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Johannes de León
Wednesday, July 7th, 2004, 06:09 PM
By Jennifer Viegas, Discovery News

June 23, 2004 — Hair and fur could be our window to the past, according to scientists who have just extracted and cloned DNA from a 64,800-year-old bison and hairs purportedly from famed physicist Sir Isaac Newton. The bison DNA retrieval marks the oldest-ever genetic data obtained from hair. The age of the bison is approximately equal to the oldest authentic DNA taken from bones and teeth.


Researchers now focus on bones and teeth for DNA studies. The latest findings, published this week in a Current Biology paper, could mean that hair and fur will receive more attention because they are relatively easy to work with and they minimize damage to historical and archaeological specimens.

For the new study, scientists successfully amplified, cloned and sequenced mitochondrial DNA from four human hairs attributed to Newton (1642-1727); an Andaman islander whose hair was collected in 1953; four Russian horses that lived 2,200-2,800 years ago; and the ancient bison, which came from a mummy found in the Yukon Territory of Canada.

All samples were treated with a 50 percent bleach solution to eliminate DNA contamination from other sources, such as from the hands of other scientists who might have handled the hair and fur samples beforehand.

Tom Gilbert, lead author of the paper and a post-doctoral researcher of ecology and evolutionary biology at the University of Arizona, told Discovery News that mitochondrial DNA, which is passed down maternally, can help in phylogenetics and kinship analyses to determine how one species or individual relates to another species or individual.

It is also a great fraud buster. The recent DNA work determined that each of four Newton hair strands, obtained from separate museums in England and America, had different mtDNA sequences.

"They are unlikely to be from one source," Gilbert said.

Genetic studies have been conducted for years now, but not often on hair.

"On the whole it has been ignored, especially from samples going back so long," he said, and explained that, due to its structure, hair is not a good source for nuclear DNA, which is packed with primary data and could be used to clone an individual.

"Although there is lots of hair in museums, there isn't so much in the archaeological record compared to bone and teeth, although naturally this may be because no one is looking for it," he said. "It's much easier to find bone and teeth than hair."

The hydrophobic nature of the keratin in hair seems to reduce water damage to mtDNA, which could explain why Gilbert and his colleagues were able to obtain mtDNA from all but two of their samples.

They originally had six strands of hair that supposedly belonged to Newton, but two of the samples were eliminated from the study because at some point they might have been artificially colored or bleached.

Ian Barnes, a researcher in The Center for Genetic Anthropology at University College London, said the hair news is "most useful" to DNA scientists such as himself because it presents "a very good way of getting around the problems of bone and teeth specimen damage and DNA contamination."

"Gilbert's work as a whole is a real contribution to our understanding of how ancient DNA works," Barnes told Discovery News. "mtDNA extraction from hair has been known in forensics, but it is fairly new to archaeological hair."

While the Newton hair study thus far has not revealed much about the creator of the laws of motion, more hair from famous scientists may get the mtDNA treatment soon.

Barnes said that he has hair strands that purportedly belonged to philosopher Jeremy Bentham (1748-1832) and Egyptian archaeologist Flinders Petrie (1853-1942).



[ source (http://dsc.discovery.com/news/briefs/20040621/bison.html) ]

Dr. Solar Wolff
Monday, July 19th, 2004, 06:13 AM
There is plenty of wooly mammoth hair and plenty of Russians and Japanese interested in cloning a mammoth. I'll bet they are interested in this work.