In a study reported in Scientific Reports, cells derived from a woolly mammoth that perished over 28,000 years ago have been partially reactivated within mouse egg cells. This breakthrough demonstrates the potential for reviving biological activity in cells from long-extinct creatures. However, it’s important to note that this does not signify an imminent resurrection of extinct animals like mammoths.
Led by Kazuo Yamagata, a biologist from Kindai University in Japan, the research team obtained cells from the remains of “Yuka,” a juvenile female mammoth unearthed in 2010 along the Dmitry Laptev Strait in the Russian Far East. Yuka was remarkably well-preserved due to being encased in permafrost, a frozen layer of ground that often maintains the integrity of skin, fur, brains, and other soft tissues in deceased animals. Thanks to Yuka’s exceptional condition, Yamagata’s team managed to extract 88 nucleus-like structures from her preserved muscle tissues.
These mammoth cells were then introduced into mouse oocytes, which are ovarian cells crucial to embryonic development. Additionally, the researchers included elephant cells in mouse eggs to establish a control sample.
Following an incubation period, the cell nuclei displayed signs of reactivation, albeit to a limited extent. While the cells didn’t undergo division, they did complete certain pre-division stages. For instance, the mammoth nuclei engaged in a process known as “spindle assembly,” which ensures that chromosomes are properly connected to spindle structures before a parent cell undergoes division into two daughter cells.
Determining the functionality of mammoth DNA posed a formidable challenge. Scientists initiated the process by extracting samples of bone marrow and muscle tissue from the creature’s leg. These samples underwent analysis to identify intact nucleus-like structures, which were carefully extracted once located.
Upon combining these nucleus cells with mouse oocytes and introducing mouse proteins, it became evident that a portion of the mammoth cells exhibited the capacity for nuclear reconstitution. This crucial finding ultimately indicated that even in remains dating back 28,000 years, active nuclei could potentially be present.
In essence, this suggests that the prospect of resurrecting a specimen of this nature may indeed be within the realm of possibility.