The cell nucleus contains the blueprint "DNA" of life, but it was unclear whether the cell nucleus obtained from fossils functions biologically. The whole genome information of the Kenaga mammoth "Yuka" discovered in the permafrost of Siberia in 2010 was deciphered, and there were reports on the reconstruction of hemoglobin and the appearance characteristics such as the color of hair.In this study, bone marrow and muscle tissue were collected from the mammoth body to decipher various biological information and restore the function of the cell nucleus.

　First, the genetic information was compared with that of African elephants, and the characteristic DNA and protein sequences of mammoths were confirmed.Next, when the protein storage state was analyzed, Yuka's muscle tissue was in a relatively good state, and the components of the cell nucleus were present.Therefore, the mammoth cell nuclei collected from the muscle tissue were injected into a mouse egg, and the movement of the cell nucleus was observed while keeping the mouse egg alive.

　As a result, mammoth cell nuclei began to take up new mouse-derived cell nucleus proteins, and some of them were in the form just before cell division.We also confirmed that part of the mammoth cell nucleus is finally incorporated into the cell nucleus of the mouse egg.Furthermore, it was shown that mouse eggs may repair damage to mammoth DNA.

　The results of this research are expected to make new discoveries in paleontology and evolutionary biology in the future, such as the reproduction of life phenomena in extinct animals at the cellular level.

Paper information:[Scientific Reports] Signs of biological activities of 28,000-year-old mammoth nuclei in mouse oocytes visualized by live-cell imaging