First genome of an extinct species deciphered

Researchers have 70 percent of the genome Wollhaarmammut reconstructed - a scientific first: Never before has the genome of an extinct species as largely deciphered. Already is a resurrection of the giants of speculation, even if it still pure science fiction.

Under his feet trembled once the icy expanse of the North, but that was long ago: Before about 10,000 years, the Wollhaarmammut extinct in Europe. The last copies of the furry giants lived on the Wrangelinsel in the extreme northeast of today's Russia - but they disappeared around 3700 years ago.

Wollhaarmammuts skeleton of a (simulation): 70 percent of the genome is sequenced

Now, a US-Russian team of researchers the genome of the mammoth largely deciphered. It was the first genome of an extinct species, the more widely available, reported the British science magazine "Nature" in which the researchers imagine their work. The team led by Stephan Schuster of Pennsylvania State University had for DNA analysis, hair samples collected from two mammoths, which for millennia were frozen in the ice.

4.2 billion genetic information sequenced

The genome of the extinct ice-age Elefantenart (Mammuthus primigenius) differed only in the analysis of around 0.6 percent from that of his closest living relatives today, the African elephant, the researchers write in Nature (vol. 456, p. 387) . Thus the genome differences only about half as large as between man and his closest relatives, the chimpanzees. Mammoth and elephant have in the course of evolution about the same time as auseinanderentwickelt humans and chimpanzees, perhaps even a little earlier.


For the analysis, the researchers had hair of two Siberian Wollhaarmammuts with the numbers used M4 and M25. M4 was around 20,000 years in ice; M25 approximately 60,000 years. Hair is an ideal source of ancient DNA, because they are far less concerned with bacteria and fungi are polluted as some bones, such as Michael Hofreiter from Leipziger Max Planck Institute for Evolutionary Anthropology in an accompanying Nature contribution writes. Overall, the researchers have 4.2 billion base pairs of genetic information sequenced. 3.3 billion of which they were able to assign the Wollhaarmammut, representing a rate of 80 percent.

Based on the genome size of the African elephant, whose genome as almost one and a half times as big evaluated as the human, the researchers reckon that around 70 percent of the mammoth genome deciphered have. They were also to genes, in a comparison of 50 different mammalian species occur only in the mammoth.

Analysis only possible through new technology

In order to obtain reliable analysis, had the genome to be sequenced several times. Because of the enormous number of bases in the nucleus DNA of mammoths, this was only by the year 2005 presented in the so-called 454-technology is feasible, several million base pairs per run can determine. Previously, when fossil finds mainly the DNA in the mitochondria, the body's cells with energy supply, investigated. The genetic material contained therein, however, is less extensive than that from the nucleus of the hair roots.

Although the present working version of the mammoth genome yet to be incomplete and error-prone to make standard genes deduce this species, says Hofreiter. Nevertheless, the work inspires fantasies about the revival of the mammoth. Japanese experts had so recently successfully clones of mice created the unprotected 16 years in the freezer beaten. The technology used there, they saw as a possible way to the reawakening of extinct animals like the mammoth.

"Nature" studied in a further contribution the chances that the mammoth with modern biotechnology resurrect it. As yet no intact mammoth cell nuclei were found would have to begin artificial chromosomes produced and placed in a cell nucleus - which from today's pure science fiction. Could then using ova of elephants be tried to clone mammoths, which then of the elephant-out to be surrogate mothers.

However, it has never been someone an embryo into an artificial uterus elephant used, and the extraction of elephant egg cell is connected with great difficulties. The entire process of mammoth revival, according to "Nature" in accordance with the present state of the art impossible, but seems not for all future excluded.