Scientists create complete genetic map of a Neanderthal from a TOE - and put it online for free

Scientists from Germany's Max Planck Institute sequenced genome from toe bone found in southern Siberia

New techniques allowed them to sequence every position in the genome 50 times over for greater accuracy

They hope it will help answer questions about our own genetic history and how we're related to Neanderthals

Sequenced: The first full Neanderthal genome has been sequenced and made available free-of-charge by the Max Planck Institute

The first complete Neanderthal genome sequence has been completed and made available free-of-charge to researchers across the world.

Scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have made the data available as a free download from their website.

The group will present a paper describing the genome later this year.

'But we make the genome sequence freely available now to allow other scientists to profit from it even before it is published' said Dr Svante Pääbo, who led the project.

Dr Pääbo and his colleagues in 2010 presented the first draft of the Neanderthal genome from data collected from three bones found in a cave in Croatia.

They have now used a toe bone excavated in 2010 in Denisova Cave in southern Siberia to generate a high-quality genome from a single Neandertal individual.

The Leipzig team used sensitive techniques developed there over the past two years to sequence every position in the genome about 50 times over, using DNA extracted from 0.038 grams of the bone.

The analysis of the genome together with partial genome sequences from other Neanderthals, and the genome from a small finger bone discovered in the same cave, shows that the individual is closely related to other Neanderthals in Europe and western Russia.

Remarkably, Neanderthals and their relatives, Denisovans, were both present in this unique cave in the Altai Mountains on the border between Russia, China, Mongolia and Kazakhstan.

In the 2010 draft version of the Neanderthal genome, each position was determined, on average, once. In the now-completed version of the genome every position was determined on average 50 times over.

This allows even the small differences between the copies of genes that this individual inherited from its mother and father to be distinguished.

This family tree relates this genome (top) to the genomes of Neanderthals from Croatia, Germany and the Caucasus as well as the Denisovan genome recovered from a finger bone also excavated at Deniosva Cave

HOW THE DENISOVAN GENOME WAS SIMILARLY SEQUENCED The Neanderthal genome was sequenced thanks to the discovery of just a toe bone, and it was an even tinier fragment of finger that allowed the same researchers to map out the entire genetic code of Denisovan man.

Evidence suggests that the Denisovans, a little-known ancient cousin of modern humans who lived in Siberia around 50,000 years ago, had dark skin, brown hair and brown eyes.

The existence of the Denisovans was only confirmed in 2010, but previous research has already suggested they co-existed with Neanderthals and interbred with our own species, Homo sapiens.

Scientists made the discovery after studying DNA from a piece of finger bone and two molars found at same Denisova Cave in the Altai Mountains of southern Siberia as the Neanderthal toe bone.

Because they had only a tiny sample of material from the finger bone, Svante Pääbo and his research team developed a treatment that unzipped the DNA so that each of its two strands can be used to generate molecules for sequencing.

This method allowed the team to generate an extremely thorough genome sequence (30X), similar in quality to what researchers can obtain for the modern human genome.

The scientists found that the Denisovans were most genetically similar to Australian aborigines and island populations from south-east Asia.

The Leipzig group has made the entire genome sequence freely available for the scientific community over the internet.



'The genome is of very high quality', said Dr Kay Prüfer, who coordinated the analyses. 'It matches the quality of the Denisovan genome, presented last year, and is as good as or even better than the multiple present-day human genomes available to date.'

Dr Pääbo added: 'We are in the process of comparing this Neanderthal genome to the Denisovan genome as well as to the draft genomes of other Neanderthals.'

'We will gain insights into many aspects of the history of both Neanderthals and Denisovans and refine our knowledge about the genetic changes that occurred in the genomes of modern humans after they parted ways with the ancestors of Neanderthals and Denisovans.'

The project, part of 30 years' worth of efforts by Dr. Pääbo's group to study ancient DNA, was made possible by financing from the Max Planck Society.

The bone used to sequence the genome was discovered by Professor Anatoly Derevianko and Professor Michael Shunkov from the Russian Academy of Sciences in 2010 during excavations at the Denisova Cave.