The Internet has been burning up with an ice age storyline over the past few days: Researchers in Japan led by Akira Iritani announced their plan to clone a woolly mammoth within four to six years, recreating a colossal beast not seen on Earth in thousands of years. But as enthusiastic as DISCOVER is for cloned mammoths (and believe us, we’re psyched), the project is still a long way from success.
First, the backstory.
Researchers from Kinki University’s Graduate School of Biology-Oriented Science and Technology began the study in 1997. On three occasions, the team obtained mammoth skin and muscle tissue excavated in good condition from the permafrost in Siberia. However, most nuclei in the cells were damaged by ice crystals and were unusable. The plan to clone a mammoth was abandoned. [Daily Yamiuri]
That initial effort was a DISCOVER cover story back in 1999. Now, though, the dream is back, thanks to newly developed methods to get around that icy problem.
The team, which has invited a Russian mammoth researcher and two US elephant experts to join the project, has established a technique to extract DNA from frozen cells, previously an obstacle to cloning attempts because of the damage cells sustained in the freezing process. Another Japanese researcher, Teruhiko Wakayama of the Riken Centre for Developmental Biology, succeeded in 2008 in cloning a mouse from the cells of another that had been kept in temperatures similar to frozen ground for 16 years. [AFP]
Here’s the plan: This summer, the Japanese researchers plan to visit a Russian lab where mammoth remains discovered in Siberia have been preserved, though the scientists estimate that just 2 to 3 percent of the preserved cells will be viable for this experiment. They must then use Wakayama’s method, extracting nuclei from those viable mammoth cells and then attempting to place them inside egg cells of the African elephant that have been stripped of their own nuclei (the eggs were donated by zoos when their females elephants died). If Iritani and colleagues succeed that far, then they must implant the embryo into a living African elephant so it could grow during the elephant’s 600-day gestation period to be born (hopefully) as a live mammoth.
Simple, right? Iritani says that there’s a “reasonable chance” of success for the plan to clone a live mammoth within the four to six year window, but that might depend upon how one defines “reasonable.” The technological advances by Wakayama and others have succeeded in mice and upped the success rate for cattle to 30 percent, Iritani says. But cattle also haven’t been extinct for millennia.
Still, we’ve already seen some of the curious results of transplanting different genetic material into an egg, and Iritani and colleagues certainly have a chance.
The good news (I think) is that even if Iritani and his scientists manage to clone a mammoth that then grows to be 13 feet tall at the shoulder and weigh 8,000 pounds, it’ll still be smaller than an adult male African elephant (which can grow to be about 13 feet at the shoulder and weigh up to 13,000 pounds). [PC World]
Trying to clone a mammoth may not carry the ethical implications of resurrecting, say, a Neanderthal. But that doesn’t mean the team has its endgame all worked out.
“If a cloned embryo can be created, we need to discuss, before transplanting it into the womb, how to breed [the mammoth] and whether to display it to the public,” Iritani told Yomiuri. “After the mammoth is born, we’ll examine its ecology and genes to study why the species became extinct and other factors.” [CNN]
DISCOVER: Cloning the Woolly Mammoth
80beats: Scientist Smackdown: No Proof That a Comet Killed the Mammoths?
80beats: Spores in Mastodon Dung Suggest Humans Didn’t Kill Off Ancient Mammals
80beats: The Last Mammoths Made a Round Trip Across the Bering Land Bridge
80beats: Mice Two Dads: Scientists Create Mice With Two Genetic Fathers
Image: Wikimedia Commons