Wednesday, December 7, 2011

Clone a woolly mammoth? Not so fast!

Hendrik Poinar, a scientist who believes he is close to cracking the woolly mammoth's genetic code, says that cloning extinct species is now possible. NBC's Jim Maceda reports.

By Alan Boyle

Reports from Japan?suggest that long-extinct woolly mammoths could be cloned back into existence within five years, but don't hold your breath.

"C'mon, it'll never happen. Not in my lifetime," said Webb Miller, a Penn State computer scientist and?genomicist?who?helped decipher the genetic code of a woolly mammoth.

Japanese and Russian researchers have been working for years to find a suitable woolly mammoth specimen in?the Siberian permafrost, and they recently?told Japan's Kyodo news service that they recovered what they hope will be viable bone marrow from a frozen thigh bone recovered?near Batagay in?eastern Russia's Sakha?Republic (a.k.a. Yakutia).


Their plan is to take the nuclei from bone marrow cells, transplant them into?egg cells extracted from elephants,?and implant the cloned embryos?into the wombs of mama elephants for gestation. This is the technique that has given rise to cloned?mammals ranging from?Dolly the sheep to pigs, cats, dogs and monkeys.

Kyodo's report says "there is a high likelihood" that biologically active nuclei can be extracted from the frozen marrow. Researchers on the case include Russian experts?from Yakutsk's Mammoth Museum and Japanese biologists from Kinki University in Osaka Prefecture. Kyodo said a full-fledged joint research project would be launched next year.

Woolly mammoths haven't walked the earth for thousands of years, but the idea of resurrecting the species seems to have a powerful hold on the collective psyche. Some folks have even talked about setting aside a "Pleistocene Park" for mammoths and other Ice Age animals.

Miller, however, isn't buying it.

"DNA from a woolly mammoth is a mess," he explained. "It's fractured into very short pieces, and there's a lot of postmortem DNA damage other than just breakage. The code gets damaged a lot."

Even if the DNA is intact and the nuclei are successfully merged with elephant egg cells, the success rate for cloning animals ? and particularly extinct and near-extinct species ? is not good. Generally speaking, there are scores of failures for each successful pregnancy brought to term.

A couple of years ago, scientists succeeded in producing?a Pyrenean ibex from tissue that was taken from the last representative of the subspecies in 1999, but the cloned progeny survived for only seven minutes. Attempts to clone an Asian gaur didn't end much better. Australian researchers had to scrap plans to clone the Tasmanian tiger back from extinction, although they later succeeded in transferring part of a Tasmanian tiger gene into mouse embryos.

These cases?suggest that there's not much of a chance of?re-creating?the mammoths.?Genetic engineering may eventually produce a "hairy elephant" with mammoth-like characteristics. But a creature genetically identical to the behemoths of the Ice Age? "If somebody does that, I will eat my hat," Miller said. "And I'll wonder why they did it."

Miller said studying the DNA of long-extinct species has value, even if the efforts don't result in a resurrection.

"I'm looking out my window, and 13,000 years ago, there were some really interesting animals out there," he mused. "They're gone now, and I'd like to know why. ... Understanding which species survived and which ones didn't, looking at their genome and trying to figure that out, that's interesting to me."

But when it comes to living, breathing animals, "I'm personally more interested in keeping the species we have," Miller said. "I'd like to keep tigers around for a while."

Despite Miller's qualms, the quest to re-create the woolly mammoth could well continue for the next five years or longer. And that's not all. Paleontologist Jack Horner is moving ahead with his plan to modify chicken DNA?and make the barnyard birds look more like the dinosaurs they descended from. Dino-chickens vs. woolly mammephants? That sounds like?a great?plot for the next "Jurassic Park" sequel. ...?

More about mammoths:


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Source: http://cosmiclog.msnbc.msn.com/_news/2011/12/06/9254548-clone-a-mammoth-not-so-fast

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