Bringing Back the Woolly Mammoth - Maybe

By Aussiegirl

Imagine meeting one of these creatures during a stroll in the park.

My Way News - Bringing Back the Woolly Mammoth - Maybe

Bringing Back the Woolly Mammoth - Maybe
By RANDOLPH E. SCHMID

WASHINGTON (AP) - Descendants of extinct mammals like the giant woolly mammoth might one day walk the Earth again. It isn't exactly Jurassic Park, but Japanese researchers are looking at the possibility of using sperm from frozen animals to inseminate living relatives.

So far they've succeeded with mice - some frozen as long as 15 years - and lead researcher Dr. Atsuo Ogura says he would like to try experiments in larger animals.

"In this study, the rates of success with sperm from 15 year-frozen bodies were much higher than we expected. So the likelihood of mammoths revival would be higher than we expected before," Ogura said in an interview via e-mail.

While frozen sperm is commonly used by sperm banks, the team led by Ogura, at Riken Bioresource Center in Ibaraki, Japan, worked with sperm from whole frozen mice and from frozen mouse organs.

"If spermatozoa of extinct mammalian species can be retrieved from animal bodies that were kept frozen for millions of years in permafrost, live animals might be restored by injecting them into (eggs) from females of closely related species," the researchers said in a paper appearing in Tuesday's issue of Proceedings of the National Academy of Sciences.

Intact mammoth bodies have been excavated from Siberian permafrost.

Dr. Robert W. McGaughey, laboratory director at the Institute for Reproductive Studies in Scottsdale, Ariz., commented that since some of the whole frozen mice had been held for 15 years before obtaining the sperm nuclei "it clearly is possible that some day we may be able to obtain offspring from extinct animals frozen at reasonable temperatures for very long periods of time."

The downside, added McGaughey, who was not part of the research team, is that an extinct animal probably would have to have been continuously maintained at a low temperature to avoid thawing/refreezing damage.

Elephants would be a potential candidate for insemination with frozen mammoth sperm, Ogura said. He also suggested experiments might be tried with extinct feline species and their modern relatives.

Less enthusiastic was Dr. Peter Mazur, a biologist at the University of Tennessee who has worked with frozen eggs and sperm and is a past president of the Society for Cryobiology.

Mazur thinks the chance that frozen sperm from mammoths could be used to fertilize a related species is near zero.

"The storage temperature of frozen mammoths is not nearly low enough to prevent the chemical degradation of their DNA over hundreds of thousands of years," he commented. And "even if the temperature were low enough to prevent chemical degradation, that would not prevent serious damage over those time periods from background radiation, which includes cosmic rays."

Bringing back extinct species is an interesting suggestion, Dr. Douglas E. Chandler of the Arizona State University School of Life Sciences commented.

"The trick however is to find an acceptable species that would act as the mother," added Chandler, who was not part of Ogura's research team. If an elephant egg were used "the offspring would not be a mammoth but a hybrid between an elephant and a mammoth. If one wanted a true mammoth one would have to find a source of viable mammoth (eggs) to fertilize and implant and this is a much dicier proposition."

McGaughey agreed, "It is unlikely eggs from such frozen animals would survive; therefore only the sperm would be available to put into eggs from an existing and appropriate modern mammal to approximate the extinct one." [....]

If you just can't wait to learn more about the possibility of encountering a real live woolly mammoth, here's an article from last December.

Mammoth plan for giant comeback

Mammoth plan for giant comeback
By Roger Highfield, Science Editor
(Filed: 20/12/2005)

The first serious possibility that the woolly mammoth, or something like it, could walk on Earth again was raised yesterday by an international team of scientists.
Woolly mammoths died out approximately 10,000 years ago

A portion of the genetic code of the mammoth has been reconstructed and, to the surprise of scientists, the team that carried out the feat believes that it will be possible to decode the entire genetic make-up.

The tusked beast stood 12-feet tall, weighed up to seven tons and had a shaggy dark brown coat that hung from its belly.

DNA was extracted from a well-preserved 27,000-year-old specimen found in the Siberian permafrost. So far, about 30 million "letters" of the genetic code have been read, albeit in small pieces, representing around one percent of the entire code.

The team says it could take as little as a year to finish the estimated 2.8 billion-letter code that provides the genetic wherewithal to create the animal.

Scientists in Japan and Russia have announced plans to attempt to clone woolly mammoths with the help of living relatives and, despite scepticism that they will be successful, today's work will renew interest in the idea.

Dr Stephan Schuster of Pennsylvania State University, one of the team that announced the new work in the journal Science, said last night that it may also be possible to genetically alter an elephant to turn it into a mammoth.

The work is described by an international team of researchers, including one from Oxford University, who sequenced a chunk of ancient DNA belonging to the mammoth and "fellow travellers" from its remains, including bacteria, fungi, viruses and plants that lived at the same time as the mammoth.

The team extracted nuclear DNA from the mammoth's jawbone, concentrating it before it was amplified and sequenced by a relatively new technique called pyrosequencing.

The researchers say nearly half of the "metagenome" they sequenced belongs to the mammoth and is very similar to the African elephant.

The techniques produced an impressive amount of nuclear DNA, which is normally less prevalent than mitochondrial DNA - found in the "power packs" of cells and the usual target of such studies - and thought to be more difficult to extract from ancient remains.

Dr Hendrik Poinar, a molecular evolutionary geneticist at McMaster University, said: "To acquire the genome of an extinct species is a rare feat. With this level of genetic data we can begin to look at genes to determine what makes a mammoth a mammoth.

We can finally understand the subtle differences between a mammoth and its closest living relative, the Indian elephant. But more importantly our discovery means that recreating extinct hybrid animals is theoretically possible.