By The Japan News/ANN
When placed in the ova of mice, the nuclei developed to a state just before cellular division, according to a paper published Monday in the British journal Scientific Reports.
The team includes researchers from Japanese and Russian universities. It has been working for about 20 years on a project to use cloning to resurrect mammoths, an animal that has long been extinct.
The cell nuclei used in the team’s recent findings were extracted from muscle and other tissue from Yuka, a female woolly mammoth about 3.5 meters long excavated nearly intact in 2010 from permafrost in Siberia. When inserted into mouse ova, five out of 43 nuclei were observed to develop to a point just before the nuclei would split in two as a result of cell division.
Cell nuclei contain DNA, the so-called blueprint for life, and mouse ova have been found in experiments to have a reparative function for DNA. It is said to be possible that the mammoth’s DNA, damaged as a result of being frozen for a long time, was repaired and its biological functions invigorated.
However, the predivision development stopped before completion in all the ova.
“Yuka’s cell nuclei were more damaged than we thought, and it would be difficult to resurrect a mammoth as things stand,” said team member Kei Miyamoto, a lecturer in developmental biology at Kindai University. “There’s a chance, if we can obtain better-preserved nuclei.”
Teruhiko Wakayama, a professor in reproductive biology at the University of Yamanashi’s Advanced Biotechnology Center, said: “This can be praised as a first step in research toward the dream of resurrecting extinct ancient animals. I hope they can determine to what extent the DNA was repaired and how much activity there was.”