, nails, antlers, hooves and even feathers.

They say museum collections must hold countless specimens of recently extinct creatures from which researchers would love to get genetic information but had never bothered because they believed their DNA to be corrupted and beyond analysis.

Ice mummies

Gilbert and colleagues targeted the mammoths' mitochondrial DNA, a special type of DNA frequently used to measure the genetic diversity of populations - how closely different groups of organisms are related to each other.

Where previously only two mitochondrial genomes had been published, the Science paper reports the production of 10 new genomes, including one from the very first mammoth that was studied - the so-called Adams mammoth, which was found in 1799 and has been stored at room temperature for the last 200 years.

"From our experience working with old samples, the colder a sample has been preserved the better the quality of DNA. So, we're looking at permafrost animals -woolly rhino, for example.
"There are also a lot of old bison and horse mummies turning up in the permafrost. It's not just animals, there are humans [too]; there are a lot of mummies around the world with hair, ranging from Egypt, South America to the more cold, better-preserved ones in Greenland."

Asked the classic question about whether it would be possible to clone any extinct creatures back into existence, Dr Gilbert said that even if the full genetic sequence of a mammoth could be retrieved, the technology did not currently exist to turn that biochemical information into a live animal.

Concern over DNA database access

Strict controls are needed to ensure genetic information collected for research is not used inappropriately by outside parties, experts have warned.

Many DNA databases have been collated for specific studies on genes and disease, a British Society of Human Genetics meeting in York heard.
But pressure from other researchers to access the data puts patient anonymity at risk, experts warned.
Safeguards to protect patient data are imperative, speakers said.
Professor Marcus Pembrey, an expert in paediatric genetics, said there was increasing pressure from organisations funding the research to let other people see the information.
The worry is there is a trend coming from pressure from the funders saying that all scientists should have unfettered access
Professor Marcus Pembrey
But the original research team needed to retain control in order to maintain the trust of those who agreed to take part in the study, he said.
There is a real risk that data, which is supposed to be anonymous, could be made available on the internet if researchers are allowed unrestricted access, he warned.

Anonymisation

Professor Pembrey, who was involved in two large UK genetic studies - the Children of the 90s study and the 1958 British Birth Cohort - said the information can be made available for other research teams through collaboration and careful anonymisation.
"The success of such research is based on the trust between the study participants and the team responsible."
He added that participants also entered in the knowledge they would not be told about their genetic results.
"That makes us even more convinced it's essential there isn't inadvertent disclosure of the results on the web.
"The worry is there is a trend coming from pressure from the funders saying that all scientists should have unfettered access."
Professor Pembery has been involved in advising projects such as the UK Biobank, a Department of Health and Medical Research Charity-funded project of 500,000 people aged 40-69, which has just begun recruiting.
He added that "genuine benefits" of such research should not be undermined by lack of public trust in what was happening to their samples.
Professor Rory Collins, chief executive officer and principal investigator of UK Biobank, said in the consent form they were explicit about how the samples would be used.
"It is entirely clear that this information will be available to bone fide researchers whether they're academic or commercial."
And no identifiable information about participants will be available to anyone outside of UK Biobank.
Professor Steve Bain, a member of the Human Genetics Commission, said much greater consideration had gone into databases put together for research purposes than for the national DNA database used for forensic purposes.
Also speaking at the British Society of Human Genetics meeting in York, he said ethics of the national DNA database was only just being discussed despite it being in place for many years.
"When you have research you have to go through the ethics committee and that's always been the case."

Concern over DNA database access

Strict controls are needed to ensure genetic information collected for research is not used inappropriately by outside parties, experts have warned.

Many DNA databases have been collated for specific studies on genes and disease, a British Society of Human Genetics meeting in York heard.
But pressure from other researchers to access the data puts patient anonymity at risk, experts warned.
Safeguards to protect patient data are imperative, speakers said.
Professor Marcus Pembrey, an expert in paediatric genetics, said there was increasing pressure from organisations funding the research to let other people see the information.
The worry is there is a trend coming from pressure from the funders saying that all scientists should have unfettered access
Professor Marcus Pembrey
But the original research team needed to retain control in order to maintain the trust of those who agreed to take part in the study, he said.
There is a real risk that data, which is supposed to be anonymous, could be made available on the internet if researchers are allowed unrestricted access, he warned.

Anonymisation

Professor Pembrey, who was involved in two large UK genetic studies - the Children of the 90s study and the 1958 British Birth Cohort - said the information can be made available for other research teams through collaboration and careful anonymisation.
"The success of such research is based on the trust between the study participants and the team responsible."
He added that participants also entered in the knowledge they would not be told about their genetic results.
"That makes us even more convinced it's essential there isn't inadvertent disclosure of the results on the web.
"The worry is there is a trend coming from pressure from the funders saying that all scientists should have unfettered access."
Professor Pembery has been involved in advising projects such as the UK Biobank, a Department of Health and Medical Research Charity-funded project of 500,000 people aged 40-69, which has just begun recruiting.
He added that "genuine benefits" of such research should not be undermined by lack of public trust in what was happening to their samples.
Professor Rory Collins, chief executive officer and principal investigator of UK Biobank, said in the consent form they were explicit about how the samples would be used.
"It is entirely clear that this information will be available to bone fide researchers whether they're academic or commercial."
And no identifiable information about participants will be available to anyone outside of UK Biobank.
Professor Steve Bain, a member of the Human Genetics Commission, said much greater consideration had gone into databases put together for research purposes than for the national DNA database used for forensic purposes.
Also speaking at the British Society of Human Genetics meeting in York, he said ethics of the national DNA database was only just being discussed despite it being in place for many years.
"When you have research you have to go through the ethics committee and that's always been the case."