Japanese scientists have awakened the cells of an extinct woolly mammoth in an experiment that could one day bring the prehistoric beasts back to life.

Researchers from Kindai University in Osaka extracted bone marrow and muscle tissue from a long-frozen beast and injected it into the ovaries of a mouse, according to a study published Tuesday in the journal Scientific Reports.

The experiment revived the 28,000-year-old creature’s cells, triggering “signs of biological activity,” according to the researchers.

“[It’s] a significant step towards bringing mammoths back from the dead,” Kei Miyamoto, one of the study’s authors, told the Nikkei Asian Review.

Scientists recovered cell nuclei from the well-reserved mammoth, named Yuka, which was discovered in Siberia’s permafrost in August 2010.

The same team of scientists had tried to use a nuclear transfer to spark activity in a different mammoth’s cells several years ago but had no luck.

This time, they found Yuka’s remains had not been contaminated, allowing them to collect 88 nucleus-like structures from the animal. They were then injected in into mouse oocytes, the cell in the ovary that splits to form an ovum.

The researchers saw activity in a structural formation that sometimes precedes cell division, according to the report.

Woolly mammoths, which had tusks and weighed roughly 6 tons, lived in East Asia until their extinction about 10,000 years ago.