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Home / Health / Mammoth DNA & # 39; woke up & # 39; in mice. But cloning mammoths is still a dream.

Mammoth DNA & # 39; woke up & # 39; in mice. But cloning mammoths is still a dream.



A handful of 28,000-year-old woolly mammal parts have recently been "woken up" for a short time in a new experiment, but the cloning of the glacial beasts is still a long way off.

In an experiment, researchers extracted cells from Yuka, a woolly mammoth mummy ( Mammuthus primigenius ) whose remains were discovered in Siberian permafrost in 2011. Then the scientists found the least damaged nuclei (structures containing genetic material) from each cell and decoupled the nuclei into mouse eggs.

Initially, these maneuvers "activated" the mammoth chromosomes, as various biological reactions took place prior to cell division within the mouse cell. However, these reactions soon came to a standstill, probably in part because the mammoth DNA was buried in permafrost after 28,000 years, the researchers said. [In Photos: Mummified Woolly Mammoth Discovered]

Why did the researchers give mammoth DNA into mouse eggs? The answer has to do with the ability of an egg to replicate DNA and divide it into more cells.

"The eggs have all the living cellular machinery you need to perform an error correction and repair damage that has happened inside the cores, said Beth Shapiro, professor of ecology and evolutionary biology at the University of California, Santa Cruz who was not involved in the study. "[The scientists] basically just stuck there [the mammoth nuclei] and said," All right, cell machinery, do your thing. "

And first, the cell machinery tried to damage DNA in the Chromosomes and the piece fix together the broken pieces, Shapiro said. "But 1

9459013 can only do so much," she told Live Science. "If the nuclei are badly damaged, it simply can not be reconstructed as you would actually do to bring them back to life."

As a result, none of the mouse mammoth hybrid cells entered cell division, which is necessary to produce an embryo, and perhaps one day to clone a mammoth.

"The results presented here clearly show us the factual impossibility of cloning the mammoth through today's NT [nuclear-transfer] technology." Researchers wrote in the study, which was published online on 11 March in the journal Scientific Reports.

In other words, "It's a pretty clear demonstration that this approach will not work to clone a mammoth," Shapiro said. "The cells are too damaged."

Once the mammoth died, its DNA began to degrade. This is because bacteria from the gut of the mammoth and the surrounding environment fidgeted on the cells of the dead mammoth. The sun's ultraviolet (UV) radiation also broke down more genetic material, and these processes lasted for eons. As a result, core DNA fragments that have survived to date could only be tens to hundreds of bases long, rather than the millions found in modern elephant DNA, Shapiro said.

However, the study is still exciting, said Rebekah Rogers, assistant professor of bioinformatics at the University of North Carolina in Charlotte, who was not involved in the research. For example, if researchers could even insert small fragments of mammoth DNA into a cell line, it could show what that DNA does to a living being, she said. [Mammoth Resurrection: 11 Hurdles to Bringing Back an Ice Age Beast]

In the study, researchers added, "Our approach paves the way for assessing the biological activities of cores in extinct species."

However, Rogers said that she would like to see more evidence that the mammoth chromosomes have actually made it into the mouse egg. "It's possible that you have a severely modified mouse chromosome or possibly other DNA contamination," she said. "They have the extraordinary claim that they put mammoth chromosomes in a mouse [egg] .I would really like to see a lot of evidence for this kind of claim."

Other research groups are also trying to revive the mammoth with the help of other technology. George Church, a geneticist from Harvard University and the Massachusetts Institute of Technology, who leads the Harvard Woolly Mammoth Revival team, is pursuing an approach. He uses CRISPR – a tool that can be used to process DNA bases or letters to insert woolly mammoth genes into the DNA of Asian elephants, which are closely related to extinct animals.

"They are not trying to revive a mammoth genome," Shapiro said. "They try to create one by optimizing an elephant genome, so they could have a living cell as the end product."

Returning the Ice Age mammals, however, is controversial. Many conservationists argue that resources should be used for animals that are currently threatened or endangered, and not for animals that were extinct long ago.

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