Hoxful Monsters

The genome sequence of woolly mammoth,an extinct species of Elephant is almost complete.This species of Elephant was adapted to live in cold and was found in Tundra region.Scientists from Penn state university have sequenced four billion DNA bases using next-generation DNA-sequencing instruments and a novel approach that reads ancient DNA highly efficiently.Stephan C. Schuster, Penn State professor of biochemistry and molecular biology believes that the genome size of this extinct mammoth might be similar to that of modern day’s African Elephant genome.

The sequencing of nuclear genome of extinct animal was possible using the DNA extracted from hair of two female woolly ,one being around 20,000 year old and other died roughly 60,000 years ago.Researchers suspect out of four billion bases in dataset ,only around 3.3 billion could account for extinct elephant and rest could be contaminants in the form of bacteria and fungi.The answer to this problem and how much of the full woolly-mammoth genome they have sequenced can be known only by comparing with the sequence of African elephant,which currently is being generated by scientists at the Broad Institute of MIT and Harvard.

The sequence data obtained by group of Schuster suggest that mammoths and modern-day elephants separated around six-million years ago, roughly the same time that humans and chimpanzees separated.However ,unlike in the case of Humans and chimps ,which evolved rapidly ,mammoths evolved gradually.The data also reveals that woolly mammoths had low genetic diversity and that might made them susceptible to some disease and climate change ,leading to their extinction.

The scientists can now use this sequence data to understand exact reason of woolly’s extinction from the planet and unique characters ,which enabled them to survive is extreme cold conditions. Researchers hopes that clues from the mammoth genome about why some animals go extinct while others do not will be useful in protecting other species from extinction, such as the Tasmanian devil.

One of the other interesting aspect of this work is that the sequence was completed by a small group of scientists at a relatively low cost and over a short period of time.

How times change. Within the space of less than a decade, the development of high-throughput technologies has transformed the task of sequencing a mammalian genome from the years-long, multimillion-dollar endeavour it was originally, to a project that can be performed by an individual laboratory within a few months–Michael Hofreite ,Max Planck Institute for Evolutionary Anthropology.

Reference:

Sequencing the nuclear genome of the extinct woolly mammoth

Webb Miller, Daniela I. Drautz, Aakrosh Ratan, Barbara Pusey, Ji Qi, Arthur M. Lesk, Lynn P. Tomsho, Michael D. Packard, Fangqing Zhao, Andrei Sher, Alexei Tikhonov, Brian Raney, Nick Patterson, Kerstin Lindblad-Toh, Eric S. Lander, James R. Knight, Gerard P. Irzyk, Karin M. Fredrikson, Timothy T. Harkins, Sharon Sheridan, Tom Pringle & Stephan C. Schuster

doi:10.1038/nature07446

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