Remember the days when woolly mammoths traversed the tundra, and dodos waddled across the Mauritius Island terrain and the quagga (a horse-zebra hybrid) roamed the African plains? Of course you don’t, because these beasts have been extinct for centuries.

But Japanese scientists aim may be making strides towards bringing extinct critters back to the land of the living. Researchers at the Riken Center for Developmental Biology in Kobe, Japan, recently cloned mice from specimens that were dead and frozen for 16 years — they say that the process could be applied to animals that went extinct years ago, so long as there’s a frozen sample to be found.

Prior to this experiment, animals were cloned using only live specimens. In fact, researchers didn’t think cloning from frozen animals could occur — ice crystals formed during freezing were thought to damage DNA, making cloning impossible. Researchers obtained cells from mice-cicles that were frozen for 16 years at -4° F, extracted the nucleus, and injected it into egg cells (the same process used in cloning animals like Dolly the Sheep, without the freezing part, of course). After a few more complex steps that we don’t need to bore you with the details of, voila! Live mice cloned from frozen specimens.


“This is the first time a mammal has been cloned from a sample stored at conditions reasonably close to what might be expected in permafrost,” Teruhiko Wakayama, who led the study, said in a statement.
“(It) gives some hope for those who might seek to clone extinct species from frozen carcasses.”

Some of these frozen species could include the woolly mammoth, whose remains have been found packed in ice. However, scientists do warn that the process could be extremely difficult, as DNA deterioration could occur after so many years.

We won’t attempt to raise all the controversial issues associated with animal cloning — especially the cloning of animals who haven’t walked the earth in centuries. But we will say this: The situation seems to have Jurassic Park: The Reality Show written all over it.

Story by Sarah Parsons. This article originally appeared in Plenty in November 2008. The story was added to

Copyright Environ Press 2008

Hello Mickey
Scientists clone frozen mice, and open up a new door for bringing back extinct species.