Cloning From the Frozen Dead

Nov. 4, 2008 — -- Scientists in Japan say they have successfully cloned a mouse from a body that had been frozen for 16 years, theoretically opening the door to a range of possibilities from preserving endangered animals, to resurrecting extinct animals to cloning Ted Williams.

The authors of the study made no bones about what they believe the implications of their work could be.

"It has been suggested that the 'resurrection' of frozen extinct species, such as the woolly mammoth, is impracticable, as no live cells are available, and the genomic material that remains is inevitably degraded," wrote the authors in the Monday edition of the Proceedings of the National Academy of Sciences.

But the researchers say they got around the dead tissue issue by adapting new fertilization techniques for damaged sperm into a cloning technique for damaged frozen tissue. The authors of the study concluded these "techniques could be used to 'resurrect' animals or maintain valuable genomic stocks from tissues frozen for prolonged periods without any cryopreservation."

Other cloning scientists say cloning a wooly mammoth may not be so easy, but that cloning frozen dead tissue without the work of cryopreservation could have useful applications.

The term "cryonics" often summons images of baseball legend Ted Williams, who was controversially frozen at the Alcor Life Extension Foundation in Scottsdale, Ariz., by his children in hopes of reviving him with future scientific advances.

Yet, much more cryonic work is done to clone prized livestock than to preserve loved ones. Cloning typically requires intact cells, so breeders turn to cryonics to preserve their prized animals.

To circumvent cryonic cloning, which must use high-tech equipment and protective chemicals, the researchers looked to past experiments with dried sperm.

"It's not surprising that it worked," said Randall Prather, a professor of animal sciences at the University of Missouri at Columbia.

"It has been shown that you can take sperm and desiccate [dry] them and leave them out on the table, then rehydrate them and inject those into eggs and get a viable embryo," said Prather, who works with cloning pigs.