Mammoth DNA reveals natural selection clues
Posted on 5 May 2010
Professor Michi Hofreiter, of the University’s Department of Biology and a member of York’s BioArCh research group, was part of an international team that extracted ancient DNA from a mammoth bone to reconstitute the animal’s haemoglobin, the protein responsible for delivery of oxygen to the body.
The team, which also involved scientists from Canada, Australia, Germany, USA, Japan and Denmark, wanted to investigate how the mammoth which originated in tropics managed to colonize the Arctic. They aimed to compare the reconstituted mammoth haemoglobin with that of its living relatives, the African and Asian elephants, which still live in the tropics. The team’s research is published in Nature Genetics.
Our study is the first one to reconstruct an evolutionary important, adaptive trait from an extinct species using ancient DNA
Professor Michi Hofreiter
The scientists extracted ancient DNA from a well-preserved woolly mammoth bone and sequenced both its alpha- and beta-like globin. This revealed that the latter demonstrated three specific amino acid changes at functionally important positions. The researchers used the DNA sequences to express the two proteins and reconstituted authentic mammoth haemoglobin.
They discovered that the mammoth haemoglobin releases oxygen at low temperatures much more efficiently than that of elephants allowing mammoth to live in colder climates. The adaptations are similar to those exhibited by other warm-blooded animals living in Arctic environments, such as reindeer and muskoxen.
Professor Hofreiter said: “Our study is the first one to reconstruct an evolutionary important, adaptive trait from an extinct species using ancient DNA.
"It therefore opens up the possibility to build up a much more complete picture of morphology, physiology and evolutionary adaptations than would be possible using non-molecular study of fossil bones.”
Notes to editors:
- The paper “Substitutions in woolly mammoth hemoglobin confer biochemical properties adaptive for cold tolerance” is published in Nature Genetics.
- The research involved scientists from the Departments of Biological Sciences and Chemistry, University of Manitoba, Winnipeg, Canada; the Australian Centre for Ancient DNA, School of Earth and Environmental Sciences, University of Adelaide; Protein Design Laboratory, Yokohama City University, Yokohama; Junior Research Group Molecular Ecology, Max Planck Institute for Evolutionary Anthropology, Leipzig; Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania and the Zoophysiology, Institute of Biological Sciences, University of Aarhus, Denmark.
- More information on BioArCh at http://sites.google.com/a/palaeo.eu/xtnl-bioarch/Home/staff.
- The University of York’s Department of Biology is one of the leading centres for biological teaching and research in the UK. In the recent Research Assessment Exercise, the Department was equal first among broad spectrum bioscience departments. The Department both teaches degree courses and undertakes research across the whole spectrum of modern Biology, from molecular genetics and biochemistry to ecology.
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