Untangling woolly mammoth DNA

Stephan C. Schuster and Webb Miller of Penn State University, working with Thomas Gilbert from Copenhagen and a large international consortium, discovered that hair shafts provide an ideal source of ancient DNA -- a better source than bones and muscle for studying the genome sequences of extinct animals...
The research team obtained hair from ten woolly mammoths collected from a wide swathe of northern Siberia and with dates of death spanning approximately 38,000 years -- from 50,000 years to 12,000 years ago. Before this study, only seven mitochondrial genomes from extinct animals had been published: four from ancient birds, two from mammoths, and one from a mastodon. "DNA in bones and muscle usually degrades and becomes contaminated with genetic material from other sources such as bacteria, limiting its usefulness in scientific studies," Schuster explains. Because only a tiny proportion of ancient bones and muscle are preserved in such a way that uncontaminated DNA can be recovered, research with such materials has involved laborious efforts, sometimes spanning as long as six years for a single study. In contrast, Miller said, "Once I get the data from the genome sequencer, it takes only five minutes to assemble the entire mitochondrial genome." The discovery to be published in Science demonstrates that hair clippings can give researchers enormous power and efficiency for divining the genetic makeup of ancient species...
"The data already generated from this study set the stage for the sequencing of a complete mammoth genome," said Schuster...
Several of the hair samples investigated were up to 50,000 years old. One of the samples came from the first specimen ever recorded: the so-called Adams mammoth, found in 1799 and dug out of the permafrost between 1804 and 1806 by the botanist Michael Adams and members of the Tungus tribe. This mammoth died around 36,000 years ago. "Hair samples from this find were stored in a Russian museum for 200 years at room temperature, but still allowed for a complete analysis of its mitochondrial genome using only 0.2 grams of hair," Schuster said...

See Hair Untangles Woolly Mammoth Puzzle | Eberly College of Science for the complete article.

WOOLLY DATA. Mammoth hair, including this 25,000-year-old sample from Siberia, may contain enough genetic material to allow reconstruction of mitochondrial DNA.
A. Sher and F. Shidlovskiy/Ice Age Museum, Moscow