The 28,000-year-old remains of a woolly mammoth, named ‘Yuka’, were found in Siberian permafrost. Here we recovered the less-damaged nucleus-like structures from the remains and visualised their dynamics in living mouse oocytes after nuclear transfer. Proteomic analyses demonstrated the presence of nuclear components in the remains. Nucleus-like structures found in the tissue homogenate were histone- and lamin-positive by immunostaining. In the reconstructed oocytes, the mammoth nuclei showed the spindle assembly, histone incorporation and partial nuclear formation; however, the full activation of nuclei for cleavage was not confirmed. DNA damage levels, which varied among the nuclei, were comparable to those of frozen-thawed mouse sperm and were reduced in some reconstructed oocytes. Our work provides a platform to evaluate the biological activities of nuclei in extinct animal species.
Signs of biological activities of 28,000-year-old mammoth nuclei in mouse oocytes visualized by live-cell imaging
This is pretty cool. Still not enough to wake the mammoth up though.
Will have to ask George Church how things are going.
I would love to be proved wrong, but reconstructing a synthetic mammoth genome seems like a more plausible route for resurrecting the mammoth at this point. Techniques for both sequencing ancient DNA and synthesizing long DNA molecules are maturing at a rapid pace.