London: German anthropologists have decoded the entire genome sequence of a Denisovan, representative of the extinct Asian group related to Neanderthals, from a finger bone fossil, a study reveals.
The team from The Max Planck Institute for Evolutionary Anthropology, Germany, has now developed sensitive novel techniques which have allowed them to sequence every position in the Denisovan genome about 30 times over, using DNA extracted from less than 10 milligrams of the finger bone.
This level of resolution was sufficient to establish the relationship of Denisovans to Neanderthals and present-day humans, but often made it impossible for researchers to study the evolution of specific parts of the genome.
The now-completed version of the genome allows even the small differences between the copies of genes, that this individual inherited from its mother and father to be distinguished, a university statement said.
The finger bone was discovered by Anatoly Derevianko and Michail Shunkov, professors at the Russian Academy of Sciences in 2008 during their excavations at Denisova Cave, in southern Siberia.
In 2010, Svante Pääbo and colleagues from Max Planck presented a draft version of the genome from the finger bone fragment.
The Leipzig group will make the entire Denisovan genome sequence available for the scientific community over the internet Feb 8.
"The genome is of very high quality", said Matthias Meyer, who developed the technique.
"We cover all non-repetitive DNA sequences in the Denisovan genome so many times that it has fewer errors than most genomes from present-day humans that have been determined to date," said Meyer.
The genome represents the first high-coverage, complete genome sequence of an archaic human group -- a leap in the study of extinct forms of humans.
"We hope that biologists will be able to use this genome to discover genetic changes that were important for the development of modern human culture and technology, and enabled modern humans to leave Africa and rapidly spread around the world, starting around 100,000 years ago," said Svante Pääbo.
The project is being financed by the Max Planck Society and is part of efforts since almost 30 years by Pääbo's group to study ancient DNA.
IANS
First Published: Thursday, February 09, 2012, 12:50