TOKYO , Japan ( CNN ) -- Japanese scientists have produced clones of mice that have been dead and frozen for 16 years -- a feat that could lead researchers to one day resurrect long-extinct species , such as the mammoth . Dolly was cloned using cells from live animals . Now scientists believe they can resurrect extinct species . Until now , scientists have only been able to produce clones using cells from live animals . This is how researchers created Dolly the Sheep , the first mammal to be cloned from an adult animal . Researchers had thought that frozen cells were unusable because ice crystals would have damaged the DNA . That belief would rule out the possibility of resurrecting extinct animals from their frozen remains . But the latest research -- published in the journal , Proceedings for the National Academy of Sciences -- shows that scientists may have overcome the obstacle . Researchers at the Riken Center for Developmental Biology in Kobe , Japan , used cells from mice that had been frozen for 16 years at -20 Celsius ( -4 degrees Fahrenheit ) . They extracted the nucleus and injected it into eggs whose DNA had been removed . Several steps later , the scientists were able to clone the mice . `` 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 . ''
Japanese scientists produce clones of mice dead and frozen for 16 years . Feat could allow researchers to study long - extinct species , like mice . Researchers produce mice from mice that were frozen for 16 years at -20 Celsius .