- In a new experiment, cells taken from a 28,000-year-old woolly mammoth mummy that were inserted into mouse cells were ‘switched on’ for a short time before it stopped failing to reach cell division.
- The cellular repair that took place in the study was only temporary because of the damage that the DNA cells had incurred through millions of years.
- Mouse eggs are used because they possess the cellular mechanisms needed to repair the damage that has occurred in the nuclei.
Although cloning mammoths remains an impossible dream, a small bit of 28,000-year-old cells extracted from a wooly mammoth mummy was momentarily ‘awoken’ in a new experiment.
Scientists drew out cells from a woolly mammoth (Mammuthus primigenius) called Yuka, whose remains were discovered in the 2011 Siberian permafrost. From each cell, they recovered the least-damaged nuclei which they placed into mouse eggs.
Initially, the mammoth chromosomes were ‘activated’ but only for a short while. Researchers said this is due to the severe damage inflicted on the mammoth DNA from being buried in permafrost for 28,000 years.
Why was the mammoth DNA thrust into the mouse eggs?
“The eggs have all of the living cellular machinery that you might need to do error correction and fix damage that has happened within the nuclei,” according to Beth Shapiro, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, who was not involved with the study.
True, the broken bits of DNA inside the chromosomes were pieced together by the cellular machinery however, ‘the eggs can only do so much’. “When the nuclei are badly damaged, then it’s just not possible to reconstitute this to what you would need to do to actually bring it back to life,” Shapiro told Live Science. This resulted in no mouse-mammoth hybrid cells entering cell division, which is a vital step to create an embryo or clone.
Shapiro concluded that due to extensive DNA damage, this approach won’t work when cloning the mammoth. The researchers also wrote in their findings that, “the results presented clearly show us again the de facto impossibility to clone the mammoth by current NT [nuclear-transfer] technology.”
Nevertheless, University of North Carolina assistant professor of bioinformatics Rebekah Rogers still finds the study exciting but wants more evidence that the mammoth cells actually reached the mouse egg.
While other research institutes are trying to regenerate the mammoth using different technology, many conservationists argue that resources be rather spent on presently endangered animals rather than on animals that have died thousands of years ago.
The study was published online in the journal Scientific Reports on March 11.
Source: Live Science